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TR2/3/3A Replacing rear seal on gearbox?

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K

karls59tr

Obi Wan
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The gearbox has been out of the car and sitting on the bench for awhile and I see there is a noticeable leak at the rear seal. To replace the seal is it just a matter of removing the large Nut and pulling off the Flange to gain access? Leave in gear to remove the Nut? Is there a torque value for this nut? Anything else I should be aware of when doing this?:uncomfortableness:
 
The nut should be very tight.

Get a bit of flat-bar about 3ft long and drill a hole in the end. Bolt to the flange and use as a lever.
You will likely want a similar length on the socket-bar for the nut.

100ft lbs comes to mind but look it up.

There is a kind of hooked tool for prising out these oil seals which avoids having to chop it into pieces.
 
The TR3 books don't seem to give a torque for that flange, but the TR4 workshop manual gives 80-120 ft lb; which I take as meaning tighten to at least 80 ftlb, plus what it takes to make the pin line up with the holes.

If you download the PDF file at https://www.vtr.org/maintain/TransRebuild/TRTrans02.pdf, page 11 shows the installation of the seal & flange, including the tool that Alan is talking about.

Here is one type of seal puller. https://www.harborfreight.com/seal-puller-35556.html#.UyjAVc6Feec
I had a similar one years ago that worked well, but the one I got from HF broke at the first yank, so I made do with a big screwdriver.
 
And take some care when you pull the old seal - its easy to score the aluminum housing if you aren't careful. Don't ask, painful story.
 
My humble opinion is don't waste time or money on the the HF seal puller. I tried to pull a pinion seal on a TR6 and the hook bent with the first attempt. I returned it and bought a Lisle puller of the same design for a few bucks more (even made in the US), which was capable of doing the job.
Berry
 
I agree about the Harbor Freight seal puller, one yank and it broke. A friend had a Craftsman that looked like it, and was very strong. But to get out a 50 plus year old seal on the outer axle we made a puller out of a bolt and pieces of metal. We cut a piece of metal to fit behind the seal and put the bolt through that piece then used a bar across the end of the axle with a hole for the same bolt. I was surprised at how easy the seal came out after we had so much trouble with the other types of pullers.
Charley
 
And don't forget to check the location on the shaft where the new seal will rub. The new seal may leak if there is a worn spot/grove on the shaft. Also, lube/grease the new seal rubber before you reinstall the shaft. I wish someone had told me this before I replaced my seal.

Chuck
 
Chuck Murphy said:
And don't forget to check the location on the shaft where the new seal will rub. The new seal may leak if there is a worn spot/grove on the shaft. Also, lube/grease the new seal rubber before you reinstall the shaft. I wish someone had told me this before I replaced my seal.
Is there a "speedy sleeve" if there is a spot/groove on the shaft?
Click to expand...
 
karls59tr said:
Is there a "speedy sleeve" if there is a spot/groove on the shaft?
Click to expand...
Probably. Do you (or anyone) know the diameter offhand? I don't have one handy to check.

Note that in this case, the seal rides on the output flange, not the shaft. If there is a wear groove on the flange that you can't polish away, you can usually compensate by not driving the new seal all the way home in the tail housing, so it doesn't ride on exactly the same spot. Modern seals frequently don't ride in the same place as originals anyway, due to changes in the seal construction.
 
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