911vet

I changed the fluid in my tranny and I'm not sure I used the right stuff. I was in a hurry because I was having trouble getting into gears (turns out it's bad bushings in the shifter --- replacement parts on the way).

I put in Valvoline Synthetic 75W90 Gear Oil (GL-5 rated).

Should I dump it and replace it with Redline? If so, which one?

I do have a limited slip. I've got the original window sticker for my car, and it was an option.

So, given the LS, I think I should not use the Redline 75W90NS. Correct? Do I use the plain Redline 75W90 Gear Oil? Is it GL-5 rated? Got what I need for my synchros?

Thanks for advice to the newbie.

Shannon
87 Carrera Cabriolet

Droops83

The Valvoline that you have in it should be fine. I would get a little bottle of Redline LSD additive, drain a tiny bit of the gear oil out, and add the additive. It might take 20 miles or so to work its way through the gear oil and stop chattering around turns. Redline does make gear oil w/ LSD friction modifiers already in it, but I don't think it's worth it to drain your new oil out which is perfectly good.

Kudos on getting a car w/ factory LSD, they are great for aggressive street/autox driving, you can really tell the difference, I got one on my 951. For heavy track driving you'd want a better one of course. But, it goes to show how Porsche has changed, you can't even get a Boxster/Cayman or non GT3 996/997 with LSD from the factory!

rberry951

I don't mean to hijack the thread, but was LSD gearboxes uncommon on the Carreras? I checked mine when we had it up on the lift changing wheels, I was happy to see that it was LSD. I know the 951s it was hit and miss, as not all have it, which I think is odd since they are turbo. But I am not familiar enough yet with the 911 series to know what percentage of cars have it.

Droops83

I'd say 20% or so, common enough but not ubiquitous. What's most surprising is that Shannon's car is a cabrio and has LSD, that is pretty rare. Mostly coupes have em. BTW 951 '86-87 and non-S '88s seem to be about the same percentage LSD as 911 3.2s, but '88 Turbo S and all '89s had em.

Shannon do you have sports seats as well? If so then you can join my super-exclusive Porsche sports-options club!

911vet

Alas, no. Standard seats. But they did for the "sports shocks" too. Does that qualify me?

Peter Zimmermann

Regarding the amount of 911s fitted with LSD, my experience was quite different than what Chris sees. My shop cared for fewer than 5% of SCs and 3.2 cars that were fitted with LSD, but this was a Los Angeles customer base. I'm sure that local P-car dealers thought that it was far more important to fit the cars with other options, like sunroofs. Sport Seats were also rare; in L.A. it's all about comfort and lookin' good while sitting in traffic, very little to do with driving. Ain't that a shame?

BMWDavid

So you are saying that all '89 Carreras had LSD. How would I verify that my '89 Carrera has LSD if it does?

Thanks,

David

rberry951

David,

With the car on a lift in neutral, rotate one of the real wheels forward, if the other wheel rotates forward as well, you have LSD.

Regards,
Russell

911vet

From what I can tell so far, this car was made for DRIVING! I upgraded the suspension on the BMW Z3 that I owned before this. Put on coilovers w/ 400lb VVS springs and Koni adjustable shocks. Beefed up the rear sway bar and turned it into a go-kart. But this stock 911 is even better.

I've never tracked/autocrossed, so I may lack the ability to dicern the difference between LS and non. Maybe I will see it when I finally get to DE school next spring. Nonetheless, I'm thrilled to find out I have it --- because I do drive "spiritedly" in the twisties

So any advice on exactly what lube to use in this transaxle??

911vet

So, I'm still trying to figure this out.

Seems like lots of people have used the Redline 75W90NS Gear Oil. But that is for non-LS diffs. Since most SE and 3.2s are NOT limited slip, I'm guessing that's why they use it.

I think what I need is Redline 75W90 Gear Oil. Can anyone verify that?

Here's what the Paragon website says about it:
75W90 Gear Oil - recommended for most street driven and racing differentials. Excellent performance in conventional and limited-slip units. Also for limited-slip manual transaxles which require a 90 WT oil. Contains limited-slip friction modifiers.

Thanks,
Shannon

Droops83

Shannon, like I said, put a little bottle of Redline limited slip additive in there and you'll be fine. I think it's a waste to drain perfectly good gear oil that you just put in. It'll take a few miles of driving to work itself in, and then you'll be good to go. FWIW we use Lubri-Moly 75W-90 in all G50-based gearboxes (as well as in Boxsters/996s) and put on the Redline additive if it is LSD. Your Valvoline which is 75W-90 and GL5 rated will be fine, just get the Redline next time if you must.

"BTW 951 '86-87 and non-S '88s seem to be about the same percentage LSD as 911 3.2s, but '88 Turbo S and all '89s had em."

BMWdavid, sorry to confuse you, not all '89 Carreras have LSD, only a small percentage do, maybe 10-20%. I was referring to 944 Turbos in the above statement, also known as 951. I was pointing out that when LSD was optional on 944 turbos, the proportion of LSD to open diff cars was similar to that of the 911 3.2. The way to tell if you have a factory Porsche clutch-type LSD is to jack up one rear and turn it. If it spins freely, you have an open diff. If it does not turn or is very hard to turn, chances are you have LSD (or you left the parking brake on). If you are still in doubt check your options sticker in the front trunk for M220. Or do a burnout and see if you leave one or two skid marks.

Pete, maybe 20% LSD is a bit high of an estimate, maybe closer to 10% is accurate. It's not like Santa Barbara is all that different from LA in terms of posing, but we do have some enthusiast customers luckily. In my experience, which is far less than Pete Z's, it seems that cars that have sports seats from the factory have a good chance of having LSD as well.

911vet

OK, that sounds like a plan. Thanks for the advice.

I've been assuming my window stick is telling the truth, but I should double check that I really do have a LSD. The original owner paid an extra $741 for it. Everything else on the options list is correct, so I assume the LSD is too.

And from the way it handles in the twisties... I think it is

Shannon

BMWDavid

Thanks everyone. I did the easy thing and checked for M220 on the options sticker. Nope...don't have LSD.

David

911vet

Checked my options sticker and 220 is there (no "M" in front of it... but none of the option numbers on my sticker have any letters).

By the way, how do I decode the other option numbers?

And thanks to advice from Charles Navarro at LN Engineering www.LNengineering.com
I decided to go with Delvac 1 75w90. It's available from www.lufteknic.com.

Thanks Charles and everyone else. I'm gonna feel a lot better when the Delvac is in my tranny and the Swapco 306 is in my engine

Naplesguy06

i have 220 as well but no m220 on my 86 951 is that the lsd code?