Edward

Yeah, I know what the Factory recommends, but am curious to see what others here, especially those who track regularly, do (perhaps just to justify my own OCD )

Odometer: 76K
Annual milage: 12-14K
Track: 5-6 weekends/year
Tranny Oil Change Interval: Every Summer
Tranny Oil: Mobile 1 75W/90

TIA

Edward

Tim Ashfield

Edward

As you know the book specifies changing at 48k miles. My car was 6 years old with 30k miles on it when I got it and had never had it changed. I had it done straight away and it is now changed annually - got to be cheaper than a new tranny! Gear change much improved too.

Ditto: Mobilube 1 SHC 75W/90 synthetic transmission oil.

All the best <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />

Glen

I change it after each Race and after every other DE. I know thats overkill but the fluids are so much cheaper than the metal they surround. I also change Oil after every driving event. This keeps me abreast of any funny stuff hopefully well ahead of a major failure. I also have a lift in my shop with a 55 gallon drum of 15-50 Mobil One and a 16 gallon keg of Mobil One gear lube...makes this pretty easy for me each time...

Pete Lech

Does the Limited Slip tranny use the same fluid as the regular one? Any LSD additives, or just Synthetic 75W-90?

993Widebody

I would follow the factory recommendations if I were not tracking the car. But with 4 or so DE events a year, once a year is what makes me feel better. The Mobil1 gear oil makes the shifting butter smooth, shifting is such a pleasure with that stuff in there.

amfp

I just use Mobil Synthetic 75W-90 for my LSD,no additive. I change once a year as it a easy DYI, as described by Robin's site.

Edward

Thanks, all! I was just curious what others do. It seems my annual Trans Oil change is not as obsessive/compulsive as I thought...unless we all need therapy.

Glen, wow, a drum and a keg. Now YOU'RE serious

Thanks for responding, all. Antone else?

Edward

George A

Ok, I'll be a little different here. I use Swepco 201 and change it annually.

George

DamonsCarrera

George,

Have you always used Swepco? If not, notice any difference compared to other oils? Do you have an LSD?

-Damon
'94 325i
'95 993

George A

Damon,

I started using Swepco over a year ago. I originally had Mobil 1 in there. Is there a difference, I would say “yes”. Is it significant, “no”. It’s difficult to describe the difference, but to me it just “feels” better. It could be all in my head, but I think the shifts are smoother, especially when the transmission is hot. It’s a little stiff on cold days for the first five minutes, but we really don’t have those down here in Texas. BTW, the stuff is made here in Texas so I figured I’d give it a try before I tried RedLine. I liked it enough to stick with it. Also, it’s not a synthetic which might be a big deal to some.

I don’t have a limited slip, so I can’t comment on its effect. I know several guys that use it in their 915 tranies with LSD’s and they always recommend it.

I actually want to hear why not to use it.

George

Steve Weiner-Rennsport Systems

Hi Edward:

First, I'd offer that the Factory's maintenance recommendations are not always in the best long-term interests of the owner, and any deviation from "normal" usage such as DE or track events compels me to change things more frequently.

I rather like Glen's philosophy,......its much better (and cheaper) to be proactive about things like this, rather than wait for something to happen.

Lastly, all of these GL-5 rated gear lubricants mentioned above include the additives necessary for LSD operation, so that should not be any case for worry and preclude any need for additives. Mobil 1 synthetic & Swepco are both very fine lubricants and suitable for these transmissions. The Swepco is not as easy to shift when cold but aside from that, I would not have any concerns about either one. That said,..........due to the extreme operating temperatures of racing, my recommendation for competition use is always a synthetic in the G-50's.

H20NOO

Steve W,

Any experience with or comments about Amsoil Synthetic? I change mine once a year and have had good results but we don't really get any cold weather round these parts.

Thanks in advance!

MC

Edward

Hi Steve,

Thanks for the added GL5/LSD information. Always good to hear from you and glean from your experience!

As for the "Factory Service Intervals," I've always done my maintainence sooner than recommended. And my gut feeling has always led me to behave thus. But every now and then, you know like when I have to BUY all that oil and such, I wonder if I'm being too maintenence cautious. Yet, as you say, "proactive" makes more sense (unless one's leasing ) so I'll just repress all those fiscal anxieties and rest assured I'm doing the right thing for its long-term health. Prescription to self: Drive the car. Yeah, that's it!

Edward

Ray Calvo

Every 30K miles; tranny feels great at 76K miles. Used 75W90 Havoline Synpower at last change.

Steve Weiner-Rennsport Systems

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by H20NOO:
<strong>Steve W,

Any experience with or comments about Amsoil Synthetic? I change mine once a year and have had good results but we don't really get any cold weather round these parts.

Thanks in advance!

MC</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Hi MC:

I've not used any Amsoil products nor have I disassembled any tranny's that have used it so I have no firsthand experience with that gear oil.

My experience is with products that I've had a long-term experience with and know what things look like over the long haul and in race cars. Transmissions and modifications to same, are not cheap so I tend to be rather conservative with my customer's (and my own) $$$$.