4.10 Dmax?

[whitesnake01]

After I switched to 285s, I've been thinking of changing the gear ratio on my 2005 2500HD with a DMAX from 3.73 to 4.10. Just called the dealer. He tells me that 4.10 uses a completely different rear end. Is that so?

 

Thanks,

[dewfpo]

After I switched to 285s, I've been thinking of changing the gear ratio on my 2005 2500HD with a DMAX from 3.73 to 4.10. Just called the dealer. He tells me that 4.10 uses a completely different rear end. Is that so?

 

Thanks,

 

I'm not an expert on this but from what I've seen and read I don't believe that to be true at all. I have the 4.10's on my 05, 8.1L and from the outside at least, the 3.73 and the 4.10 look identical in size and shape.

 

DEWFPO

[2000DV4.8]

Sounds like BS to me... I always thought a 14bolt FF was a 14 bolt FF. I could be wrong though.

[98silvz71]

Sounds like BS to me... I always thought a 14bolt FF was a 14 bolt FF. I could be wrong though.

 

Maybe different clearances inside? Thats about all I can guess. I wouldn't worry about the 4.10s if I was you. I just put my 285s on my 04 Dmax and I don't feel that much difference.

[Q101ATFD]

After I switched to 285s, I've been thinking of changing the gear ratio on my 2005 2500HD with a DMAX from 3.73 to 4.10. Just called the dealer. He tells me that 4.10 uses a completely different rear end. Is that so?

 

Thanks,

 

 

People swap out rear end gears all the time out there. I don't know much about specifics, but if you have the auto-locking diff, that may cause you some problems. But for a straight swap, you can replace a 3.73 with a 4.10 pretty easily.

 

What will cause you problems is if you put your old tires back on - or if you sell the truck to somebody who might put factory size tires back on it without telling them...

[Kodiak450]

I would go 265's max, that is all about the stock wheel is suppose to handle. Though I've seen 285's on a GMC 2500, I have a locking rear on my truck, and it wore down my BFG all terrain KO's in 14,687 miles. One tire actaully blew out on me, luckily I got pro rated and got a check in the mail for $250.00 for both tires. I was told since I am using 265's I should keep the pressure around 50 psi in front, and 45 in rear. But when I am towing , they recommended adding more air. The last set lasted exactly 1 year running them at 65 psi. I personally think it is the locking rear that wore them down that fast, not to mention all the towing going up and down the mountians to service my accounts weekly. I also alternated the tires twice a year, or every 3rd oil change.

[95Sierra2500]

As far as I know, the housings are the same. The only issue you might run into would be the spool, but even that might be about the same. It'll be costly, and remember that if you have a 4x4 you NEED to do the front diff. as well, or you're asking for trouble.

[merlin5577]

There are two different versions of the 14-bolt in your truck a 9 & 1/2 inch and a 10 & 1/2 inch. Regardless of which one you have it would just be a simple gear swap. Check out sites like summitracing.com or jegs.com for everything you will need.

[Q101ATFD]

There are two different versions of the 14-bolt in your truck a 9 & 1/2 inch and a 10 & 1/2 inch. Regardless of which one you have it would just be a simple gear swap. Check out sites like summitracing.com or jegs.com for everything you will need.

 

All of the D/A combinations use the 10.5" rear end...

[merlin5577]

Thanks for the info Q!

[svensk]

I always thought the final drive ratio with an allison couldn't be 4.10.

[98silvz71]

Well it can if you have the 8100 BB. But I think you are right about the Dmax/Ally Combo. I would think that the 4.10s would be pretty weak behind the Dmax. I have seen countless 4.10s snap behind a 383 Stroker with about 400 ft-lbs at the motor.

[BigJayDogg3]

I always thought the final drive ratio with an allison couldn't be 4.10.

 

It seems to me it wouldn't make sense from GM because you would be taking the D-max right out of its power band. Personally, I would say leave it alone.

[Q101ATFD]

I always thought the final drive ratio with an allison couldn't be 4.10.

 

It seems to me it wouldn't make sense from GM because you would be taking the D-max right out of its power band. Personally, I would say leave it alone.

 

 

I think he wants to do it to bring the Duramax back into it's powerband. 285's effectively turn the final drive into a 3.5:1 from 3.73 - compared to the factory 245's...

 

snake, I think you might actually be in alright shape if you put in the 4.10 rear end. I'll have to look for an old drivetrain spreadsheet I made that compares ratios.

[Ranger]

Little correction, Duramax and Big Blocks, Duallys use an 11.5" rear end, 6.0L HDs have a 10.5"...The 9.5" ones are for 2500LDs far as I know.

 

Diesels make all their power under 3,000 RPMs so there's no real point in regearing unless you're going monster tire size, all it's gonna do is wind the motor up a lot more and cause lower fuel mileage.