What's the best synthetic fluid to go with and how much do I need? I believe the stock fluid is not synthetic, correct? If so, have there been any problems switching over? My last car was a '98 Cobra and the T45 transmissions did not like being switched. It caused some synchro problems.

Anyone had it done at Jiffy Lube? Yeah, I know most people hate them but they don't have to lift the car and they do just fine on my oil changes. I watch them and make sure.

 

Redline D4 ATF. You will need 4 qts. It only takes 3 and a little of the 4th. Might as well do the diff while your at it. Redline 75-90 with limited slip additive.

 

I got the recommendation to use RedLine MTL for the transmission and plain RedLine 75w90 for the diff.

What is the difference between MTL and D4 ATF ? Is the limited slip additive an extra addition you add to the 75W90 or is it in the oil ?

Thanks.

:cheers:


[Modified by seanr, 11:00 PM 5/28/2002]

 

I just replaced my transmission fluid with Redline D4 ATF fluid this past weekend. As was stated already, you'll need 4 quarts since it takes a little more than 3. The GM Manual states to use ATF fluid in the manual transmission, so that's what I used. Draining the fluid is easy. Filling it back up requires a fluid pump. I'm not sure I'd trust a quick change place to have a pump that's not cross contaminated with other fluid. If you have them do it, make sure the pump is clean.

- Mark

 

Amsoil 2000, http://www.amsoil.com :smash: :)

 

Amsoil ATF :smash: First & Still the BEST! :yesnod: :yesnod: :yesnod:

 

Pics and tips for diff and gearbox fluid change:
http://www.picturetrail.com/gmblack3/647207

Limited Slip Axle Lube Additive
The GM part # is 1052358. You should add this before putting the new fluid in the diff.
The local stealer here charges $9 for it. GMpartdirect.com shows a list of $5 but you have to buy 12 of them.

Amsoil and Redline claim that there fluids already have an additive in them. Amsoil says it both ways on there website:

AMSOIL gear oils are formulated with friction modifiers for limited slip differential applications. There is no need to add limited slip or additional additives.

AMSOIL Series 2000 Synthetic Gear Lube provides limited slip performance. Although generally not necessary, original equipment manufacturers' limited slip additives may be used in conjunction with AMSOIL Series 2000 Synthetic Gear Lube.

Redline says:

LIMITED-SLIP COMPATIBILITY Red Line Gear Oils, with the exception of the 75W90NS, already contain friction modifier required for operation in limited-slip differentials. Additional additive is not required.

I have emailed Redline and asked them if it would not hurt to add the GM additive to Redline.

Here is the reply from redline

The 75W90 would be suitable for the limited slip in your Z06 it contains 5% friction modifier, typically what is needed to reduce the chatter from the limited slip when making a slow tight turn. Adding more friction modifier if it isn't needed reduces the lock up of the limited slip and reduces it's effectiveness, so I wouldn't add it unless it is needed due to chatter and then only just what is needed. The friction modifier isn't a lubricant but just an additive to make the fluid slipperier for chatter control. The 75W90 should be suitable right out of the bottle without the need for the additive. Thank you for your interest in Red Line Oil.

It states in the GM manual that no WOT for 300 miles after the diff fluid is changed

 

For warranty issues, is it true that Redline is not an accepted fluid and Amsoil is :confused: How about Royal Purple :confused:

 

If it is a DEXRON III Fluid, it is covered. :yesnod:

 

Here' a tip for RedLine users: RedLine fluids come in quart size bottles with smaller caps than are usually found on transmission fluid bottles. The typical $5 hand pump works very good, even on 75W90, but has a screw on cap for the standard size necks and is too loose for the RedLine bottles. I took a piece of duct tape, 13" long, tore it into 3 strips, and wrapped around the threads on the RedLine bottles. Now the standard size cap on the hand pump fits tight enough to stay in place when you pump. You do have to pour additional bottles into the first, which is probably easier than wrapping them all. Or, if you had an empty trans fluid bottle available, you could wash it out and then pour the RedLine in. It's a minor pain, but would not exist if RedLine used standard size caps. Maybe the smaller necks make it easier to pour directly into the fill holes on a lot of cars, but this is usually not possible on many models. :smash:

 

Used Redline on my tranny and rear differential