More Power
01-15-2004, 10:51
I received the following email message from George Fahrenholz regarding a perceived driveability problem when shifting his new ZF 6-speed manual transmission. I forwarded George's email to ZF for their consideration. I thought the resulting email exchange might be of interest to others.
MP
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Date: Tue, 6 Jan 2004
Subject: 2004 Chevy 3500 Diesel Transmission
I have a 2004 Chevy diesel 3500 dually with a 6 speed ZF transmission. When the truck is cold it does not want to shift into 3rd gear (I start out in 2nd then try and shift to 3rd - no amount of double clutching works) - once it has been driven a few miles and warmed up a bit then it is fine - any suggestions?
George W. Fahrenholz
Response from ZF:
Subject: 2004 Chevy 3500 Diesel Transmission
In order to more accurately answer the question, I need to get a little more information. Can you please provide me with the following information:
Mileage of vehicle:
Has transmission fluid already been changed?
If so, what fluid was used?
Once I have this information, it will be easier to attempt to diagnose the problem.
ZF / Best regards
Second email from George:
Subject: RE: 2004 Chevy 3500 Diesel Transmission
The truck has 1200 miles on it - I received the truck from the dealer in October 2003 (brand new). The transmission fluid is still original from the factory.
George W. Fahrenholz
Second response from ZF:
Subject: RE: 2004 Chevy 3500 Diesel Transmission
The transmission is not broken in yet. It is going to take some time (approximately 5000 - 6000 miles, possibly up to 10,000 miles) for the gears / synchro rings to "shape" themselves to match the corresponding part(s). This is normal break-in. Another factor could be the cold weather. If the temperature is below freezing, the trans fluid becomes thicker and will not thin out until it warms up. That's probably why the problem goes away after the vehicle is driven a bit.
ZF
MP
--------------------------------------------------
Date: Tue, 6 Jan 2004
Subject: 2004 Chevy 3500 Diesel Transmission
I have a 2004 Chevy diesel 3500 dually with a 6 speed ZF transmission. When the truck is cold it does not want to shift into 3rd gear (I start out in 2nd then try and shift to 3rd - no amount of double clutching works) - once it has been driven a few miles and warmed up a bit then it is fine - any suggestions?
George W. Fahrenholz
Response from ZF:
Subject: 2004 Chevy 3500 Diesel Transmission
In order to more accurately answer the question, I need to get a little more information. Can you please provide me with the following information:
Mileage of vehicle:
Has transmission fluid already been changed?
If so, what fluid was used?
Once I have this information, it will be easier to attempt to diagnose the problem.
ZF / Best regards
Second email from George:
Subject: RE: 2004 Chevy 3500 Diesel Transmission
The truck has 1200 miles on it - I received the truck from the dealer in October 2003 (brand new). The transmission fluid is still original from the factory.
George W. Fahrenholz
Second response from ZF:
Subject: RE: 2004 Chevy 3500 Diesel Transmission
The transmission is not broken in yet. It is going to take some time (approximately 5000 - 6000 miles, possibly up to 10,000 miles) for the gears / synchro rings to "shape" themselves to match the corresponding part(s). This is normal break-in. Another factor could be the cold weather. If the temperature is below freezing, the trans fluid becomes thicker and will not thin out until it warms up. That's probably why the problem goes away after the vehicle is driven a bit.
ZF