I have a 2001 Sierra 1500 4x4, what years are compatable for the rear gears? What years are compatable for changing the whole rear diff? What years are compatable for my front diff actuator?

If you change out the rear gears, you must also change out the front gears also. A gear mismatch can cause serious drive train damage.

If this is the actuator your talking about Dorman 600101, then it fits a wide variety of platforms...

I hate that you can't really copy and paste from Rockauto.com

If you go to RockAuto Parts Catalog, you can lookup the part your looking for and click on the blue part number, it will cross-reference all the other platforms for you.

CADILLACESCALADE(1999 - 2009)CHEVROLETAVALANCHE(2007 - 2013)CHEVROLETAVALANCHE 1500(2002 - 2006)CHEVROLETAVALANCHE 2500(2002 - 2006)CHEVROLETC1500 SUBURBAN1996CHEVROLETC2500 SUBURBAN1996CHEVROLETCOLORADO(2004 - 2012)CHEVROLETK1500 PICKUP(1996 - 1999)CHEVROLETK1500 SUBURBAN(1996 - 1999)CHEVROLETK2500 PICKUP(1996 - 2000)CHEVROLETK2500 SUBURBAN(1996 - 1999)CHEVROLETK3500 PICKUP(1996 - 2000)CHEVROLETSILVERADO 1500(1999 - 2013)CHEVROLETSILVERADO 1500 CLASSIC2007CHEVROLETSILVERADO 2500(1999 - 2013)CHEVROLETSILVERADO 2500 CLASSIC2007CHEVROLETSILVERADO 3500(2001 - 2013)CHEVROLETSILVERADO 3500 CLASSIC2007CHEVROLETSUBURBAN 1500(1996 - 2013)CHEVROLETSUBURBAN 2500(2000 - 2013)CHEVROLETTAHOE(1996 - 2013)GMCC1500 SUBURBAN1996GMCC2500 SUBURBAN1996GMCCANYON(2004 - 2012)GMCK1500 PICKUP(1996 - 1999)GMCK1500 SUBURBAN(1996 - 1999)GMCK2500 PICKUP(1996 - 2000)GMCK2500 SUBURBAN(1996 - 1999)GMCK3500(1996 - 2000)GMCSIERRA(2011 - 2013)GMCSIERRA 1500(1999 - 2013)GMCSIERRA 1500 CLASSIC2007GMCSIERRA 2500(1999 - 2013)GMCSIERRA 2500 CLASSIC2007GMCSIERRA 3500(2001 - 2013)GMCSIERRA 3500 CLASSIC2007GMCSIERRA C32001GMCSIERRA DENALI2010GMCYUKON(1996 - 2013)GMCYUKON XL 1500(2001 - 2013)GMCYUKON XL 2500(2001 - 2013)ISUZUI-2802006ISUZUI-2902007ISUZUI-3502006ISUZUI-3702007

The rear gear set is a 8.6" ring and pinion that fit 99 and up on all 1500 applications. As far as swapping it any truck with leaf springs in that year range will swap because the SUV full size 1500 had coil springs. The front diff is a 9.25" reverse rotation gear set and that case was used from 2001-2010 except for the full time 4WD on the Denali and escalade.

Oh yeah the some of the 05-07 had drum rear brakes so make sure if you change the whole assembly make sure as Mike said it has the proper ratio and you get the correct brake package. Instead of reengineering the crappy park brake system they went back to drum brakes for some reason

the 4wd and 2wd are different widths, and they went to drum in 05 so 99 nbs to 04 4wd pickup
look at the tag in the glove box for the ratio RPO

GT4 -- AXLE REAR, 3.73 RATIO
GT5 -- AXLE REAR, 4.10 RATIO
GU4 -- AXLE REAR, 3.08 RATIO
GU5 -- AXLE REAR, 3.23 RATIO
GU6 -- AXLE REAR, 3.42 RATIO
G80 -- locker

all the disks did was double the cost of maintenance, they certainly didnt stop any better than the drum vehicles. and they arent even close to being as good as the ford or dodge truck brakes, one of the only things they get better but its been hat way so long its hard to understand why gm doesnt do something about it. and why they use a half dozen different setups in the same year too thats very aggravating, should just be one design thats good enough for the highest rated truck and it will be that much better for everything else

I wouldn't say double the cost my neighbors 01 K1500 has 211k on it and I just replaced the rear rotors on it due to the park brake went metal to metal. The park brake shoes were 60 bucks and the rotors were 40 a piece. I reused the factory pads because they still had 50-60%. If it weren't for the stupid park brake it would still be rolling on OE brake parts.

not the norm. my old man has a 04 1500 that i take care of, and i have had 2 03'* and a 06 for work trucks. all of them lasted about 50k before needing all the rotors and pads replaced. on the trucks with drums you only had to do the fronts every 50 and clean and adjust the rear. never had any gm rear disk last more than 50-60 on my wbodies either

@ Justin, must be the road salt back there or something. I worked at the dealer till 06 and I can only remember doing one brake job on a 2500 NBS because the guy had a fishing boat and he launched it in the bay all the time causing his rotors to rot and that took out the pads. The 88-99 body style on the other hand was a gold mine for selling brakes.

i dont think its that because it would effect all the brakes not just the rear. i think it has more to do with the bias, you can feel the rear kick in before the front every time you stop. the drums you dont feel so much