New to me Z71

[ECUpirate]

Hey all, I posted a while back about looking for a "new to me" truck here:

http://www.bobistheoilguy.com/forums/ubb...095#Post3118095

Well, after looking at countless Silverados and F-150s, I'm the proud new owner of an extended cab 2001 Silverado 1500 Z71 with the 5.3, 4L60-E trans and 3.73 gears. No rust, minimal dings and no apparent problems. It currently has 167k miles but it literally drives like new. After talking with the PO I knew the truck had a fresh fill of 10w-30 Valvoline conventional, Microguard oil filter and Lucas oil stabilizer added a week ago. I asked him why he added the Lucas and he told me he did it because he read it was good stuff on a GM truck forum. Naturally, as a BITOGer, I got it home and replaced the oil in favor of 5w-30 Maxlife and a P1 filter. I'm sure I'll be good on my oil and filter choice but I know NOTHING about the rest of the truck.

There is no history of maintenance and the PO (owner for the last 40k miles) stated he had no idea if the trans or motor had ever been rebuilt (this was factored into the price, and there is no evidence suggesting either). Obviously I want to swap the trans, xfer case, brake and diff fluid in order to get a starting point for maintenance.

I have a few questions:

1. The 4L60-E, assuming it has never been rebuilt, shifts fine. I'll use Dexron-VI, do a drain and fill, drive for a week, do a pan drop/filter change then do another drain and fill a week later. Thoughts?

2. Engine looks fine through the fill hole, no crud in the pan when the oil was changed, purrs like a kitten at idle and pulls nicely at higher RPM. No miss, no pinging, seems perfect. 5w-30 Maxlife a good choice?

3. Front and rear diff - Has the G80 Eaton locker in the rear, no clue about the front. I'm getting conflicting info and am completely lost here.

4. Transfer case - Autotrac. Do I really need the GM juice? Completely lost here, too.

5. Coolant - Dexcool or what?

 

[glock19]

Good buy!

I wouldn't sweat it too much. If the guy was reading forums he was probably maintaining the truck. Also, the 5.3 is a pretty solid motor.

 

[cchase]

1. Should be fine with Dex-VI.

2. Should be fine with whatever flavor you want.

3. Believe the manual will spec 75w90 for both front and rear.

4. I've never heard of an alternative to the Autotrac fluid. Don't use a Dex product in there.

5. I'd stick with Dexcool. These trucks did not have Dex issues like some of the older designs.

 

[hisilver]

As an owner of an 06 similar truck, the front diff prob specs 80w90, and its been said syn will make the front axle seals leak. My passenger side front axle seal leaked after using Mobil 1 75w90. I replaced the seal and now use conventional 80w90.
Probably not the oils fault. These seals are problematic, but decided to follow the manual recommendation.
Sounds like you know what's up otherwise...congrats on the new truck.

 

[jeepman3071]

Originally Posted By: glock19
Good buy!

I wouldn't sweat it too much. If the guy was reading forums he was probably maintaining the truck. Also, the 5.3 is a pretty solid motor.


+1 if he was on the forums, he was at least concerned about the condition of his truck and what was best for it, which is more than most people do.

I think your method of changing the transfluid is the best method. I did the same with the AW4 in my Jeep, and helped my friend do the 4L60E on his previous Silverado. Its a great way to change out most of the fluid without flushing the trans, which can be harmful in some cases.

I would stick with the recommended Autotrac fluid in the transfer case. You can't go wrong using the recommended stuff.

Those 5.3s are pretty reliable. They can develop lifter ticks when at higher mileage, but that all depends on maintenance. Keep the oil changed and it will outlast the body.