Triumphrat

Aussie Dave

Bike info: 1977 T140V

Hi,

Thanks for the information that made this job easy to do but now......

I've replaced the gearbox seal/O ring plus the seal in the door behind the clutch basket....It is now LEAKING worse than it did before I changed the seals.

I'm using NULON G70 Manual Gearbox & Diff Treatment with gearbox oil.

Should I drain oil and replace all seals/O rings again and use straight gearbox oil???? Please help!!!!

RetroRod

Hi Dave,

I presume you have checked up around the inside of the gearbox sprocket and find oil running down the gearbbox case. Likewise we are dealing here with gearbox oil and NOT engine oil. OK? If this is so, then my answer is as follows:

I have not seen your previous thread and so I assume nothing about that. I do however assume that the '77 is going to be the same as my '72 5 speed (Triumph designs don't change all that quickly) and on that basis here goes.

There will be three oil seals keeping oil in the gearbox on the primary side:

1. ( the gearbox sprocket seal)
2. (the high gear seal)
3. (a mainshaft 'O' ring)

I addition to good seals, the running surfaces should also be in good order, free of any dent, wear etc that breaks the surface where the seal sits. You need to check this on the inside of the gearbox sprocket, and also on the high gear mainshaft where it exits the gearbox.

My '72 does not have the 'O' ring seal, but I am assured by others with experience, that the 'O' ring seal is not always reliable, and will sometimes allow oil out of the gearbox via the sprocket splines.

There are one or two fitting issues. I have no idea of your experience in these matters and so will attend to the basics. Don't be offended if I oversimplify.

Seals. The spring and lip always face the direction of oil you are trying to retain. Check you have not overdriven them, as this will distort them. A little rubber grease on the edges and lips will aid installation.

'O' Rings: These little buggers have a capacity to roll out of their grooves, or distort on installation. Again some rubber grease on both surfaces should overcome this tendency.

Others have said to seal the front sprocket splines with a silicon sealer after you have fitted the gearbox sprocket as added insurance for the 'O' ring. Add plenty, it does not have to be pretty!!

Check also the welsh plug behind the layshaft bearings (immediately under the mainshft). You'd expect it to be tight, but check it any way.

I cannot think of anything else though others may.

If the oil is running from behind the gearbox sprocket then it will be necessary to drain the box and get back to the seals mentioned above to check your work, and or other likely sources of the leak.

I hope things go OK and you find the problem without too much frustration. Cheers, RR

pookybear

I would just like to add to RetroRod's fine post.
A small note about seals. You add a small layer of
grease not only to help in install time, but it lubercates
the seal on start up as well, until some oil can do the
job. Also pack the back of the seal with grease as well.
This will hold the small spring in place, when installing,
that places tension on the lip seal itself.

Pookybear

Aussie Dave

Thanks for your replies. Will give it another go using your advice. Cheers Dave