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TR4/4A tr4 pops out of second gear on deceleration

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Onefuntr4

Freshman Member
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My tr4 pops out of second gear under deceleration.
Everything else is good with the transmission.
Thanks for the help
 
Mine does the same thing.
It has been suggested that it is either the "Top Hat Bronze bush" that is worn or the synchro rings are worn. Either way fixing that would require the gear box to be removed.

I have found an OD transmission and plan a winter install.

David
 
What fluid are you using? When I used Redline in mine I had a similar issue. Switching to 30 nondetergent motor oil cured my problem (was a newly rebuilt J-type OD). This was several years ago. Cheers, Mike
 
It could be the selector fork or a problem with the detent ball on the shaft or one of the springs and balls in the gear slider has broken and fallen out. If the problem is in the selectors you can fix it with the box in if the problem is in the gear slider you will have to take the box out.

Graham
 
Graham H said:
It could be the selector fork or a problem with the detent ball on the shaft or one of the springs and balls in the gear slider has broken and fallen out. If the problem is in the selectors you can fix it with the box in if the problem is in the gear slider you will have to take the box out.

Graham
Click to expand...
If it's in the selector, you can sometimes hold it in gear with the shift lever. If it's the top hat, you can't. Tom
 
I had that same issue, was convinced it was the 2nd gear bush as I had seen several broken previously and I didn’t test per Toms suggestion. All mine was was was a weak spring on the selector shaft.
 
I have gone back and forth with same kind of issue for 20 years on this one trans. Does anyone know how tight to make those 3 springs and balls deal on the back of the shifting tower or are you taking about the ball that goes in on its side in the tower between the 2 shafts? In addition, I remember a post where the discussion was about the O rings on the shafts and how they are difficult to seal and the correct O rings had to be improvised somehow. Mine pops out going downhill only and leaks, something like tightening up or replacing the spring and ball would not surprise me for a fix-- plus I have the trans cover off so now would be a good time.

steve
 
I adjusted the ones on the end - easy to do in my case because I had the screw in plug style. I didn’t get fancy with measuring any kind of release tension, just tightened down more and tried it out.
 
Does the “screw in plug style” mean that you have access to the screw with the shifting tower on the car and in place? On my tr3 I need to pull the tower off and flip it over and then are 3 screws in the back that can be screw down to put more pressure on the shaft.
 
No you still have to pull the cover - later covers, I think later TR6 had small freeze plug style plugs instead of the screw in plugs which seem to me to be more of a pain to deal with.
 
sp53 said:
Does the “screw in plug style” mean that you have access to the screw with the shifting tower on the car and in place? On my tr3 I need to pull the tower off and flip it over and then are 3 screws in the back that can be screw down to put more pressure on the shaft.
Click to expand...

Interesting, I've never tried to "adjust" those screws, instead I've left them very slightly lower than the surface, as they seemed to be when I took them out. I also find no mention of adjustment in the Service Manual. I suppose there is no harm in screwing them in more to put more tension on the springs but there's really nothing to hold them in place (loctite maybe). But from my experience, they should work properly just below the surface and will be held in place by the mating surface on the transmission. But if screwing them in tighter works, that might at least prolong the required rebuild, which would be a good thing.
From what I gather, the newer style plugs are best replaced by tapping the housing and using the threaded type. Also kind of fun to remove or so I'm told.
Tom
 
Any time I have had poping out of 2nd (not truimph) it was worn synchros.
 
It's the synchro hub with it's spring loaded balls that hold the gears in mesh, the box would have to be well worn for that to be the problem but still possible

Graham.
 
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