Silverado, Sierra & Fullsize Pick-ups The Silverado & Sierra have been two of the best selling trucks in the US for decades, and is truly proven to be "like a rock".

2014 Chevy Silverado
Platform: Truck, GMT 400, 800, & 900

3.42's to 3.73's???

Thread Tools
 
Search this Thread
 
Old Jan 23, 2011 | 7:49 PM
  #1  
northey87's Avatar
Thread Starter
Super Moderator
 
Joined: Oct 2007
Posts: 1,275
Likes: 0
From: Dayton PA
Default 3.42's to 3.73's???

Hi yall, it has been a long time since I have been on the forum, life has just been too busy!!! But I digress.

I have found myself in an interesting situation. I am going to be replacing my open carrier to a limited slip so I can get around better in the snow around where I live here in western PA. My question is, while I have everything torn apart in the diff should I make the switch from 3.42 to 3.73 gears? I am thinking that the 3.73's would serve me better with the rolling hills here in PA, because right now I find my foot having to step on the gas a bit harder to get up the hills on my daily commute and the tranny dropping out of overdrive then dropping from 4th to 3rd Just to keep up. Anyways, I would like to hear yalls thoughts. Thanks.
Reply
Old Jan 23, 2011 | 8:03 PM
  #2  
RacerX's Avatar
CF Veteran
 
Joined: Aug 2010
Posts: 1,054
Likes: 5
From: New York City USA
Default

It is supposed to drop out of Overdrive when climbing steep hills. They recommend that if you are in that type of terrain that you shift into 3rd to prevent gear hunting on the incline. And if the steep is too grand then the transmission will continue to downshift to match the throttle demand. The transmission isnt the problem, its where you live.
Reply
Old Jan 23, 2011 | 8:31 PM
  #3  
northey87's Avatar
Thread Starter
Super Moderator
 
Joined: Oct 2007
Posts: 1,275
Likes: 0
From: Dayton PA
Default

Thats what I figured, thats why I am thinking about changing the diff gears to help out the tranny. If I do change the diff gears, will that mess with the computer? I know that I will need to change the vssb/drac unit, but will need to do anything else to the computer system?

Last edited by northey87; Jan 23, 2011 at 8:38 PM.
Reply
Old Jan 24, 2011 | 9:11 AM
  #4  
northey87's Avatar
Thread Starter
Super Moderator
 
Joined: Oct 2007
Posts: 1,275
Likes: 0
From: Dayton PA
Default

Anybody else?
Reply
Old Jan 24, 2011 | 9:31 AM
  #5  
RacerX's Avatar
CF Veteran
 
Joined: Aug 2010
Posts: 1,054
Likes: 5
From: New York City USA
Default

Nah it wont mess with the computer. Disconnect the battery to erase all runtime programs and when you finish the computer will relearn all sequences.
Plus 1995 is an electronic case so when you run it it should refigure shift points and pretty much nothing should change. Higher top speed, and quicker acceleration time but lower fuel efficiency is all.
Reply
Old Jan 24, 2011 | 11:09 AM
  #6  
northey87's Avatar
Thread Starter
Super Moderator
 
Joined: Oct 2007
Posts: 1,275
Likes: 0
From: Dayton PA
Default

Thanks, I'm not sure that I will lose mpg's by going with 3.73's, with the engine not having to work as hard. The best highway mileage I have ever seen with this truck is about 19.5mpg. My uncle has basically the same truck but its a '94 and has a 3 speed trans and he gets 20 consistantly on the highway with 3.73's. IDK?
Reply
Old Jan 24, 2011 | 3:01 PM
  #7  
Cpb200's Avatar
CF Active Member
 
Joined: Jul 2010
Posts: 172
Likes: 0
Default

u probly will get less with 3.73 there more of power gears but the 3.42 is more of mpg gears but in the hills where u live might actualy being doing better by goin to 3.73
Reply
Old Jan 24, 2011 | 4:15 PM
  #8  
RacerX's Avatar
CF Veteran
 
Joined: Aug 2010
Posts: 1,054
Likes: 5
From: New York City USA
Default

lower gear ratio=higher rpms to maintain same speed. higher rpms=lower fuel efficiency. The last dude is right, 3.73 is the middle of the road ratio for people who arent towing nor racing. With all the hill climbing, you ll move faster but not much more. Plus you re looking for positraction anyway and speed isnt your concern
Reply
Old Jan 24, 2011 | 9:55 PM
  #9  
BigR's Avatar
CF Beginner
 
Joined: Apr 2010
Posts: 9
Likes: 0
Default

I asked my dealer about switching from 3.08 (big mistake!) to 3.42 rear end, and he mentioned that the power control module would have to be reprogrammed. Not a problem, because it could be done. Just thought you should know. I didn't make the change because It would have cost $3,650 for them to do it. Sounds like you can do the job yourself. You're lucky, I wish I could. I'll just live with this dog for awhile.
Reply
Old Jan 24, 2011 | 10:04 PM
  #10  
BigR's Avatar
CF Beginner
 
Joined: Apr 2010
Posts: 9
Likes: 0
Default

How do you start a new thread on this website?
Reply



All times are GMT -5. The time now is 12:04 PM.


Top


© 2026 MH Sub I, LLC dba Internet Brands

Follow Us    



When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.