Differential Shaft Seal Replacement

[ron69912t]

Can I replace the left & right side differential shaft seals without dropping the engine & transmission?

Mine are leaking and throwing oil all over the place. I kept thinking it was the engine leaking oil but not so.

I have read only about the driver side seal replacement hopefully the passenger side is just as simple.

Thanks for your help.

Ron D

[craign]

Ron,

I beleive it can be done without dropping the engine etc. But when i did mine I think it was a whole lot easier with the engine out.

Are the actual gaskets leaking or the dust boots? either way you might as well change them all since you are going in there.

For the 69 you have 4 bolts and 2 guide pins, you might have to pound a screwdriver between the mating surfaces to get them to seperate. No worries though as that is some very hardened steel and can take a good beating with no problems.

Craign

[ron69912t]

Craig:
From what I can see the oil is leaking out the output shaft seals next to the trans body and under the flanges. The oil is being flung out as the shafts rotate. The starter motor and the underbody are covered with oil in the area around the shafts.

The CV joints and boots are fine.

The oil deposits on the hot engine block and runs down the heater boxes, some gets on the exhaust headers too.

Thanks,
Ron

[Morrie]

Hi Ron!

I just did this within the last week or so. IMHO there's no reason to pull the motor, though mine was out for other reasons.

The seal is an easy change out. there's an O ring behind the half shaft that keeps fluid out of the CV joint. Mine had also failed so I replaced it and repacked the CV joints. I bet the whole job takes you less than 2 hours.....

[ron69912t]

Craig/Morrie:

The Porsche factory Shop Manual lists the seals as P/N 99-113-058-050 (45 x 65 x 10 mm) for the "Chilled" trans Housing.

It lists seals P/N 999-113-111-50 (45 x 68 x 10 mm) for the "Investment Cast" trans housing.

What of the two types of transmissons do we have on our 5 speed 69 912's?

What was the seal size that you used??

thanks,
Ron

[Morrie]

Wow.. I just called Zimms and told them I had a 67 912 with a 5 speed. The seal fit...... looks like I got lucky???

Morrie

[ron69912t]

Morrie:
Do you know the dimensions of the seal you used??

I am surmising that the 69 912 came with either a cast aluminum transmission housing (chilled) or the magnesium (Investment Cast) transmission housing. Probably based on when in 1969 it was made.

I just don't know which one I have.

Thanks,
Ron

[Morrie]

Will reading the Porsche PN off the side of the casing help you? Maybe someone can reference it to the correct seal. I cant say I know the size of the one I used in my 67.... due to my ignorance, I just pulled the old and pressed in the new.....

[ron69912t]

Stoddard's catalog lists the Side Cover Seal 45 x 65 x 10 mm for the 65-69 with aluminum case and the 45 x 68 x 10 mm for the 69-86 magnesium case. P/N's 999-113-058-50 and 999-113-183-40 respectively.

I'll just buy two each of both sizes and return the ones that don't fit.

Thanks,
Ron

[Morrie]

once again it looks like I misunderstood. The seals I replaced are the ones around the output shafts, not the side covers..... sorry for the confusion...

Morrie

[adot]

Ron

Sell the others on ebay !!! you might get what you paid for all, if not more. Sell the used ones TOO. Ebay's a funny thing sometimes. Buying both set WAS the right way to go.

GoodLuck

Brett

[ron69912t]

Morrie:

You are right, the Porsche shop Manual & Stoddard refers to them as "Side Cover Seals". You and I call them output shaft seals. There is a side cover to the trans casting on the drivers side of the transmission. The left seal seal sits in the center of the cover and the left shaft goes thru it.

The other side of the trans does not have the side cover, the seal cavity is machined into the trans casting.

Same-same.

thanks,
Ron

[Morrie]

gotcha.....