Steering shudder in 97 Riviera

[edwinn]

I bought a 97 Riviera from a dealer in Feb 98 with very low miles. It was a lease vehicle AFAIK from docs found in the glove box (the original window sticker was also in there.) The dealer fixed a number of issues (mostly minor) under warranty that was still in effect.

One of the major problems was a Steering Shudder, during idle (foot off the accelerator) at very low speed, typically during parking maneuvers. The dealer followed the SBs and replaced one hose. That didn't solve the problem, then replaced another hose. I have records and can post what hose in what order. Still shuddered, and finally they replaced the steering pump. None of these repairs solved the problem.

One must consider 'they' claimed to replace the components, but didn't really do the work. Is that possible? Why has the shudder problem never been solved? Yes I searched the forums for key words "steering shudder."

-Ed

[gmtech1]

I'm sure the work was done since warranty parts need to be turned in for the dealer to get paid for the repair. GM had seveal issues with steering shudders, and some were never resolved. Its possible the problem lies in the steering gear, since it's the only thing that was not replaced. But shudders are ususal caused by pulsations created by the pump, the replacement hoses usually had longer sections of rubber hose to help absorb the pusations and reduce the shudder.

One more thing, if the shudder only occurs when turning in one direction, then its the steering gear itself, because the pump and lines don't care what direction you are turning.

[edwinn]

Originally Posted by gmtech1

One more thing, if the shudder only occurs when turning in one direction, then its the steering gear itself, because the pump and lines don't care what direction you are turning.

I'd say the shudder is more prevalent in one direction, but will have to nail that down by doing some specific tests (turning wheel L then R) and report back. In the past few weeks, my local dealer did another complimentary 20-point inspection (or Fitness Inspection & Treatment Plan as it's known) and said the Steering Rack is leaking fluid and recommended replacing it. Not a cheap activity!! The steering is still pretty tight but there's some very minor play in it, like when rapidly moving steering wheel 1 or 2" at the top L & R, there's a slight 'knock' or run-out. (emphasis on 'minor')

Will replacing the rack address the 'steering gear'? If they can solve the shudder at the same time, then maybe I'll have it done.


-Ed

[gmtech1]

The Steering Rack and the Steering Gear are the same part, just different terms for the same thing.

[enslow]

I did change my own rack myself. It wasn't easy, but it wasn't impossible. For now my best advice is to get ACDelco parts.

[edwinn]

Here's some Warranty Service history and P/Ns for the steering shudder issue:

Dealer in Pennsylvania (purchased there)

3/13/98 - Customer states there is a shudder turning wheel in drive at idle - 21,021 miles
INNER DIA OF PRESSURE HOSE INCORRECT
REPLACE PRESSURE HOSE #26059162

3/20/98 - Customer states steering chatter on turns at low speeds.
INSUFFICIENT FLOW FROM POWER STEERING PUMP
REPLACE POWER STEERING PUMP #26043363

4/15/98 - Customer states steering shudders.
REPLACE RETURN HOSE #26070138


Dealer in New England

4/13/98 - Check for steering shudder when backing up - 23,733 miles
MOANS AND VIBRATION PRESENT, LATEST TSBs ALREADY PERFORMED
SP PART ON ORDER


So there you have the history. I'll need to check turning LEFT vs turning RIGHT when the vehicle is back in the home garage, but it had only 21,021 miles on it then, so now could the RACK have been worn or defective? Or am I some kind of a sucker? Did they really replace all those parts? and is the problem solvable.. or is it a design flaw? I believe the steering pump isn't powerful enough to PUMP fluid at engine idle.

Any comments or words of wisdom?


Edit: 1

Have found GM Document ID: 777322

#99-02-32-007A: Steering Vibration / Shudder During Parking Maneuver - Jan 31, 2001

http://home.comcast.net/~edwinn/GM-Doc-777322_99-02-32-007A_2001-0131.pdf

Edit: 2

Past discussion thread: 98 Riv steering - Feb 20, 2006

http://www.automotiveforums.com/vbul...d.php?t=525681

-Ed

[edwinn]

Just to restate.. I'm not sure the shudder is coming from the rack because the problem existed in 1998 with 21k miles on it. The PDF doc (see link) mentions something about the Harmonic Balancer?

Update: was able to contact the DEALERSHIP in Philadelphia area (where I bought the car) through their web feedback forum, and actually got a callback from a service rep!! But that probably won't go anywhere.


-Ed

[gmtech1]

Looks like you're on it. See what happens with the call back? Maybe they will help with a balancer replacement? Fingers crossed!

[edwinn]

Originally Posted by gmtech1

Looks like you're on it. See what happens with the call back? Maybe they will help with a balancer replacement? Fingers crossed!

Do you think it's the balancer? Driving around yesterday, I've noticed a shudder turning RIGHT but will have to test it more. That means designing a test, in Drive and Reverse, turning Left and Right, then making note of the results.

-Ed

[gmtech1]

I personally have not seen a balancer cause a power steering shudder. They can cause virations and noises, but they are usually heard and felt at all times. If you find the the shudder is worse in one direction I would lean towards a gear issue. Make sure there is no air in the system as this can cause a shudder also, but usually felt in both directions.

[edwinn]

Originally Posted by gmtech1

I personally have not seen a balancer cause a power steering shudder. They can cause virations and noises, but they are usually heard and felt at all times. If you find the the shudder is worse in one direction I would lean towards a gear issue. Make sure there is no air in the system as this can cause a shudder also, but usually felt in both directions.

A couple things to mention.. I did a couple tests (on different days) maneuvering in a parking lot, idle throttle, both Drive and Reverse and turning Right & Left. The shudder is happening in BOTH directions. At first I thought it was only turning RIGHT. Gosh.. with the 350ci GM cars from the 70's.. you could spin the wheel around with your finger at idle with no problem!!!

A young lady from the local Buick dealer in Leesburg called and offered to change out the RACK at a reduced price.. 10% IIRC. It would be best to have a discussion with them as enslow lays out, which is about the other components in the system. I'm thinking changing the rack would cause additional service alter on. Seems whenever you "mess" with something, there's always a downside.

Frankly, the rack and steering isn't bad enough to spend that much $$ right now. If it's leaking fluid just a bit, then so what? just top it off maybe once a year? Is there a risk the PARTS might not be available later on?

-Ed

[Albertj]

You might want to look at your motor and transmission mounts. Do this at your own risk (I do it but real carefully) - with a buddy in the drivers seat, parking brake set, service brake on (her/his foot pressing on the brake), blip the throttle. If the engine moves a lot in the cradle then it would not be a waste of time to check/replace the motor and transmission mounts. Inspect them one by one for cracks in the rubber, and/or outright collapse. The transmission mounts on the Riviera are not very stout, basically rubber straps in a metal housing, and really don't last more than 75000 miles or so (well, 1500 - 2000 hours) of driving. They last longer if you are not a "spirited" driver, and less if you are.

You might want to replace the harmonic balancer as PM if your vehicle is high mileage. Be sure you get the correct P/N (it's stamped inside the balancer IIRC). You may want to double check the harmonic balancer number at a GM dealer using the VIN lookup, if you bought the car used and don't know if it was replaced before, or if it was replaced with the wrong one to begin with at some point (not likely). What you are looking for in the HB is any cracks in the polymer damper inside the device. You may have to stretch it around to find cracks. Any cracks = "replace me" sign... You will need a puller specifically for GM cars to get the HB off - the puller is usually available for loan or rent from auto parts stores that offer rental tools. It is a common puller, just with different bolts that fit the GM HB.

Albertj

[012620]

Howdy,
I bought a 2000 P/A in Aug. 2006 with 18,000. It's had this same shudder from time to time. Maybe a few times a week. Sometimes the shudder is not much and other times it seems like a lot. I have read that this happens on some late 90's to thru maybe 03's. I have read also that it could be the power steering hose. It's been said that the inside diameter of the hose is not large enought. The shudder in my car has never got any worst. We have put about 54,000 miles on this car. My shudder only happens at very low speed when turning to the right. When turning right and the shudder makes it sound I just stop turning for a moment and the shudder goes away then I continue my turn with no shudder. This shudder is annoying but has never seem to cause any steering problems. One of those dam things you learn to live with.

[Albertj]

Originally Posted by 012620

Howdy,
I bought a 2000 P/A in Aug. 2006 with 18,000. It's had this same shudder from time to time. Maybe a few times a week. Sometimes the shudder is not much and other times it seems like a lot. I have read that this happens on some late 90's to thru maybe 03's. I have read also that it could be the power steering hose. It's been said that the inside diameter of the hose is not large enought. The shudder in my car has never got any worst. We have put about 54,000 miles on this car. My shudder only happens at very low speed when turning to the right. When turning right and the shudder makes it sound I just stop turning for a moment and the shudder goes away then I continue my turn with no shudder. This shudder is annoying but has never seem to cause any steering problems. One of those dam things you learn to live with.

I did not want to say it - but one way to fix this is drain the fluid from the reservoir. And refill with a higher viscosity PS fluid like Lucas. I do not like it - mechanic in a bottle is BS - but after about a week of driving the shudder will diminish if not vanish.

[edwinn]

Here's an update of the Steering Rack, Steering Shudder and leaking seal/PS fluid.


Shudder worse - leaking fluid

The shudder has gotten worse, and that meant (in the past) the fluid was getting low. Checking underneath over the weekend, there is definitely a fluid leak from the DRIVER side boot on the rack. The dealer SA (service adviser) said something about replacing the seal.. instead of the whole rack. I don't think it needs a new rack yet. There isn't much play at all, just fluid leaking. Here's a photo taken yesterday (Sunday) of the LF rack boot:




The driver side boot is wet for sure. The RIGHT boot is quite dry!!


Does replacing the seal sound like a good fix?


-Ed