Hey there Guest!
Hey - did you know if you click on the title of a thread it will take you to the first unread post since you last visited that thread?
but were afraid to ask: 
STOP!! Never post your email address in open forums. Bots can "harvest" your email! If you must share your email use a Private Message or use the 
smilie in place of the real @
Pretty Please - add it to our Events forum(s) and add to the calendar! >> 
CJD
Yoda
Offline
The TR3 side is a bit slow...so I thought I'd report on my little side project. The kids helped me finish off the TR4 tranny and we installed it 2 days ago. What a difference having a 1st gear synchro! Now they are zipping around the neighborhood learning to drive a stick.
For those that don't remember, I bought a $100 tranny, along with a pile of odd triumph parts about 2-1/2 years ago as part of an estate sale. The pile paid for itself many times over during the TR2 rebuild...but the tranny was the reason I bought it at all in the first place.
The no-synchro first is a true PITA. Any time I let someone drive it (like during state inspections), they always ground 1st, no matter how many times I warned them about it. I even occasionally ground 1st if I got distracted and wasn't paying attention to which car I was driving. Anyway...I HIGHLY recommend the swap if you plan to actually drive your TR3!
For the technicals...the swap is straight up, no surprises. The bolts and studs have to be exactly 1/4" longer if you go with a later box, with the thicker flange. I just took the bolts to the hardware and replaced them for longer. The TR3B or early TR4 boxes have the same thin flange as the 2/3, so no new bolts if you use that one. The drive shaft has enough play to take the 3/4" longer location of the drive flange with no trouble, as the TR4 box is about 3/4" longer total than the 2/3 box.
The only real mod that is required is to the rear tranny mount, which is also 3/4" farther aft for the TR4 box. I had planned to modify the cross-member support, but when I looked at it, I chose to simply slot the tranny mount holes. That way the mod is only to the replaceable rubber mount, and not to any parts that are permanent. The slotting took all of 5 minutes.
Oh...due to the thicker flange, the clutch cylinder actuating rod was a bit too long after the swap. The flange moved the cylinder closer to the clutch lever by 1/4". I merely mounted the cylinder on the front of the mounting plate, and I then had enough adjustment so that even that worked out great.
This particular box was in very bad shape, if you have followed the pics in my tranny rebuild thread. Broken countershaft, broken gears, chipped dog clutches, starter pinion exited the bell housing through 2 holes, etc. I rebuilt it on the cheap, grooming gears and parts to see how far I could go with it. So far the results are great. No sticking going into reverse or forward gears and smooth shifts. I'll update with a long term report if any problems pop up...
But...these old TR4 boxes are available on Ebay for less than the cost of shipping. So, if you are still fighting that 3 synchro box, I highly recommend this as a relatively quick and painless upgrade!
For those that don't remember, I bought a $100 tranny, along with a pile of odd triumph parts about 2-1/2 years ago as part of an estate sale. The pile paid for itself many times over during the TR2 rebuild...but the tranny was the reason I bought it at all in the first place.
The no-synchro first is a true PITA. Any time I let someone drive it (like during state inspections), they always ground 1st, no matter how many times I warned them about it. I even occasionally ground 1st if I got distracted and wasn't paying attention to which car I was driving. Anyway...I HIGHLY recommend the swap if you plan to actually drive your TR3!
For the technicals...the swap is straight up, no surprises. The bolts and studs have to be exactly 1/4" longer if you go with a later box, with the thicker flange. I just took the bolts to the hardware and replaced them for longer. The TR3B or early TR4 boxes have the same thin flange as the 2/3, so no new bolts if you use that one. The drive shaft has enough play to take the 3/4" longer location of the drive flange with no trouble, as the TR4 box is about 3/4" longer total than the 2/3 box.
The only real mod that is required is to the rear tranny mount, which is also 3/4" farther aft for the TR4 box. I had planned to modify the cross-member support, but when I looked at it, I chose to simply slot the tranny mount holes. That way the mod is only to the replaceable rubber mount, and not to any parts that are permanent. The slotting took all of 5 minutes.
Oh...due to the thicker flange, the clutch cylinder actuating rod was a bit too long after the swap. The flange moved the cylinder closer to the clutch lever by 1/4". I merely mounted the cylinder on the front of the mounting plate, and I then had enough adjustment so that even that worked out great.
This particular box was in very bad shape, if you have followed the pics in my tranny rebuild thread. Broken countershaft, broken gears, chipped dog clutches, starter pinion exited the bell housing through 2 holes, etc. I rebuilt it on the cheap, grooming gears and parts to see how far I could go with it. So far the results are great. No sticking going into reverse or forward gears and smooth shifts. I'll update with a long term report if any problems pop up...
But...these old TR4 boxes are available on Ebay for less than the cost of shipping. So, if you are still fighting that 3 synchro box, I highly recommend this as a relatively quick and painless upgrade!
A friendly reminder - be careful what links you click on here. If a link is posted by someone you don't know, or the URL looks fishy, DON'T CLICK. Spammers sometimes post links that lead to sites that can infect your computer, so be mindful what you click.