Advise on 2004 GMC Sierra purchase

[mleo40]

I purchased a 2004 GMC Sierra 4.8l 4wd automatic with 165k miles on it.

 

I am looking for advise on making sure I get the most out of it.

 

My plan now is:

 

Oil/filter change

 

K&N Air filter, + cabin air filter (if it has one)

 

Radiator flush, thermostat and lines changed -- there was reference to a wiki/how to on this site but I've yet to find it. Any links here would be helpful.

 

Rear diff fluid change

 

Transmission oil/filter change

 

Belt(s)

 

Fuel, oil and radiator caps -- I've heard bad things about air getting into the dex-cool so I thought I'd get new caps. Rockauto has them cheap enough.

 

Fuel filter -- probably unnecessary but again, rockauto has them for $2.

 

This is about everything I know how to do to a truck that I feel comfortable doing in my driveway.

 

Too much? Too little?

 

Any other areas I should look at as I take ownership of this?

 

Thanks

 

 

[8.1HD/ALLISON]

Looks good, but don't forget the front diff and transfer case.

[joshw1303]

Yup you are doing good, do all fluids, depending on where u live, do a rust spray protection ex. Krown.

[mleo40]

" front diff and transfer case. " ....this seemed a bit more difficult than the rear, or am I over analysing this? Any advise here would be welcome.

 

The seller/dealer did do a rubberizing undercoat already. I feel it was to hide some rust for the sale, but it should help slow it down at least.

 

Thanks for the feedback.

[Chris]

I purchased a 2004 GMC Sierra 4.8l 4wd automatic with 165k miles on it.

 

I am looking for advise on making sure I get the most out of it.

 

My plan now is:

 

Oil/filter change

 

K&N Air filter, + cabin air filter (if it has one)

 

Radiator flush, thermostat and lines changed -- there was reference to a wiki/how to on this site but I've yet to find it. Any links here would be helpful.

 

Rear diff fluid change

 

Transmission oil/filter change

 

Belt(s)

 

Fuel, oil and radiator caps -- I've heard bad things about air getting into the dex-cool so I thought I'd get new caps. Rockauto has them cheap enough.

 

Fuel filter -- probably unnecessary but again, rockauto has them for $2.

 

This is about everything I know how to do to a truck that I feel comfortable doing in my driveway.

 

Too much? Too little?

 

Any other areas I should look at as I take ownership of this?

 

Thanks

 

No cabin filter on an 04, If you have the extra money go with a Volant cold air kit with the Donaldson Powercore filter. I will never go back to an oiled filter

 

Fuel filter is in tank and part of the pump assembly.

 

Everything sounds good. More than I have actually serviced on mine, but I am only at 125K

[Bad Bowtie2]

With that many miles, might as well replace the power steering fluid, upper O2 sensors (AC Delco), have the front end alignment checked, flush out the old brake fluid- with new, replace the spark plugs (AC Delco), and do the 2 can Sea Foam brand fuel system treatment.

 

Enjoy your "new" dependable ride.

[mleo40]

for p/s and brakes: I assume I would just suck the fluid out from the top as best I could and refill?

 

Is there any bleeding needed of either system post suckage?

 

I'll add the sensors and plugs and google what the Sea Foam thingy is.

 

I am seeing left, right, upper and lower 02 sensors. Advise?

 

Also, any recommendation on the plugs? Iridium vs platinum or other?

[Chris]

Upper O2 is before the cats, so you will need left and right upper. Go Iridium plugs

[Daryl LBZ]

I would skip the K&N air filter, but that's just my opinion.

[mleo40]

i will most likely skip the trans since i am reading bad things about it now.

 

why would i even think about an engine change? something about this engine i should worry about?

[Chris]

I got rid of the 4.8. I wanted something with more power. It's a good engine. I changed mine earlier than planned because it didn't make sense to replace a head gasket then change engines 3 months later

[mleo40]

My other car is a Fiat 500 (which I love), so a 4.8l v8 will be power enough for me.

[govener71]

Differential and Transfer Case are very easy.

[govener71]

" front diff and transfer case. " ....this seemed a bit more difficult than the rear, or am I over analysing this? Any advise here would be welcome.

 

The seller/dealer did do a rubberizing undercoat already. I feel it was to hide some rust for the sale, but it should help slow it down at least.

 

Thanks for the feedback.

 

To do the front differentials and transfer case are very easy. Dont let it scare you.

For the front differential:

Jack up and support driver side. (Just high enough to take the tire off.)

Remove skid plate. (If you dont want to you dont have to it will just keep oil off it.

Remove fill cap and drain cap. (They look pretty much right at you when the wheel is off.)

Put the plug in.

Fill to spec, 2qts ish I think. (You are going to want a 12-16" length of hose to go over the bottle neck to fill the diff.)

(Keep it a 1/2 from the fill hole. Close it up and your good to go.

Transfer Case:

Crawl under the truck and drain the fluid. (Plug is on lower right I think and fill is on upper left.)

If you have push button 4x4 you will need to go the dealer and get Autotrek II fluid.

You can use the same hose from above or you dont have to, to fill it up.

Tighten the fill cap and your good to go.

You can easily do these your self. Your front diff you can do without taking the tire off its just a little more difficult. But would deffinitly take off the skid plate your you will have oil dropping every where.

[ohenryx]

I used to participate in Cadillac forums, and there was an old timer there who liked to say, "Flushing is for toilets!" I tend to agree with that statement (being an old timer myself). Forget about flushing the transmission, but DO service the transmission. Just drop the transmission pan, clean it out, replace the filter, put it back together and refill with fresh Dexron VI fluid.

 

If your truck is not overheating, I would not flush the radiator either. Just drain it and refill with a 50/50 mix of DexCool. In the old days, I would flush a radiator when there were problems, but not today, new radiators are relatively inexpensive, so why bother?