Gear change

[jwc9]

I have an 03 6spd with 4. 10 gears. I would like to change these to 3. 55. How or what do you use to correct the speedo?

 

[Matt400]

Recalibration is done in the ABS section of the computer. Once accessed you would subtract 104 RPM (revolutions per mile) from the RPM listed for your tire by the tire maker and plug that number in.

This would effectively "fool" the system that you have added a larger diameter tire when in reality you changed the gears.



I had to think about that for a sec. . and worked the numbers around so fine tuning the adjustment with a GPS and the scan tool connected would be the most accurate but the -104 RPM should get you close.

 

[klenger]

As far as I know, 3. 55 gears are not available for the AAM 3rd gen axles. There is rumor of 3. 42 gears becomming available, but as far as I know, no one has tried them yet.

 

[Mrudolph]

As far as I know, 3. 55 gears are not available for the AAM 3rd gen axles. There is rumor of 3. 42 gears becomming available, but as far as I know, no one has tried them yet.

I have pre-ordered them, and will install as soon as they come in.

 

[jwc9]

So is programming the computer something I would have to take it to a dealer to do or is there a program I can use a laptop with? Thanks

 

[Matt400]

I don't know about a laptop, any independent shop with updated software in their snap-on scanner can do it.

 

[DPKetchum]

Speed is read off the tone wheel on the differantial carrier. If I'm not mistaken no recalberation is needed with a gear change. Only gear other then 4. 10 is 3. 73. Been rumor of 3. 42 for the AAMS forever.

 

[jwc9]

Ok I give. What is a AAMM

 

[DPKetchum]

American Axel manufacturing. Its who makes the axels and gears that are used in 03 up Dodge diesels. No 3. 55 gear is offered by them or anybody for AAM axels. DANA was used 02 and below. 3. 55 gears where used in DANAS but Danas are not used in Dodge diesels anymore.

 

[DGoyer]

I made the change from 4. 10 to 3. 73 in feb. the spedo will not be effected
only if you go to a different tire. The guys at aam told me a 3. 42 will be here soon. I went to a set of 315 tires 1,900 rpm 71 mph 21mpg empty.


03 2wd lb

 

[Matt400]

Well dang. . I guess I was thinking the ring gear on a 3. 42 would travel slower than a 4. 10 but its only the the pinion speed that changes. My bad, scratch that gibberish calcs.

 

[jwc9]

Well that sounds good. No calibrating. Why did they not think of that before. Ok so when do they think the 342 will be out? Also are these axles like the ford 9 inch where you change out the entire gear set as one unit? If so it should be an easy swap. Thanks

 

[DGoyer]

No easy swap the pinion bearing has to be pressed off, my buddy teaches auto tech at a local col. He said to use the shims that came on the stock pinion.
Set up is not bad, since the adjusting on the ring depth is adjustable.

 

[jwc9]

Anyone have any good dealings with a vendor for a new set of gears?

 

[DGoyer]

yukon gears worked fine for me.

 

[TowPro]

yukon gears worked fine for me.

Did you get 3:42's for the Dodge from Yukon gears?

 

[steved]

3. 42 are out for the AAMs now... a vendor on another board is currently offering them and quoted me a price around $900 (front and rear).

The only "drawback" is they only cover the 9. 25 and 11. 50 (sorry 10. 50 owners) and the fact you need a ring gear spacer for the front 9. 25 gearset.

steved

 

[LesStallings]

jwc9, have you had a diesel very long?



When I got my first diesel I thought 3. 73's were too much. After a few years it seems that 4. 11 would be the ticket, especially if you ever go to a taller tire. If you put larger diameter tires on your truck, you will appreciate the higher numerically gears.

 

[jwc9]

Yes I have. 2 FORDS and this is my third dodge diesel. The fords had 4. 10 or4. 11 and both my other dodges had 3. 55 as I ordered those new. They pulled all I wanted and would get over 20 mpg. This truck seems like it revs to much at 70. I know the others were around 1800 where this one is around 2300 or more. also I would not put taller tires on this it already has 17inch on it. It is a two wheel drive. Thanks