water pump pully wobble
Thread Starter
Melting Slicks
Joined: Dec 2005
Posts: 2,291
Likes: 0
From: sterling ct
water pump pully wobble
power steering pump pully wobble- not water pump
i picked up my new (new for me) 96 lt4 this past weekend from md. drove home 370 miles. quite the car, the prior owner had installed zz9 cam, 4:10's, all of the R& D braces made fot he car, and a list of other things.
when i got home i did the typical check- oil etc...what i did find that concerns me is the large pully front top center of the engine (i think it is the water pump pully) has a wobble to it. the belt does not shift it tracks perfectly dead center from idle to 6k rpm. the pulley itself deflects 3-4 mm every turn. all of the other pulleys are tracking perfect. question..is this common? if left alone will it cause problems? how difficult is it to fix?
thanks..
btw a new amg c55 was playing with me through ny...he was 3 cars ahead of me doing around 70 and smashed the gas (amg benz's do sound nice) by 130 i had pulled by him and put 2 lengths on him. when we slowed i get the thumbs up from the driver of the amg..
i picked up my new (new for me) 96 lt4 this past weekend from md. drove home 370 miles. quite the car, the prior owner had installed zz9 cam, 4:10's, all of the R& D braces made fot he car, and a list of other things.
when i got home i did the typical check- oil etc...what i did find that concerns me is the large pully front top center of the engine (i think it is the water pump pully) has a wobble to it. the belt does not shift it tracks perfectly dead center from idle to 6k rpm. the pulley itself deflects 3-4 mm every turn. all of the other pulleys are tracking perfect. question..is this common? if left alone will it cause problems? how difficult is it to fix?
thanks..
btw a new amg c55 was playing with me through ny...he was 3 cars ahead of me doing around 70 and smashed the gas (amg benz's do sound nice) by 130 i had pulled by him and put 2 lengths on him. when we slowed i get the thumbs up from the driver of the amg..
Last edited by 9secondflat; Nov 19, 2007 at 01:57 PM.
Race Director
Joined: Jun 2004
Posts: 13,960
Likes: 707
From: WI
Are the pulley bolts loose or missing? If not and you can move the whole water pump snout, the pump needs to be replaced ASAP. Mine wore out that way and made a scraping sound, there was a lot of play in the pump shaft.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Can you post a pic of your pulley including the front of the motor? There shouldn't be a pulley at the top center of the motor.
Here's a generic pic of the 96 motor:
Note that the alternator has a pulley assembly that includes a cooling fan that's about 5" in diameter. The A/C compressor is below and to the left.
Here's a generic pic of the 96 motor:
Note that the alternator has a pulley assembly that includes a cooling fan that's about 5" in diameter. The A/C compressor is below and to the left.
Racer
Joined: Aug 2007
Posts: 252
Likes: 1
From: Ellicott City, MD
The harmonic damper is the only "pulley" directly below the MAF.
However, you've indicated the "pulley" you're talking about is on the top, not bottom, part of the front of the engine.
The damper's on the bottom, not top, so I'm interested in hearing what you're talking about.
However, you've indicated the "pulley" you're talking about is on the top, not bottom, part of the front of the engine.
The damper's on the bottom, not top, so I'm interested in hearing what you're talking about.
Last edited by 89FX3; Nov 19, 2007 at 12:24 PM.
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Pro
Joined: Feb 2005
Posts: 560
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From: Hamilton New Jersey
got a camera? can you take a picture for us? I've actually had a bent ps pulley before. When I got the car it came without a pump but did have a pulley so I put the pulley on a new pump and noticed it had a 1/4th inch wobble when running, turned out someone bent the pulley..
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
In this cutaway view of a 92 LT1:
there is a black pulley almost directly under the alternator ^. That is the power steering pump pulley. Is that the one?
The LT1 and LT4 motors have the accessories in pretty much the same place so your's should be no different.
there is a black pulley almost directly under the alternator ^. That is the power steering pump pulley. Is that the one?
The LT1 and LT4 motors have the accessories in pretty much the same place so your's should be no different.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
IIRC, the pulley is a press-on fit to the pump shaft. You most likely have a bent shaft in the pump or a bad internal bearing or bushing.
Does the pump make any noise or do you feel any sort of pulsation when turning the steering wheel?? If you remove the serp belt, try to move the pulley around. It's even possible that the bolts that hold the pump to the accessory bracket are loose.
Does the pump make any noise or do you feel any sort of pulsation when turning the steering wheel?? If you remove the serp belt, try to move the pulley around. It's even possible that the bolts that hold the pump to the accessory bracket are loose.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
Could be excessive RPM, the pump going dry due to low fluid level, bad bearings/bushings, bad or weak metal in the shaft.
I would think excessive RPM and cavitating/overheating of fluid would be most likely.
I would think excessive RPM and cavitating/overheating of fluid would be most likely.
Drifting
Joined: Feb 2003
Posts: 1,978
Likes: 2
From: San Antonio Texas
I'd check the pully first before I bought a new pump. The pully has to be removed from your old one, and re-installed on the new, when you replace the PS pump. They'll bend rather easily, as I once found out.
Drifting
Joined: Aug 2006
Posts: 1,326
Likes: 18
From: Los Angeles California
Yeah those pulleys don't stand up to much force before they get a wobble.
Replacement is a very simple job:
-leverage the tensioner and remove the loosened belt
-use a puller tool on the old pulley
-use a pusher tool to get the new one on
-leverage the tensioner and put the belt back on
No other parts need be moved out of the way. A standard angled serpentine tool plus a very short 1/2 drive socket will clear the accordion to leverage the tensioner.
The GM PS pulley puller/pusher set is a cheap little thing at autozone. They are a bitch to use though; they require a LOT of force to turn.
Replacement is a very simple job:
-leverage the tensioner and remove the loosened belt
-use a puller tool on the old pulley
-use a pusher tool to get the new one on
-leverage the tensioner and put the belt back on
No other parts need be moved out of the way. A standard angled serpentine tool plus a very short 1/2 drive socket will clear the accordion to leverage the tensioner.
The GM PS pulley puller/pusher set is a cheap little thing at autozone. They are a bitch to use though; they require a LOT of force to turn.
Last edited by LouisvilleLT4; Nov 19, 2007 at 09:14 PM.