Rally Gearbox Fluid?

[Rallyho]

I must be getting old...I can't remember what the heck to pour into a four-speed with an lsd to keep it all lubed up and happy.

MTL?
70wt Gear Oil
Sperm Whale Oil
?
?

I will be running a pump/cooler if it matters.

thanks.

[happyandy]

[321go]

I was given a few quarts of the MTL when I got my car. Previous owner always used that, so I will too.

[Hans]

I use Redline Shockproof Light (blue) in my 4-sp. +Quaife. Shifting isn't great until warm but is fine once it's up to temp.

I have driven tens of thousands of miles with regular Redline MTL in my daily driver w/5-speed and find that the shifting quality suffers when I drive the car really hard (e.g., autocrosses with short wait times between runs, or on back roads). It just feels like I'm wearing down the synchros. If you use MTL and find the same thing, you might try thickening it up with some MT-90.

[DrewP]

Hans,

How does the Shockproof Light shift when it's cold? How cold? I have Heavy in my 5-speed 900 box and it doesn't even get all that cold here in LA (down maybe 35*-40*F overnight this winter) and it still doesn't want to shift to 2nd the first few times in the morning till it gets some heat into it, and I've been wanting to throw some Lightweight into it at next change.

Did you experiment with less slippery stuff for the Quaife, or do you get enough lockup with the Shockproof? (I know it's not a viscous- or clutch coupled diff, but oil weight will still have a little bit of effect on lockup).

Best,
Drew

[Rallyho]

Right. I know I have run MTL in street boxes for years. The variable here, and what I can't remember, is what mix did I use to keep both the syncros and the plate diff happy. A Quaiffe is different...no clutch plates.

[Mezzanine]

I have been running shockproof light in a fairly new four speed for quite a while, as recommended by Scanwest. It is a little more balky when cold, but no issue getting it into gear. Doesn't take much to warm up to normal either.
I have run honda mtf, redline mtl, and motor oil in addition to shockproof blue in various transmissions... I couldn't tell much difference between honda and motor oil; MTL was a small step above those two. I concur with Hans about the wear feeling when hot- the shifting was clean, but it felt like the synchros were totally dry. The shockproof blue always feels pretty good to me. I plan to stick with it.

C

[Hans]

Drew,

I'm in Seattle, so similar low temps as you: mid-30s to mid-40s. As Mezzanine notes, it's balky for a few shifts/couple minutes but not horrible. I have run it at sub-zero temps, too, and I don't recall it being that much worse. As noted above, the Quaife is mechanical, no friction components, so oil viscosity doesn't affect its operation.

[Geoff]

Mike,
I remember you giving me some MTL from your service truck at Maine one year when I had a leak. I don't know if you mixed that with anything.

[Luke]

MTL is too light for rally, will turn to water like viscosity under stage temps. Try Mt-90 it works great.

Luke

[Rallyho]

MT90...that rings a bell. I think I had MTL, until I put the lsd in there...then maybe I switched.

anybody with clutch type lsd's finding they need any sort of additive to make the plates play nice?

[Sean Tennis]

MT90...that rings a bell. I think I had MTL, until I put the lsd in there...then maybe I switched.

anybody with clutch type lsd's finding they need any sort of additive to make the plates play nice?

Yes put one or two bottles of whale oil in there for LSD plates ... I always run lightweight (blueish) shock proof in syncro cars and heavyweight (red) in crash box's ... for many, many years now!