Fluid change recommendation

A question for the certified GM Service Tech's.

At what mileage should I consider changing the:

-- Power Steering fluid

-- Differential fluid

in my 4.3 liter Silverado. All highway miles, currently at 85000.

Is changing these fluids really neccesary?

If yes, what generic types of fluids can I use?

Thanks for the help on this.

First off, read the owners manual for the maintenance schedule for your vehicle.

Power Steering System
GM Hydraulic Power Steering Fluid (GM P/N 1052884 - 1 pint, 1050017 - 1 quart, or equivalent).



Front Axle
Axle Lubricant (GM P/N 1052271) or SAE 80W-90 GL-5 Gear Lubricant.

Rear Axle
Axle Lubricant (GM P/N 12378261) SAE 75W-90 Synthetic or equivalent meeting GM Specification 9986115.

There is no fluid change recommendations for the rear differential due to the fact that it has synthetic fluid.

Off the record, I would change it at 100k

Front Axle
Axle Lubricant (GM P/N 1052271) or SAE 80W-90 GL-5 Gear Lubricant.

Rear Axle
Axle Lubricant (GM P/N 12378261) SAE 75W-90 Synthetic or equivalent meeting GM Specification 9986115.



My GMC 4x4 Sierra has these owners manual recommendations at 50,000 miles/83,000 Kilometers.

I was wondering if I could substitute to 75W-90 Synthetic in front in place of 80-90 and use the same as back as we get temperatures to -40 here metric or imperial. The rear is limited slip so I am wondering if that would suggest a different front oil, preferably in a Synthetic ?

-40 is -40 and synthetics tend to retain fluidity.

Ken

My GMC 4x4 Sierra has these owners manual recommendations at 50,000 miles/83,000 Kilometers.

I was wondering if I could substitute to 75W-90 Synthetic in front in place of 80-90 and use the same as back as we get temperatures to -40 here metric or imperial. The rear is limited slip so I am wondering if that would suggest a different front oil, preferably in a Synthetic ?

-40 is -40 and synthetics tend to retain fluidity.

Ken

I have the 2000 4X4 and I use the recommended OEM fluids...do not think you are smarter than the spec. engineers..use the correct stated fluids...and replace at the recommended intervals at a minimum....I use the 30-40,ooomi interval on these items..


this posting is tooo old .....2003 ...........

I have the 2000 4X4 and I use the recommended OEM fluids...do not think you are smarter than the spec. engineers..use the correct stated fluids...and replace at the recommended intervals at a minimum....I use the 30-40,ooomi interval on these items..


this posting is tooo old .....2003 ...........

GM Service Manual Update bulletin #05-00-90-010 titled Revised Front Drive Axle Carrier Lubricant Information dated Dec 7, 2005 advises that some vehicles use a synthetic from the factory, but on those that don't have it from the factory, a synthetic 75W-90 axle lube meeting GM Spec 9986115 can be used. The GM part number is 12378261 or 89021667 fro US use, in Canada use 10953455 or 89021678. The bulletin applies to 1999-2005 Light Duty Trucks, 2003-2005 Hummer H2, 2005 Saab 9-7X. These vehicles have 4 wheel or all-wheel drive and seperate front drive axle carriers.