Notices
GM Drivetrain & Suspension Chassis | Transmission| Driveshaft | Gears/Rear End/Differential | Traction Aids

gear ratios

Thread Tools
 
Search this Thread
 
Old 01-26-2015, 07:48 AM
  #1  
On The Tree
Thread Starter
 
GM-only's Avatar
 
Join Date: Apr 2011
Location: baton rouge, la
Posts: 127
Likes: 0
Received 0 Likes on 0 Posts
Default gear ratios

guys i blew up the rear axle in my truck. im pretty sure its the gov lock. so im looking at getting a new ring and pinon along with a truetrac diff. i was planning on 4.30. any body running a gear like that? right now it has 3.23. and 275/55r17s about 29 inch tall tires.

Old 01-26-2015, 10:35 AM
  #2  
TECH Enthusiast
 
turboal1's Avatar
 
Join Date: Nov 2010
Posts: 672
Received 11 Likes on 11 Posts
Default tires

why such tall tires ? there HP killers.
Old 01-26-2015, 11:07 AM
  #3  
TECH Fanatic
iTrader: (3)
 
gamble686's Avatar
 
Join Date: Apr 2011
Location: Arizona
Posts: 1,642
Likes: 0
Received 3 Likes on 3 Posts
Default

Originally Posted by turboal1
why such tall tires ? there HP killers.
Huh??? Lol 29"? Tons of guys around here run north of 30". All the 275/55-20 guys are close to 32".

To the OP you will really love 4.30s and a trutrac is a great option for a daily.
Old 01-26-2015, 05:37 PM
  #4  
On The Tree
Thread Starter
 
GM-only's Avatar
 
Join Date: Apr 2011
Location: baton rouge, la
Posts: 127
Likes: 0
Received 0 Likes on 0 Posts
Default

Yeah 29 is really very short. For a truck anyway. I had a truetrac on my old blazer and loved it. Supposedly much much stronger than a g80.

I know people ask this all the time and it can get old. But I drive to pick up my kids in Texas once a month. 1600 miles in a weekend. My in town gas mileage should go up. But how bad do yall thing highway mileage will be?
Old 01-26-2015, 09:45 PM
  #5  
TECH Regular
iTrader: (1)
 
Jordan927's Avatar
 
Join Date: Nov 2009
Location: Victoria BC Canada
Posts: 419
Likes: 0
Received 0 Likes on 0 Posts
Default

It shouldn't be that bad...you'll turn 2300rpm on the highway @65 mph VS 1700 with your old setup. Almost like driving down the highway in 3rd.

most places online say 15% MPG drop on the highway...but you should gain a mile or two in town.

Assuming you get 18MPG highway...you'll go to about 14-15MPG.
Old 01-26-2015, 10:28 PM
  #6  
TECH Fanatic
iTrader: (3)
 
gamble686's Avatar
 
Join Date: Apr 2011
Location: Arizona
Posts: 1,642
Likes: 0
Received 3 Likes on 3 Posts
Default

You might consider 4.10s if you drive a lot of highway miles. It blows my mind how big of a difference between 2100 rpm and 2300 on mpg.
Old 01-27-2015, 04:42 AM
  #7  
On The Tree
Thread Starter
 
GM-only's Avatar
 
Join Date: Apr 2011
Location: baton rouge, la
Posts: 127
Likes: 0
Received 0 Likes on 0 Posts
Default

I had thought about 4.10s once or twice but eventually decided 4.30s for sure. It'll help me out doth speeding tickets on the interstate. Lol. If it kills me to bad I'll do a 6 speed swap. Or maybe finally bite the bullet and get something with more that 4 doors for the highway.

That bein said, right now my truck is in the high 13s 1/4 mile wise. How much of a difference should this make there?
Old 01-27-2015, 08:59 PM
  #8  
TECH Apprentice
 
bobfig's Avatar
 
Join Date: Oct 2010
Location: Houston, TX
Posts: 363
Likes: 0
Received 3 Likes on 3 Posts
Default

whats your trap speed?
Old 01-27-2015, 09:39 PM
  #9  
On The Tree
Thread Starter
 
GM-only's Avatar
 
Join Date: Apr 2011
Location: baton rouge, la
Posts: 127
Likes: 0
Received 0 Likes on 0 Posts
Default

just over 100 mph if I remember right
Old 01-27-2015, 09:45 PM
  #10  
TECH Apprentice
 
bobfig's Avatar
 
Join Date: Oct 2010
Location: Houston, TX
Posts: 363
Likes: 0
Received 3 Likes on 3 Posts
Default

4.3 would be good maybe squeeze 4.56 but i wouldnt dd that


Quick Reply: gear ratios



All times are GMT -5. The time now is 11:42 AM.