Rearend Swap Need Help?

[MrYin334]

i own a 06 gmc sierra crew cab stock 3.23 pos rearend. i want to do a rearend swap to 3.73. is it easy as just swapping the rearend or is there more to it?

[gmtech4]

get the BCM reprogrammed after,your speedo will be out

 

why are you doing it?

[MrYin334]

get the BCM reprogrammed after,your speedo will be out

 

why are you doing it?

 

 

more low end torque for towing. can the bcm be reprogrammed at the dealer?

[MrYin334]

how hard is it to change the gears than swapping the whole rear end?

[gmtech4]

it that gear ratio is offered in tis(and I doubt it) then you'll be fine,what i mean by doubt it is the programing uses drop down items and I have programmed many veh's and come to think of it ,you may be screwed

 

other chime in plse if I am wrong.

 

a dealer can change your ring and pinion easily at a cost approaching stupid for parts and labour,

 

but think it thru and research hard outside of this forum

[Nytemare]

Yup its just as easy as unbolting one lowering it down and jacking up another one, and bolting it back in. Like Rob said though...you need to tell the ECM what gears you now have or your speedo will be out to lunch.

 

Do not reuse the U-bolts...it may be fine, but why take chances.

 

You cannot do this if you have a 4X4/AWD as the front diff needs to have the same gears as the rear...so you'd need to swap both.

 

If your doing it for towing, I would jump up to the 9.5" 14 bolt rear out of an SS silverado...GT4 RPO is for 3.73 gears and AXN is the RPO for this "hybrid 14 bolt" rear. It has the 1500's 6-lug wheel pattern but is way stronger. They go for about the same price as a 10-bolt and will hold up to much more abuse.

[MrYin334]

it that gear ratio is offered in tis(and I doubt it) then you'll be fine,what i mean by doubt it is the programing uses drop down items and I have programmed many veh's and come to think of it ,you may be screwed

 

other chime in plse if I am wrong.

 

a dealer can change your ring and pinion easily at a cost approaching stupid for parts and labour,

 

but think it thru and research hard outside of this forum

 

 

even if gm offered a 3.73 rear end in the sierra for that year its still not likely this could be an easy swap and program?

[Nytemare]

it that gear ratio is offered in tis(and I doubt it) then you'll be fine,what i mean by doubt it is the programing uses drop down items and I have programmed many veh's and come to think of it ,you may be screwed

 

other chime in plse if I am wrong.

 

a dealer can change your ring and pinion easily at a cost approaching stupid for parts and labour,

 

but think it thru and research hard outside of this forum

 

 

even if gm offered a 3.73 rear end in the sierra for that year its still not likely this could be an easy swap and program?

 

Swap is super easy....hell I swapped jeep front coils in a suzuki rearend last weekend....took about 3 hrs....and there were a few stubborn bolts too.

Programming, should be simple to get done...some dealerships dont want to do it...but theres always the route of getting a superchips programmer for changing tire size and gear ratios...they run about 200 bucks....or get an ECM tune from one of our fine sponsors like Blackbear or Wheatley, and have them tune it for the proper gear ratio....and get you a little more power and fuel economy too.

[asilverblazer]

it that gear ratio is offered in tis(and I doubt it) then you'll be fine,what i mean by doubt it is the programing uses drop down items and I have programmed many veh's and come to think of it ,you may be screwed

 

other chime in plse if I am wrong.

 

a dealer can change your ring and pinion easily at a cost approaching stupid for parts and labour,

 

but think it thru and research hard outside of this forum

 

 

even if gm offered a 3.73 rear end in the sierra for that year its still not likely this could be an easy swap and program?

 

Yes, they offered it, and yes it's that easy.