Trans fluid question

[Corbusa]

I see that Castrol is a 10w60 for the trans .. and from what I can tell Amsoil MTF is 5w30.... Is that still ok???
I'll be ordering Power steering fluid and Motorcycle oil So I'd like to just get all the fluids I need... thanks

[sammy]

i know we all get a rash having to go to the bmw dealership to by the 10-60 but nill boudreau says its the very best stuff for our trannys

[Jim Nolan]

You only need a couple of quarts and it's not like you change it as often as your engine. It's worth the price.

[Corbusa]

10-4 I'll go with the 10w60

[mike100]

The Amsoil shifts better. Maybe I would switch to the BMW oil for track duty.

I think the original GM fill was closer to a 5w-30 also.

[sammy]

the problem with the 5 30 really shows up if you use the car for road racing or have 410s. the sixth gear reverse gear ends up welding to the main shaft. the cost of redoing our trannys is 2-3k . so why even take the chance of using anything else other than what bill recommends just isn't very smart in my opinion . no offense intended to anyone

[PhillipsLT5]

bmw 10/60 castrol is a liter, you will need a hair over 2 liters

[mike100]

Originally Posted by sammy

the problem with the 5 30 really shows up if you use the car for road racing or have 410s. the sixth gear reverse gear ends up welding to the main shaft. the cost of redoing our trannys is 2-3k . so why even take the chance of using anything else other than what bill recommends just isn't very smart in my opinion . no offense intended to anyone

Because if I lift off the clutch pedal a smidge too early, I might catch a notch in 3rd gear. The car goes into third soooo much easier with the Amsoil and therefore, in my case, the trans will be better off with the lighter oil. Already had to spend $600 just on second gear assemblies, don't need to take out third

[Corbusa]

How about 2 bottles of 30 and some Lucas oil stabilizer?

[tomtom72]

Corbusa, before you buy anything for the trans I would say to go over to Bill's site and do some reading. Look I'm not trying to talk you into brand X or whatever.

Just a fwiw, a little back ground info on our trans fluid. The zf guys told GM that the box uses GL3 or was it GL5 fluid. Yes, gear lube, not trans fluid. And you know that GL #'s are not backwards & forwards swappable, right? Soooo, GM had Texaco ( I think? ) make the specific fluid that zf wanted because it was logical as all C4's were going to use our trans. After the 5th gen car came out the stores were depleted and then replaced with a more generic fluid for dealer stock. You can read all this stuff over at Bill's site.

Now my personal experience is this as I have driven my car with the factory fill and it worked great. The car was a one owner car @ 7400 miles when I bought her. I then switched to the GM fluid ava in 06. I went to Bill's site & did the reading before hand. I change my trans oil every year. I can tell you yes it shifts easier with the GM stuff, even when it below 40* . But, I was kind of nervous that the new GM stuff was close, but not exact. So I switched to the BMW stuff in 07. If you read the results of Bill's Lubricity Remaining test you'll know why I change it every year no matter what fluid I was using. Oh, yes it takes twice as long on cold days for the BMW fluid to get to a happy temp!

http://zfdoc.com/ here's the link to Bill's site.


Tom