• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

TR2/3/3A TR3 Overdrive to transmission mating problem

Share this page

D

decibeldesign

Freshman Member
Offline
Part One:
I am having trouble mating the overdrive back onto the transmission. The engine and gearbox are installed in the car.

I undid the overdrive from the transmission and pulled it back about 1 inch in order to insert a new gasket as the gearbox was leaking from the mating surface between the OD and the Transmission. I got the new seal in and went to push the two parts back together and they won’t go back together. The OD start to go back into the transmission and then stops about a half inch from fully inserted. I have tried for hours lifting it with jacks, shifting it around etc and no luck. Is there a trick to this?

Does anyone have any advice on how to get the OD to seat back onto the transmission?

Part Two:
I thought at first the wheel on the plunger was clearing the Cam lobe. Then I noticed the Cam lobe ring could move back and forth on the shaft. So I pull the spring plunger down as suggested by a user and slid the ring back and released the plunger and it lined up as it should where the plunger/wheel was riding on the ringed Cam part as is should. I thought it would then all slide together.

But something else has now gone wrong. Where I used to be able to use a pry bar and push the OD half way into position, which is when it probably was getting suck on the Cam lobe and the plunger, now it won't even do that. I cannot get the OD to move forwards at all. It is now stuck.

Before I discovered the Plunger/Cam lobe interference, I had don't things like turning the shaft manually, and putting it in gear and manually cranking the engine to turn it, which it did turn. Some how it has now gotten to a point where I cannot push it in at all, not even the half way I could before.

Thanks for your help.
David
 
After bumping the starter, the shaft splines are now out of alignment. Remove the drive shaft and turn the yoke until they realign.
 
No I am not trying to make baby transmissions. I just want the OD and Transmission to kiss.
So far no luck getting it to re-align and mate together, now that I know I have to pull the oil pump plunger down below the Cam on the drive shaft. I found that out to late and have somehow misaligned things so they won't go back together.
I have tried turning the driveshaft while pushing on the OD and it still won't align.
 
I think that when all is said and done, that you will find it is easier to remove the trans.from the car and mate it in the conventional way (in this case, standing up). Mount the OD on a stand (Just bolt it to a 2"x12" or whatever). With the OD in the vertical position, lower the trans. on to it. Gravity becomes your friend and helps to keep the clutch return springs in position. Before the mating process, align the 2 sets of splines in the OD. A good detailed description is found on the VTR site, step 13 https://vintagetriumphregister.org/maintain/TransRebuild/OverDriveA02.pdf
Berry
 
Berry has a great point...if you pulled the 2 apart too far, then the springs likely dropped and are all out of place. If that is the case, you will have to do as Berry suggests and remove everything and rebuild it according to the manual. The springs cannot be installed with the tranny horizontal...unless you have 9 hands and 8 screwdrivers.

At this stage I don't think there is really a choice, as if even 1 spring dropped in the case the risk of damaging the OD is too great. It has to come out and go to the bench.

Don's suggestion may be the easiest. But there is a bright side...I bet the gasket would have leaked anyway after having been installed without fully separating the 2 boxes.
 
Thanks for the suggestions. I think you guys are right and the transmission is going to have to come out. Shame for such a simple thing, I just finished rewiring the car and getting the engine running properly.
Do I have to remove the engine and gearbox or just the transmission on its own. Here is another problem I have with this situation. I cannot pull the OD or transmission back any further than I already have it separated. Someone put the bolts on the OD mount in backwards and I cannot completely remove the bolts from the OD to the bracket, or the brackets bolts out from the mounting plate. Only the mounting plate is free and in order to slide to OD backwards, essentially the mounting plate slide back between the floor and the frame so it wont go back any further.
 
That will be a problem. Normally you can just remove the tranny easily from inside the car, leaving the engine in place. But, to do that the tranny must be able to move straight rearward about 5-6".
 
To get the trans. out, the rear of the engine will have to be supported. Use a 2"x6" near the rear of the oil pan to avoid damage. Jack the engine up until the bell housing contacts the accelerator shaft. This may give room to slide the trans. back. Plan B might be to remove the OD first, then the trans.
I remember many years ago trying to mate the OD to the trans. while it was in the car and decided against it. Also, while the trans.&OD are out, you will probably want to address all of the areas that could leak.
Berry
 
Back
Top