Question for GM Techs on Chevy Tahoe

[18WCmerc]

Re: Question for GM Techs on Chevy Tahoe

WOW, a lot of back yard mechanics around here...

Its called friction modifier, roughtly 4-6oz with your specific pumpkin juice. do a few parking lot manuevers to mix.

A diff service is a great place to start, usually overdue anyhow, and towing too! 15k is a good place to start.

as for your transmission, it is not your torque converter. if your trans slips in both D and manually putting your trans into 1st (valve body fluid paths will differ) you may have clutch (cvi) variences that need to be addressed. most scan tools can disply your CVI's and you can see whats going on with the clutch packs.

90% of all transmission issues are due to low fluid levels or improper fluids.

ASE certified Master Technician- if you care

 

[18WCmerc]

Re: Question for GM Techs on Chevy Tahoe

in addition to other responses.

your ring/pinion is NOT worn, you would hear growls and howls on either drive or coast sides.

it is NOT your driveshaft ujoints, you would have noticable vibrations due to failed needle bearings and a audible click would be heard shifting from d to r.


i second whoever said drop the pan and do a service w/filter. this is a great place to start, your pan and magnet is a plate of evidenct to what is going on. small snapring peices, coffee ground looking stuff is from your torque converter, which isnt your problem) dont sweat a little metal shavings, more than a little make your magnet look like a metal dandylion.

 

[98Shabah]

Re: Question for GM Techs on Chevy Tahoe

This is exciting.

Actually, yes, you can have driveline slop in the ujoints with no noticeable vibration, you can also have a worn ring an pinion causing slop it the driveline and not hear the whine since it most likely has all terrain tires on it, which inherently make some noise. Although now I see that the OP checked the driveshaft and didn't get any ujoint slop.

We're all just giving him ideas of other things to check.

Level and correct fluid type are certainly important, but I've never heard that 90% of transmission issues are caused by low or incorrect fluid, but i have heard that 90% of all transmission failures are caused by heat.

I've rebuilt 3 automatic transmissions, a 2004r, a th350, and a th400. - "if you care"

 

[642mx]

Re: Question for GM Techs on Chevy Tahoe

WOW, a lot of back yard mechanics around here...

Its called friction modifier, roughtly 4-6oz with your specific pumpkin juice. do a few parking lot manuevers to mix.

A diff service is a great place to start, usually overdue anyhow, and towing too! 15k is a good place to start.

as for your transmission, it is not your torque converter. if your trans slips in both D and manually putting your trans into 1st (valve body fluid paths will differ) you may have clutch (cvi) variences that need to be addressed. most scan tools can disply your CVI's and you can see whats going on with the clutch packs.

90% of all transmission issues are due to low fluid levels or improper fluids.

ASE certified Master Technician- if you care

Careful before you start calling folks back yard mechanics.... some of us have a degree in automotive service technology, a stack of Ford certificates, ASE masters certification (easiest tests I've ever seen...lol, I even passed the M1 thru M3 tests) and years of experience.... IF YOU CARE!...lmao!!

I haven't drove the vehicle... but I'd bet a dollar to a donut that he's got a stator clutch problem. But like I said, I haven't drove the vehicle, but if I did, I would be able to diagnose it.

 

[18WCmerc]

Re: Question for GM Techs on Chevy Tahoe

i apologize for my input and showing my credability.

Hope some of this have helped the OP.

 

[Gary H NC]

Re: Question for GM Techs on Chevy Tahoe

Thanks for all of the info everyone.
The trans fluid and filter was changed about 30k miles ago.The fluid is full and pink...no burnt smell.No leaks at all on this truck.

Getting ready to go drive it now after the rear diff. service.

Strange thing is that i do not feel the chatter or slip feeling every time i take off from a stop.It comes and goes.

I will do a highway run to get everything up to temp and see if i can duplicate the problem.

Should i plan on draining the Valvoline gear lube and going to the Chevy dealer for gear lube?

 

[642mx]

Re: Question for GM Techs on Chevy Tahoe

Should i plan on draining the Valvoline gear lube and going to the Chevy dealer for gear lube?

The Valvoline fluid will be fine.

 

[jeeperman]

Re: Question for GM Techs on Chevy Tahoe

i apologize for my input and showing my credability.

Hope some of this have helped the OP.

Why is it you mention the friction modifier additive??

Surely you are not reccommending that the OP add it to his G80 diff.

 

[Gary H NC]

Re: Question for GM Techs on Chevy Tahoe

Ok,Just back from the test drive.Got it on the highway and ran 70 mph for about 20 miles then took all the back roads home.
I could not get it to chatter or slip one time.I tried stop and go about 50 times...
Shifts smooth,trans fluid still full and very clean.

So,I hope the rear diff fluid service did the trick...

On another note it did throw a check engine code a few weeks ago.
P-0440, I called the parts store and they said that was an emissions code.
I cleared it and it has not come back.
Truck just had a full tune up,Plugs,cap,wires,ect..Runs very smooth.

 

[18WCmerc]

Re: Question for GM Techs on Chevy Tahoe

your right, i had g86 on the mind.

 

[dolluper]

Re: Question for GM Techs on Chevy Tahoe

Hey Gary...me thinks you may have a 98 rearend that could be the reason they did put the additive in....check your tag....if it is they have smaller pinion bearings...gave Gm alot of problems...like losing the pre-load and failing bearing ..it will whine or whirl when it gets bad or pinion seal leaks ....hope your lucky and don't have one ...they were 10 bolt also

 

[Gary H NC]

Re: Question for GM Techs on Chevy Tahoe

Thanks dolluper...i will check into that.
So far no sound at all from it.

 

[68C15]

Re: Question for GM Techs on Chevy Tahoe

if what you're feeling is what I think you're feeling it sounds to me like the rear shaft slip yoke is doing the typical "stick-slip" in the back of transfer case. there is an updated nickel plated yoke to solve this. I get them from a local drive shaft shop for about $45