[Motohead1]

I have a stock 2001 Dakota 9.25 rear axle with factory 3.55 gears. I need to swap to 4.56 so I can actually use 5th gear. I have never done a gear swap. I have been reading as much as I can but still unsure if there is a brand I should stay away from. I see there is some price differences shopping around but not much to compare as to why? can anyone shed some light on this? Also I have read that some people putting the 9.25 back together are using a GM pinion nut as it locks down better. Im having trouble nailing down what the part number is. Any help would be appreciated.

 

[Blackduck596]

Cannot help with direct Dodge info.
I would question why you need to drop the gearing that much.
Are you towing heavy?
Swaps are not that hard if you have the tools to do it and a good manual
Cheers Steve

 

[oshpunit987]

I'd say swapping from 3.55's the 4.56 would make 5th gear slower than 4th. What's wrong with just running in 4th gear?

 

[Motohead1]

Cannot help with direct Dodge info.
I would question why you need to drop the gearing that much.
Are you towing heavy?
Swaps are not that hard if you have the tools to do it and a good manual
Cheers Steve

Yea I think I have read enough to figurit out I just need to decide factory crush or eliminator. I am running an ALH Tdi that spins to 5K it is really happy on the hwy at 2500 RPM. tires will be 31.6 nch tall Trans is the stock NV3500 and it has a .73 5th gear.

I'd say swapping from 3.55's the 4.56 would make 5th gear slower than 4th. What's wrong with just running in 4th gear?

I dont follow? 4th is 1:1 and 5th is .73:1

 

[Death Row Dave]

Adjusting 9 1/4 Mopar

I have used crush sleeve many times no issues . Just remember adjusting nuts for backlash are accessed through axle tubes . Make the final preload adjustment on the passenger side . All will be well . 9 1/4s get a bad wrap They are good diffs when they are kept adjusted properly . Sometimes after many miles they require backlash adjustments .

 

[oshpunit987]

I was wrong. With your added info 3.55's @ 2500 in 4th is 66 MPH and 4.56 in 5th is 70. I use this converter to calculate speeds and RPM, http://www.onlineconversion.com/bigger_tires.htm

 

[Motohead1]

I have used crush sleeve many times no issues . Just remember adjusting nuts for backlash are accessed through axle tubes . Make the final preload adjustment on the passenger side . All will be well . 9 1/4s get a bad wrap They are good diffs when they are kept adjusted properly . Sometimes after many miles they require backlash adjustments .

Good to know. Thanks.

I was wrong. With your added info 3.55's @ 2500 in 4th is 66 MPH and 4.56 in 5th is 70. I use this converter to calculate speeds and RPM, http://www.onlineconversion.com/bigger_tires.htm

Yea the NV3500 has a tall 5th. 4.56 sounds tall but might be just right.