Technically, you are putting AISIN parts in your transmission.
1989 4Runner R150F Rebuild
- Thread starter BrickRunner
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- Thread starter
- #62
Whelp, I have a definitive answer as to why my first rebuild lost 4th gear. The 5th gear synhro is very similar in size to the 3rd and 4th gear synhros. Close enough so it could be assembled in place of one of those if you aren't careful...
I had put the 5th gear synchro on 4th gear. The 5th gear synchro is axially thicker, so when placed on 4th, it saw increased axial load which wore it out over the 7000 miles. The axial loading could also have transfered the the bearings and bearing thrust surfaces.
Live and learn.
I had put the 5th gear synchro on 4th gear. The 5th gear synchro is axially thicker, so when placed on 4th, it saw increased axial load which wore it out over the 7000 miles. The axial loading could also have transfered the the bearings and bearing thrust surfaces.
Live and learn.
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How'd you figure that out? You're a transmission detective. NOT to be confused with TRANS detective. Are you able to get it fixed?
- Thread starter
- #64
When I was opening up my new rebuild kit this time, I noticed one of the three smaller synchros had a slightly different tooth profile than the other two. I couldn't see anything else different about it until I measured the thicknesses with my calipers. The rebuild kit and the FSM didn't really give me any clue as to which one went where, so I checked the diagram on Megazip and it lists the same synchro part number for 3rd and 4th, and a different one for 5th.
I pulled my old broken bits from the rebuild and re-rebuild out, and took a close look at the broken synchro from when I lost 4th gear. Sure enough, it matched the new 5th gear one from the new rebuild kit.
I'm just waiting on one more part and then I will get it back together and back in.
dohcdelsol93
snoogans
Yota1 put out some r150 tear down and reassembly videos.
Unfortunately they didn't get into the measurement of anything, just basic inspection of trust surfaces, discoloration and bearing surfaces.
Would you consider using a micrometer and feeler gauges to test for synchro/gear gap or thrust washer thicknesses a must on these old transmissions with well over a 1/4 of a million miles on many of them?
Unfortunately they didn't get into the measurement of anything, just basic inspection of trust surfaces, discoloration and bearing surfaces.
Would you consider using a micrometer and feeler gauges to test for synchro/gear gap or thrust washer thicknesses a must on these old transmissions with well over a 1/4 of a million miles on many of them?
- Thread starter
- #66
I do now! I didn't the first time, but did this time. The FSM has instructions for measuring thrust clearances.
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- Thread starter
- #67
Last part showed up, the plastic first gear bearing spacer. It shipped from Carson California to Akron Ohio and then back to California... go figure.
I got the transmission assembled yesterday and installed today. Back on the road with all gears accounted for!
I got the transmission assembled yesterday and installed today. Back on the road with all gears accounted for!
dohcdelsol93
snoogans
Getting these out of the case is apparently the easy part. The 1st and 2nd gear synchros don't look great for 6 months old.
On your 4th gear synchro. Is it tight against the gear? All other synchros I can easily move a little forward/back and side to side with a little screw driver.
On 4th I have to pull the input shaft away from the main shaft and she'll move. Otherwise I the synchro sits tight against the gear.
Shifts by hand into 3/4 and 5 with ease. 1 and 2 is extremely difficult.
On your 4th gear synchro. Is it tight against the gear? All other synchros I can easily move a little forward/back and side to side with a little screw driver.
On 4th I have to pull the input shaft away from the main shaft and she'll move. Otherwise I the synchro sits tight against the gear.
Shifts by hand into 3/4 and 5 with ease. 1 and 2 is extremely difficult.
- Thread starter
- #69
I saw somewhere in a video that the 4th gear synchro can stick when the transmission is on a stand without the cases installed. This is because you don't have the input shaft bearing snap ring holding the input shaft in place axially, allowing it to move towards the output shaft more that it would be allowed to when fully assembled. Haven't found that video again.
dohcdelsol93
snoogans
I think you're correct. If I put a little support on the input shaft the synchro spins like the rest of them.
dohcdelsol93
snoogans
Any tips or tricks to pressing these things together/apart on a 6-12 ton press. I have access to a few and all have a working bench about 3 inches in with making it too narrow to set the main shaft down between the beams
Since I keep having synchro issues I checked for clutch drag. Reving to 4000 rpms in 1st with clutch in, nothing.
If I put it in 4L I can feel if grab a little, enough to feel pressure on flat ground. Only does this warm. New aisin master and slave. Stainless braided line. Rebled. 6 month old centerfoce clutch. New O'Riley's flywheel. New koyo tob and nsk pilot bearing. I don't think I've ever had to use 4L since it was put on the road years ago and I usually don't rev my engine to make noise so I don't know if this is normal.
Thinking about a new clutch fork and pivot stud.
No play on clutch pedal bracket. Pedal 5.25 inches from floor and .25 inches of play before catching pressure.
Since I keep having synchro issues I checked for clutch drag. Reving to 4000 rpms in 1st with clutch in, nothing.
If I put it in 4L I can feel if grab a little, enough to feel pressure on flat ground. Only does this warm. New aisin master and slave. Stainless braided line. Rebled. 6 month old centerfoce clutch. New O'Riley's flywheel. New koyo tob and nsk pilot bearing. I don't think I've ever had to use 4L since it was put on the road years ago and I usually don't rev my engine to make noise so I don't know if this is normal.
Thinking about a new clutch fork and pivot stud.
No play on clutch pedal bracket. Pedal 5.25 inches from floor and .25 inches of play before catching pressure.
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dohcdelsol93
snoogans
I purchased a 4 inch bearing splitter and got some 6x6 wood blocks I think I can stack to press it apart. We've not had a press in the shop since about 2007 so I ordered a cheap 12 ton so I don't tie up the race shops press for a couple hours stacking blocks and scrap metals. I have a few flat head blocks I can strip down as well to figure something out. I think every gear but first will slide down into a Briggs 12 horse cylinder.
dohcdelsol93
snoogans
So, synchro interchange question for you gurus. I ordered cheap synchros as this is my first r150 tear down and didnt want to throw away 300 on OEM synchros if I see it up. I'm learning on 50 dollar cobra synchros.
3, 5 and 5 have the same size syncro (on my trans at least). 1st and 2nd have the same synchro (again, based on what I removed from my trans.
They 3 small synchros are stamped 945. The 2 big ones are 943 stamped
To my knowledge on the ax15, the 945 is the updated 5 th gear synchro and is shaped like home base.
What I got from Cobra was one 945 home base cut synchro and two 944 angle cut synchros. This trans got a new 3/4 hub about two years ago(1992/93 vintage trans)
Will the angle cut synchros work with the new style cut hub or do I need all the updated sychros?
New synchros are the ones on my hand, old are with the hub showing how all my shift hub teeth are shaped (like home plate).
Thank you ahead of time.
3, 5 and 5 have the same size syncro (on my trans at least). 1st and 2nd have the same synchro (again, based on what I removed from my trans.
They 3 small synchros are stamped 945. The 2 big ones are 943 stamped
To my knowledge on the ax15, the 945 is the updated 5 th gear synchro and is shaped like home base.
What I got from Cobra was one 945 home base cut synchro and two 944 angle cut synchros. This trans got a new 3/4 hub about two years ago(1992/93 vintage trans)
Will the angle cut synchros work with the new style cut hub or do I need all the updated sychros?
New synchros are the ones on my hand, old are with the hub showing how all my shift hub teeth are shaped (like home plate).
Thank you ahead of time.
- Thread starter
- #76
I used the rebuild kit from USA standard gear and it had the same numbering and three distinct synchros, including the angle cut synchros like you show. It's been working for me.
- Thread starter
- #77
Drained the gear oil after 1000 miles of light driving. Looks ok. Shifting has been gradually improving and starting to get nice and smooth.
And now for another road trip adventure! Hey, check out that cruiser, it looks just like mine! Oh wait...
And now for another road trip adventure! Hey, check out that cruiser, it looks just like mine! Oh wait...
