I have a 1997 12 valve with a auto trans, and the axles are dana60 up front and a 70 in rear, well i picked up a parts truck a 1995 dodge v10 with a 60 up front and a 80 in rear, only 50,000 miles on whole truck. with a blown engine, but my question is that i wasnted to swap the low milege axle into the cummins and becaue of the rear 80. but the cummins is a auto and the v10 is a 5speed, so the axle gears in the auto are 4.10 and the 5speed has 3.53 or somthing close to that. how bad will it affect the cummins with the higher gea ratio? Sorry if im hard to understand, Thanks , Kodi

 

You should go to the user control pannel and fill in the info for your truck , to much missing to answer .
If your talking about swaping just the rear then , is it a 2+4 , no problum , but if its a 4+4 then the ft. & r. need to be the same gears .
The 3:55 would give you better mpg's and less gear advantage but with the Cummins you can mod it to get more power , so the 4:10 would be realy heavy loads in the mountains .

 

Are you sure of which gears each truck has? just because it is auto or 5 speed does not denote the axle gearing.

check for a tag under the hood near where the latch bolts on , or ontop of the diff for the gear ratio.

swapping from 4.10 to 3.55 gears will get you more speed for each gear in the transmission, and a higher overall speed (if so desired). The 3.5's will get you more fuel milage , but will hurt your towing abilities if you tow HEAVY in the hills. My 95 and my fathers 97 both have 3.55 gears in them.

 

Shouldn't hurt the power of the cummins very much at all, unless you are towing real heavy. The 3.55 gear ratio will help your mileage, and keep the rpms down a little while at interstate speeds. More or less exactly what everyone else has said.

 

another way to check your gears is jack your truck up and put it in neutral, turn the driveshaft and count how many times it turns for one tire revolution. if it turns 3 1/2 times, you got 3.55s, and 4.1 times for 4.10s. I didn't really notice a difference going from 3.55s to 4.10s with the big tires on. it might be more noticeable with stockers though.

 

My cummins truck is a 4x4 with 4.10 gears. and the axles i want to put in are 4.10's . I read them off the tags on the axle housing, just wondering how much loss i will have going from 4.10's to 3.55's

 

this is a legit excuse to put bigger tires, with the rite size upgrade you wont notice any difference at all

 

Id have to put smaller tires to make up for the higher gears, you are thinking 180* in the oposite direction. Kodi

 

NORKAL you have confused me now, In the first post the cummins is equipped with 4.10's and youre wanting to put 3.55's in it.

Later on you say the cummins truck is 3.55's and you want to put 4.10's in it.

 

im with Kemble.....you got us all confused. how about you fill out your sig so we know which set of axles is under which truck this would be a big help

 

The sig is fixed

 

I'm still confused.... So They truck you have now has 4:10's???

and the truck you are parting out has 3:55's??

If this is the case I'd say go for it..... I love my 3:55 and would buy another like that. I have never OWNDED a CTD with 4:10 but have owned some big block gassers with 4:10 and hated it..... Always wished I had a higher axle ratio....

4:10 can be good if you are towing a big load with not enough power, the torque of the Cummins is perfect for 3:55 even when towing in my oppinion.

 

I would swap 3.55's into the cummins truck. There will still be ample power to tow, and you should see a gain in fuel mileage (which is good at todays prices) .

One thing I thought of this morning though that you might want to consider. Does the stock rearend in the cummins truck have a limited slip? Does the 3.55 rearend have limited slip? Keep us posted.

Brian

 

Ok , so it wont be gutless or anything if i swap then, cool, that was what i wanted to hear. one more thing, the 97 has a abs sensor on top of the rear axle housing, the 95 does not have this option, what will happen when i swap it in and dont hook that sensor up?. oh yah both are limited slip.