ZF 6 oil

[tomtom72]

Originally Posted by secondchance

I hear ya, Tom. I think I have a solution - drain the old fluid, run it through a coffe filter and the refill - JUST KIDDING!
I guess I am stuck with an additional annual fluid change. Knowing my personality, once I hear these things it tends to make me lose sleep until done the way it suppose to be.
Thanks guys for all the info.

First, Yun I'm not ranting at you. I'm in a foul mood today pending the snow storm arriving tomorrow.

My view is what costs more? A zfdoc rebuild or some lousey trans oil even at the local BMW dealer's prices? I look at it this way, if there is even a chance that I can forestall a visit to zfdoc's shop by doing the fluid every yr or 10k then it's worth it to me. But that's just me. To me it's the same as my DD's upkeep, you don't want it to break then you gotta do maintenance. I don't want anyone to think it's easier for the garage queens vs Yun's Z that sees more use in a yr than my Z sees in two years! No matter which car, DD or "prized possession", maintenance is what makes the anxiety level remain low(er)! Of course this is still just my thinking, and it sure don't carry the weight of any actual mechanical experience or expertise in my possession!

[Dynomite]

Originally Posted by secondchance

I think I have a solution - drain the old fluid, run it through a coffee filter and then refill

Just let me know what coffee filter you are using and if you can get that filter on Ebay

Originally Posted by tomtom72

The only thoughts that I have are: what's the big deal on changing the trans fluid every two yrs or so, or even every year?
Tom

Tom.....Hammer is now concerned with the use of Mobile 1 75W-90 in differential without additives (he has new 410s). What oil are you (or anyone) using in the differential?

Do you use any additives to that primary differential oil such as Amsoil Slip Lock™ Differential Additive (ADA) designed to eliminate gear-housing chatter associated with limited-slip, posi-traction and locking differentials?

I did install the differential oil drain plug (91' Z) without taking the differential apart. I then filled with Mobile 1 75W-90. That drain plug installation went perfect

[xlr8nflorida]

I am running Mobil 1 75W-90 in my differential. Even though in 98% of cases, you don't need (ADA) according to Mobil 1, I did add 1 4 OZ bottle of GM additive for added safety. I've done a few hundred miles and no issues but its going to be dropped shortly and refilled. You should drain the rear end after break in of adding new rear end gears - probably around the 400 mile mark.

For what its worth, Haibeck uses the GM stuff in the ZF-6.

[WydGlydJim]

I'm running the Amsoil stuff......seems to shift well so far. GM part #1052931 is under the list this fluid replaces.......website says you can go 50,000 miles between changes.........


http://www.amsoil.com/storefront/mtf.aspx

[ZR1Vette]

I use Amsoil AMO for the engine and Amsoil 75W-90 Severe Gear+ Amsoil Slip Loc additive for diff and Castrol TWS for the tranny.

[tomtom72]

Cliff, long story longer.... My car I got from the O.O., 7400 miles / 14.5 yrs old. Everything in the car was OE/BG save the motor oil & coolant ( thank god! this guy was questioning the use of synthetic motor oil in a 90 Z!!!!! ).

I used to use the GM replacement fills for the gear & trans, until one session I had time on my hands and I was comparing P/N's in the owner's manual to the stuff I just bought at the local chevy dealer ( after I had put the stuff in both! I know I'm sooooo very perceptive! ). I nearly choked when I saw that the gear lube was not spec'ed to the exact specs as the OE/BG stuff that came in the car. I figured who cares as I change it every year anyway, same with the trans fluid from GM. I asked at the dealer about the two fluids and read up here & at Bill's site.

Result: I stuck with the GM gear fluid + two bottles of additive ( as per Gordon's instructions ) because the chevy parts guy said it was the same GL # but that the additive pkg was tailored to the 5's & 6's. The trans stuff he couldn't give me a GL # on for either what came in the car from BG or what the new stuff was from GM. He said I was on my own on that call.

I got caught up in the "bad, poorly made" clutch hydraulic parts a few yrs back that GM had on the market. I changed six sets, yes six sets, of M/C's + slaves in my car in the span of six months. That's when I decided to go with the BMW oil exclusively for the box and ditch the newer GM stuff. I was switching out the box oil every time I had a hydraulic failure because no one picked up on GM quality control problems. I didn't know what was causing my box to make the grinding noises till Bill doped the issue out & told all of us.

The last gear oil I just switched last winter to the sever duty amsoil fluid + one additive(theirs) and it went 5,036 miles without a hick-up....but that is going to be changed as it's part of my "winter get ready schedule". I will proly go with something I can get local, maybe M1 stuff or back to GM for their stuff. I hate to say this, I'm less worried about the gear lube than the box fluid. The gear lube is GL5(?) by the specs for a C4 ( I maybe wrong on that ), but my point is that the correct GL # lube for the gear is easily obtained almost anywhere. The box's correct GL # lube seems to me to be impossible to find for sure. Therefore, I'm OCD about the gear box lube changes as ( hopefully ) a precaution to forestall syncro failure.

btw, I know that on this subject I'm out where the buses don't run. In terms of my "maintenance schedule", some people could use the stuff I throw out every winter! Any one wanna buy a set of correct date coded 1990 FR2LS spark plugs?

[Aurora40]

Originally Posted by secondchance

I know this subject has been beat to death. One simple question - what was the factory fill?

I believe the factory fill was a motor oil made by Texaco that had the correct properties GM was looking for. It stopped being produced about 10 years ago. The fluid GM sells now is not the same stuff as the original fill.

This is why it is debated as to what the "best" fill now is.

Originally Posted by secondchance

I am not too crazy about changing fluids every year (10 - 12,000 miles) if I can avoid it.
I have 110,000 miles and perhaps changed it once at around 40,000 miles or so with no issue.
Am I taking too much risk? I was thinking if I stayed w/ factory fill, perhaps I could avoid anual change.

Your thoughts, guys?

Even with the factory fluid i would step up the intervals. Price out a ZF6 rebuild and let us know if a yearly or every other year fluid change is worth it.

[secondchance]

I hear you guys. I know I get a bit lazy. Besides, all my old cars were good with hardly any tranny oil change. But then again, I use to change my car quite frequently...

Thank you for your concern and advise. Next time I change motor oil I will drain and fill with that fancy BMW-Castrol.

[Dynomite]

Originally Posted by Hammer

Did you have to use any of the posi additive with the Mobil 1?

I am now convinced even though I am using 75W-90 Mobile 1 synthetic in differential, I should add 4 oz of GM Performance 1052358 Limited Slip Lubricant Additive

The Mobile 1 75W-90 says limited slip applications right on the bottle. The GM Performance 1052358 Limited Slip Lubricant Additive will add a bit of insurance.

http://www.zr1.net/forum/showthread.php?t=11315