ZF 6 oil

[Hammer]

Originally Posted by Dynomite

I think you are with majority

I prolly change transmission and differential oil every 50,000 miles on some vehicles....longer change interval on most vehicles.

But then again...the Z gets special treatment......and I will prolly change transmission and differential oil every 15,000 miles more or less on the Z. I did add the drain plug in the differential to make changing oil a lot easier on the 91' Z

I use castrol TWS 10W-60 (transmission), Mobile 1 75W-90 (Differential) and Amsoil 10W-40 (Engine).

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

[Dynomite]

Originally Posted by Hammer

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

No...you said I did not have to with Mobile 1 75W-90

Actually I have installed Mobile 1 75W-90 in the differential but have not driven the Z. On the Mobile 1 75W-90 it says limited slip applications right on the bottle. Kind of matches the tag on my differential fill plug (Use limited slip oil only....or something like that)

If I have to go with a slippery additive, let me know
I know.....you are now concerned with going to BG on that long trip with new 410 gears and experimental Mobile 1 75W-90

[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

[tomtom72]

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?

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? The original fill is NLA from GM. The new P/N is probably not the same as the OE/BG fill as when the C4 was in production, no? That makes sense to me. The C5 & C6 box and for that matter most of the other manual gear boxes that GM uses now use the same stuff. You guys have lifts & a place(s) to work! Try doing this stuff in a parking lot or in the middle of the night so you don't loose your rented space, or worse yet trusting your prized possession to some non-caring tech!

Also, I remember reading somewhere that GL numbers are not substitutable in that if you need GL3 a GL4 fluid will not cover your needs. I think I saw that on Bill's site. I also remember seeing on his site that the zf was spec'ed at an odd ball GL number not commonly used here. I want to say GL3(?) but I don't remember now, sorry. Oh, it's the same with the gear fluid that GM sells, it's not exactly what came with our cars from BG either. It's for the 5's & 6's set up.

Lastly, when I looked at that wear test/fluid lubrication degradation test over at Bill's site I was kind of amazed at the rate of fall off of viscosity. Now I'm not a Petro/chem Engineer but the fall off was alarming to me. Take those results and add them to the issue of the synchronizer collar getting gummed up with the sludge causing bad things to happen, eventually...I might add that this is probably the weakest argument for frequent changes...you wind up at Bill's shop for a rebuild which costs a few thousand dollars.

I know it's a PIA, but then if you do the schedule so that once the car is up on stands, or a lift, you do all the fluids at once. This way you're not doing them at any number of separate sessions, which to me is a PIA! I used to do all my "under car" work at the same session: motor oil, trans oil, gear oil, fuel filter, clutch fluid & brake fluid bleed thru's, coolant + stat change. The last three fluids were once every two yrs, to lighten the work load.

To me it's a question of having a schedule & sticking to it. Also, and this is a bit half-assed, I like to think that once my maintenance session is over, I'm go to go for the rest of the year except for oil changes.

Sorry for what looks like a rant Yun. It's just that I'm old school, or maybe just old & senile, but machines need maintenance.


Tom

[secondchance]

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? The original fill is NLA from GM. The new P/N is probably not the same as the OE/BG fill as when the C4 was in production, no? That makes sense to me. The C5 & C6 box and for that matter most of the other manual gear boxes that GM uses now use the same stuff. You guys have lifts & a place(s) to work! Try doing this stuff in a parking lot or in the middle of the night so you don't loose your rented space, or worse yet trusting your prized possession to some non-caring tech!

Also, I remember reading somewhere that GL numbers are not substitutable in that if you need GL3 a GL4 fluid will not cover your needs. I think I saw that on Bill's site. I also remember seeing on his site that the zf was spec'ed at an odd ball GL number not commonly used here. I want to say GL3(?) but I don't remember now, sorry. Oh, it's the same with the gear fluid that GM sells, it's not exactly what came with our cars from BG either. It's for the 5's & 6's set up.

Lastly, when I looked at that wear test/fluid lubrication degradation test over at Bill's site I was kind of amazed at the rate of fall off of viscosity. Now I'm not a Petro/chem Engineer but the fall off was alarming to me. Take those results and add them to the issue of the synchronizer collar getting gummed up with the sludge causing bad things to happen, eventually...I might add that this is probably the weakest argument for frequent changes...you wind up at Bill's shop for a rebuild which costs a few thousand dollars.

I know it's a PIA, but then if you do the schedule so that once the car is up on stands, or a lift, you do all the fluids at once. This way you're not doing them at any number of separate sessions, which to me is a PIA! I used to do all my "under car" work at the same session: motor oil, trans oil, gear oil, fuel filter, clutch fluid & brake fluid bleed thru's, coolant + stat change. The last three fluids were once every two yrs, to lighten the work load.

To me it's a question of having a schedule & sticking to it. Also, and this is a bit half-assed, I like to think that once my maintenance session is over, I'm go to go for the rest of the year except for oil changes.

Sorry for what looks like a rant Yun. It's just that I'm old school, or maybe just old & senile, but machines need maintenance.


Tom

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.

[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

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.