1990 c3500 steering gear box compatibility question

[7beast]

Hey fellas I have a 1990 c3500 and I'm going to have to replace the steering gear box in it pretty soon it is leaking bad.. Truck sat in the elements with no drivetrain and no front clip for years before I rescued it and now it's a running truck. My question is what years and what models will interchange with my steering box? Will a 96-98 or 99-2000 c3500 steering gear box work work with my 1990 c3500? I would think all 88-00 c3500 use the same one since being that it's a 1ton they all use the hydro-boost.. please if anyone has any input or answers feel free to chime in. Thanks in advance fellas..

 

[Erik the Awful]

My '89 C1500 and '88 C3500 both appear to have the same steering gearbox, but note that my C3500 has vacuum assist.

 

[someotherguy]

Look your truck up on Rockauto, pick a brand, click the part #. I believe you'll find the same part # fits all years of GMT400 C1500-2500-3500 / K1500-2500-3500, vacuum or hydroboost brakes, and even a few years of Dodge trucks.

Richard

 

[7beast]

Thanks fellas for the help suggestions! I tried one on from a 1998 c3500 dually and it fit right on.

 

[skylark]

When I looked it up the 7200# trucks used a different box than the 8600#+ trucks. I was slightly surprised that the 15k rated 3500hd uses the same box as the 8600#+ trucks.

 

[dfarr67]

When I looked it up the 7200# trucks used a different box than the 8600#+ trucks. I was slightly surprised that the 15k rated 3500hd uses the same box as the 8600#+ trucks.

I think it's piston bore diameter- the 2500 will fit the 1500, don't know about the rest.

 

[JDGMC]

When I looked it up the 7200# trucks used a different box than the 8600#+ trucks. I was slightly surprised that the 15k rated 3500hd uses the same box as the 8600#+ trucks.

The difference is indeed the rack piston size. In your case, it’s the larger piston (GVWR 8600 and up). You have a Saginaw 800 series steering gear. If your problem is just a leak, you could just purchase a seal kit and mark your preload adjustment nuts before disassembly (worm gear plug/retainer and pinion shaft nut) to keep the proper preload post-rebuild - that is if it was correct to begin with. Either way, check the gears and shafts for wear and always check your preload (gearbox empty with no fluid) before disassembling or installing a steering gear. A must post rebuild, remanufactured, and take-offs from a parts vehicle. Do flush the steering gear with the correct fluid. In your case DEXRON(R)-VI Automatic Transmission Fluid (ATF).