Do I need differential oil seals?

[H.G.P.]

I looked over the upcoming CV boot job today. First, I can't yet tell whether I have those "star" bolts (but I think so). However, upon general inspection, I noticed what appears to be oil (gear oil maybe), coming down from both inner "joints", where the CV joints meet the differential.

Is this something that can be remedied with the driveshafts removed while doing a boot job?

Thanks.

[keithdog72]

If it is on the flange, it might be moly grease coming through an old cv joint gasket. BTW, you will want to replace these when you replace boots.

[Jim Sims]

Yes, the seals (called side cover seals) may be replaced with the transmission in place. You will need two new seals; for 1969 aluminum transmission housing: PN 99911305850 45mm x 65mm x 10mm or for the 1969 magnesium housing: PN 99911318340 45mm x 68mm x 10mm. Measure the OD of your present seals. You will also have to put a couple of the screws back into the CV joint flange and react against them while you loosen the bolt in the center attaching the flange shaft. Jim

[H.G.P.]

It runs down, drips slowly from the "little small square protrusion" at the lowest point on the bottom of the engine. ( located between the heat exchangers by the curved moon shaped line).

It drips somewhat faster after driving. I think it starts at the smallest diameter junction where the axle meets the differential housing.

[H.G.P.]

Originally posted by Jim Sims
Yes, the seals (called side cover seals) may be replaced with the transmission in place. You will need two new seals; for 1969 aluminum transmission housing: PN 99911305850 45mm x 65mm x 10mm or for the 1969 magnesium housing: PN 99911318340 45mm x 68mm x 10mm. Measure the OD of your present seals. You will also have to put a couple of the screws back into the CV joint flange and react against them while you loosen the bolt in the center attaching the flange shaft. Jim

"Side cover seals"..ok. I hope the old seals won't be too difficult to extract.

Thanks

[H.G.P.]

Another factor that seems to confirm this is when I first changed the tranny oil first time, it was low, and the same problem has been there for some time now. The tranny is shifing great though.

[Jim Sims]

Carefully pry the seals out; do not mar housing bores that seals engage. Moisten the new seal lips and sides with transmission oil before installation. Carefully drive in with installer of apppropriate diameter (you can likely make or find something with the correct diameter). Tighten drive flange bolts to 33 to 36 ft-lbs.



Jim

[Jim Sims]

another useful image

[H.G.P.]

Thanks for those diagrams Jim!