Original Message -----
From: Tony H
Sent: Tuesday, November 07, 2000 1:52 PM
Subject:  tranny and final drive fluids
questions to all
What are the good recommendations for tranny fluid in an 87s4 AUTO?
brand ..type etc etc Also ..when i have my tranny tipped on end as i work on it, small amounts of oil leak from the black cap on on the top of the AFT section of the final drive area. I ASSUME THAT THIS IS THE OIL USED IN THE FINAL DRIVE CASE/GEARS.
Question is...since i've lost a bit of the oil, i plan on draining all this as well and putting new stuff in.....same question as above.
WHAT TYPE OF GEAR OIL DO YOU ALL RECOMMEND IN THE FINAL DRIVE CASE/GEARS?
also any do's and don'ts in servicing the oil in this area?
Thanks...i feel like i should be paying some of you by the hour!!! haha (i said feel...not that i will : ) OK!
I just put Mobile 1 75w90 oil in my differential. I am amazed at the difference. I highly recommend it.
Quick question... before i head to the library for another dizzy...vertigo inducing Microfiche session.
On the Final drive case i assume the two plugs for the diff.fluid are the ones with the appx 10mm allen key fittings on them. The one under being the drain... the one the back being the fill hole (has "AUTOMAT" and an arrow towards the hole).
Im aware of the diffs fluid capacity (per the manual) but to fill you just pour/funnel the oil into the upper hole until the capacity is met or the oil flows out??
> On the Final drive case i assume the two plugs for the diff.fluid are the ones with the appx 10mm allen key fittings on them. The one under being the > drain... the one the back being the fill hole (has "AUTOMAT" and an arrow towards the hole).
> I'm aware of the diffs fluid capacity (per the manual) but to fill you just pour/funnel the oil into the upper hole until the capacity is met or the oil flows out??
Yep. I used 75w90 Valvoline Synthetic and a couple of tubes of diff.
additive. Pouring it in there was the challenge. Hint: With the driver side tire off, run a hose from automat hole to a funnel. This allows the funnel to be higher the hole. Put a catch basin under the diff and wait for the fluid to overfill.
P.S., The diff fluid is the most foul smelling stuff on earth. So try not getting soaked with it. (Don't ask.)
At 01:19 AM 6/9/2003, BrianG wrote:
>Having just finished the timing-belt project, including the tensioner re-build, I just read that I should have used regular engine oil for the tensioner. As per the usual souces, I did the tensioner re-build with heavy-weight oil recommended. Should a guy purge the tensioner with regular oil?
I doubt that it makes much difference, especially in the later cars with
the fill/bleed nipples. It didn't seem to be important enough for Porsche
to change the Factory Workshop Manuals, even though they issued a Tech
Bulletin recommending engine oil for the later cars. It perhaps isn't common knowledge that there isn't as much difference in
the viscosities of gear oil and engine oil as the numbers would suggest. The SAE viscosity numbering system adds 40 to the viscosity of gear oil to help distinguish it from engine oil. In other words, SAE 80 gear oil is the same viscosity as SAE 40 engine oil. The additive packages don't make a lot of difference in this particular application. The gear oils have EP (Extreme Pressure) wear additives, the engine oils have other additives to make it suitable for engine use.