Made the switch to Mobil 1

Adair,

Change oil + filter @ 1,000 miles, then switch to 3-4k intervals immediately afterwards. No need for another 1-2k change.

Doc

thanks for the question and the answer, i was wondering the same thing. as i too, am thinking of changing over to moble 1 i have a 2000 z71 w/5.3 also. thanks again. this group is so great, i have learned alot from it.

Thanks Doc, any idea on the synethic in the diffs. from the factory?

Adair

I don't know about your diff's, call the dealer and ask if you want to know for sure. As for the oil/filter, go with what Doc said and do both at 1000 miles. While the filter takes out the big chunks, you will be surprised how black the oil will be after only 1000 miles. As for change intervals, I usually do my truck (Mobil 1) between 4000 and 4500 miles. Most of my miles are in town/metro driving, so not the best conditions. My previous work vehicle(s) I would drive 45-60K each year, 90% of which was over the road driving, and I would then comfortably switch oil/filter at 5500 miles (roughly once a month, 10 or so times a year) and never had any problems, and the oil was coming out very nice even at those intervals. Driving habits and conditions do impact your intervals. We had a truck at the camp I used to run that got it's oil changed roughly every 1000 miles, as those were about the roughest miles a vehicle could endure.

Big Chris

Not a clue bud, although this is the first I've heard of GM using synthetics in differentials. It won't affect your switching over to Mobil 1 either way.

Doc

right, just was curious, I was kinda thinking the guy at the parts store didn't really know what he was talking about.. anyway, like I said either way, I'm going to use synthetic..

Adair

Thanks for the info guys.. Have learned alot here.

Have you thoroughly checked out the liability of Mobil 1 if you switch to this? You didn't say how many miles your rig has on it. I switched to Mobil

1, and two weeks later I had to rebuild my engine. Mobil 1? I don't know for sure, but I talked to my freind who just retired form the National Guard, [he was a jet engine mechanic if that says anything, he said, "I, personally would not have used syn oil], in this, [mine], truck were it mine. Also, the guy who rebuilt my engine said NO too. He wouldn't warrant it if I did. In fact he told me to never use 5w oil again. Not even in winter. And he said, "I don't care what dealers and manufacturers say." "No oil pressure," he said. Your oil pressure gauge don't mean shit. [and he went into details of why, but I forget]. For the record my truck is an '88. Unknown mileage, but the odo said 95 thousand when I made the switch to syn. The engine had been into before by someone, [as discovered when it went kaput], the crank had been ground .030 under. Anyway, after Mobile 1, and two weeks, [and before the rebuild], I lost my cam bearings, main bearings AND the lobes of the cam were as much as .060 undersize from wear. Not here to flame, just stating my experience.

Hatt

The damage was done pre=Mobil 1. I switched my truck 2 years ago, I think, at 90,000 or so, maybe higher. No complaints, nothing has failed, nothing burns, nothing drips. 5w-30 goes in, that's the weight listed on the oil cap...

parts

would

warrant

I'm glad you've had a good experience, and I believe you are probably right about damage pre Mobile 1. I did experience some leaking after Mobile

1, and I understood that I might, before I switched. I chose to make the switch, and can't blame anyone but myself at this point. However for me, the switch would not make sense then, does not make sense now, cause, as I said, my engine rebuild is not warranted if I use it.

It has been suggested that Mobile 1 accelerated pre Mobile 1 damage, [wear], in my engine. If thats true, I choose to look on the bright side, in that it forced me to get an engine rebuild sooner, rather than later. Perhaps if I'd used it immediately after buying the truck last Feb. I would not have had to spend

4 thousand in repairs to the outside of the engine that did nothing to fix the inside of that engine.

As regards 5w oil, well, my engine won't be warranted there either, if I use it.

For what is already commonly known about dealership practice, and manufacturing practice for that matter, I think many might be suspicious of why there is a recommendation to use 5w oil. I know why others "say" a person should,but it don't hold water with me. 5w oil "is" water, and 10w is pretty close too. In winter? Well, in winter, if below zero either use a heater on the engine, or keep it in the garage. Thats my solution.

Hatt

Can't keep it in the garage, can't run a heater. Would be dragging an extension cord the length of our 60 foot driveway to plug the truck in. As I said, no problems with what I've been using, so I'll just stick with it. I'd certainly use what my engine guy told me to use if he told me he'd void the warranty if I used anything else, but I'm not sure why he's not liking Mobil 1. This link may have been posted in this group, may have been another group, but I'll link it again.

said.

details

thousand

lobes

probably

damage,

Haven't seen the link yet. Is it safe to go there with Internet Explorer and active scripting and active X?

As pertains to oil in this case, he's an old timer, like me and my jet engine buddy. None of us believes in anything until its proven and proven again. And again.

Hatt

said.

details

thousand

lobes

probably

damage,

Very interesting. However, I stopped when they said they weren't willing to risk the engine to test.

Hatt

message

synthetic..

don't

Guard,

personally

someone,

nothing

either,

engine,

dragging

Thats fine cause they are both Mozilla compatible, anyway, my IE browser headers says so.

Hatt p.s. If you are talking about Netscape, I believe the most current version supports active X.

Mozilla is the base for Netscape, so it may support it.

"George" wrote

Good info, George. It's Thanksgiving weekend up here in Canada, so haven't been on the newsgroups as much. One small change to your info...you can have buttons on the dash, and still have t/case that uses ATF. What you are looking for is the "Auto4hi" button. That signifies a t/case that uses the clutch packs to engage the front driveshaft. Which needs autotrak.

Ian

Good info, as mine has the auto 4hi feature..

Adair