No Overdrive!

Gary Lee · November 29, 2004

First off...my truck...2000 Chev. 3/4 ton, ext. cab long bed, w/ 6.0. I was driving along the other day bout 60 mph, truck running good...when all of a sudden...the truck started to act like it was bogging down (almost like it was running out of gas). Then it dropped itself into the next lowest gear, and everything seemed to be fine. Then I went to see if it was still acting funny. I put the truck in D, and was riding along ok, until it went to shift into overdrive...then a few seconds in...it did the same thing...bog down...then downshift itself. Does anyone else know what the world is going on here, or know of anyone that has had a similar problem? It seems to me that the truck just doesn't want to stay in overdrive. Thanks in advance to all.

Peter_C · November 29, 2004

Any codes?

Gary Lee · November 30, 2004

No, I have yet to take it to get looked at. Being my little woman and I car pool during the week, I don't need to drive it. I wanted to get an idea of what was wrong before I go to the dealership and get the runaround. I had no idea that there would be a code for that, truck is smarter than I thought. Any more smarter and it could fix itself!

Pewter Pro-Tec · November 30, 2004

Gary,

Does it have a tow/haul button on the end of the shifter? Maybe someone pushed it in by accident?

Peter_C · November 30, 2004

Even though the check engine light is not on it does not mean there are not codes in it. Instead of the dealer I would find a good reputable shop that has top notch test equipment, and give them business. In my area we have a few GM specialists that are better techs than the dealer.

Gary Lee · December 9, 2004

Follow up!

Went to the tranny specialist today and got the "word!" The word is $2000!!! Plus a couple of words I can't post on here! Anyways...the deal is this:

When going to overdrive there are two different kinds of clutches, a manual (with a 1:1 ratio), and a mechanical clutch. The manual clutch is supposed to disengage when going into overdrive and free wheel. Then the mechanical clutch is supposed to carry the tranny into overdrive. Please forgive me if I have this bass ackwards, he was talkin kinda fast. But anyway...the manual clutch doesn't disengage causing the motor to try and turn both clutches and is binding up the tranny causing strain on the motor until the rpms lower just enough to drop the tranny into the next lowest gear. Something about the rollers and pins. Anywho...a couple grand and a couple dayz and it should be fixed with a 12 month/12,000 mi warranty!!

He also said that he had the same year/style truck in about a month ago with the same problem! What do ya'll think about that? It's hard to believe that no one on this board has had or know someone that has had a similar problem. Thanks for any and all replies!