Automotive Forums .com - the leading automotive community online! Automotive Forums .com - the leading automotive community online!
Automotive Forums .com - the leading automotive community online! 
-
Latest | 0 Rplys
Go Back   Automotive Forums .com Car Chat > Chevrolet > General Discussion
Reply Show Printable Version Show Printable Version | Email this Page Email this Page | Subscription Subscribe to this Thread
 
Thread Tools Search this Thread
Old 01-07-2016, 08:48 PM   #1
johnw1944
AF Newbie
 
Join Date: Jan 2016
Location: Osceola, Missouri
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
OD Transmission

I have a 2004 chevy Tahoe 4x4. I need to know what should the RPMS be at 70 Mph. My Tahoe tacks 2300 Rpms at 70. Is this correct or is my overdrive not working>
johnw1944 is offline   Reply With Quote
Old 01-07-2016, 10:09 PM   #2
777stickman
AF Enthusiast
 
Join Date: Jan 2004
Location: Maybe, California
Posts: 1,860
Thanks: 6
Thanked 92 Times in 91 Posts
Re: OD Transmission

To tell you if the RPM's vs Speed is correct would need a whole lot more info from you.

Here's an easy way to tell if your OD (aka Torque Converter Lockup) is working.

At cruising speed, add some throttle, not enough to down shift, just enough to maybe get from 60 to 70. Watch the tach!! If you get an immediate 200-300 jump in rpm's, the TCC is not locked up.

If the rpm's steadily increase with MPH then the TCC is locked and OD is working.

Hope this helps and welcome to AF.
__________________
57 Chevy 210
65 Olds 442 Convertible (Another one sold)
75 GMC Vandura 3/4 Ton
1999 K2500 Old Body Style Suburban (Gone but not forgotten)
05 Dodge Ram 3500/5.9 Cummins
2012 Toyota FJ Cruiser
777stickman is offline   Reply With Quote
Old 01-07-2016, 10:21 PM   #3
maxwedge
A990 racer
 
Join Date: Mar 2002
Location: Chestertown, New York
Posts: 16,676
Thanks: 16
Thanked 340 Times in 334 Posts
Re: OD Transmission

To add if the o/d wasn't was inop. it would set a code so the cel would be on.
__________________
maxwedge is online now   Reply With Quote
Old 01-08-2016, 12:14 AM   #4
Blue Bowtie
Registered Offender
 
Blue Bowtie's Avatar
 
Join Date: Mar 2006
Location: Rural
Posts: 6,096
Thanks: 4
Thanked 267 Times in 263 Posts
Re: OD Transmission

3.73 axles? 3.42 axles? 3.08 axles? It all make a difference in final drive and RPM at speed.

What tires?

I won't ask it that's in 4HI or 4LO, but you get the idea.
__________________
Permanent seat assignment on the Group W bench...
Automotive Forums Survival Guide
Blue Bowtie is offline   Reply With Quote
Old 01-08-2016, 09:40 PM   #5
j cAT
AF Fanatic
 
Join Date: Oct 2007
Location: EVERETT, Massachusetts
Posts: 10,849
Thanks: 6
Thanked 432 Times in 431 Posts
Re: OD Transmission

Quote:
Originally Posted by johnw1944 View Post
I have a 2004 chevy Tahoe 4x4. I need to know what should the RPMS be at 70 Mph. My Tahoe tacks 2300 Rpms at 70. Is this correct or is my overdrive not working>
my 2000 silverado 4x4 3.73 rear diff RPM is about 2K..@70MPH.. 2300 is too high IMO..... I think your running in 3rd . when I tow my 4K LBS boat I run in 3rd @ 2300 RPM @ 70 MPH ... normally I tow @65 MPH.. with the 4 speed tranny my vehicle shifts into 4th at 35-38 MPH.... my 96 impala shifts also at 38 MPH... 2004 GM used DEXRON III this fluid is no longer an approved GM fluid because it put GM into bankruptcy . If you never changed to the GM approved dexron VI then it is very possible the valve bodies are eaten away from the dexron III fluid turning to an acid metal eating mess. DEXRON III is only good in a tranny for 20K miles then the acid begins .. gm dumped this fluid in 2006 !
j cAT is offline   Reply With Quote
 
Reply

POST REPLY TO THIS THREAD


Bookmarks
Go Back   Automotive Forums .com Car Chat > Chevrolet > General Discussion

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 01:33 PM.

Community Participation Guidelines | How to use your User Control Panel

Powered by: vBulletin | Copyright Jelsoft Enterprises Ltd.
 
 
no new posts