Replaced rear main, 1999 Silverado shaking

jsthunter9093 · 04-06-2008, 01:20 AM

Greetings Members

I recently had my 1999 Silverado Rear crankshaft seal replaced from at
a local mechanic. Since i have picked it up i have noticed a severe shimmy or more like harmonic buzz that kicks in at about 40mph. Also, now i am getting a "Service" 4wd" in the message center. They claim there is no way
that repalcing the RMS could affect the balance of the running gear. I tend to agree. If i am not mistaken the flexplate is indexed to the crank, so no chance to mess that up....What happened to my nice truck? There is also a strange squeal now, in the left front hub area that is NOT affected by brake activity. Any help appreciated...

justin

Chevy_Finatic79 · 04-06-2008, 08:10 AM

My grandpa has a 99 sierrea with 60k that does the same thing the service 4x4 light has a mind of its own and the shimmy was a bad U-joint we still havent figured out where the squel is coming from cause it is very hard to isolate since it only makes noise while driving. It's not the brakes i know that much for sure. the noise seems to come from the transfer case or the tranny.

every time he took the truck in for that service 4x4 light they'd say it was fine and they got no codes. and sent him on his way not fixing anything.

I have a snap-on Scan tool (the red brick) and when i hook it up I get the same thing no codes present.

keep me posted on what you find I would love to get my grandpas truck running good again

jsthunter9093 · 04-06-2008, 07:56 PM

I was 99.9 % sure u had discovered the source of my squeal and shake but was miserably mistaken. I jacked one side of the truck up and, what do you know, the tire wobbles around with about 3/4 of an inch of play. So
i go down and buy a hub assembly at napa. (176.00), installed in about 2 hrs.

no difference!!! i could not believe that wheel bearing assembly
was worn out, that after installed, the vehicle still shakes...

...what could have happened to that truck.? They did change U joints? could those be the problem?

87c10slammer · 04-06-2008, 08:15 PM

yeah if they replaced your u joints and didtn allign them correctly they would vibrate like crazy. or if your universals were so bad they oblinged the mounts. things happen like that all the time. if you want a cheap way to check for vibrations. get a small camcorder and strap it to the bottom of your truck and have it pointed at your criveshaft. drive for about 15 mins at differnt speeds and then look at the video on your computer. it may work it has worked for me before

shadow · 04-14-2008, 04:02 PM

A Vibration And Sqeal Sounds More Like A Bearing I'd Check To Make Sure They Monted Everything Back Properly

436'd skylark · 04-15-2008, 06:30 PM

well they must have dropped the tranny pop the seal. I believe the genIII motors are interanally balanced, so there would be no issue there, unless they bent the flexplate, or fudged something while bolting the torque converter to it. of course then it would vibrate in neutral with a free rev.

budder · 04-16-2008, 04:33 PM

the torque converter has a hub on it that fits into the end of the crank shaft if the torque converter was not tightened up even ,it could cause this and if run long enough will crack the flywheel, just loosen up converter bolts,slide converter back and draw up each bolt a little at a time

04-06-2008, 01:20 AM	#1
jsthunter9093 Junior Member Join Date: Apr 2008 Posts: 2	Replaced rear main, 1999 Silverado shaking Greetings Members I recently had my 1999 Silverado Rear crankshaft seal replaced from at a local mechanic. Since i have picked it up i have noticed a severe shimmy or more like harmonic buzz that kicks in at about 40mph. Also, now i am getting a "Service" 4wd" in the message center. They claim there is no way that repalcing the RMS could affect the balance of the running gear. I tend to agree. If i am not mistaken the flexplate is indexed to the crank, so no chance to mess that up....What happened to my nice truck? There is also a strange squeal now, in the left front hub area that is NOT affected by brake activity. Any help appreciated... justin

04-06-2008, 07:56 PM	#3
jsthunter9093 Junior Member Join Date: Apr 2008 Posts: 2	changed front hubs....no help I was 99.9 % sure u had discovered the source of my squeal and shake but was miserably mistaken. I jacked one side of the truck up and, what do you know, the tire wobbles around with about 3/4 of an inch of play. So i go down and buy a hub assembly at napa. (176.00), installed in about 2 hrs. no difference!!! i could not believe that wheel bearing assembly was worn out, that after installed, the vehicle still shakes......what could have happened to that truck.? They did change U joints? could those be the problem?

04-15-2008, 06:30 PM	#6
436'd skylark Senior Member Join Date: Mar 2007 Location: Buffalo Ny Posts: 620	well they must have dropped the tranny pop the seal. I believe the genIII motors are interanally balanced, so there would be no issue there, unless they bent the flexplate, or fudged something while bolting the torque converter to it. of course then it would vibrate in neutral with a free rev. __________________ Joe 89 K2500 Chevy, Wee-Oh-five 285K miles, completly rebuilt needs a motor, bad 1962 IHC Scout All Wheel Drive (Scout speak for locking axles) 152 ci, dana everything else

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
1999-2006 Chevy Silverado 1500/Tahoe/Suburban Westin Sportsman grille guard	snyper07	Truck Classifieds	0	06-12-2007 03:21 PM
Shaking 1995 Silverado	m-3mike	Chevy Truck Forum	12	01-05-2007 08:31 AM
89 chevy suburban rear main oil seal	The Bondo King!	Chevy Truck Forum	3	09-21-2006 06:45 PM
rear main oil seal 2000 f-250 super duty	colocat	Ford Truck Forum	4	04-20-2006 12:48 AM
1999 f250 rear brakes	dw74	Ford Truck Forum	3	01-11-2006 01:36 PM

04-06-2008, 08:10 AM	#2
Chevy_Finatic79 Senior Member Join Date: Mar 2008 Location: Lincoln NE Posts: 442	My grandpa has a 99 sierrea with 60k that does the same thing the service 4x4 light has a mind of its own and the shimmy was a bad U-joint we still havent figured out where the squel is coming from cause it is very hard to isolate since it only makes noise while driving. It's not the brakes i know that much for sure. the noise seems to come from the transfer case or the tranny. every time he took the truck in for that service 4x4 light they'd say it was fine and they got no codes. and sent him on his way not fixing anything. I have a snap-on Scan tool (the red brick) and when i hook it up I get the same thing no codes present. keep me posted on what you find I would love to get my grandpas truck running good again

04-06-2008, 08:15 PM	#4
87c10slammer Banned Join Date: Mar 2008 Location: levittown pa Posts: 2,197	yeah if they replaced your u joints and didtn allign them correctly they would vibrate like crazy. or if your universals were so bad they oblinged the mounts. things happen like that all the time. if you want a cheap way to check for vibrations. get a small camcorder and strap it to the bottom of your truck and have it pointed at your criveshaft. drive for about 15 mins at differnt speeds and then look at the video on your computer. it may work it has worked for me before

04-14-2008, 04:02 PM	#5
shadow Junior Member Join Date: Apr 2008 Location: new augusta , ms Posts: 8	A Vibration And Sqeal Sounds More Like A Bearing I'd Check To Make Sure They Monted Everything Back Properly

04-16-2008, 04:33 PM	#7
budder Full Member Join Date: Apr 2008 Location: central fl. Posts: 14	the torque converter has a hub on it that fits into the end of the crank shaft if the torque converter was not tightened up even ,it could cause this and if run long enough will crack the flywheel, just loosen up converter bolts,slide converter back and draw up each bolt a little at a time