Difficulty shifting following cold start
Thread Starter
Team Owner
Joined: Sep 2002
Posts: 22,209
Likes: 12
From: OBAMA IS HITLER
Difficulty shifting following cold start
I have a 1990 with manual ZF transmission that I just purchased. After a "cold start" (sitting maybe 6-8 hours or so), experiencing severe difficulty putting car into gear (only neutral is possible). After several mins. "warm up" and FINALLY putting car into gear, then everything is ok, shifting smooth, etc. Is this a case of improper manual transmission fluid (ie, too heavy) that was put in by the previous shop/owner? There are no rattles, transmission noises, etc. and all else seems fine. It has 47,000 miles on it. This is extremely annoying, please help! :(
[Modified by bradvette, 12:16 AM 9/17/2002]
[Modified by bradvette, 12:16 AM 9/17/2002]
Le Mans Master
Joined: Apr 2000
Posts: 6,294
Likes: 0
From: Amateur driver on open course.
Re: Difficulty shifting following cold start (bradvette)
:confused: I had a Camaro that suffered from those same symptoms. Not quite as severe though. After a fluid change, all was good. Don't know if the old fluid was too thick, or just too old. I would change it. :yesnod:
Safety Car
Joined: Jul 2002
Posts: 4,548
Likes: 3
From: SCMR Rat Pack'r Charter Member, Inland Empire Chapter
Re: Difficulty shifting following cold start (bradvette)
First off Welcome to the Forum and welcome to the addiction. Both are great!
Its very possible someone put the wrong fluid in it. Most manuals use an 80-90 weight gear oil but the ZF's 5w-30w trannie lubricant. What Ive heard actually works best is BMW M5 engine oil.
Quote: TRANSMISSION OIL (status) - Vascular flow of oil through the porous Phosphorus-bronze (Pb) material of each synchronizer is essential for effective British Thermal Unit (BTU) heat exchange occurrence. Frequent transmission oil changes will ensure lower Pb particle levels suspended in the oil. The ZF S6-40 6-speed transmission is lubricated by engine type oil. Manufacturer recommendations specify the use of GM P/N 1052931 (5w-30) or BMW P/N 07510009420 (10w-60) oil.
Approximate oil capacity of the ZF S6-40 is 2.2 qts.
FYI - the BMW 10w-60 oil is fully-synthetic and is used in the BMW M5 engine.
http://www.zfdoc.com/techinfo.htm
Wow...I just saw this made 600 posts for me in the Forum....boy I sure talk a friggen' lot :lol: :lol: :lol:
[Modified by DarkHalo, 5:05 AM 9/17/2002]
Its very possible someone put the wrong fluid in it. Most manuals use an 80-90 weight gear oil but the ZF's 5w-30w trannie lubricant. What Ive heard actually works best is BMW M5 engine oil.
Quote: TRANSMISSION OIL (status) - Vascular flow of oil through the porous Phosphorus-bronze (Pb) material of each synchronizer is essential for effective British Thermal Unit (BTU) heat exchange occurrence. Frequent transmission oil changes will ensure lower Pb particle levels suspended in the oil. The ZF S6-40 6-speed transmission is lubricated by engine type oil. Manufacturer recommendations specify the use of GM P/N 1052931 (5w-30) or BMW P/N 07510009420 (10w-60) oil.
Approximate oil capacity of the ZF S6-40 is 2.2 qts.
FYI - the BMW 10w-60 oil is fully-synthetic and is used in the BMW M5 engine.
http://www.zfdoc.com/techinfo.htm
Wow...I just saw this made 600 posts for me in the Forum....boy I sure talk a friggen' lot :lol: :lol: :lol:
[Modified by DarkHalo, 5:05 AM 9/17/2002]
Thread Starter
Team Owner
Joined: Sep 2002
Posts: 22,209
Likes: 12
From: OBAMA IS HITLER
Re: Difficulty shifting following cold start (bradvette)
Thanks for the opinion, I'm pretty sure its the fluid and I'm taking my vette
to the shop for a full inspection. If its the case, I'll be sure to have them
do a complete flush. :crazy:
to the shop for a full inspection. If its the case, I'll be sure to have them
do a complete flush. :crazy:
Burning Brakes
Joined: Sep 2001
Posts: 1,011
Likes: 0
From: Jupiter Florida
Re: Difficulty shifting following cold start (bradvette)
Thanks for the opinion, I'm pretty sure its the fluid and I'm taking my vette
to the shop for a full inspection. If its the case, I'll be sure to have them
do a complete flush. :crazy:
to the shop for a full inspection. If its the case, I'll be sure to have them
do a complete flush. :crazy:
Make sure they put the right stuff in. 5w30 does not make it motor oil, one sniff will tell you that.
Burning Brakes
Joined: Oct 2000
Posts: 897
Likes: 0
From: My Own Private Idaho
Re: Difficulty shifting following cold start (bradvette)
Do you park on an incline? Maybe the hydraulic clutch???
From: http://www.zfdoc.com/clutch_hydraulic.htm
"Try to put it into reverse when it first gets started (cold).
Note: Difficulty getting into reverse when in this condition indicates that the clutch master cylinder is not at 100%. "
This link is very informative about the ZF and the hydraulic clutch assy.
Good luck.
[Modified by cgtarga1, 2:26 PM 9/17/2002]
From: http://www.zfdoc.com/clutch_hydraulic.htm
"Try to put it into reverse when it first gets started (cold).
Note: Difficulty getting into reverse when in this condition indicates that the clutch master cylinder is not at 100%. "
This link is very informative about the ZF and the hydraulic clutch assy.
Good luck.
[Modified by cgtarga1, 2:26 PM 9/17/2002]
Thread Starter
Team Owner
Joined: Sep 2002
Posts: 22,209
Likes: 12
From: OBAMA IS HITLER
Re: Difficulty shifting following cold start (yoslambo1@cs.com)
I just got the car back and the bill was only $104! (about 2 hours labor)
The problem turned out to be very low hydraulic clutch fluid. The system was tested for leaks and there were none, master & slave cylinders in excellent shape. There was some fluid left in the slave cylinder (very lucky). The mechanic said that sometimes the factory puts in a lower amount of fluid, since the car is 13 yrs. old much of it probably evaporated over time since its alcohol-based. He seriously doubts anyone ever checked the fluid level to top it off over time. At any rate, the ultra low level caused the clutch not to engage properly. NOW its solid as a rock and shifting is smooth as silk.
I've never driven such a nice solid 6 speed! This is my 1rst Vette and I'm in total heaven, just got it 3 weeks ago. I want to thank all of you for your help. This forum is a great place to be! :D
[Modified by bradvette, 10:32 PM 9/18/2002]
The problem turned out to be very low hydraulic clutch fluid. The system was tested for leaks and there were none, master & slave cylinders in excellent shape. There was some fluid left in the slave cylinder (very lucky). The mechanic said that sometimes the factory puts in a lower amount of fluid, since the car is 13 yrs. old much of it probably evaporated over time since its alcohol-based. He seriously doubts anyone ever checked the fluid level to top it off over time. At any rate, the ultra low level caused the clutch not to engage properly. NOW its solid as a rock and shifting is smooth as silk.
I've never driven such a nice solid 6 speed! This is my 1rst Vette and I'm in total heaven, just got it 3 weeks ago. I want to thank all of you for your help. This forum is a great place to be! :D
[Modified by bradvette, 10:32 PM 9/18/2002]
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