http://www.c4guru.com/articles/ChangingZF6Fluid.pdf

My searches led me to that link, however that link is dead.

The owners manual says that you don't need to change it, just keep it full. My searches tell me that it should be changed every 30k miles or perhaps 5 years or so.

My car is sitting at 34k and 14 years, so I figure I might as well change it. I get the options on fluid, GM dealer vs BMW dealer vs Pennzoil vs Royal Purple vs Amsoil.

I still haven't decided on which oil, but I'm more curious about the procedure.

Are their any guides online or is it not all that ambiguous? I get you should get the fill plug loose first as you don't want to dump your fluid and then not be able to fill it back up.

 

yes, any of the fluids work fine. You can get the pricy stuff or some pennzoil sycromesh from Pep Boys doubt youll feel a difference, they all do the same thing

 

I am very happy with Amsoil in mine.
http://www.amsoil.com/storefront/mtf.aspx

As you stated, make sure you can get the fill plug out first.
You'll want to get a 17mm hex bit socket similar to this:
http://www.sears.com/shc/s/p_10153_12605_00942670000P

I also use a hand held fluid pump similar to this to add the new fluid.
http://www.northerntool.com/shop/too...8074_200008074
You'll either need a pump like that, or route a hose down from above to the fill hole. You won't be able to tilt the fluid bottle up to actually pour it into the hole.

Also, make sure you have the car level. You'll need to raise it up in order to crawl under and perform the work. I used ramps to drive the front up on.
Then used jack stands on the rear to level it to the same height as the front.
Keeping the car level, will allow all the old fluid to drain and allow for an accurate fill of the new fluid.

 

Don't bother changing it, your old fluid will look brand new when you drain it.

 

I changed mine last year with the BMW stuff, and it's pretty easy. Get a cheap hand pump, and I just bought a 17mm allen key from sears. Definitely crack the fill plug open before draining, for the possible problem you mentioned.

 

My car only had 20k on it, didnt think it shifted bad, but wanted to change it so went with Amsoil on the change. Not bad before, but just better and smother all the way around now. Make sure you can remove the fill plug before you ever mess with the drain

 

Here's an updated link:

http://www.corvette-guru.com/uploads...ngZF6Fluid.pdf

 

Do NOT overtighten the drain and fill plugs when you reinstall them. Snug is plenty.

Live well,

SJW

 

 

Thanks for that. That should make it a little easier.

It sounds like the hardest part for me is to get the car jacked up and level.

I'm gathering that it's not really possible to do this with the car sitting on the ground.

 

no way

 

Not unless your about as thick as a deck of cards.

It also helps if the fluid is warm before draining.

 

Check out this option for raising the car and keeping it level. Its a "lift on a budget".

www.raceramps.com for more info.

 

I'm a cheapskate so I made my tool. Went to Lowe's and bought a 3/4inch long 17mm bolt and 2 17mm nuts. I put Loktite on the threads of the bolt and then jammed the two nuts onto it. Now I can stick the end of the bolt into the drain plug and a wrench fits over the jam-nuts and everything turns without danger of stripping the plugs.

My ZF was a Little fussy going into 3rd and didn't get much better after a change to the Castrol from the BMW dealer. Later changed to the AmsOil synchromesh and it shifts like a new transmission! (no more 2nd tries for 3dr gear shifts) The Amsoil has an additive specially for brass synchros that is almost like a rebuild kit in a bottle for ZF's. You won't go wrong with the AmsOil, worth every penny

 

Change it for sure...smoother shifts and less heat guaranteed versus old fluid. My plugs came out fine no problems in or out on the 1995.

 

"old fluid" The car only has 34k miles. I guarantee that fluid is as good as new.

 

So you don't think the fluid breaks down at all with age?

What about the fluid in the rear? I was considering changing it as well.

I have a friend that can give me access to a lift so I figure I can knock out those two jobs at the same time.

 

Fresher is always better. Gets out the acids and moisture and puts in all good things. If somebody thinks that fluid is still OK, sell it to them as "Vintage original" and see how much they are willing to pay you for it.
Changing the rear end oil can be a big job. You'll have to drop the rear-end and separate the carrier from the "bat wing". A big time consuming job, but technically not really too difficult. If nothing needs to be replaced in the rear-end, I'd look into the "drill and plug" way of doing that job. There are some posts here with pictures of how & where to drill and tap a drain hole.

 

Changing the rear end oil is very easy. You need a pump to suck out the old fluid. There is a fill plug only. Just open the fill plug, suck out the old fluid and the pump in the new fluid (with additive for the LSD) as manual states and then put the plug back in.

 

I changed my tranny and diff at 53k miles. Fluid still looked good when it came out. I put the GM stuff back in and it does shift noticeably better now. As others have said, make sure you get it level and remove the fill plug first. You will need the little hand pump to do the diff. I havent drilled mine yet and installed a drain plug but I plan on doing it soon. I did it on my C3 and made for a much easier job to change. Finding the GM fluid is getting to be a challenge.