3-speed transmission swap to a 4-speed? (1 Viewer)

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So I got everything all back together and installed. I definitely needed to cut that floor brace to fit the transfer case. You can reuse and reroute the 3 speed cables.
But my issue now is the clutch won’t grab. I adjusted the clutch so the throw out bearing was not touching the 3 prongs. The slave is fine and bled and there is good movement in the throw out bearing. So I can shift easily but when I go to release I get nothing. No noise either. Maybe a small rumble? I thought maybe the clutch might be in backwards because I saw the cone pointing to the transmission where most people said it should point to the flywheel. So I pulled it back out and looked at the clutch. I did not put it in backwards. But it was designed a little different. It’s a duralast clutch. So I got a new heavy duty clutch from SOR anyway but it is the same thickness of the duralast.
I am still not sure this will fix my issue. I have a brand new pressure plate from Aisin but the flywheel looks smooth like glass. The step seems to be 15.76mm which should still be functional. The PO told me he resurfaced the flywheel but this looks too smooth. I think the clutch is slipping on the flywheel which is why it’s not grabbing and moving the transmission? What should a resurfaced flywheel look like? Should it be like glass or should it have some grooves? Should I lower the step on the flywheel to 14mm? That way the pressure plate could grab more?
Any advise would be appreciated. It is very frustrating to get this far and have no power.
 
Ok. I took it all apart again and took the flywheel to get it resurfaced. It looked much better after the resurface. I put it all back together with the new heavy duty clutch plate from SOR and everything shifts fine now.

This early H41 has 4 gears and synchromesh so that’s good but the 1st gear is so low I am only in it about 10 feet. Actually I just start off in 2nd and it runs just like my 3 speed did. I think 1st gear will be much more fun off road.

It’s a big relief to have it all working again. I am still having one issue remaining. I am still experiencing a whine from the transmission/transfer case. It gets worse and louder the faster I go. After rebuilding both I expected things to be much quieter.
If I step on the clutch the whine goes away. To me that eliminates the drive train and differential as noise sources.

Any ideas? Any way to isolate the noise source between the transmission and the transfer case?
 
Here are some final pictures. On the hump I had to cut the hole more to the center and the 4 speed trans cover was a little taller than the 3 speed so I had to make the hole a little larger than I wanted.
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You can see the hole is a little bigger than the shift cover. I will have to find a creative base plate that will cover the hole.
 
I got some used drive shafts from a 4 speed. The sizes worked perfect. I wanted the 11 mm bolt holes to give it the most strength. I think they were from a 1976.
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Rear shaft.
A5389A44-CF7D-4993-A535-5D952F70C37D.jpeg

Front shaft.
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Front Ujoint.
 
The final clearance on the crossbar was tight but it all fits with a few mm to spare.
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This is the parking break and rear drive shaft clearance. It looks tight but it Is down below the crossbar by 1/2 inch.
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You can see the rear of the trans cover and the cross member. It looks about 2 inches to spare.
 
Finally a picture of the transfer case shift rod and 3 inch extension. Since the transmission is moved back about 3 inches you have to lengthen this as well.

The clearance above the transfer case is very tight as well but it is not rubbing or hitting the floorboards.
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This is where the shift rod connects to the transfer case. You can also see the vacuum lines to the 3 speed.

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The 3 inch extension.
 
@mrtodds77
Kickass, you did it!! Awesome work and great of you to include pictures along the way. How are you liking it as opposed to your original 3-speed transmission? Has the "whining" noise settled down since you've started driving it? Is 1st gear too low? :steer:

I finally got the necessary time off from work and feel like i can finally progress on this early h41 installation as well. What did you finally end up doing in finding the necessary bearings and remaining parts for the transmission?

Thanks for any help you can provide and, again, great to see how you completed the build :cheers:
 
Thanks. It was a little challenging but I like figuring out the small problems and doing the work myself. It gives you more knowledge to fix things if they break down off road.

I tend to start off in 2nd most of the time which feels like I am using it just like the 3 speed. I use 1st for hills and off road. The cruiser does not stall at all starting off in 2nd. The 3 speed transmission looks like a toy compared to the 4 speed.

The whining has settled down some but I am still planning on putting in some sound deadening materials and heavy rubber mats. The noise is not bad under 50 mph which is mostly where I keep it anyway.

The H41 rebuilt kit I got from SOR but they charged a lot for the kit. When I talked with Mark my mechanic he said they were just standard Toyota bearings. SOR tried to make it sound like they were rare bearings so that is why it costs more. I spent weeks trying to find and order the right cage bearings because the kit came with the wrong ones for my older H41. Reuse what you have if they don’t look too warn. I probably didn’t need to rebuild my transmission. The cost to benefit ratio was pretty high.

Good luck and feel free to PM me for any questions.
 
Thanks. It was a little challenging but I like figuring out the small problems and doing the work myself. It gives you more knowledge to fix things if they break down off road.

I tend to start off in 2nd most of the time which feels like I am using it just like the 3 speed. I use 1st for hills and off road. The cruiser does not stall at all starting off in 2nd. The 3 speed transmission looks like a toy compared to the 4 speed.

The whining has settled down some but I am still planning on putting in some sound deadening materials and heavy rubber mats. The noise is not bad under 50 mph which is mostly where I keep it anyway.

The H41 rebuilt kit I got from SOR but they charged a lot for the kit. When I talked with Mark my mechanic he said they were just standard Toyota bearings. SOR tried to make it sound like they were rare bearings so that is why it costs more. I spent weeks trying to find and order the right cage bearings because the kit came with the wrong ones for my older H41. Reuse what you have if they don’t look too warn. I probably didn’t need to rebuild my transmission. The cost to benefit ratio was pretty high.

Good luck and feel free to PM me for any questions.
Were you able to install your trans/tcase combo into the truck, with the engine still in the truck? My engine is currently out of the FJ, so I can do it either way, but it's going to be crazy heavy with everything all bolted together.
 
Were you able to install your trans/tcase combo into the truck, with the engine still in the truck? My engine is currently out of the FJ, so I can do it either way, but it's going to be crazy heavy with everything all bolted together.
I just did the same exact conversion as @mrtodds77, same transmission and everything. I installed the Trans/t-case while the engine was installed into the truck. It appears Mrtodd did it the same way. Unfortunately, I haven't seen Mrtodd on ih8mud for a while now. I hope he returns.

in your case, and i've seen a few people post around on ih8mud about it, you should be able to put everything in from the front of the vehicle. I think you'd need to take out the radiator and lower down the front hinge part of the landcruiser to put the entire engine/trans assembly in. You would be needing an engine hoist/cherry-picker and I would suggest to buy an "engine hoist leveler." this will allow you to tilt the engine assembly to be either level, more forward, or rearward with ease. It's gonna be heavy, but it might be the easiest approach going from the front of the vehicle.

The way I did it, and since Im assuming you own a pre-1973 fj40 like me, the rear cross member ("torque-tube") is too far forward. If you happen to have a 1973, consider yourself lucky because that was the transition year for USA model fj40s. The cross member will already be far back enough to not require you to tilt the engine. In the pre-1973 models, This does required the the front motor mounts to be loosened and the rear ones to be removed (at least in my case) so the engine could be tilted rearward far back enough. This allows the transmission and t-case to have enough room to mate with the engine and clear the rear cross-member. During this process, I had a cherry-picker holding the load of the transmission from my passenger side door. It was chained up to the entire assembly through the opening of the floor where the transmission hump goes. I also had my bottle jack and a thick piece of wood underneath the oil pan to support the engine. This allowed me to lower/raise the engine with precision. You need to be raising the engine back up so it could finally mount correctly onto the frame. Lastly, I had a transmission floor jack cradling the t-case ( I bought it from harbor freight for about $70) . All together, you can make micro adjustments to everything and slide the transmission/tcase on. it's a pain but doable. I had my father assist with guiding the assembly from the inside and I remained underneath the vehicle to make the adjustments from there. We used two guide-bolts threaded onto the bellhousing to help guide the tranmsison into place.

*Importing before you install it back together if you're using a 4-speed tranmsison*
if you have a vacuum actuated t-case (or even possibly a direct floor shift t-case) and you have a pre-1973 fj40, you may need to add washers to the front motor mounts. This will tilt the engine back just enough so that the lever-arm ontop of the t-case can clear a piece of square tubing on the underside of the fj40. It's on the passenger side. You can also take an angle grinder and cut it back about 3 inches and it will clear. This is the approach that I did as well as Mrtodd. I checked underneath a few fj40s and the 1973+ has it cut back from the factory. I know mark has said in a few forum post that you can "dimple" that piece of square tubing, with a hammer, so that it can fit. Let me tell you, it won't work. At least not for a 1971 fj40. It's gonna block the t-case from being raise into position and you won't be able to drive your fj40. I tried it and had to ran into this issue.

If you have any questions or wish for me to clear things up, just let me know. Everything is still fresh in my head.
 
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I just did the same exact conversion as @mrtodds77, same transmission and everything. I installed the Trans/t-case while the engine was installed into the truck. It appears Mrtodd did it the same way. Unfortunately, I haven't seen Mrtodd on ih8mud for a while now. I hope he returns.

in your case, and i've seen a few people post around on ih8mud about it, you should be able to put everything in from the front of the vehicle. I think you'd need to take out the radiator and lower down the front hinge part of the landcruiser to put the entire engine/trans assembly in. You would be needing an engine hoist/cherry-picker and I would suggest to buy an "engine hoist leveler." this will allow you to tilt the engine assembly to be either level, more forward, or rearward with ease. It's gonna be heavy, but it might be the easiest approach going from the front of the vehicle.

The way I did it, and since Im assuming you own a pre-1973 fj40 like me, the rear cross member ("torque-tube") is too far forward. If you happen to have a 1973, consider yourself lucky because that was the transition year for USA model fj40s. The cross member will already be far back enough to not require you to tilt the engine. In the pre-1973 models, This does required the the front motor mounts to be loosened and the rear ones to be removed (at least in my case) so the engine could be tilted rearward far back enough. This allows the transmission and t-case to have enough room to mate with the engine and clear the rear cross-member. During this process, I had a cherry-picker holding the load of the transmission from my passenger side door. It was chained up to the entire assembly through the opening of the floor where the transmission hump goes. I also had my bottle jack and a thick piece of wood underneath the oil pan to support the engine. This allowed me to lower/raise the engine with precision. You need to be raising the engine back up so it could finally mount correctly onto the frame. Lastly, I had a transmission floor jack cradling the t-case ( I bought it from harbor freight for about $70) . All together, you can make micro adjustments to everything and slide the transmission/tcase on. it's a pain but doable. I had my father assist with guiding the assembly from the inside and I remained underneath the vehicle to make the adjustments from there. We used two guide-bolts threaded onto the bellhousing to help guide the tranmsison into place.

*Importing before you install it back together if you're using a 4-speed tranmsison*
if you have a vacuum actuated t-case (or even possibly a direct floor shift t-case) and you have a pre-1973 fj40, you may need to add washers to the front motor mounts. This will tilt the engine back just enough so that the lever-arm ontop of the t-case can clear a piece of square tubing on the underside of the fj40. It's on the passenger side. You can also take an angle grinder and cut it back about 3 inches and it will clear. This is the approach that I did as well as Mrtodd. I checked underneath a few fj40s and the 1973+ has it cut back from the factory. I know mark has said in a few forum post that you can "dimple" that piece of square tubing, with a hammer, so that it can fit. Let me tell you, it won't work. At least not for a 1971 fj40. It's gonna block the t-case from being raise into position and you won't be able to drive your fj40. I tried it and had to ran into this issue.

If you have any questions or wish for me to clear things up, just let me know. Everything is still fresh in my head.
Thank you so much for the thorough info!! My FJ is a '67. I was curious about the tube being in the way, so looks like I should make some modifications there. I may just make it removable, but at the same time, rotate it back some. I will also plan on modifying the support tube on the floorboard!

I do have a cherry picker. I would like to assemble it all, outside the truck, and install the whole combo that way (that's how I removed it all), but it gets VERY tail heavy, and is a bit of a tedious operation!! Kind of has me wishing I had sprung for the "beefier", more expensive, cherry picker from harbor freight!!
 
Yeah, either way you do it, it's not a fun process. Doing the cross member modification is the best option and will allow you to install/remove the transmission assembly later on in life without tilting the engine or taking it all out from the front. But, it's not necessary. At the time, I didn't feel like doing it because it would only prolong the entire project and keep me from driving the Fj40 as soon as possible. I decided to leave that project for another day, if any. It just makes the process easier. As far as the square tubing part, I'll share a picture of it tomorrow. I did end up looking underneathe a 1964 fj45 and that one was more flat compared to my 1971 one.... Maybe your 1967 similar to the fj45? Who knows, only with pictures will we know. I'll post it here tomorrow in the late evening.
 
Thank you so much for the thorough info!! My FJ is a '67. I was curious about the tube being in the way, so looks like I should make some modifications there. I may just make it removable, but at the same time, rotate it back some. I will also plan on modifying the support tube on the floorboard!

I do have a cherry picker. I would like to assemble it all, outside the truck, and install the whole combo that way (that's how I removed it all), but it gets VERY tail heavy, and is a bit of a tedious operation!! Kind of has me wishing I had sprung for the "beefier", more expensive, cherry picker from harbor freight!!
It’s very doable without moving the torque tube. I put a 84 2F with a 74 4 speed/transfer case. Lower the rear of the engine a bit and you can get it in. Then just put the rear mounts back. I have a 69 ( manufacture date of 68 ).
 
Here is a picture that I took before I made the swap to a 4 speed. You can see the arrow pointing at the "square tubing". Since the 4 speed pushes everything back, the transfer case shifting lever gets moved far back enough to sit right at that square tubing support and make direct contact.

brace 1.jpg



And finally here are a couple of pictures of that square tubing cut. You can obviously do a more clean job that what I did. You can see the pivot arm on top of the transfer-case cover. Without that square tubing being cut, it would hit and you would not be able to shift from hi/low or even line up the entire assembly onto the frame/motor mounts.

brace 2.jpg


brace 3.jpg
 
Here is a picture that I took before I made the swap to a 4 speed. You can see the arrow pointing at the "square tubing". Since the 4 speed pushes everything back, the transfer case shifting lever gets moved far back enough to sit right at that square tubing support and make direct contact.

View attachment 3860239


And finally here are a couple of pictures of that square tubing cut. You can obviously do a more clean job that what I did. You can see the pivot arm on top of the transfer-case cover. Without that square tubing being cut, it would hit and you would not be able to shift from hi/low or even line up the entire assembly onto the frame/motor mounts.

View attachment 3860240

View attachment 3860241
 

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