Gearbox rebuild

[Derek Hunt]

Hi all.

I am steadily working my way through my early MK3 rebuild , and have now got to the gearbox. It's an overdrive, and I think I remember it was working fine when I took it off the road ( about 30 years ago! ).

What I was wondering is, is there anybody out there that supplies a kit of all the standard parts that are typically needed in a rebuild - bearing,seals, gaskets etc ?

Thanks.

[glang]

wow thats quite a big job youre taking on there! The main Triumph parts suppliers do rebuild kits which include the mechanical components but the gaskets and seals come separately. However the bearings now come from Korea while the synchro rings etc seem to be of unknown origin so I would think carefully before changing them for what might be better quality original components. I know its a lot of work to install the box only to find later that its got a problem but this might be the best course of action....

You could easily replace the oil seals at each end and perhaps the gearlever linkage bushes, check all bolts are tight and give it a try?

[nang]

In my experience the problems with the overdrive are normally the electrics and hydraulics. Electrics normally wiring, earths and terminals. Hydraulic faults are usually caused by worn and dried out O  rings.

This is for J types. A types I have no knowledge of.

Tony.

[RobPearce]

Quoted from nang-

This is for J types. A types I have no knowledge of.

For a GT6 it would originally be a D type. That adds a couple of other potential problems - adjustment of the solenoid and wear in the shuttle valve bore being the obvious ones. I've also repaired a completely non-functional D type many years back which had failed because the oil pump was installed badly (probably the previous rebuilder had failed to align the cam and clouted the thing when fitting to the gearbox) and jammed.

[glang]

What do you think of my suggestion to try running it Rob? As you say, I would add testing/adjusting the solenoid before installing the gearbox in the car....

[RobPearce]

Quoted from glang-

What do you think of my suggestion to try running it Rob? As you say, I would add testing/adjusting the solenoid before installing the gearbox in the car....

It depends on the history of the box. If it worked OK when taken out, even if that was 30 years ago, then I'd say check it turns and selects gear on the bench, test/adjust the solenoid, possibly the bush kit, then fit it, change the oil, and see. You can test basic OD operation with the propshaft not fitted (probably need speedo and rev counter) but slipping/baulking/noise are all load dependent so the car needs to be driveable for that.

[Derek Hunt]

Oh no - now I'm in a quandary.

My mindset so far is to do everything, and not leave it as it was, but now you've all got me doubting that !

I do remember the O/D had packed up, but I knew that was electrical, but I think mechanically the 'box was ok.

I'll give it good clean up on the bench tomorrow and look at the oil to see if that shows anything alarming.

Then I'll probably tear it apart and regret it🤣!!

Thanks all.

 

[thescrapman]

I would fit a new rear oil seal after cleaning the flange, oil seals on speedo drive and hopefully that will deal with any leaks, then just fit it and run it.

As the other say, rebuilding will make it worse in all probability.