02 yukon denali howling/whining on acceleration.

[Kris Gray]

So I got myself a 2002 :gmc:Yukon Denali XL a while back and the transfer case was acting up.

The "dealer" changed it out for a used one and it took the problem away BUT...Gave me two more problems and now the "dealer" says theres nothing more he will/can do.

 

So after they replaced the transfer case it gained 2 problems..

#1.The truck will now roll while in park

#2.The truck will howl/while only during acceleration. Felt like it was slipping.

 

3 weeks ago the transfer case goes out while on steep grade.Full on perma-neutral!

 

I buy a rebuilt one from Transfer Case Express in oakland Ca.(Great customer service btw)

So I just installed it this sunday. Tested it out..all was GREAT! No problems like before!

 

Today I take the truck out and I go a little further from home and park at a store and I notice its rolling in park again.

A little while later on my way home I roll the windows down and hit the gas from the light and hear that same ol howl/whine!! This time its not as bad.

 

Im at a loss for words at this point...im not a well off guy..the $1000 for the transfer case killed me. So at this point im just looking for some help on the situation.

 

 

[arcasey]

The truck rolling in park shouldn't have anything to do with the transfer case. The parking pawl should be on the output end of the transmission. That truck has a 4L60E tranny, correct?

 

The howl/whining could be a number of things. First thing I would check is fluid level in both tranny and t-case. It could also be caused by a failing transmission pump. Could also be a torque converter going bad. Bad U-joints can also make a whining/churping noise. Can you give a little more information about where the whine appears to be coming from?

[number9l]

Whine could also be gear noise - from the rear axle. Maybe OP just didn't notice it before?

 

My guess would be though, that it's something related to trans/tcase issue.

 

How many miles on the truck OP? You maybe looking at a tranny replacement soon?

 

BTW - a cooperating GM Dealer Service Dept (or someone with access to) can run your VIN and give you the Service History. Likely it will only show time during warranty coverage, but you can get a picture of what issues this truck may have been born with. Actually, should have done prior to buying.

 

I had one ran on a MINT, CHERRY, beautiful Tahoe we were ready to drop the cash on a few years back and Service History showed it was plagued with tranny issued from Day1. Owner had brought it back to dealer almost every 3 weeks up until 36,000 miles when she traded it. That was a close one for me.

 

...

[Kris Gray]

180k on the truck

 

Just checked the fluid on the tranny and its in the crosshatching

and the tcase is good cause i just filled it with about 2-1/4qts after installing it.

 

The whining is for sure part of a slipping problem that got really bad near the end of the tcase's life

and when I replaced it the slipping and noise was gone.

 

and it came back after a day.

 

The sound is for sure coming from the front end of the truck.

 

and just to be more detailed about the sound...it only happens when im taking off....right now its not bad just a second or 2 and not loud but before I changed the tcase it could make the noise all the way through an intersection and it was loud.One day it was making that noise goin up a hill and it just gave out like i was in neutral.

 

I hope I answered all the questions.

[Chris]

180k on the truck

 

Just checked the fluid on the tranny and its in the crosshatching

and the tcase is good cause i just filled it with about 2-1/4qts after installing it.

 

The whining is for sure part of a slipping problem that got really bad near the end of the tcase's life

and when I replaced it the slipping and noise was gone.

 

and it came back after a day.

 

The sound is for sure coming from the front end of the truck.

 

and just to be more detailed about the sound...it only happens when im taking off....right now its not bad just a second or 2 and not loud but before I changed the tcase it could make the noise all the way through an intersection and it was loud.One day it was making that noise goin up a hill and it just gave out like i was in neutral.

 

I hope I answered all the questions.

With the mileage, fluid can be full and you lose the tranny. Happened to me about a month ago. Driving north on hwy 99 at 70, lost 4th, get off at downtown, lose 1st, get past downtown and no 2nd and the converter has shrapnel in it.

[arcasey]

With what your describing I think your issue is transmission related. I have also had a transmission act up on me before as well and the symptoms would come and go. Typically when they start acting up, it's not long before they go out completely. I don't know of very many 4L60's that lasted much longer than 200k and most of them that come into the local tranny shop have less than 125k on them (was told this by a friend who works on all the 4L60's that come through that particular shop).

 

Gear noise from a differential is always a possibility. Driveline noises can be hard to diagnose because the sounds can transmit down the driveline and make you think something else is the issue when it really isn't. Do you notice any engine speed surge when the noise/slipping is occurring?

[Kris Gray]

Right now I cant really notice a surge in rpm but before the last transfer case broke it would slip bad and the rpms go way up until it caught up.