i want to change the fluid in my manual tranny. went and got the stock gm oil. my question is how do you guys put the new oil in the tranny? draining isnt a prob, but that side mounted plug looks hard to get to. howd yall do it? :jester

 

To put the oil in you’ll need a hand pump or some type of pump to pump it up in there. It’s pretty easy to get to the fill plug, you’ll need to have a shallow ratchet or a 3/8 breaker bar which would fit in there between the trans to break the plug loose.


There are better fluids other than the factory GM fluid. There was a posting last week on the ZR-1 net from Bill Boudreau (ZF-Doc) stating that he prefers the synthetics over the factory petroleum fill during the discussion. But (DO NOT USE Mobil-1 in the ZF’s) when the discussion came up on fluids for the ZF 6-speed. Also mention was Redline fluids, which is pretty good too.

Here’s are copies of the posting from the ZR-1 net:

Bill Boudreau Wrote:

Hey Folks,

Mobil-1 oil, when used in the ZF S6-40 transmission, may cause
slight/gradual development of glazing of the synchronizer's phosphor-bronze binding surface.

Five out of six ZF S6-40 transmissions that I rebuilt that previously had Mobil-1 5w-30 oil in them had some degree of glazing of some or most of the synchronizer phosphor-bronze lining surfaces.
As the percentage of glazed surface area increases on any given synchronizer ring, the ability of that synchronizer to bind efficiently also becomes reduced.
Gradually over time, this condition may lead to increased shifting effort especially in the more frequently used gears.

I prefer the Castrol TWS 10w-60 (BMW P/N 07510009420 - M5 engine oil) for use in the ZF S6-40 transmission over the factory fill (GM P/N 1052931).

Other lubricants which work well in the ZF S6-40 transmission are
RedLine Manual Transmission Lubricant (MTL) and RedLine Light Shock-Proof Transmission Lubricant (Green Martian Blood).

Don't forget to check/maintain the clutch hydraulic system to ensure optimal shifting performance of your ZF S6-40 transmission.

See Ya,

Bill Boudreau billb@zfdoc.com
ZR51 Performance http://www.ZFDoc.com
5612 E. Almeda Court
Cave Creek, AZ 85331
(602) 319-6575


Hib Halverson Wrote:

RedLine Light Shock-Proof Transmission Lubricant (Green Martian Blood).

Bill may remember the ZF out of my ratty old Malibu that we rebuilt back in early 2000. It had been run on Red Line Light Shockproof for quite some time.

I'll let Bill describe the condition of the parts in that gearbox.

cYa
Hib Halverson


Bill Boudreau Wrote:

I was very impressed with how little wear had occurred in Hib's ZF S6-40 transmission.

I would have to rate the RedLine Light Shock-Proof Transmission Lubricant as being excellent for use in the ZF S6-40 transmission.
Oh yeah.... it looks like Martian Blue Blood ... not green... my bad.

See Ya,

Bill Boudreau billb@zfdoc.com
ZR51 Performance http://www.ZFDoc.com
5612 E. Almeda Court
Cave Creek, AZ 85331
(602) 319-6575

 

Thank you for posting that, that is good information to know. I am tempted to try a little Martian blood or maybe the Castrol TWS 10w-60 (BMW P/N 07510009420 - M5 engine oil). My tranny doesn't grind while shifting but sometimes it's a bit stiff.

 

Oly

For street use, go with the RedLine (MTL) The RedLine Light Shock-Proof Transmission Lubricant may be over kill for the street. The RedLine MTL is a very excellent fluid for the street.

 

Thanks for the great tip!I'll be draining my mobil 1 first thing.How much oil does this tranny hold?
:D I LOVE MY ZF :D

 

The ZF will take 2.2 quarts of fluild.