I started it on the weekend and can share pics and info if there is enough interest... Let me know
A440F Rebuild - It works!!!! Comment away
- Thread starter 80JDM
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- a440f a440f transmission
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@Cruiser Jimmy is the only other person I know who has attempted and completed a A440F rebuild.
Be interesting to see your developments.
Be interesting to see your developments.
Cruiser Jimmy
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Would love to help out where I can. I'm actually thinking of doing this again.
My strong advice: get the TC rebuilt.
My strong advice: get the TC rebuilt.
- Thread starter
- #5
Hey fellas, thanks for the chimes. I'm sure to be in touch @Cruiser Jimmy
- Thread starter
- #6
Okay so here goes the first post and I'm not sure about how to format the various stages of disassembly, rebuild and reassembly; whether in sequential order or by major component. I'll figure it out as I go along and thanks for your patience as you try to make your way through this. At the time of this post, the rebuild is almost complete with only the final two planetary assemblies to measure and the low reverse clutch to rebuild as well as the governor assembly which is basically an inspection and cleaning. I've tried to document the process with pictures and some videos mostly for my own reference. I'll be posting some of the key ones that think may be either interesting or informative doing my best to point out any pitfalls that I experienced along the way.
Disclaimer - Rebuild your transmission using this thread as your only reference at your own peril.
The Work Area
As a licensed mechanic in my previous life with many years on the bench, I was never a tranny guy. Does that even mean what it used to? Those dudes were wizards in my view when I was cutting my teeth at the dealerships and leaving apprentice marks on everything I touched. Though remembering back , there are similarities with all of them, they were always among the oldest grey breads in the shop and their bay was always super clean and organized. So with that in mind I approached this rebuild with the same philosophy in my home gamer shop. I know it seems crazy but this is a one shot deal for me with almost $1k in parts and the aggravation of ripping this beast out of the 80, its not something I intend on re-experiencing. So yes I vacuum my shop.
I am really fortunate to have a very stout bench built for a hydraulic shop with 3/8 plate top. This transmission is remarkably heavy so keep that in mind if you plan to begin this job.
Tools
You wont need anything too fancy for this job. Your FSM, mine is RM180U. I sacrificed an old Chineseium flat head screwdriver to fashion some custom pry bars turned out to be very valuable. You can have no shortage of dental pick type implements and you'll likely find a few that you go for more often than others. I made a seal installer tool from a piece of brake tube and a short piece of guitar string fashioned into a loop that proved priceless for installing the o-rings without nicking them. I used a small NEW container of Vaseline and mixed in some ATF for assembly lube, you can buy some Dr. Goo I think its called which is a specialty assembly lube for auto trannys. Take your pick. I'm super confident with the Vaseline as there are endless accounts of its being used for this online and also I remember one of the proffs from mechanics college was a tranny guy and he always told us about it in the lectures. The same prof made us build that seal installer mentioned earlier, though almost 40 years ago now. To press the clutch packs, I tried a small 12T hydraulic press first and it was just way too janky to work with. I ended up using a home fab screw press that my son cobbled together quickly one day to work with Cummins injectors. I clamped it to my workbench and it worked really great and there are a bunch of pics of it in action. I also needed to fabricate various press adapters and a puller. I collected the plastic trays from groceries and cookies for a while so I had ample storage to keep every little part organized as it all came apart. Lots of zip-lock bags, big and small along with post-it notes inside the bags and a sharpie to actually write on the major sub-assemblies in order to help me keep track of the machine as I began to get used to working with it. As for rags, they are not allowed on this side of my shop. Its paper shop towel or Kim-wipes only. Its the same philosophy as vacuuming my shop floor. All about cleanliness and being relentless about it until its all back together. Yes this is a big PITA, but understanding that a stray bit of grit can go unseen, so can a small piece of thread from that rag. If that's the case its lights out for the rebuild.
The A440F
Disclaimer - Rebuild your transmission using this thread as your only reference at your own peril.
The Work Area
As a licensed mechanic in my previous life with many years on the bench, I was never a tranny guy. Does that even mean what it used to? Those dudes were wizards in my view when I was cutting my teeth at the dealerships and leaving apprentice marks on everything I touched. Though remembering back , there are similarities with all of them, they were always among the oldest grey breads in the shop and their bay was always super clean and organized. So with that in mind I approached this rebuild with the same philosophy in my home gamer shop. I know it seems crazy but this is a one shot deal for me with almost $1k in parts and the aggravation of ripping this beast out of the 80, its not something I intend on re-experiencing. So yes I vacuum my shop.
I am really fortunate to have a very stout bench built for a hydraulic shop with 3/8 plate top. This transmission is remarkably heavy so keep that in mind if you plan to begin this job.Tools
You wont need anything too fancy for this job. Your FSM, mine is RM180U. I sacrificed an old Chineseium flat head screwdriver to fashion some custom pry bars turned out to be very valuable. You can have no shortage of dental pick type implements and you'll likely find a few that you go for more often than others. I made a seal installer tool from a piece of brake tube and a short piece of guitar string fashioned into a loop that proved priceless for installing the o-rings without nicking them. I used a small NEW container of Vaseline and mixed in some ATF for assembly lube, you can buy some Dr. Goo I think its called which is a specialty assembly lube for auto trannys. Take your pick. I'm super confident with the Vaseline as there are endless accounts of its being used for this online and also I remember one of the proffs from mechanics college was a tranny guy and he always told us about it in the lectures. The same prof made us build that seal installer mentioned earlier, though almost 40 years ago now. To press the clutch packs, I tried a small 12T hydraulic press first and it was just way too janky to work with. I ended up using a home fab screw press that my son cobbled together quickly one day to work with Cummins injectors. I clamped it to my workbench and it worked really great and there are a bunch of pics of it in action. I also needed to fabricate various press adapters and a puller. I collected the plastic trays from groceries and cookies for a while so I had ample storage to keep every little part organized as it all came apart. Lots of zip-lock bags, big and small along with post-it notes inside the bags and a sharpie to actually write on the major sub-assemblies in order to help me keep track of the machine as I began to get used to working with it. As for rags, they are not allowed on this side of my shop. Its paper shop towel or Kim-wipes only. Its the same philosophy as vacuuming my shop floor. All about cleanliness and being relentless about it until its all back together. Yes this is a big PITA, but understanding that a stray bit of grit can go unseen, so can a small piece of thread from that rag. If that's the case its lights out for the rebuild.
The A440F
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- Thread starter
- #7
Valve Body
Pretty straight forward business. Toughest thing was flipping her upside down on the bench. It took two of us so as not damage the shift rod, etc. She does balance very nicely upside down on her ears though and is super easy to work on. One thing on mine that surprised me was how well the factory FIPG works. Almost every pan bolt was rusted to a fluff with some even dropping a size to get them off. At least a Chev leaks enough to self rust proof
I made a cardboard template of the bolt pattern to sort and store all the bolts. There are lots of them and they are different lengths too. So 'who needs the head ache'? The pan was cleaner than i had expected considering the stank of the burnt ATF that spewed out of it. Nothing of significant concern on the magnets, though there were a few really fine whiskers of steel, I wasn't sure what to expect deeper in. It did drive last time it was out though it required too much throttle to move her from a cold start. The old slag, she just wasn't putting out no more.
At any rate this particular valve body is not long for this part of the world, as its being swapped for a fresh Nomad that I picked up from Georg at Cruiser Bros. Really great service, and I'll send it back so Rodney can make another one for the shelf. So not too much to show here. I will say take your time cleaning all the silicone. I used a razor blade and it worked great though easy to dig into the aluminium. The last pic is a screen shot of a video and that's why it looks squished on the horizontal. I labeled the accumulator pistons with a sharpie.
I will admit that I had full intention of rebuilding the valve body, knowing full well that this is the root cause of the failures due to reduced line pressures in order to achieve the silky smooth shifts that are demanded by the mall crawling soccer moms. I figured that at least I can return it to spec and be satisfied with it. I soon discovered though, the problem with rebuilding it comes down to the fact the Toyota had discontinued two gaskets to complete the rebuild kit that I had to piece together one o-ring at a time. I found a couple of Chinese kits that would never stand a chance of seeing the inside of my truck. I also found Cobra Transmissions online in the US that had all the gaskets for the valve body and confirmed the country of origin is Taiwan, not bad. I pulled the trigger one day when the wife went to Bingo and called Georg with the secret credit card (admit it, you got one too!). A couple of weeks later and about $300 tax and duty for Justin in order to get it past the guards at the Kanuckistan border guardhouse I had it in my hands.
Pretty straight forward business. Toughest thing was flipping her upside down on the bench. It took two of us so as not damage the shift rod, etc. She does balance very nicely upside down on her ears though and is super easy to work on. One thing on mine that surprised me was how well the factory FIPG works. Almost every pan bolt was rusted to a fluff with some even dropping a size to get them off. At least a Chev leaks enough to self rust proof
I made a cardboard template of the bolt pattern to sort and store all the bolts. There are lots of them and they are different lengths too. So 'who needs the head ache'? The pan was cleaner than i had expected considering the stank of the burnt ATF that spewed out of it. Nothing of significant concern on the magnets, though there were a few really fine whiskers of steel, I wasn't sure what to expect deeper in. It did drive last time it was out though it required too much throttle to move her from a cold start. The old slag, she just wasn't putting out no more.
At any rate this particular valve body is not long for this part of the world, as its being swapped for a fresh Nomad that I picked up from Georg at Cruiser Bros. Really great service, and I'll send it back so Rodney can make another one for the shelf. So not too much to show here. I will say take your time cleaning all the silicone. I used a razor blade and it worked great though easy to dig into the aluminium. The last pic is a screen shot of a video and that's why it looks squished on the horizontal. I labeled the accumulator pistons with a sharpie.
I will admit that I had full intention of rebuilding the valve body, knowing full well that this is the root cause of the failures due to reduced line pressures in order to achieve the silky smooth shifts that are demanded by the mall crawling soccer moms. I figured that at least I can return it to spec and be satisfied with it. I soon discovered though, the problem with rebuilding it comes down to the fact the Toyota had discontinued two gaskets to complete the rebuild kit that I had to piece together one o-ring at a time. I found a couple of Chinese kits that would never stand a chance of seeing the inside of my truck. I also found Cobra Transmissions online in the US that had all the gaskets for the valve body and confirmed the country of origin is Taiwan, not bad. I pulled the trigger one day when the wife went to Bingo and called Georg with the secret credit card (admit it, you got one too!). A couple of weeks later and about $300 tax and duty for Justin in order to get it past the guards at the Kanuckistan border guardhouse I had it in my hands.
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Hi, Glad this is being done. Mike
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- #9
OD Assembly - Direct Clutch Part 1
This is the first assembly you will see when the pump is removed. If you're interested, refer to the PDF below for an understanding of when it is activated.
The cleaned and lubed parts of the OD Direct Clutch drum assembly showing the OD sun gear. Also seen is the clutch piston with the new o-rings installed and return spring assembly. The friction discs are soaking in the ATF sausage tray on the right. The o-ring tool made with a guitar string loop can also be seen. Use it to slide the o-ring over the piston helping to prevent it from scuffing against the aluminium edges. I smeared the o-ring mating surfaces with Vaseline for obvious reasons.
The OD Direct Clutch couples the overdrive sun gear to the OD Carrier. With the exception of 2nd gear, the OD Direct Clutch is engaged during all ranges including neutral and park.
I'll add these diagrams from the FSM when appropriate and I will try to be consistent identifying the DRIVE path with blue and DRIVEN path with red. I think its helpful to see the cross section components highlighted to get a better understanding of which components are moving and which may be held stationary.
This is the first assembly you will see when the pump is removed. If you're interested, refer to the PDF below for an understanding of when it is activated.
The cleaned and lubed parts of the OD Direct Clutch drum assembly showing the OD sun gear. Also seen is the clutch piston with the new o-rings installed and return spring assembly. The friction discs are soaking in the ATF sausage tray on the right. The o-ring tool made with a guitar string loop can also be seen. Use it to slide the o-ring over the piston helping to prevent it from scuffing against the aluminium edges. I smeared the o-ring mating surfaces with Vaseline for obvious reasons.
The OD Direct Clutch couples the overdrive sun gear to the OD Carrier. With the exception of 2nd gear, the OD Direct Clutch is engaged during all ranges including neutral and park.
I'll add these diagrams from the FSM when appropriate and I will try to be consistent identifying the DRIVE path with blue and DRIVEN path with red. I think its helpful to see the cross section components highlighted to get a better understanding of which components are moving and which may be held stationary.
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- Thread starter
- #10
OD Assembly - Direct Clutch Part 2
The new friction disc fresh out of the AFT bath. I was surprised to see the metallic composition of the friction material after soaking only because I did not notice it when it was removed from the packaging. The FSM states that the friction discs need to soak for at least two hours before installation. At the pace this rebuild is going the discs get a luxurious multi day soaking.
When the disc falls into the ATF bath, the air immediately starts evacuating the material forming almost a foam of bubbles on the surface. Imagine the consequences of a dry clutch pack.
These are the original 30 year old friction discs. I don't notice any metallic particles, doesn't mean its not present. The FSM says to replace the discs if the stamped labels cannot be seen. They are barely visible in red and I'm glad I have all of the replacement frictions discs.
Though I don't have any pics, I did go back to this clutch pack later and took the shine off the steel discs with some 1000 grit and a puddle of ATF on the flat surface of my bench. It worked really well I think while removing practically nothing measurable from the surface, it provided a nice mild cross hatch for the new friction discs to mate to. You see the process in pics of later assemblies further in the thread.
Here is the OD Direct Clutch fully assembled with the flange plate and snap ring installed. the clutch mus fit together loosely obviously stacking the assembly together as Piston-P-D-P-D-P-D-Flange. The plate that was originally assembled on the piston side of the clutch pack can be flipped over to expose a new unused plate surface to a friction disc surface. As you may be able to tell, I'm trying to maximize my results in every way I can considering I took the risk of not buying any new steel plates, due to the price and shipping and also the relatively low mileage on the transmission even though the fluid was burnt.
Testing the OD Direct Clutch on the pump using shop air and a dial indicator to measure the piston travel and ensure that the piston returns to full release position without binding up. The clutch assembly fits over to top of the pump stub oil seal rings and is sealed to the inside bore on the clutch body allowing the air to move the piston to full travel. The mag base of the dial indicator is attached to the machined surface of the pump. FSM says the allowable travel is 0.0433"-0.0669" and I measured 0.053". Perfect.
The new friction disc fresh out of the AFT bath. I was surprised to see the metallic composition of the friction material after soaking only because I did not notice it when it was removed from the packaging. The FSM states that the friction discs need to soak for at least two hours before installation. At the pace this rebuild is going the discs get a luxurious multi day soaking.
When the disc falls into the ATF bath, the air immediately starts evacuating the material forming almost a foam of bubbles on the surface. Imagine the consequences of a dry clutch pack.
These are the original 30 year old friction discs. I don't notice any metallic particles, doesn't mean its not present. The FSM says to replace the discs if the stamped labels cannot be seen. They are barely visible in red and I'm glad I have all of the replacement frictions discs.
Though I don't have any pics, I did go back to this clutch pack later and took the shine off the steel discs with some 1000 grit and a puddle of ATF on the flat surface of my bench. It worked really well I think while removing practically nothing measurable from the surface, it provided a nice mild cross hatch for the new friction discs to mate to. You see the process in pics of later assemblies further in the thread.
Here is the OD Direct Clutch fully assembled with the flange plate and snap ring installed. the clutch mus fit together loosely obviously stacking the assembly together as Piston-P-D-P-D-P-D-Flange. The plate that was originally assembled on the piston side of the clutch pack can be flipped over to expose a new unused plate surface to a friction disc surface. As you may be able to tell, I'm trying to maximize my results in every way I can considering I took the risk of not buying any new steel plates, due to the price and shipping and also the relatively low mileage on the transmission even though the fluid was burnt.
Testing the OD Direct Clutch on the pump using shop air and a dial indicator to measure the piston travel and ensure that the piston returns to full release position without binding up. The clutch assembly fits over to top of the pump stub oil seal rings and is sealed to the inside bore on the clutch body allowing the air to move the piston to full travel. The mag base of the dial indicator is attached to the machined surface of the pump. FSM says the allowable travel is 0.0433"-0.0669" and I measured 0.053". Perfect.
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- Thread starter
- #11
OD Assembly - Planetary Gear
Not a whole lot to talk about here. Its a carrier with 4 planets all hardened. FSM calls to measure the end play at each planet. It also calls to measure the ID of the planet bushings. I have no good inside calipers so I didn't measure any of the bushings on the transmission. Considering the low miles and visually nice, very slight wear patterns on the bushings I'm not worried about this part of the rebuild.
This is the input shaft that extends into the torque converter. Its attached directly to the OD planets which are the input member of the OD torque path. The wafer bearing you see supports the sun gear from the OD Direct Clutch assembly.
The planet end play spec is surprisingly wide I thought when I first saw it. 0.0079" - 0.0232". I measured 0.018"
And just for some filler info since I'm allowed five attachments per post, here's more shameless plagiarizing from the Toyota Course 262 book. Never mind about the number of teeth.
Not a whole lot to talk about here. Its a carrier with 4 planets all hardened. FSM calls to measure the end play at each planet. It also calls to measure the ID of the planet bushings. I have no good inside calipers so I didn't measure any of the bushings on the transmission. Considering the low miles and visually nice, very slight wear patterns on the bushings I'm not worried about this part of the rebuild.
This is the input shaft that extends into the torque converter. Its attached directly to the OD planets which are the input member of the OD torque path. The wafer bearing you see supports the sun gear from the OD Direct Clutch assembly.
The planet end play spec is surprisingly wide I thought when I first saw it. 0.0079" - 0.0232". I measured 0.018"
And just for some filler info since I'm allowed five attachments per post, here's more shameless plagiarizing from the Toyota Course 262 book. Never mind about the number of teeth.
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- Thread starter
- #12
OD Assembly - Brake
When in OD, the brake locks the overdrive sun gear, preventing rotation either clockwise or counterclockwise. This is seen in the figure above showing the sun gear as 'held'.
The OD Brake assembly is physically bolted to the case and does not rotate.
The corpse. Lets begin the autopsy.
I had no idea if I would any burn spots or not in this clutch pack. I labeled the steel plates to keep the sides sorted out while I inspected them. And there is one on this plate at about eleven o'clock. I can't post all the pics to this post but I can tell you that the burn spot transferred to the next plates opposite the friction disc in the same location of course because the plates are held stationary in the clutch housing which in turn is physically bolted to the case from the exterior.
The three friction discs are all burnt on the inside circumference where the burn spots are. Clearly there physical evidence that the OD Brake has been slipping and causing excessive localized heat.
So this is my first trial of applying a cross hatch to take the glaze of the plates and do what I can to massage those hard burn spots. Admittedly there isn't much I can do about them as they're hard just like a burn spot on a flywheel. Anyway, I quickly abandoned this dangerous method of using a piece of glass as a flat surface and went straight to duct tape on the steel plate workbench. I ended up with excellent results. Of course this learning curve took place over the first three clutch packs so I went back to this and the previous clutch and did a more consistent reconditioning on the plate surfaces. Sheesh.... Glass?!?... what was I thinking? Learning here. Its not how you get there that matters. Right?
I removed the picture of the piece of glass to insert a new picture after the parts diagram. I think its a little more informative.
So that's the five picture limit for this post. Nothing new though. I reinstalled clutch packs and made sure that I clocked the plates around so that they were all mixed up from their initial orientations. I did the air pressure test to check the piston stroke and return. Measured in at 0.059" right in the middle of the spec.
I also had to make a new adapter for the press as this clutch pack is way bigger than the OD clutch you saw in the previous posts. I cut a triangle out from 3/16" steel plate and it fits perfectly. You can see it in action on this OD Brake up near the top of this post in Tools section.
When in OD, the brake locks the overdrive sun gear, preventing rotation either clockwise or counterclockwise. This is seen in the figure above showing the sun gear as 'held'.
The OD Brake assembly is physically bolted to the case and does not rotate.
The corpse. Lets begin the autopsy.
I had no idea if I would any burn spots or not in this clutch pack. I labeled the steel plates to keep the sides sorted out while I inspected them. And there is one on this plate at about eleven o'clock. I can't post all the pics to this post but I can tell you that the burn spot transferred to the next plates opposite the friction disc in the same location of course because the plates are held stationary in the clutch housing which in turn is physically bolted to the case from the exterior.
The three friction discs are all burnt on the inside circumference where the burn spots are. Clearly there physical evidence that the OD Brake has been slipping and causing excessive localized heat.
So this is my first trial of applying a cross hatch to take the glaze of the plates and do what I can to massage those hard burn spots. Admittedly there isn't much I can do about them as they're hard just like a burn spot on a flywheel. Anyway, I quickly abandoned this dangerous method of using a piece of glass as a flat surface and went straight to duct tape on the steel plate workbench. I ended up with excellent results. Of course this learning curve took place over the first three clutch packs so I went back to this and the previous clutch and did a more consistent reconditioning on the plate surfaces. Sheesh.... Glass?!?... what was I thinking? Learning here. Its not how you get there that matters. Right?
I removed the picture of the piece of glass to insert a new picture after the parts diagram. I think its a little more informative.
So that's the five picture limit for this post. Nothing new though. I reinstalled clutch packs and made sure that I clocked the plates around so that they were all mixed up from their initial orientations. I did the air pressure test to check the piston stroke and return. Measured in at 0.059" right in the middle of the spec.
I also had to make a new adapter for the press as this clutch pack is way bigger than the OD clutch you saw in the previous posts. I cut a triangle out from 3/16" steel plate and it fits perfectly. You can see it in action on this OD Brake up near the top of this post in Tools section.
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- Thread starter
- #13
Front Clutch
Double check your own part numbers. These are only shown for reference indicating the components I used.
The front clutch is applied to couple the input shaft to the intermediate shaft. The front clutch is applied during all forward ranges.
Zooming in on the plates, you can see the slight scuffing I was able to apply so that the new friction discs will have a better surface to mate with during the wear in process.
1000 grit taped to the bench top. I filed the surface to take down any high spots before taping the paper down. I dipped the steel plate int the ATF and then onto the paper and very lightly moved in the biggest circle I could make while rotating the ring several times. I only went as far as necessary to dull the glaze front he surface of the plates.
Double check your own part numbers. These are only shown for reference indicating the components I used.
The front clutch is applied to couple the input shaft to the intermediate shaft. The front clutch is applied during all forward ranges.
Zooming in on the plates, you can see the slight scuffing I was able to apply so that the new friction discs will have a better surface to mate with during the wear in process.
1000 grit taped to the bench top. I filed the surface to take down any high spots before taping the paper down. I dipped the steel plate int the ATF and then onto the paper and very lightly moved in the biggest circle I could make while rotating the ring several times. I only went as far as necessary to dull the glaze front he surface of the plates.
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- Thread starter
- #14
Rear Clutch
The Rear Clutch connects input shaft and front & rear planetary sun gear and is engaged during Reverse, 3rd gear in range selector 3, and 3rd gear and OD while in the D range selector.
This clutch pack had the most damaged steel plates compared to the other clutches. You cam see the small dark spots on several of the plates below.
The Rear Clutch connects input shaft and front & rear planetary sun gear and is engaged during Reverse, 3rd gear in range selector 3, and 3rd gear and OD while in the D range selector.
This clutch pack had the most damaged steel plates compared to the other clutches. You cam see the small dark spots on several of the plates below.
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- Thread starter
- #15
Second Brake
The Second Brake prevents the front and rear planetary sun gear from turning either clockwise or counterclockwise. The Second Brake is engaged during 2nd gear in range selections 2, 3 and D. Like the OD Brake, the Second Brake is physically bolted to the case.
The front and rear sun gear is shown below. You can see that the rear sun gear is a smaller diameter than the front sun gear. The intermediate shaft passes through the sun gear assembly.
I noticed this really small nick on the piston casting. It really pays clean everything really well and carefully inspect every piece during the rebuild. I dressed it out with a wet piece of 2000 grit.
Here she is all lubed and sploobed and ready to stack up on the torque converter Christmas tree. The steel plates in this clutch pack were in good shape with no burn marks. I still scuffed the plates lightly with 2000 grit soaked with ATF to break the shine of the plates and provide a nice surface for the new fiction discs to wear in to.
The Second Brake prevents the front and rear planetary sun gear from turning either clockwise or counterclockwise. The Second Brake is engaged during 2nd gear in range selections 2, 3 and D. Like the OD Brake, the Second Brake is physically bolted to the case.
The front and rear sun gear is shown below. You can see that the rear sun gear is a smaller diameter than the front sun gear. The intermediate shaft passes through the sun gear assembly.
I noticed this really small nick on the piston casting. It really pays clean everything really well and carefully inspect every piece during the rebuild. I dressed it out with a wet piece of 2000 grit.
Here she is all lubed and sploobed and ready to stack up on the torque converter Christmas tree. The steel plates in this clutch pack were in good shape with no burn marks. I still scuffed the plates lightly with 2000 grit soaked with ATF to break the shine of the plates and provide a nice surface for the new fiction discs to wear in to.
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- Thread starter
- #16
Simpson Planetary Gear Sets - Front/Rear Planetary & One Way Clutch
This assembly is inspect and measure only with the exception of replacing the gasket on the forward end of the intermediate shaft. The SUN gears are shown in pic #3 in the section above.
The Simpson-type planetary gear unit is made up of two simple planetary gear sets arranged on the same axis with a common sun gear. These gear sets are called the front planetary gear set and the rear planetary gear set, based on their position in the transmission. These two planetary gear sets result in a three-speed automatic transmission having three forward gears and one reverse gear. The physical assembly in the parts breakdown is shown below.
There are three shafts in the Simpson planetary: the input shaft, sun gear, and the output shaft. The input shaft is driven from the turbine in the torque converter. It is connected to the front planetary ring gear through the multiplate clutches. The sun gear, which is common to both the front and rear planetary gear sets, transfers torque from the front planetary set to the rear planetary set. The output shaft is splined to the carrier of the front planetary gear set and to the ring gear of the rear planetary and then provides turning torque to the rear wheels or the overdrive unit.
The planetary gear set is used to increase or decrease engine torque, increase or decrease vehicle speed, reverse direction of rotation or provide direct drive. It is basically a lever that allows the engine to
move heavy loads with less effort. The table below reads horizontally and indicates the change to rotational speed, torque and direction of rotation of the out put member. When any two members are held together and another member provides the input turning force, the entire assembly turns at the same speed as the input member.
The Sprag One-Way Clutch holds planetary components in one rotational direction. One-way clutches are small in size and release and apply quickly, giving good response for upshifts and downshifts.
A one-way clutch is a holding device which requires no seals or hydraulic pressure to apply. They are either a roller clutch or sprag clutch. Their operation is similar in that they both rely on wedging metal between two races. Two one-way clutches are used in the Simpson Planetary Gear Set. The one-way clutch No. 1 is used in second gear and the one-way clutch No. 2 is used in first gear. A one-way sprag clutch consists of a hub as an inner race and a drum, or outer race. The two races are separated by a number of sprags which look like a figure 8" when looking at them from the side view. In the illustration below, the side view of the sprag shows four lobes. The two lobes identified by L1 are shorter than the distance between the two races. The opposite lobes are longer than the distance between the races. As a result, when the center race turns clockwise, it causes the sprag to tilt and the short distance allows the race to turn.
This build series is continued on post #27
This assembly is inspect and measure only with the exception of replacing the gasket on the forward end of the intermediate shaft. The SUN gears are shown in pic #3 in the section above.
The Simpson-type planetary gear unit is made up of two simple planetary gear sets arranged on the same axis with a common sun gear. These gear sets are called the front planetary gear set and the rear planetary gear set, based on their position in the transmission. These two planetary gear sets result in a three-speed automatic transmission having three forward gears and one reverse gear. The physical assembly in the parts breakdown is shown below.
There are three shafts in the Simpson planetary: the input shaft, sun gear, and the output shaft. The input shaft is driven from the turbine in the torque converter. It is connected to the front planetary ring gear through the multiplate clutches. The sun gear, which is common to both the front and rear planetary gear sets, transfers torque from the front planetary set to the rear planetary set. The output shaft is splined to the carrier of the front planetary gear set and to the ring gear of the rear planetary and then provides turning torque to the rear wheels or the overdrive unit.
The planetary gear set is used to increase or decrease engine torque, increase or decrease vehicle speed, reverse direction of rotation or provide direct drive. It is basically a lever that allows the engine to
move heavy loads with less effort. The table below reads horizontally and indicates the change to rotational speed, torque and direction of rotation of the out put member. When any two members are held together and another member provides the input turning force, the entire assembly turns at the same speed as the input member.
| HELD | INPUT | OUTPUT | SPEED | TORQUE | ROTATION |
| RING | SUN | CARRIER | REDUCED | INCREASED | DRIVE |
| SUN | RING | CARRIER | REDUCED | INCREASED | DRIVE |
| SUN | CARRIER | RING | INCREASED | REDUCED | DRIVE |
| CARRIER | SUN | RING | REDUCED | INCREASED | REVERSE |
The Sprag One-Way Clutch holds planetary components in one rotational direction. One-way clutches are small in size and release and apply quickly, giving good response for upshifts and downshifts.
A one-way clutch is a holding device which requires no seals or hydraulic pressure to apply. They are either a roller clutch or sprag clutch. Their operation is similar in that they both rely on wedging metal between two races. Two one-way clutches are used in the Simpson Planetary Gear Set. The one-way clutch No. 1 is used in second gear and the one-way clutch No. 2 is used in first gear. A one-way sprag clutch consists of a hub as an inner race and a drum, or outer race. The two races are separated by a number of sprags which look like a figure 8" when looking at them from the side view. In the illustration below, the side view of the sprag shows four lobes. The two lobes identified by L1 are shorter than the distance between the two races. The opposite lobes are longer than the distance between the races. As a result, when the center race turns clockwise, it causes the sprag to tilt and the short distance allows the race to turn.
This build series is continued on post #27
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- Thread starter
- #17
UPDATE - The transmission works flawlessly after my rebuild. I put 100Km on it today. Nice crisp shifts and the torque converter lockup is noticeable too. Let me know if there's any interest in me posting the final build sections. I'll be doing a 600km trip this weekend.
EscapeWagon62
SILVER Star
Outstanding post.
well done
well done
- Thread starter
- #20
No
No probs. Please be patient though it's kind of busy for the next while. I hope that others can find it helpful
