Just bought a 901 transaxle with a Quaiffe LSD in it. Any recommendations for oil type and quantity for it. Don't want to burn it up.

Your diff is all gears, so no oil modifiers, but the manufacturer must have a preference.
If not just keep using what you have been using.

Swepco is popular, but i like Kendall better. My 915 trans with limited slip, shifts better with Kendall.
http://www.pelicanparts.com/More_Info/KEN-...SVSVSI=0804.htm

Looks like Kendal has changed packaging to a red bottle Not sure if it is the same or not.

My Audi has a torson diff in the transmission, similar to having a Quaife. I run Redline products. I run a 4 to 1 ratio Redline MTL to Redline 90 in my transmission. 30 track days and 50,000 miles and I have no problem with my trans or the torson.

Redline has a MT-85 now, that is supposed to be good for transmissions with Quaife in them. It is similar to what I have been doing all along, with my mixing.

In the 914 I ran the same thing. New trans will have a Quaife.

Just make sure whatever you run, it is not GL-5. You need GL-4. GL-5 does not like the material that our older sycros are made of.

Greg W.

Where are you getting your information from? The factory manuals specify GL-5

Redline redline redline

Everything else is garbage and banned in my garage. Except for maybe Royal Purple or Lucas.

-Ed

Maybe just ask Quaiffe...
From their website:
http://quaife.co.uk/customer-service/technical-support/
What sort of gear oil should I use ?

When running a Quaife ATB helical gear limited slip Differential in a standard transaxle gearbox, we recommend that you use whatever your vehicle’s manufacturer recommends. The Quaife ATB Differential does not require any special lubricants. When running Quaife gearbox internals and a Quaife ATB differential – we recommend FuchsTitan SYN5 75W90. For a Quaife ATB differential, running in a rear axle – use a hypoid 90 or 75W90, as above.

For those applications that will accept a GL5 or SAE75W90 gear oil, we recommend and sell Silkolene SYN5 75W90 gear oil. We use Silkolene in all our own Quaife racing transmissions

So can the 901 take GL5 or not? Seems to be some confusion over this.

Torco RTF in all my race stuff (Honda w/clutch diff and 914 with gear diff), MTF in the street stuff (or RTF if I'm feelin baller and/or have some left over).

Standard 90 weight gear oil.
The Synchros don't like the modern slippery stuff.

[quote name='motorvated' date='Oct 4 2017, 04:50 AM' post='2534106']
[quote name='johnhora' post='2534026' date='Oct 3 2017, 07:17 PM']
Maybe just ask Quaiffe...
From their website:
http://quaife.co.uk/customer-service/technical-support/
What sort of gear oil should I use ?

When running a Quaife ATB helical gear limited slip Differential in a standard transaxle gearbox, we recommend that you use whatever your vehicle’s manufacturer recommends. The Quaife ATB Differential does not require any special lubricants. When running Quaife gearbox internals and a Quaife ATB differential – we recommend FuchsTitan SYN5 75W90. For a Quaife ATB differential, running in a rear axle – use a hypoid 90 or 75W90, as above.

For those applications that will accept a GL5 or SAE75W90 gear oil, we recommend and sell Silkolene SYN5 75W90 gear oil. We use Silkolene in all our own Quaife racing transmissions
[/quote]
The above does not mention Porsche 901/914 or 915 gear boxes
The factory manuals specify GL-5

You'll get opinions all over the map on what people's favorite oil is. For some differentials, you need to keep in mind that for a 901, the diff and gearbox obviously use the same oil (not the case for many front engined, RWD cars), but it looks like a Quaiffe doesn't require anything special. So if you've been happy with a particular brand of oil, you can just continue to use that.

You have three types of answers to these questions:

1) What the LSD manufacturer says - for yours, it says follow normal manufacture rec.

2) What your transmission manufacturer says - for 901 it is 80w90 GL5. Yes, GL5. It is a point of contention because GL4 is better for "yellow metals" inside your transmission, but the GL5 has the proper lubrication package for your synchros. The yellow metal just gets tarnished with GL5, its not an issue. If you consider that 40yo boxes are still bumping around with the original parts in some cases, and only using good ol dino oil GL5, then their is your proof of efficacy.

2) What people have done/like - insert expensive magical fluid here. They all work, or they would be known to cause damage and failure, etc. I like to listen to what people like, why, see if there is any objectivity in the reasoning, compare cost. However, I use cheapo 80w90 GL5 and change it per the manufactures instructions and never have had an issue. I will say that I do recommend for some to use a Liter of Lucas oil stabilizer in place of one of the 80w90L as it has shown to keep the parts saturated in lube longer and likely will reduce wear. Plus, it helps with sound suppression in old worn parts. I have not used it in an LSD as that is a little special and I am not willing to experiment with that kind of $$/work. For more on my feeling about the boutique oils, check out my 31 pages of transmission notes in my link below.

The guys that do the early Boss 302 differentials for me always recommend original rear end mineral oil with the additive for LSD. I like simple.

Additive depends on manufacture and type of LSD. A Posi diff is a clutch package and most of those do need an additive that you can get at your FLAPS. However, the Porsche one may or may not need it, it really depends.

Dr I think you have opened up more than one 901 over the years and would know what works in them.

The 901 with the ZF LSD literature specked a different Shell gear oil than the regular 901 with out LSD.
The Sport Purposes docs show Shell S1747A (USA Shell Gear Oil 90 E.P.)
Original 901 boxes that came from the factory even had a little aluminum tag on them showing the the Shell SD 1747 A.
Maybe had some LSD additive like most disc LSD of the day.
Do you have any info on this Shell oil?



Click to view attachment

So it looks like the Quaife doesn't need anything special in terms of oil, since it's gears and not clutch plates, and it looks like the 901 is rated to use 80w90 GL5 dino oil. So that's what I'll use for now. I may be racing the car with this transaxle behind a stock 1.8 liter L-Jet motor for a little while, but when I re-gear it for running behind my 215 Buick V8 with higher torque, Hp, and maybe higher rotational speeds, do you think the 80w90 GL5 dino will still be OK?

Dude, that pic and info rocks! I forgot what was supposed to be in the LSD type, but last time I checked I found that info....and forgot it because it was like 2005. Lately, I have been doing a lot of LSD....er, LSD work. Old 1968, a 915, another 914, another 915.....I actually HATE doing LSD work as it always ends up being more work. I feel like a whore that keeps getting fat nasty guys, but has to go with it because she has to pay the bills. Ah well, its nice to be useful.

love the analogy

Here's a nice link on gear oils for 901, 915 and 930 trannys:

http://www.blueskymotorsports.com/index.ph...16&Itemid=6

Bottom line:

- Porsche specified SAE 90 GL-5 gear oil
- 80w90 GL-5 is a suitable replacement if SAE 90 isn't available
- Synthetic is too slippery for the Porsche synchronizer design

That really is the key that most don't get, our style of boxes NEED friction to function. You cant synchronize the gears without it.