GSL rear end fluid
 

What are you limited slip guys running in the way of diff lube? i finally got a GSL rear end today :D Sweet deal too :D Its got a few miles shy of 91k and has barley any rust on it. Now I just gotta swap it into the S.......

I swear by Redline Synthetic fluids. Almost all the road racers I know run redline, with fantastic results.

Check it out.

www.Redlineoil.com

What weight should i use? and how much of it do i need?

75W90

yea what he said....

I know most road racers use RedLine as I used to. The thing is my car is predominantly street driven with occasional autocross. I have owned 3 GSL-SE's each one having over 100k on the odometer. Everytime I have drained out the old gear lube and replaced it with a synthetic the differential eventually has gone bad within months... the noise! UGH. Could be that most road racers already have their diffs rebuilt..I dunno. Puzzled, I asked around.. spoke to rally car builders to the rebuilder of the 1979 24 Hour of Daytona winning RX-7. Both have told me not to use synthetic, it simply makes then go bad. Happy with I heard from them I now have cheap Valvoline mineral based lube in my differential. (:
~Mel

I dunno know aobut that....

Synthetics are made from a pure basestock rather than taking crude oil and purifying to the level that you want.

Synthetics are designed to have far surperior lubrication qualities, there for causing less friction and longer bearing life. they also are much less likely to breake down under heat and extended use.

Redline 75w-90 gear lube. If the lsd seems to be more of an open diff, you can add some "limited slip lube" or whatever from the auto store.

And that basestock is more often than not made using crude oil, or at least natural gas. :) Good things happen when you can dictate just what molecules go in to the oil though. Synthetics are mostly base stock, whereas 60% of more of conventional oils are additives.

I know someone who uses regular ol' automatic transmission fluid in his transmissions and rearends. Puts some extreme pressure additive in the rearend for good luck, but that's about it. If you think about it, auto trannies operate under much worse conditions than manuals. Autos have splash lubrication (the pressure is only for the hydraulic controls) but they have much smaller gears/bearings and even worse they are usually encased in drums. Manual trannies/rearends are cake to lube by comparison.

Now the question I have is about the limited-slip additives. Do they make the oil "grippier" or "slipperier"? Makes a difference as to what type of oil to buy. Type F (old Ford) is the grippy stuff, Type 7176 (new Mopar) is the slippery stuff, and regular ol' Dexron/Mercon is in the middle.

I was going to wait until I personally did this before telling the world 'bout it, I'd feel bad if someone blew their ride because of bad advice. So this isn't official advice, just an idea that someone I trust is advising. :) Be it known though that I have a good stash of Type-F thanks to owning 70's Fords for most of my driving life.

Just the opposite. You need that additive to prevent from burning out the clutches. If you don't use it, and the diff is good, the rearend will buck and chatter around low-speed corners, due to the clutches grabbing, sticking, slipping, grabbing, sticking, slipping. The LSD additive makes 'em slip smoothly with no grab. (It also helps numb your senses with its overpoweringly bad odor :) )

Hmm I think I answered by own question. :D

Redline gear lubes should already be "limited slip compliant". Check the bottle to make sure.

That's what I said. The Redline 75w-90 already has LSD additive. I said that if the LSD seems to be worn and non-functional, you can add lsd additive to help it work again.

LSD additive would make it slip MORE. That's what it's for. If the clutches chatter, they wear out faster.

Anyone use anthing besides Redline 75w-90 with good results or is this what pretty much everyone uses?

I've used Mobile 1 75w-90. Its worked well so far...

try extra virgin olive oil

I have heard that suggestion before. It provides superior lubrication and prolonged life for the gears right?

It also adds a zing to your salad!

Gears? Huh? ...... I thought we were talking about rear ends? Oh....... that rear end! sorry... yeah, definitely go Redline ;)

My rear end takes some Northern Italian Dressing with a little salt and a tad of canola oil.

hahahaha... there is nothing "virgin" about that post!:crackup: :crackup: :crackup:

yeah, i realize that this is back from the dead, but i was searching to find out on rear diff fluids, and laughed so hard that i had to comment on that!
jeff

Okay, we now know what the limited slip guys are using... what about "normal" rear ends? I'm glad I re-read this thread because I took note of the fluid type, and was going to buy some.. completely forgetting that my GS lacks the LSD of an -SE!

Jon

i use 90w gear oil mixed 5/1 with ATF

Are you serious? Why?

--Bob

I use Royal Purple in my tranny and LSD diff - it doesn't share all the hype that Redline does but it's a very good product (and expensive) and includes the additive - The RB guys swear by it and I have a very quite tranny and rear end (except when I'm on the beans:D )