TR2/3/3A Overdrive question.

[Graham H]

Hello David,

I didn't rely on sliding the chain, rather just set the box down and then slid the chain forward or back then lift and the box just moves on the balance point and because of the leverage it's not that heavy.
Don't forget to refit the throwout bearing, I put it in before getting the box back into the chassis as you do and in the process it slid off onto the floor then I entered the the input shaft without putting it back on, all good fun. Also make sure you get all the OD presser springs in the right sequence and fitted over the front locaters, some will need to be pushed with a screwdriver once you get the nuts on the long studs.
I was living in hope after my second box removal that it would be the last but no, four times, unfortunately I started with a box and OD that someone else had played with and it took a long time to get all the nasties out of it, all good now fingers crossed.

Graham

 

[DavidApp]

So far no leaks.
I filled the gearbox and ran it on my test stand at about 1200rpm in 4th gear for 3 hours. Switching the OD in and out from time to time. I used an "O" ring to seal the brass plug.

David


Low tech test stand.

 

[Graham H]

Well there you go, have to be happy with that.

Graham

 

[sp53]

Very old school cool David. My father in law had laths and saws and all kind of stuff with belts and pulleys. I was watching to see how you were going to test that out. Really impressed, and hope I can do that if or when the time comes.
Steve

 

[Graham H]

The good advice when removing or replacing the gearbox with OD is to take the solinoid off first just to be on the safe side.

Graham

 

[DavidApp]

I did remove the solenoid before I removed the gearbox. Had seen that advice somewhere. I removed it again before I replaced the gearbox. My release bearing will not come off the brass sliding piece easily. I can see how leaving that off would ruin your day.
When I said sliding it in the chain I was more referring to trying to rotate the gearbox to clear the clutch lever.

I managed all my test rig using parts I had at home. Did you notice the "V" pully on the clutch input shaft and the timing belt and pully on the motor. Did not have a timing pully with the correct bore.

It is back in and bolted up.

David

 

[Graham H]

That's great, let's hope it will be so long before you have to do it again you will have forgotten how you did it?

Graham

 

[DavidApp]

A follow up on the Adaptor plate issue. I may be the last one to get the memo on this but I now understand where the distortion is on the adaptor plate.
I had thought that it was in the lowest section of the plate but having cleaned up the gear box side of the plate on a surface table I can see 2 areas that are distorted. They are around the bolt holes that the long studs go through and cause that area to contact the OD before the rest of the mating face.
On my plate the witness marks left by the sealer indicated that the top studs and the long studs pulled up tight but the bottom ones did not.

When I used feelers to check the distortion I found 0.024" on one side and 0.022" on the other side

David

 

[Graham H]

That makes sense you can get a lot of pressure on that area if the splines are not lined up properly.

Graham

 

[DavidApp]

I was very careful when I reassembled it using a pry bar to ease the OD onto the splines taking up the slack on the long stud nuts as I went.

I was having trouble seeing how such a big gap seemed to be at the bottom of the adaptor plate but if it was closed up at the top and middle with a 0.025" distortion the bottom gap is going to happen.

David