4l60E RPM Question

[Rock Surf]

I have the exact same truck, down to the 3.73 g/r. just bought it back in April.

RpMs are correct.

You need to pump out your old transmission fluid via the cooler return line. Remove the pan, replace the filter & seal and bolt the pan back on with a new gasket. You can buy a kit with everything required for under $20.

Now refill it with AC Delco Dexron6 synthetic @ the fill tube.

After you do that, flush the power steering system with a can of sea foam TransTune & a cheap quart of PS fluid. After you work that through the pump & cooler real well, drain& refill with a can of Lucas PS conditioner and quart of GM approved synthetic PS fluid. Pump must have fluid circulating at all times, never allow it to run dry

This only puts you about 20% of the maintenance checklist but these 2 are the doozies. Gotta get new fluids & filters in your setup @ this mileage. You will find an external fuel filter on VIN-z flex engines that creates a resistance from contaminants which burns up the fuel pump. You want the NAPA Gold replacement. Replace spark plugs & wires. Flush the coolant and examine the clutch fan for proper operation.

I would bet that both of the differentials are operating in black goop (75/90 syn in the rear, 80wt convent in front) & replace the TC fluid with the blue AutoTrak2. Look over the tailshaft housing of TC for pinhole leaks caused by the pump-rub syndrome. You have to pop the diff cover on back axle to drain, NAPA sells the primo blue FelPro gasket to reseal it.

I went with the AC Delco 5w30 dexos (6qts) & Delco filter in the motor. Don't forget the $1 PCV valve and inspect the brakes, steering linkage.

Document all of the work In owners manual & pack all of the receipts in there.

Good info. The truck does have 225k, but I bought it from the original owner and it came with a folder with about 20k in receipts. The trans was replaced with a remanufactured one about 1.5 yrs ago. The guy was a realtor, so he took the truck into the shop for everything.

So far I've done oil and filter (Mobil 1 high mileage 5w-30w, AC Delco filter), Transfer case (AC Delco Autotrac II),Front Diff (75/90 Mobil 1 synthetic). Next is rear diff. All fluids removed looked good. Trans fluid looks good and red.

Any reason to go 80wt conventional in the front diff?. All vids I saw and threads I read people used 75/90 synthetic in the front.

 

[Chubbs]

GM suggest using 80wt conv in the front diff because the vent valve & axle seals leak like a sieve. You will have to reg check the fluid level given what you filled it with. It's not a fail, everybody should keep tabs on their fill levels, you just have a good excuse to pull the fill plug once a month. I do that anyways, no easy chore to replace those outer bearings or rebuild the carrier.

Trans fluid should be replaced every couple years. Why do you think the original unit $hit the bed? the best thing that you can do is drain whatever is in there & refill it with Dex6 synthetic. It will guarantee that you have done your part to extend the life of that unit as Dex6 is far superior to any previous blends in every way. In addition, you don't ever want to wait for a fluid change at the point of degradation; the idea is to keep a fresh fill at all times.

i looked up the maintenance schedule via several different resources & each cited the 80w Dino on the front diff. I can prob even pull up a TSB for it. People don't know what the hell they are doing but it's not a big deal in this instance. Folks just find it easier to use the same chemical in both places instead of following the manufacturers recomm.