zf6 grinds at high rpm shift to 2nd
06-03-2003, 02:24 PM
#1
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zf6 grinds at high rpm shift to 2nd
I have a problem with my transmission grinding on high rpm shifts from 1st to 2nd gear. It only happens over 3000 - 3500 rpm. Has anyone else had this problem, and is it an expensive fix? Thanks in advance.
06-03-2003, 04:21 PM
#2
Le Mans Master
Member Since: Jan 2000
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Re: zf6 grinds at high rpm shift to 2nd (LT4DRIVER)
May be a sign that your syncros are starting to wear out, they are expensive to fix as the whole transmission has to come apart, you will need almost $1800 +/- a few hundred.
A few things to check which are relatively cheap would be drain and fill the trans with fresh GM trans fluid and bleed the clutch to make sure you are getting it to release fully.
YOu could also contact Bill at zfdoc.com and see what he thinks.
A few things to check which are relatively cheap would be drain and fill the trans with fresh GM trans fluid and bleed the clutch to make sure you are getting it to release fully.
YOu could also contact Bill at zfdoc.com and see what he thinks.
06-03-2003, 09:21 PM
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Re: zf6 grinds at high rpm shift to 2nd (Aaron71771)
Thanks for the advice. Do you know if the grinding is causing any further damage or can this repair wait? I kinda figured on a high $$$ repair.
06-04-2003, 04:27 PM
#6
Re: zf6 grinds at high rpm shift to 2nd (81&93_Jess)
Always purge the fluid in your master and slave cylinders and transmission with fresh. If still grinding, change the master and slave cylinders for a whopping $250 in parts. These are the only sure ways to GUARANTEE that the problem is a worn synchro that need replaced. If the synchro is bad and the car has under 500K miles on it, then at some point the hydraulic clutch was not fully releasing some time in the car's past due to low fluid or weak clutch cylinder action. In this case, the tiny conical synchro assy tried to work like an 11" clutch and harness the motor torque (it can't). Neglecting clutch master cylinder fluid level is common, since it's hidden by the computer. Loss of a teaspoon of fluid can ruin the transmission by overheating, warping and/or wearing out synchros. Many folks bitch about notchy, stiff shifter until the clutch quits disengaging all together. By then, it's too late. This is a common C4 failure mode, good luck.
