sorry to take up space with another one of these. i have enough mobil 1 to go ahead and overfill the tranny and drain and fill the transfercase. the question is, on a vehicle this old, switching to a full sythetic am i just asking for problems? i have no idea if the tranny leaks right now, i just got it all cleaned off, but i think most of the junk on there was from an oil drip out of the engine oil drain plug. also looking for correct figures
tranny 5 quarts?
t-case 2 quarts?
thanks!

 

Put synthetic in the trans, non-synthetic in the t-case. The front and rear output seals on the t-case seem to leak shortly after install of synthetic. I wouldn't worry about the trans leaking. 3.5qts factory fill of getrag. Most run 1-1.5qts overfill. Not sure on the quanity in t-case. Now not everyone has experienced a leak in drivetrain parts after switching to a synthetic. But many have. Why risk it. Go to WalMart, buy the 5qt jug of MobilOne 5w30 put it in the getrag, then plain jane 80-90wt gear oil in the t-case.

 

i was told the reason for running the same in both was incase the seal between them went. any thoughts on that?

 

Howdy,

No problem with them mixing...the manufacturer's do that themselves with "blended" oil.

Personally, in my experience, I've found with higher mileage motors the thinner syn-oil makes more valvetrain noise...and I don't like using a pre-mixed 'syn/oil blend'.
I have a feeling the manufacturer's just sort of wave the the synthetic over the dyno-oil when they blend it because the dyno-oil is way cheaper...so I do it myself. That way I know just how much synthetic is in the mix.

For my turbocharged 4 cyl's I go about 3quarts dyno-oil to 2 quarts synthetic...

So, I wouldn't worry about the two mixing.

Vinny

 

I put 5 qts in my Getrag.

I replaced the fill plug with a 1/2" pipe nipple; to this I screwed on a 1/2" X 1" elbow; I capped the elbow ( turned vertical ) with a 1" pipe plug.

With 5 qts, the lube stands level with the bottom of the plug threads.

Many recommend replacing the fill plug with a 1/2" street ell, which is fine; but, my method gives a larger hole for checking/filling.

 

Actually 9 times out of 10 if the seal between the tranny and transfer case goes out, the transfer case becomes overfilled. So youll still keep most of the sythetic in the tranny.

Like Bill Gilbert said, I went to Wal-mart and bought a 5qt jug, and dumped her in. I have almost 150k and no leaks.