Driveline Screech ??? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

fatboy63k10 · 09-28-2003, 11:53 PM

63 Chev k10 454,400Turbo,12-bolt 3.73 posi

I am in the "sorting out" stage of a 2 year project. On my first trips around the block, I have 2 driveline noises.
1. a "screech" that takes place under acceleration and at times when I start it up cold and in park. (but will go away when I "goose it" in park, but comes back as soon as I drive up a grade or accelerate hard.)
2. a "whine" that takes place under load whether it be acceleration or deceleration and is constant almost from start to stop. (but will stop when I let off the accelerator and put in neutral)

I have personally rebuilt the rear, and double checked the gear pattern, it is right on.
This week I rebuilt the transfer case with all new bearings, bushings and have correct tolerances and end play.
I pulled the trans today, the flexplate has no cracks, my drain pan has clean fluid, and so far have disassembled the front pump and forward clutch assy and everything is sanitary/new.
The driveshafts have new u-joints and have been balanced.

Could I have a bad rear main/thrust bearing? I checked end play with an indicator and the crank moves back and forth about .010.
Could the torque convertor be bad?
Any ideas?

I am about ready to start a very large bonfire...

Scrub · 09-29-2003, 11:08 PM

Geez, That's a tough one.
I assume you replaced the carrier bearing in the driveshaft, If it even has one. (Hmm, Transfer case, probably one piece driveshaft)

The only other thing I can think of is somehow you are stuck in 4wd.

My ony suggestion is to jack up the rear wheels and have someone ride the brakes to try and duplicate the noise so you can figure out where it is comming from.

Good Luck

1969 GMC · 09-30-2003, 01:00 AM

this may sound dumb but how are the alt/accessry belts on the engine?

fatboy63k10 · 09-30-2003, 10:31 AM

Thanks for the suggestions. I thought it was the transfer case also but pulled it. Transfer case is good, shifts in and out like it should, gears are in good shape, just last week while apart replaced the front output shaft, constant mesh gear, idler shaft, bronze bearing on the rear output shaft and all bearings. Noise still existed. I think I can eliminate the t-case.

Not an accessory or belt noise, I've run it with out the belts.

Since the trans is out, I'm going to run the engine tonight to see if I can eliminate timing cover rub or rear main thrust bearing.

09-28-2003, 11:53 PM	#1
fatboy63k10 Registered User Join Date: Jul 2003 Posts: 33	Driveline Screech ??? 63 Chev k10 454,400Turbo,12-bolt 3.73 posi I am in the "sorting out" stage of a 2 year project. On my first trips around the block, I have 2 driveline noises. 1. a "screech" that takes place under acceleration and at times when I start it up cold and in park. (but will go away when I "goose it" in park, but comes back as soon as I drive up a grade or accelerate hard.) 2. a "whine" that takes place under load whether it be acceleration or deceleration and is constant almost from start to stop. (but will stop when I let off the accelerator and put in neutral) I have personally rebuilt the rear, and double checked the gear pattern, it is right on. This week I rebuilt the transfer case with all new bearings, bushings and have correct tolerances and end play. I pulled the trans today, the flexplate has no cracks, my drain pan has clean fluid, and so far have disassembled the front pump and forward clutch assy and everything is sanitary/new. The driveshafts have new u-joints and have been balanced. Could I have a bad rear main/thrust bearing? I checked end play with an indicator and the crank moves back and forth about .010. Could the torque convertor be bad? Any ideas? I am about ready to start a very large bonfire...

09-29-2003, 11:08 PM	#2
Scrub Collector of rusty Items Join Date: Dec 2001 Location: Sisters,Oregon USA Posts: 731	Geez, That's a tough one. I assume you replaced the carrier bearing in the driveshaft, If it even has one. (Hmm, Transfer case, probably one piece driveshaft) The only other thing I can think of is somehow you are stuck in 4wd. My ony suggestion is to jack up the rear wheels and have someone ride the brakes to try and duplicate the noise so you can figure out where it is comming from. Good Luck __________________ Scrub Sisters, Oregon - Home of the Sisters Rodeo. 70 GMC 1,000,000 + miles 72 K-20 project, 456 Dana60 front, Corp14 rear w/locker, 265R19.5 tires 20-ply. Warn 12k winches both ends, Cross-over steering with raised tie-rod, Powerbox steering, 4500 watt 120-AC power, Air, Hydraulic aux power, 4 inch lift, 5000 lb air-bags both ends.

09-30-2003, 01:00 AM	#3
1969 GMC Registered User Join Date: Feb 2003 Location: The Rubber City Posts: 5,498	this may sound dumb but how are the alt/accessry belts on the engine? __________________ 1969 GMC K2500 1996 Honda Accord 2007 Kawasaki KLR 650

09-30-2003, 10:31 AM	#4
fatboy63k10 Registered User Join Date: Jul 2003 Posts: 33	Thanks for the suggestions. I thought it was the transfer case also but pulled it. Transfer case is good, shifts in and out like it should, gears are in good shape, just last week while apart replaced the front output shaft, constant mesh gear, idler shaft, bronze bearing on the rear output shaft and all bearings. Noise still existed. I think I can eliminate the t-case. Not an accessory or belt noise, I've run it with out the belts. Since the trans is out, I'm going to run the engine tonight to see if I can eliminate timing cover rub or rear main thrust bearing.



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