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

Speedo Gear

Thread Tools
 
Search this Thread
 
Old Jan 18, 2009 | 10:49 PM
  #1  
94cummins12v's Avatar
Thread Starter
|
Diesel Bomber
Joined: Jan 2008
Posts: 4,525
Likes: 103
From: Havre mt
Default Speedo Gear

anyone know the difference in speedo gears for a 241 dhd transfer case, my truck has a grean gear which is stamped with a 31 and the new transfer case had a red speedo gear and i forgot what the number was, any one know which one to run with 35" tires
 
Reply
Old Jan 19, 2009 | 10:22 PM
  #2  
jnicewan's Avatar
Diesel Enthusiast
Joined: Jan 2009
Posts: 130
Likes: 10
From: norman, ok
Default

you dont have all info needed , would need to know your ring/pinion ratio. and also was your original "green" gear the correct gear from factory. basically though for every inch increase in tire size then drop 1 tooth on driven gear. your truck probably had 30" tires 245-75-16 with 3.54 axle if so green was correct . so 35's you might look for a 27tooth white gear. the red gear probably came from a truck with 4.10 axle.
green = 31 tooth...dodge part# 5206853
white = 27 tooth...dodge part# 5206849
red = 36 tooth...dodge part# 5206858
 
Reply
Old Jan 21, 2009 | 12:41 AM
  #3  
94cummins12v's Avatar
Thread Starter
|
Diesel Bomber
Joined: Jan 2008
Posts: 4,525
Likes: 103
From: Havre mt
Default

damn, it does have the 3.54 ration, it did come from the factory with a green gear for 245-75-16, i now have 315-75-16 on the truck but also have this red gear laying around, would it be wise to put the red one in?
 
Reply
Old Jan 21, 2009 | 10:22 PM
  #4  
jnicewan's Avatar
Diesel Enthusiast
Joined: Jan 2009
Posts: 130
Likes: 10
From: norman, ok
Default

your better of running the green 31t gear, you need to drop teeth and not gain teeth. the red gear has more teeth than green gear, you need less teeth for bigger tire
 
Reply
Old Jan 21, 2009 | 11:56 PM
  #5  
94cummins12v's Avatar
Thread Starter
|
Diesel Bomber
Joined: Jan 2008
Posts: 4,525
Likes: 103
From: Havre mt
Default

oh ok would anyone happen to have a formula to convert MPH with bigger tires?
 
Reply
Old Jan 22, 2009 | 12:28 AM
  #6  
Red_Rattler's Avatar
High Tech Redneck

Joined: Nov 2007
Posts: 6,730
Likes: 496
From: Columbus WI
Default

Any good tranny shop and even the dealer can help you get the right gear for your situation. I believe your gonna need a 27 or 28 tooth. But head to either and tell them what you need and they shouldn't have a problem helping you out!
 
Reply
Old Jan 22, 2009 | 12:31 AM
  #7  
94cummins12v's Avatar
Thread Starter
|
Diesel Bomber
Joined: Jan 2008
Posts: 4,525
Likes: 103
From: Havre mt
Default

oh im not to worried about it just checking, if i get pulled over hear it wont be causeed from speed
 
Reply
Old Jan 22, 2009 | 12:50 AM
  #8  
Red_Rattler's Avatar
High Tech Redneck

Joined: Nov 2007
Posts: 6,730
Likes: 496
From: Columbus WI
Default

Gotcha, heres your calculation.... 4x4 related Calculators, Crawl Ratio, Gears Tires Sizes, etc..
 
Reply
Old Jan 22, 2009 | 12:54 AM
  #9  
94cummins12v's Avatar
Thread Starter
|
Diesel Bomber
Joined: Jan 2008
Posts: 4,525
Likes: 103
From: Havre mt
Default

ok so what size tire is a 245/75/16"
 
Reply
Old Jan 22, 2009 | 01:36 AM
  #10  
Red_Rattler's Avatar
High Tech Redneck

Joined: Nov 2007
Posts: 6,730
Likes: 496
From: Columbus WI
Default

30.5x9.5x16

Metric Tire Conversion Calculator - Red Rock 4x4
 
Reply



All times are GMT -5. The time now is 08:55 AM.