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1982 Toyota Celica Supra P-Type
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26 Posts
Discussion Starter · #1 ·
I think I’ve mentioned on the forum before about how my w58 pops out of fifth gear under load. I’ve been recommended to buy a used transmission and swap it out with that one, but I thought I should probably contact some local transmission shops to see if they can do anything. Called around and nobody wants to take it. Time to pull it then I guess.

So I pull the trans right and I got to thinking well it’s already out I can’t do much harm to it right so I might as well pop it open and see if it looks fixable. I clean it off, 40 years of gunk, I throw it up on the workbench and start removing stuff with the help of the TSRM & Youtube University.

Pulling the shifter I notice that the mechanism doesn’t quite feel right and when I get to the little thingy that bolts on to the main internal shift lever and holds the bottom part of the external shift lever I notice that the bolt holding it onto the main internal shift lever is completely loose, it’s just sitting in the hole wiggling around. When I pull the bolt out I notice that it’s clearly been stripped, and somebody tried to repair it and ended up just shoving it back in there. The threads on the shift lever look completely destroyed too, yet somehow, the mechanism is hanging on to the shaft and the hole is staying lined up. After some gentle hammering it slides off and it turns out that the metal is discoloured and is a bit deformed which was the only thing holding it in place. The top part of this piece where the shifter slots into the hole also has something that appears to be deformed. This is of course when I remember the strange part that came in the glovebox when I bought the car. As you can see it looks like part of billyM’s bushing kit from w58bushings.com.

So the story at this point as far as I can piece it together from this evidence is that somebody who didn’t have a clue what was going on tried (and failed) to install the bushing kit, ended up leaving a bunch of parts mangled, and decided to just put it back together without an important part of the bushing inside. I have reason to believe this happened years ago. The subsequent owners, including me, proceeded to drive the car this way, which meant that because a large part of the bushing is missing, the car didn’t actually ever go completely into fifth gear.

But I didn’t stop there. I wanted to see fifth gear for myself, so I kept going. I had to file down the main internal shift shaft slightly, because it was swollen, as mentioned, and the rear case needs that shift lever to be able to slide out in order to be removed. So I remove the rear case and fifth gear of course is quite damaged. As you can see in the images, the teeth are quite rounded off on not only fifth gear engagement teeth, but also the synchroniser teeth, and the slider teeth. I should note here that some people had suggested to me that it might be an input/output shaft bearing that’s worn, and that makes sense, but these bearings seem perfectly fine with little to no play in them. The 5th gear shift fork was also suggested to me but it does not appear to be signifiantly worn.

My prediction is that the gear was not fully engaging due to part of the shift bushing being completely missing, which caused the popout, but the damage to the gear could also be part of the problem. Some part of me hopes that the wear on the 5th teeth is only a symptom and not the cause. I would appreciate if those of you familiar with the trans could take a look at the images, as horrifying as they may be ;), and let me know what you think on this. Which factor contributes more to 5th popout? Which problem came first? Does my hypothesis sound accurate?

My plan at this point is actually since I’ve gone far I’m going to try replacing the following and see what happens:

  • 5th gearset (actually only the one on the intermediate shaft, as the one on the output shaft looks extremely difficult to replace)
  • 5th synchro
  • 5th slider
  • main shift lever (the one that’s damaged, I don’t know the proper name for that part)

In addition to this I’m going to attempt to install the w58 bushing kit the right way this time since I seem to have all the parts to do it already. I will of course throw new gaskets and seals in the transmission while it’s out.

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Thanks in advance!!!
 

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I've rebuilt lots of transmissions and those rounded corners are normal - all the engagement hubs and rings will look like that. You should take the rest of the case off at least to reseal it and compare. And change the input and output seals.

Unless you plan to tear it down all the way to replace synchronisers the easiest repair would be to take that shift select shaft into a machine shop with the arm and bolt and have them use a thread repair kit and some machining to fix the threads. Then reassemble with the bushings etc and new input / output seals.
 

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1982 Toyota Celica Supra P-Type
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26 Posts
Discussion Starter · #3 ·
I've rebuilt lots of transmissions and those rounded corners are normal - all the engagement hubs and rings will look like that. You should take the rest of the case off at least to reseal it and compare. And change the input and output seals.

Unless you plan to tear it down all the way to replace synchronisers the easiest repair would be to take that shift select shaft into a machine shop with the arm and bolt and have them use a thread repair kit and some machining to fix the threads. Then reassemble with the bushings etc and new input / output seals.
Thanks for the reply. My plan is definitely to do the seals. If I’m not able to obtain the shift select shaft then plan B on that was to take it to the machine shop and have them tap new threads or whatever they do to attempt to salvage it. Correct me if I’m wrong but are you saying that you believe that part of my issue could lie inside the front case? What should I be looking for exactly in there?

Thanks
 

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No I am saying the engagement rings and hubs look ok. If you want to confirm you can compare to the ones for the other gears. The rounded corners etc are normal.

the synchros might be worn but it's the teeth on the inside where they grip the cone of the hub that wear. The teeth on the outside look fine.
 

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Well, I never heard of this kit, so I went out to the garage, and my shifter had about an inch or more play. I guess 186,000+ miles will do that! So I have ordered the kit, and I am looking forward to installing it when I return north in March. There is no way to thank everyone for all the help and information this forum provides. I'll do a write up on how easy or difficult it turns out to be.
Bob
 

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1985 Toyota Celica Supra MK2 with P trim
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Well, I never heard of this kit, so I went out to the garage, and my shifter had about an inch or more play. I guess 186,000+ miles will do that! So I have ordered the kit, and I am looking forward to installing it when I return north in March. There is no way to thank everyone for all the help and information this forum provides. I'll do a write up on how easy or difficult it turns out to be.
Bob
It's pretty easy to do (although removing the ring gasket without opening the transmission can be annoying, get some long and thin pliers for that job !) and it'll be night and day shifting around !
 
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