12 Valve 2nd Gen Dodge Cummins 94-98 Discussion of 12 Valve 5.9 Liter Dodge Cummins Diesels with P7100 Injection Pumps

new gears for bigger tires?

Thread Tools
 
Search this Thread
 
Old Apr 14, 2010 | 08:07 AM
  #1  
dan33klein's Avatar
Thread Starter
|
Diesel Bomber
iTrader: (-1)
Joined: Nov 2008
Posts: 1,019
Likes: 11
From: cherry,il
Default new gears for bigger tires?

hey guys, when my truck gets paint on it and i put my new 37" tires on it, would i be smart to upgrade to a set of 4:10 gears from my 3:55's? i think i would be better off with the 4:10s
 
Reply
Old Apr 14, 2010 | 08:41 AM
  #2  
glfredrick's Avatar
Diesel Enthusiast
Joined: Mar 2010
Posts: 238
Likes: 34
Default

With a gasser truck I would tell you to go for 4.56 in a heartbeat, but with the diesel, 4.10s would work with 37s. It would be a tad flat-footed with 3.54s. Our Cummins like the low rpms, but if you can't even get into OD until 70, that ends up not working out very well.

Here's a table of tire sizes and gear ratios with RPMs in 3. Take about 25% off the RPM for OD. You may have to increase the zoom of your screen to read it well.

Name:  RPMvsTIRESIZE.jpg
Views: 3970
Size:  80.6 KB
 

Last edited by glfredrick; Apr 14, 2010 at 08:45 AM.
Reply
Old Apr 14, 2010 | 08:44 AM
  #3  
12vcummins96's Avatar
Administrator

Joined: Aug 2009
Posts: 5,765
Likes: 340
From: Pearland Tx
Default

4.10s would work well
 
Reply
Old Apr 14, 2010 | 09:20 AM
  #4  
94 12valve's Avatar
Diesel Bomber
Joined: Jan 2009
Posts: 3,504
Likes: 157
From: Pylesville, Maryland
Default

I think you should keep the 3.54's
 
Reply
Old Apr 14, 2010 | 09:41 AM
  #5  
NadirPoint's Avatar
Diesel Bomber
Joined: Aug 2009
Posts: 2,257
Likes: 186
From: CO
Default

37's would suck with 3.54 gears.
 
Reply
Old Apr 14, 2010 | 11:03 AM
  #6  
94 12valve's Avatar
Diesel Bomber
Joined: Jan 2009
Posts: 3,504
Likes: 157
From: Pylesville, Maryland
Default

Originally Posted by NadirPoint
37's would suck with 3.54 gears.
I know 3.54's and 35's work well. I really don't like 4.10's on a street truck
 
Reply
Old Apr 14, 2010 | 11:11 AM
  #7  
FastCR's Avatar
Diesel Bomber
Joined: Aug 2007
Posts: 1,525
Likes: 79
From: Livingston Montana
Default

4.10s might be good, kinda depends what your doing with it. high gears and big tires are nice rollin down the freeway but suck if your towing a lot or tryin to get rollin fast with a stick.
 
Reply
Old Apr 14, 2010 | 11:21 AM
  #8  
94 12valve's Avatar
Diesel Bomber
Joined: Jan 2009
Posts: 3,504
Likes: 157
From: Pylesville, Maryland
Default

Originally Posted by FastCR
4.10s might be good, kinda depends what your doing with it. high gears and big tires are nice rollin down the freeway but suck if your towing a lot or tryin to get rollin fast with a stick.
I will agree with the 3.54's and 37's being no fun to tow with ... and prob a good deal of broken parts to go along with it. Course if you are gonna do a good deal of heavy towing why would you put 37's on the truck?
 
Reply
Old Apr 14, 2010 | 11:22 AM
  #9  
tltruckparts's Avatar
Diesel Bomber
Joined: Aug 2009
Posts: 2,124
Likes: 102
From: Lincoln, CA
Default

i have 4.10's and 35's. works great on the freeway but around town kind of sucks. im leanining towards 4.56's when i go to 37's. no way i would ever do 3.55's on 37's
 
Reply
Old Apr 14, 2010 | 12:00 PM
  #10  
jrad989's Avatar
Diesel Enthusiast
Joined: Jul 2009
Posts: 355
Likes: 22
From: Canby, Oregon
Default

do the 4.10s bro. we already had this conversation dan.
 
Reply



All times are GMT -5. The time now is 05:31 AM.