Trans Third Gear Shift / Fluid - ZR-1 Net Registry Forums

gbmidyear66 · 07-24-2010

My ZF does not shift cleanly into third gear. Below about 2500 RPM it will stop short of going fully into gear and needs an extra "push" to fully engage. At 3K and above it goes into 3rd clean and smooth. Anybody else experience this?

The shifter returns well to the center position. It appears from the records I have that the fluid was changed 10K miles ago (7 years) and it has the GM fluid in it.

Other than the obvious solution... "never shift below 3K!" - I am wondering if switching to the Castrol product or to the Amsoil product might be helpful?

Scrrem · 07-24-2010

Quote:

Originally Posted by gbmidyear66

My ZF does not shift cleanly into third gear. Below about 2500 RPM it will stop short of going fully into gear and needs an extra "push" to fully engage. At 3K and above it goes into 3rd clean and smooth. Anybody else experience this?

The shifter returns well to the center position. It appears from the records I have that the fluid was changed 10K miles ago (7 years) and it has the GM fluid in it.

Other than the obvious solution... "never shift below 3K!" - I am wondering if switching to the Castrol product or to the Amsoil product might be helpful?

Sounds like you may have a synco going bad. You can try chaing the fluid but some trans work may be in order.

Rich

sammy · 07-24-2010

best bet ,run this by bill boudreau the zfdoc .he is the best with our trannys

thethrillofspeed · 07-24-2010

Mine does the same thing. I was considering changing the fluid, even bough the socket, but I have not changed it yet. My Wrangler is also similar, I changed the fluid in it, but it didn't make any difference. I fear it is just wear in the trans.

gbmidyear66 · 07-25-2010

Rich, that was the conclusion I was trying to avoid coming to.....

Guess a call to the ZF doc is in order.

Z51JEFF · 07-25-2010

My 91 does the same thing if Im bangin the gears through the RPMs and this car had 7,000 miles when I got it.Anymore I just pay attention going into 3rd if I know theres a chance it might not go in.Ill try the Castrol here pretty soon.This was only an issue when going through the gears cookin at a nice pace.

07-24-2010	#1
gbmidyear66 Join Date: Feb 2008 Location: Vancouver, BC Posts: 252	Trans Third Gear Shift / Fluid My ZF does not shift cleanly into third gear. Below about 2500 RPM it will stop short of going fully into gear and needs an extra "push" to fully engage. At 3K and above it goes into 3rd clean and smooth. Anybody else experience this? The shifter returns well to the center position. It appears from the records I have that the fluid was changed 10K miles ago (7 years) and it has the GM fluid in it. Other than the obvious solution... "never shift below 3K!" - I am wondering if switching to the Castrol product or to the Amsoil product might be helpful? __________________ [SIGPIC][/SIGPIC] __________________ 1990 Corvette ZR-1 #2824 4.10's, Custom PROM, Flowmaster, Top End Port NCRS BC Chapter

07-24-2010	#3
sammy Join Date: Jun 2010 Location: back in lone pine Posts: 591	Re: Trans Third Gear Shift / Fluid best bet ,run this by bill boudreau the zfdoc .he is the best with our trannys

07-24-2010	#4
thethrillofspeed Join Date: Dec 2006 Location: Reno, Nevada Posts: 20	Re: Trans Third Gear Shift / Fluid Mine does the same thing. I was considering changing the fluid, even bough the socket, but I have not changed it yet. My Wrangler is also similar, I changed the fluid in it, but it didn't make any difference. I fear it is just wear in the trans. __________________ 90 ZR1 Dark Red/Black, Borla, 4:10, Chip 01 Z06 01 Z06 Lingenfelter 427 Twin Turbo

07-25-2010	#5
gbmidyear66 Join Date: Feb 2008 Location: Vancouver, BC Posts: 252	Re: Trans Third Gear Shift / Fluid Rich, that was the conclusion I was trying to avoid coming to..... Guess a call to the ZF doc is in order. __________________ [SIGPIC][/SIGPIC] __________________ 1990 Corvette ZR-1 #2824 4.10's, Custom PROM, Flowmaster, Top End Port NCRS BC Chapter

07-25-2010	#6
Z51JEFF Join Date: Dec 2007 Location: Fremont,Ca Posts: 3,080	Re: Trans Third Gear Shift / Fluid My 91 does the same thing if Im bangin the gears through the RPMs and this car had 7,000 miles when I got it.Anymore I just pay attention going into 3rd if I know theres a chance it might not go in.Ill try the Castrol here pretty soon.This was only an issue when going through the gears cookin at a nice pace.