mobil 1 in the gear box?

brett25 · brett25's Garage

Hi. i am thinking of using mobil 1 for my gear box oil. its a 75W oil -the 944 owners manual and haynes say use an 80W oil. is this OK? thanx
Brett

adrian jaye · 11-22-2001, 02:10 AM

I'd go with what the Haynes Manual or the Porsche Handbook say's

All oils are different. A gearbox has different stresses, presuress and charachteristics than an engine, a diff or even for that matter a deep fat fryer !

Don't mess around with lubricants unless you know what your doing, or sure of the result's . Else wise **** load of money !

Adrian

CrazySOB · 11-22-2001, 05:51 AM

I hear that SWEPCO 201 is very very good, but it's between 50-55 dollars a gallon.
I use Red Line manual trans fluid 75W90NS and I like it so far (used about 3 months now). It's about $10- $11 a quart.

divezic · divezic's Garage

I just filled my transmission with Mobil 1 and there is a noticeable difference. With regular trans fluid, I needed to be at almost a complete stop to slide it into first. Also, downshifting to second was tough. Now it's very smooth.

Adrian Jaye has a good point; you can't go wrong with the factory specs. The problem I see with this thinking is that the factory manual was written in 1983 (for an 84 model) and Haynes is a reflection of the factory specs. There was no Mobil 1 in 1983. There has been a huge jump in lubricant technology in the past 18 years. Porsche periodically updates their recommendations for lubricants and now recommends 0W40 Mobil 1 for winter use. That was not a recommended oil in 1983 because is was not available. I don't know if Mobil 1 is a recommended trans fluid, but I just can't see anything wrong with using it if it improves the transmission's performance. I have read, though that some people have a problem with it because it's too "slippery" and doesn't allow the synchros to engage properly. This is not the case on my 944.

Just my opinions. Hope they help.

T86951 · 11-22-2001, 10:01 PM

I have Mobile 1 in both my 951 and my NA 944. My NA944 is my daily driver and it has 206,000 miles on it and the gearbox is smooth and shifts great.

The dif between 75w and 80 is nothing, not relavant at all. 206,000 miles of daily driving and since it had 77,000 when I got the car I have used Mobile 1 75 w I think it is in the gearbox.

adrian jaye · 11-23-2001, 03:21 AM

Quote:

Originally posted by divezic
The problem I see with this thinking is that the factory manual was written in 1983 (for an 84 model) and Haynes is a reflection of the factory specs.

You should be able to get round that as the manual should also give a specification or equivalence.

Any "newer" oil conforming to the spec or equivalence shold be ok, your Porsche dealer will also be able to advise

Adrian

"your Porsche does'nt compromise
So why should you ?"

CrazySOB · 11-23-2001, 04:27 AM

Brett, I think you got your answer- T86951 has been using it for 130,000 miles, no better test than that.

threesticks · 11-23-2001, 07:09 AM

I use the Mobile 1 oil in both my 951 and '66 911 and have noticed an improvement in the performance of both transmissions. I have used the Mobile 1 in the "66 901 gearbox for about six or seven years now and it still works great. My mechanic uses mobile one in his cars so I guess that it works.

Threesticks

brett25 · brett25's Garage

thanx alot guys. its done. mobil 1 (15/50) in the engine and Mobil 1 (75/90) in the gear box. for the benefit of the readers here's a report: engine temperature is now consistently lower, feels like smoother acceleration as well. the car is shifting better. very solid feeling when i engage a gear. the "crunchy" feeling has gone. it took a little driving to get the oil worked in there, but now its doing a good job. thanx for the replies
Brett