POS Chevy truck problems again

[Tony]

On the road all day today I started hearing a hum in the transmission or transfer case like the truck was locked into 4x4 and running at freeway speed. I stopped and checked the fluid level in the tranny and it was fine and didnt smell burnt. On down the road a metal on metal noise started developing, sounds sort of like light metal rubbing on the driveshaft. I stop again and crawl around all over under the truck and find nothing. Back on the road about 50mi. down the road there was a huge poping/grinding for a few secconds similar to the sound of a drywall screwgun clutch but WAY louder. Pulled over looked all around and found nothing. Started back down the road with the metal on metal noise, 50 or so miles down the road POP CRUNCH GRIND. About every 50 miles or so Im getting the same poping grinding and it goes away after a minute. I tried 1st, 2nd,3rd,Drive, and neutral. 2 and 4x4 and the same metal on metal sound is still there.

Seems like a trans, or transfer case problem. Aside from the god awefull sounds its making the truck is driving just fine. Truck is an 03HD

Ideas?

[sledge]

Parking brake shoes.

Just a random brainfart guess.

Did the sound change with engine RPM or speed?

[Tony]

Yeah, it gets louder at speed. My first thought was brakes but the high pitched pop and grinding every so often sounds/feels like its comming from right above the tranny area. If its a tranny or transfer case after the amout of nasty noises I heard today I cant belive theres not an exploded pile of parts and oil on the turnpike, but yet the truck drives just fine and theres no problem to be seen under the truck and the tranny oil level and temp are just fine.

There is some slight jolting to the truck when slowing to a stop at the 5mph and less mark...could be brakes...

[Buoy]

You two have had the worst vaca!
Sorry to hear it.
I hope the truck gets well soon.

[Tinkerer]

U joints???

[phragle]

Do you have a rubber carrier bearing supported split driveshaft?? any vibration with it???

[BUIZILLA]

transfer case oil level?

[Knot 4 Me]

Carrier bearing in front diff? Pull the drain plug and see what you got for metal on the magnet. The pump in the transfer case is notorious for wearing a small pinhole in the case allowing the ATF to leak out. Check for that as well.

[searaycer]

any grease coming out of the cv boots up front? My 95 3/4 ton I bought new, spit them all the time...my 03 Silverado SS has never given me one iota of trouble.

[mrv8outboard]

This happens on newer ones as well. Check out the PDF.

[Chris]

Had something very similar happen on one of mine a few years back. A snap ring in the transfer case popped off the shaft allowing the low range to try and engage while high range was in synch. Big noise.

I've heard it continues to be an issue with that case.

[tommymonza]

A Planetary bearing has failed. Had the same thing going on with my 98 Chevy van.I changed the ujoints and pulled the rearend cover and checked the bearings and wheel bearings trying to locate my metal on metal noise. it sounded like a branch was caught on the driveshaft. A week later it it died. I pulled the tranny pan and found little roller cage bearings. Changed the fluid and filter and drove it to my dads across town and paked it. It seemed fine when i drove it. but no bearing on the one planetery gear can;t be good.

[Tony]

I made it home, something under there is toally fuked though, I'm willing to bet it wont make it another ten miles. It seemed to run OK at freeway speed but with the rubbing noise, under ten mph stop and go and its crunch pop snap in and out of gear. It slipped out of gear a few times during a high speed coast. Last time I toasted a transmission out ot state it left me stranded for two weeks and I paid dearly for the half ass rebuild in the long run. No way in hell was I going through that again so I went with the Brooks mentality "run it until it sounds expensive"

[Buoy]

I made it home, something under there is toally fuked though, I'm willing to bet it wont make it another ten miles. It seemed to run OK at freeway speed but with the rubbing noise, under ten mph stop and go and its crunch pop snap in and out of gear. It slipped out of gear a few times during a high speed coast. Last time I toasted a transmission out ot state it left me stranded for two weeks and I paid dearly for the half ass rebuild in the long run. No way in hell was I going through that again so I went with the Brooks mentality "run it until it sounds expensive"

Glad you made it home bud.
Sucks that now you have to deal with this after a ****ty vacation.
Next year you and Donzi can come out here for Barrett-Jackson. You'll spend the same amount of money, but you'll have a car to take home with you.

[MikeyFIN]

any grease coming out of the cv boots up front? My 95 3/4 ton I bought new, spit them all the time...my 03 Silverado SS has never given me one iota of trouble.

That happens when they are overfilled at the Factory...
On racecars we put a small pipe on the axle side under the clamp so the excess air and grease comes out.

[MikeyFIN]

Do you have a rubber carrier bearing supported split driveshaft?? any vibration with it???

Hey, it´s a Chevy Truck...engineered by bean-counters.... no they have been unchanged more or less the last 40+ yrs.

As for Chris and Tommymonza thanks for the reminders of the "great" TH 700/4L60E and NP 241 transfer case...

[insanity]

Carrier bearing in front diff? Pull the drain plug and see what you got for metal on the magnet. The pump in the transfer case is notorious for wearing a small pinhole in the case allowing the ATF to leak out. Check for that as well.

From what I had read I thought this only effected the Duramax/Allison combination? The Dmax's had a different transfer case than the gasser and was notorious for the pump rub, I didn't think it effected the gassers?

[Knot 4 Me]

From what I had read I thought this only effected the Duramax/Allison combination? The Dmax's had a different transfer case than the gasser and was notorious for the pump rub, I didn't think it effected the gassers?

I might be mistaken but I thought it was any full-size GM 4WD.

[insanity]

I might be mistaken but I thought it was any full-size GM 4WD.

I think you are right, I did a little more searching and that is what it is looking like. I may have had the diesel thing in my head from when I was researching a couple years ago for a new truck. Shiet, I thought I escaped it with the gasser...

[tommymonza]

This is where i am going to get my new tranny from.http://www.4l60-e.com/

I had AAmco rebuild a 700r for me years ago. Thank god i bought the warranty because it failed 7 times after the 1st rebuild. Everytime they tried to snake out of the warranty. Last time it blew i was just leaving the Outerbanks of N.C.I had to have it towed a 100 miles from there up to Norfolk to the Aamco dealer there.Spent 2 weeks waiting on it. Someone broke into it and stole all the stereo crap but they did not see the 10,000 dollar Yamaha outboard under alll my stuff in the back.

That tranny made it to my dooorstep a thousand miles away and blew again. I had Aamco put another one in and sold yhe van.Nothing scares me like tranny problems. They are one of those things you can.t hear coming until it happens.

Glad you made it back home .