Engine/Transmission (1998.5 - 2002) Differential swap

[whathill]

After finding out California is not going to get the high output '03 Cummins (only a de-horned model), and only gaining three inches in the cab, I've decided to keep my high output 6 speed '01. Being that I will be pulling a heavier trailer , does anyone know the cost of going from a 3:54 rear end to a 4:10 rear end? Dearler wants $1500?

 

[Boost]

$1500 wow. I was quoted $3500 for parts only. There are people wanting to trade there 4. 10 for 3. 55 though.



Rob

 

[ToolManTimTaylor]

Boost you were Whatted How much :--) many Trans /perf shops get 400. to install/setup and I completely forget what a R&P set goes for ..... I mean what 500 Most?

 

[willyslover]

is yours disc or drum model '01

 

[Snow man]

The problem with the Dana 80 is that there is carrier change when going from the 3 series ratio's to the 4 series. So you can either put 3. 73 in there which isnt worth the time/money for such a small change,or you have to swap the carrier too,so its going to be $$$$$$$$$$. I did this swap on a 3500,we are keeping the 4. 10's though we may reinstall them if we get a bigger trailer,the 3. 55's we put in are nice on highway,but towing isnt there strong point. Whathill,it would be cheaper in this case to lightly bomb your 01,this will likely eliminate your need for 4. 10 gears,and give you power to spare,you got a strong trans,just need a SBC clutch,EZ,and 275's and your set. You should be able to pick up a used EZ,and a set of injectors for under 650. Get a westach combo boost /EGT ,PF guage,and your set.

 

[whathill]

sorry for the slow come back, been out on the highway and away from the net. Boost, i didnt think there was any place higher than ca. dealer still says about $1500. as far as swaping, as soon as i close this reply i'm going to the classifieds thanks. willyslover, i have the disc model with the towing and camper pkgs. Snowman, your reply is interesting and informative. out here in ca my hands are tied as far as bombing, they check diesels out here like gas jobs! its saposed to get worse. your right the 3:54s are nice in states that have 75 mphs not that i run that pulling my wagon. maybe U S GEAR is the ansewer? speaking of clutch, you mentioned sbc clutch, i'm getting a shaking of sort when taking off, and almost feels like a drive line out of balance or holding rpms at 1400 you get the same thing. dealer says possibly the trans but can't confirm till they pull it! gentlemen, i don't have time to do things myself cause were always on the go, self employed. so being that, i'm at the mercy of dealers. i just call them up ahead of time tell them my problem and make the appiontment. it's pretty quick!anyway guys, i just wish dodge would of made a real full size crew, than i'd have, big hourse, higher gvw, and nice comfy cab! i'd better qiut dreaming. thanks again gentlemen

 

[Snow man]

You should be able to pass emission testing with 275's. Pull the ez off before you test,all of 2 minutes time. Also you can put the jumper on #1 or 2 on the ez,it will fuel later,so no smoke. You shouldnt have any smoking issues with 275's and an ez. For 1500,id ask if that includes a carrier too,they told us the same thing until it was apart on the bench,then the price went to 2300 real quick. Unless shops do these swaps often,they may not be looking into exactly what is needed to finish the job. You shudder sounds like a bad carrier bearing,if you have a 2 piece driveshaft.

 

[whathill]

SnowMan,



EZ and 275's??? Ive always had stock motors, they have always seemed to be sufficient. Help me with my ignorance. What issue of TDR do I need to read about this. What about warranty? Currently have 40K miles on truck. You mentioned carrier bearing. Thats what I thought it felt like. I will investigate further. Hope you are right. Cheaper than clutch or trans. What about this clutch you are mentioning? Everyone says trans and clutch are weak link on high output 6 speeds.



Thanks for a quick response after a very slow reply.

 

[Snow man]

If stock is sufficient,why swap differentials?Just run it the way it is. The 275Rv injectors are stock Cummins parts,just not the ones that come in our engines,as for warranty-well you know how that it,its up to that particualr dealer,and if the failure is related to the aftermarket part. My buddies HO clutch started slipping 1 week after we put the EZ in,at only 7K miles. So id say the clutch is weak,as for the trans,IMO its far from weak.

 

[whathill]

SnowMan



Stock is sufficient but we are grossing about 20k and on some hills in town starting in first is a must with the 354's. We will be getting heavier trailer and don't think the clutch could handle that gear ratio for very long. The differential swap was for the near future, not for what we are doing now. Thanks for the info. We are getting ready to leave town for a few days with our business. We'll talk later.