Transaxle oil for 901 With Quaiffe LSD, Just bought one. Options

[motorvated]

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.

[Dr Evil]

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.