MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Rear Seal on LH Overdrive Leaking

Has anyone replaced the rear seal on a LH overdrive? Can this be done with the tranny in the car? I'm tired of the oil leak!

RES Schultz

Yes, it can be done on the car.

Take off the propshaft and undo the large nut on the OD shaft flange - use a bar or large screwdriver wedged between the trapped bolts to stop the flange rotating.

Pull the flange off and prise the old seal out - push the new one in flush with the end of the casing. replace flange and nut, tighten to 60 ft lbs, refit propshaft.
Chris at Octarine Services

Can anyone tell me if the large nut on the OD shaft flange is a reverse thread? I fabricated the mother of all pry bars and all I did was bend the bar when I tried to break the nut free! Maybe I'm not holding my mouth right or I haven't guzzled enough cold beer!! It's really going to piss me off if I have to pay somebody to do this job!

Bob in Atlanta
RES Schultz

Bob,
It's a regular right-hand thread. So while underneath - you would be pulling down on driver's side or pushing up on the passenger side.

High-torque impact wrenches (e.g., 1,000 ft. lbs. loosening torque) really help on such jobs.
Steve Buchina

OK! I finally got the OD shaft flange nut loose. Now the next problem is removing the old oil seal. All suggestions are welcome! All I can think of is to use a cold chisel and hammer to bust the old one out.

Thanks in advance
Bob in Atlanta
RES Schultz

Bob. I use an impact wrench to remove and replace the nut on the tailshaft. Mine is a Campbell-Hausfelt brand which is "hobbyist grade". Most of the time, it works. When it does not, a professional grade unit (borrowed or rented) will take care of the problem.

The rear seal is either yanked out using a "Y" shaped tool having two hooks which are outboards of the arms, or is levered out using something like a common screw driver. If using the screwdriver method, just move the seal a little bit outwards at a time, taking three or four revolutions to remove the seal entirely.

When installing the new seal, lubricate the outside and inside with oil. Then, tap it back into place with a hammer having a smooth face. (A "smooth faced hammer is one which shows no damage to the face--damage which can cut the surface of the oil seal when applied. I have an old ball-pien hammer which has had the face sanded smooth for this purpose, then polished.)

Make sure the flange that you will be installing is smooth around the surface which will be in contact with the oil seal. Lightly sanding it with 400 grit wet-or-dry paper will tell you if there are any projections. Clean throughly after any sanding.

Les
Les Bengtson

This thread was discussed between 12/07/2007 and 21/07/2007

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.