llesg

About 125,000 miles.What is the best oil for the zf6?
I plan to put a zfdoc short shifter while the transmission is out and also Ive heard that the back up light switches don't last very long on these ,so was planning on changing that as well.
should I do the output seal also??
First time doing one of these, I got all the clutch parts from power torque systems. I'm doing the job mainly because the clutch makes a machine gun sound when the clutch petal is depressed all the way in.
Any input welcome

gdl2165

I also have a 96, now with 141,000 miles. I changed mine out at about 125,000 with Amsoil Synchromesh and love the way it shifts. Before the change I sometimes had a bit of stiction going into 3rd, the Amsoil cleared that up.
http://www.amsoil.com/shop/by-produc...?code=mtfqt-ea

I'm running the Hurst short shifter in mine but you can't go wrong with the zfdoc shifter. The short shifter is the way these cars should have been stock, that stock shifter is just ridiculously long.

And I just today swapped out the backup light switch today. It was becoming intermittent recently, I tried cleaning it but that only made it worse. Got the replacement from Ecklers and it works perfectly now. My vote would be go ahead and replace it while you have easy access.

STEVEN13

That "machine gun sound" is more than likely due to the pivot ball assembly getting loose. Happened to my 1992.

Let us know.

Steve

Lt4-396

I had the am soil synchro mesh 5-30 fluid and it was OK but I noticed a big difference when I went to the Castrol RS 10-60 oil made for the "M" series cars. The synchro mesh only had 400 miles on it so it was still new when I changed it out.
It was night and day, the Castrol also shifted smoother and with less resistance.
You really can't go wrong with either one but since you have to order either one anyway I would go with the Castrol oil.

MatthewMiller

I agree. It either got loose or the pivot shoulders are really worn out. If the pivot stud looks okay (including those shoulders), then make sure the little locking screw that threads into it from the other side of the bellhousing has all its threads intact. They tend to strip very easily. If it's good, then screw the stud all the way back in to 33lb/ft (12mm allen wrench). The screw torque the locking screw into it to 11lb/ft (6mm allen) and use blue Loctite on it. If you find that you need a new locking screw and/or pivot stud, contact Jim Jandick at PowerTorqueSystems again and see if he has one. Otherwise, you will have to search for it.

I would advise you to NOT throw away your original pressure plate! If it hasn't been abused or damaged by the "machine gun sound," you may be able to resurface it. Jim knows how to do that, too. The thing is that you can't buy quality new ones anymore, so those OE Valeo units are valuable.

dizwiz24

i had a nightmare result with the castrol 10w-60 motor oil in my zf transmission.

the shifting was notchy and the shift lever would get stuck and not physically go into the next gear during wot shifts.

i changed the oil and found it full of bronze flecks.

i put in amsoil syncromesh and the problems went away immediately.

i changed out the amsoil (during a clutch change) and found virtually no bronze flecks in the oil. i think i found 2 or 3.

this is not weather-related (no weather conditions would allow the castrol to work) but was definitely worse when it was cold.

my transmission on my 93 is a blue tag zf6, with a remanufactured for gm plaque on it. i bought the car woth 26k miles on it (in 2000) and it had that transmission in it when i bought it

haxxx

I had bad results with the 10w-60 as well. My gut told me this stuff made no sense but there was a lot of praise for it. After I switched to the 10w60 my shifts went to hell 1st and 2nd were bad, and 3rd felt impossible. Dumped that crap and went with Penzoil Synchromesh. It is a replacement for GM 12345349 which was the original fluid in our cars. The Amsoil looks like a good replacement as well. The Penzoil is sold pretty much anywhere off the shelf.

dizwiz24

bmw engine oil belongs in your bmw motor, not in your transmission.

i have no idea if my re manufactured for gm transmission was made to tighter (or looser) tolerance, but that castrol stuff doesnt work.

i think the problem is the synchros. maybe its just too slippery? i dont really know.

i would love to know if you too have a blue tag, remanufactured for gm transmission as well

haxxx

Manual transmission fluids have additives that help protect the synchros. Motor oils obviously do not care about this and could even have additives that are bad for the bronze synchronizers. I read the whole thing where the 10w-60 was tested backwards and forwards and the transmission were checked for wear, blah blah blah. Load of crap apparently. Live and learn.

I've never looked for the tag but since I have a 96 I believe that means I have a blue tag.

Lt4-396

I've had the exact opposite. I had problems with the am soil and when switched to Castrol everything was fine again. The notchiness went away and just better overall feel.
I always have a blue tag and have run the Castrol in a black tag as well with zero problems.

hcbph

Here's something to be at least aware of if you have any bronze parts in a differential or tranny. I'm not to swear to the number but I think it was fluid with a GL5 rating on it. I happen to do woodworking and had a need to flush out the gearbox in my planer which has some bronze gears and bushings in it. This machine takes GL3 or GL4 diff fluid IIRC, which I couldn't find at the time. I got ahold of Valvoline and they basically said normally you can't use GL5 fluid as it attacks bronze pieces in the unit unless the fluid is de-something-or-other that makes it compatible with bronze parts.

If you deviate from the 'approved' fluid, if there are bronze parts involved then be sure your fluid is compatible with the internals.

Just 2 cents worth of info.

1985 Corvette

May be a good time to also do your rear main seal while you're already in there. If you don't use CAGS, you get rid of that as well. Just firmly tap the solenoid with a weighty hammer until it comes off then you should be able to get a wrench around the base of it to unthread. A spring and a little pushrod will fall out of the hole. You can plug the hole with an M22 bolt, if I remember the size right. Oreillys auto carried the oil pan bolt.

Lanaue

What clutch you going with?

llesg

Im going with old stock parts from power torque systems.
I wanted to use the dual mass flywheel.

llesg

I don't know what CAGS is.
What does it do?
I have not really driven this car other than home from where I bought it.

haxxx

When your driving slow in first gear the car lights a 'One to Four' indicator on the dash and locks out the gears so you can shift from first to fourth. If you accelerate aggressively it will turn off. It was an emissions/MPG thing. Pretty much everyone has eliminated this thing because who likes being told how to shift? If I'm not driving aggressively I generally shift one to four anyway because I'm lazy even though it's eliminated on mine.

llesg

So how to eliminate?
Can it just be unplugged?

Lt4-396

Yep just unplug it and put some tape so you don't get dirt in the connections, or buy the harness for I believe $20-30 that does nothing but keep the terminals/connection clean.

I personally unplugged it and used a zip lock bag on each side and taped the bag onto the wires to keep dirt/moisture out of the terminals.

gdl2165

Technically yes you can just unplug it but on a 96 you'll end up with a warning light. You can use one of these, it has a resistor in it to simulate the switch.
http://www.ecklerscorvette.com/corve...peed-1996.html

Lt4-396

Are you sure it throws a CEL? I thought it sets a "code" that is stored but doesn't throw a cel.