I ended up pulling the gearbox because there was a spring and other starter parts that were too big to remove with the gearbox in place. I decided that with box out I may as well upgrade the clutch while I'm in there. This is a TR6 box in a TR3. After the box was reinstalled I realized that the shift lever was jammed in 4th gear and would not budge from the straight up position?? I came to the conclusion that I must have installed the clutch disc backwards as I had heard that it sometimes can happen on installation. So I pulled out the gearbox again and discovered that the clutch disc was installed correctly! So I now have the gearbox on the bench. I pulled the gear shift lever expecting to find that little spring and button on the bottom to have jammed up and caused the problem. But no they were in good shape. So now I am going to remove the top cover and see if I can find out what the issue is. Not sure how to proceed or what to look for never having messed with the guts of a gearbox before. I found this online: Check rail alignment. Ensure the notches on all three selector shafts are perfectly lined up in a straight horizontal line, meaning they are all in their neutral Detents. Test with a Pry Bar or large flat head screwdriver to move the forks(about 30 lbs of force is usually required) to make sure the rails can slide into gear and return to neutral. Where exactly do you pry? Any advice on doing this and what to look for? Karl
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TR2/3/3A Update on the Clutch and Stuck Transmission.......
- Thread starter karls59tr
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Karl
You should (from memory) take off the top of the gearbox to a move the gear lever to check the selector forks move. Just see where they sit in neutral for reassembly
In my picture ignore the yellow arrow- this was a 2nd gear I thoroughly stripped whilst doing a hill climb or sprint in competition
The red arrows are where the forks fit to slide the gears to change gear try levering here.
The red circle is where reverse selects and should correspond to a fork in the lid when you come to refit the lid.
This is an early full synchro tr6 box on my 1959 3a
You should (from memory) take off the top of the gearbox to a move the gear lever to check the selector forks move. Just see where they sit in neutral for reassembly
In my picture ignore the yellow arrow- this was a 2nd gear I thoroughly stripped whilst doing a hill climb or sprint in competition
The red arrows are where the forks fit to slide the gears to change gear try levering here.
The red circle is where reverse selects and should correspond to a fork in the lid when you come to refit the lid.
This is an early full synchro tr6 box on my 1959 3a
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The spring and button were properly sitting inside the slot of the shift lever? In other words, both were not only in good shape, but were still in the lever slot?
If so, that top shift selectors must be jammed somehow. Maybe selector fork broke? It's possible the detents are the problem, but I'd think not because the steel balls are held by a spring and screw that must be flush to the face of the machined cover flange. Not sure for a TR6, but on a TR4 the release force for 1st/2nd is 32 to 34 lbs, for 3rd/4th is 26 to 28 lbs, and reverse is 26 to 28 lbs. You check using a typical spring pull scale from a hardware store, like the ones you weigh your tournament trophy bass with on the winner's dock.
But something still makes little sense to me. That shift lever should've slid side to side, and one messed up selector rod should not have impacted the others unless something just broke off inside transmission. And each steel ball, as well as its set force, should impact only that one selector rod. If you're positive nothing was down in the shift well impeding movement, then I guess something will get quite clear when you take off the top cover. Something broke; maybe a taper pin or peg bolt holding a fork in place.
One last thought. Whenever I've removed the shift lever and the surrounding cap that holds the lever and spring, as well as the spring cap disc, everything falls out under the car. I remember crawling around to find the button and spring on at least two occasions. So--be sure to take a look in case there was anything else jammed or caught in the "well" space of those selector rods. Examine that lever spring, too, and be sure a piece didn't break off.
Good luck.
If so, that top shift selectors must be jammed somehow. Maybe selector fork broke? It's possible the detents are the problem, but I'd think not because the steel balls are held by a spring and screw that must be flush to the face of the machined cover flange. Not sure for a TR6, but on a TR4 the release force for 1st/2nd is 32 to 34 lbs, for 3rd/4th is 26 to 28 lbs, and reverse is 26 to 28 lbs. You check using a typical spring pull scale from a hardware store, like the ones you weigh your tournament trophy bass with on the winner's dock.
But something still makes little sense to me. That shift lever should've slid side to side, and one messed up selector rod should not have impacted the others unless something just broke off inside transmission. And each steel ball, as well as its set force, should impact only that one selector rod. If you're positive nothing was down in the shift well impeding movement, then I guess something will get quite clear when you take off the top cover. Something broke; maybe a taper pin or peg bolt holding a fork in place.
One last thought. Whenever I've removed the shift lever and the surrounding cap that holds the lever and spring, as well as the spring cap disc, everything falls out under the car. I remember crawling around to find the button and spring on at least two occasions. So--be sure to take a look in case there was anything else jammed or caught in the "well" space of those selector rods. Examine that lever spring, too, and be sure a piece didn't break off.
Good luck.
CJD
Yoda
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Karl, I'd love to offer a suggestion, but I am at a loss as to what would cause a functioning tranny to simply jam-up without having come apart first. I'm afraid you'll have to open it and look it over. Once the top cover is off, you can isolate the problem to either the cover with shift assembly...or an internal gear problem. I suspect it's in the detent/lockout assembly in the cover.
Thx for the info and the photo. I think I know what may have caused the problem. When I removed the speedometer gear mistakenly loosened the bolt above it thinking that it locked the speedo cable somehow as that was difficult to remove. Anyway I came to find out that that bolt affected the Reverse gear. I made a mental note to tighten that bolt down again. I Forgot to do that unfortunately and I think that was the cause of the whole problem? Now that I see in the photo you sent how things are supposed to line up I will attempt to set things up like that and tighten that reverse gear bolt down.
See my response that I just sent to Hamish. I think that is what happened. Does that make sense? Now that I have a visual of the way things are supposed to be set up for neutral I will attempt to line things up that way and put the cover back on. Is it tricky to move those levers forward with a screwdriver or do I need to get one of those weigh scale things to pull them forward to 30lbs. Any thoughts?
CJD
Yoda
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Do not close the top until you reach in and align the little reverse stub gear and shaft it goes on. If I remember correctly, there is a hole in the gear shaft. The bolt reaches into the case and into the shaft hole, to keep it in position. Also, if the shaft got too far out of position, the little reverse stub gear can fall out into the bottom of the case. So make sure the little gear and shaft are in the correct position, then align the holes in the case and shaft...then re-install the long bolt.
CJD
Yoda
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Oh, also Karl, the shifter lever should operate relatively easily when off the tranny. You will feel the detent balls, but with a mild "pop" against the shifter, you should be able to easily overcome the detents and move the lever to each gear position. If something is not moving correctly, now is the time to figure it out.
Once your gear, shaft, and bolt are properly installed...and the shifter lever feels normal...then you must place all gears into neutral position and the shifter assembly in neutral. Then the top cover can be gently lowered into position, ensuring the shift fingers go into the gear slots. The reverse fork can be tricky.
Once your gear, shaft, and bolt are properly installed...and the shifter lever feels normal...then you must place all gears into neutral position and the shifter assembly in neutral. Then the top cover can be gently lowered into position, ensuring the shift fingers go into the gear slots. The reverse fork can be tricky.
