1500hd/2500hd Rear End Swap

stonedigity · December 10, 2010

I've got an '05 1500HD (w/ 3:73's) that I use for occasional weekend towing (6-7k# travel trailer) and primarily daily driver duties. I recently put new 285/75-16 tires on, and it has become a bit 'doggy' for both regular driving and towing. I'd like to swap in a set of 4:10 gears to bring things back to relatively stock. Question is whether or not a 2500HD rear-end can be swapped in rather than doing the gear swap on my current axle. Is this a straight swap? The local driveline shop wants just north of $1000 for the gear swap alone. 2500HD rearends are plentiful in the area and may be a bit cheaper to do (iff possible) all while getting the stronger full-floating design.

Any guidance here would be appreciated.

8.1HD/ALLISON · December 11, 2010

Should bolt right up to the springs. Not sure about the driveshaft and yoke though. Hopefully someone else can chime in.

builderpaul · December 11, 2010

I've got an '05 1500HD (w/ 3:73's) that I use for occasional weekend towing (6-7k# travel trailer) and primarily daily driver duties. I recently put new 285/75-16 tires on, and it has become a bit 'doggy' for both regular driving and towing. I'd like to swap in a set of 4:10 gears to bring things back to relatively stock. Question is whether or not a 2500HD rear-end can be swapped in rather than doing the gear swap on my current axle. Is this a straight swap? The local driveline shop wants just north of $1000 for the gear swap alone. 2500HD rearends are plentiful in the area and may be a bit cheaper to do (iff possible) all while getting the stronger full-floating design.

Any guidance here would be appreciated.

I know the 2500HD rear end is totally different from the 2000/1500HD rear end. The 2500HD is a full float design and the 1500HD is a semi float. I think the 2500hd is 10.5" and the 1500 is 9.5". I think is is a bit wider.

If 4x4 you will need to change the front gears also.

IMHO you will notice little with such a small ratio change.

You will need to get your computer reset for the different gear size.

A "tune" will do more for you than the gear change and be cheaper and for the new tire size and gear change.

marine_devildog801 · December 11, 2010

+1 on the tune. I put larger tires on, got a tune, and felt better power than before the large tires. AND it is cheaper. There is plenty of information on here to search through.

8.1HD/ALLISON · December 11, 2010

I've got an '05 1500HD (w/ 3:73's) that I use for occasional weekend towing (6-7k# travel trailer) and primarily daily driver duties. I recently put new 285/75-16 tires on, and it has become a bit 'doggy' for both regular driving and towing. I'd like to swap in a set of 4:10 gears to bring things back to relatively stock. Question is whether or not a 2500HD rear-end can be swapped in rather than doing the gear swap on my current axle. Is this a straight swap? The local driveline shop wants just north of $1000 for the gear swap alone. 2500HD rearends are plentiful in the area and may be a bit cheaper to do (iff possible) all while getting the stronger full-floating design.

Any guidance here would be appreciated.

I know the 2500HD rear end is totally different from the 2000/1500HD rear end. The 2500HD is a full float design and the 1500HD is a semi float. I think the 2500hd is 10.5" and the 1500 is 9.5". I think is is a bit wider.

If 4x4 you will need to change the front gears also.

IMHO you will notice little with such a small ratio change.

You will need to get your computer reset for the different gear size.

A "tune" will do more for you than the gear change and be cheaper and for the new tire size and gear change.

All very true. Can also get 11.5 rear end in 2500's as well.

markw8 · December 11, 2010

I don't believe the full floater is any wider than the semi floater. They use the same wheels/same offset. Now, the diff in the 3500 duallies is wider by about 4". I don't think anyone has given a good answer to his question.

On tunes the power is usually higher up in rpm's. Not usually the best for towing.

Mark

stonedigity · December 12, 2010

I don't believe the full floater is any wider than the semi floater. They use the same wheels/same offset. Now, the diff in the 3500 duallies is wider by about 4". I don't think anyone has given a good answer to his question.

On tunes the power is usually higher up in rpm's. Not usually the best for towing.

Mark

I've got a Wait4Me tune, and you're right it definitely woke it up as well as corrected for the tire size/speedo issue. Mark here is correct. The tune's power is up in the higher RPM's and I wanted to get the low-end back and help get the trailer load moving easier. All the online gear calculators show the swap will bring the truck back to relatively stock ratios (at the original 245 tire size).

So nobody here has performed the swap? Guess I'll have to hit the boneyard and take the tape measure.

markw8 · December 12, 2010

I don't believe the full floater is any wider than the semi floater. They use the same wheels/same offset. Now, the diff in the 3500 duallies is wider by about 4". I don't think anyone has given a good answer to his question.

On tunes the power is usually higher up in rpm's. Not usually the best for towing.

Mark

I've got a Wait4Me tune, and you're right it definitely woke it up as well as corrected for the tire size/speedo issue. Mark here is correct. The tune's power is up in the higher RPM's and I wanted to get the low-end back and help get the trailer load moving easier. All the online gear calculators show the swap will bring the truck back to relatively stock ratios (at the original 245 tire size).

So nobody here has performed the swap? Guess I'll have to hit the boneyard and take the tape measure.

A good salvadge yard should maybe able to get the info from their interchange book. An expierenced truck tech at a dealer or good parts man also.

Mark

ken1mod · December 15, 2010

As long as the spring perchs are the same dimension, i do not believe you will have a problem. Any good driveline shop can put the right yoke on for you , not too expensive. I agree on the tunes but gears will make a noticeable difference. IMHO. Programming the computer for the new ratio is not a problem.

Ken

bigoilman · June 23, 2016

I realize this is a very old thread but I'm in a similar situation and wondered if the OP or anyone else had performed this swap. The stock rear in my truck is bent and needs to be replaced. I'd like to change gears and get a heavier duty axle at the same time. The truck has 3.73s and 35" tires. It's my daily driver and I pull an 8000# boat with it. It's a dog, to put it mildly.