Van

Just one product, as far as I know. I get it from Lufteknic: http://www.lufteknic.com/Merchant2/m...ode=lubricants

Taymar

Delvac is what my local shop was going to use in the car. But on the Mobil site it looks like it says not for LSD and not for use in GL4 applications. http://www.mobil.com/USA-English/Lub...0_80W-140.aspx

That page on Lufteknic does say it's not the same fluid as the stuff found in auto parts stores though, I wonder what the differences are?

Dougs951S

Was just talking about diff fluid with a friend of mine today, I'm running M1 synth (not the Delvac, what I'm using has LS modifiers in it) in my LSD box and it's been great for over a year. Nice and quiet, shifts like butter and it goes into 1st easily from neutral at 20+ mph, which is a pretty good test I think.

mel_t_vin

Van, I was just about to ask what you run in your two race cars. Thanks for your real world input.

That's very interesting to hear that you've not experienced any unusual/unwanted chatter/vibration from your LSDs running Delvac. I, also, have heard that Delvac is a wonderful product for non-LSD boxes for the same reasons you mention: improved shifting, especially in cold conditions.

Have you ever re-built/re-shimmed your LSDs? Is it possible the disc packs are worn and simply not locking to spec [40%?] under load? If that was the case, where a diff was not "inclined" to lock due to excessive wear, I could imagine that a fluid like Delvac [without LS additives] might not have as great an [unintended] affect.

Does that sound plausible?

mel_t_vin

I saw that LSD disclamer, as well. But Van's track experience begs to differ...

The stuff sold over the counter at various FLAPS is Mobil 1 LS 75W-90, which has additives/modifiers for LSD applications. That's what I'm using, and appears to be the same gear oil that Doug is using, with great success [see 2 posts up].

Van

I have never opened up my LSD transmissions to check on things... my old car, a Turbo S, ran great until I crashed it (used Delvac for 4-5 years). My new car car has a Guard LSD and I've been using Delvac for 2 years.

I need to order more, so I'll call Lufteknic and see what they say about LSD applications. But, my hunch is, if this is really the OEM fluid for 996 and 997 cup cars, they've thought of LSDs before.

Taymar

To make sure I understood this correctly - If I buy delvac in a quart bottle at an auto parts store, I'm actually getting Mobil 1 LS 75w90? Whereas if I buy Delvac from Lufteknic and get the larger container, I'm getting delvac?

(I can absolutely believe that's the case, just wanted to check I've understood correctly).

I don't suppose anyone here has done a used oil analysis on the transaxle fluid?

Thank you all for your continued input.

Dino V

I have been using Red Line in all my cars and extremely happy with the product. I don't think I'd ever use any other product.

Van

Lufteknic's answer: for an aftermarket LSD, like my Guard, there is no problem with the Delvac. However, with a factory LSD, which has much less pre-load on the slip plates, they do recommend an LSD additive, otherwise you can get some chatter. But, if you don't need the additive, don't add it - it can reduce some of the other properties of the gear oil.

Taymar

Thanks for checking Van.

mel_t_vin

No.

I do not believe Delvac is sold over the counter in any FLAPS [someone correct me if I'm wrong]. You would have to purchase it through a speed shop [like Van does], in gallon containers, or from ExxonMobil, if that's even possible.

Most FLAPS sell quart bottles of Mobil LS 75W-90, labeled as such. This is the formulation with friction modifiers for LSD applications. As mentioned on the ExxonMobil webpage, the Delvac formulation does not contain these LS additives.