hirdlej

iTrader: (31)

I am writing this thread here in hopes of helping at least 1 other person on this board with a clunk/rattle free steering column. Since the release of the GMT-800 truck in '99, we Silverado owners have been plagued with the fact our trucks develop a clunk in the steering column, some going down roads with bigger cracks in them, some experiencing it while turning in a parking lot, some cruising down the highway at higher speeds. It's extremly annoying and frusterating that our 20-50K dollar trucks are built so well but GM lacked attention to detail when engineering the steering mechanism. We've all had the dealer BS with getting our shafts replaced, then once replaced the clunk still comes back. Then GM offers to do nothing but grease our shafts for the next couple years. It wasn't until recently GM released a shaft that had tighter tolerances and eliminated the clunking. If you're still experiencing rattles and clunks, read on. Otherwise if your truck rides like a mercedes and you're going to make a smartass remark that "oh, my truck doesn't rattle." Or "It's a truck, it's supposed to ride like that" please do not read on or reply. I will continue going on with my story that I've been through 2 shafts and 1 relube. The 3rd shaft that just was recently released, solved my clunking down city streets, however ever since I had the shaft replaced, my truck developed a rattle that sounded like it was coming from the defrost vent area. It sounded as though there was a BB in the vent and would "click" whenever I took off aggressively or stopped quickly (later I would learn this was the shaft causing this, keep reading). I have a hearing disability and I wear hearing aids so this was not easy for me to isolate. With the help of another board member, he suggested I check my lower steering shaft bearing for play. I got down on the floor and checked for play where the ISS (intermediate steering shaft) goes into what looks like a white collar. There was a few thousandths worth of play there and although one would think it wouldn't be enough to cause a rattle while driving, I followed my instincts and said to myself it doesn't feel quite right. I went out and purchased revised part GM part # 88963617 as per Brian's suggestion. Once I got the new updated bearing, I looked at it and couldn't believe that there was literally a plastic bearing inside this plastic retainer and that is what the ISS inserts itself into. I got home last night, removed the 15mm nut from the bolt and pushed the steering shaft into the firewall (you don't need to remove the whole shaft to do this.) And then locked the steering wheel into place with the key off (don't want to ruin your clockspring). With a big flat straightblade screwdriver, I tapped it inbetween the flange on the retaining ring and the actual metal tubing of the steering column housing. Right where the red line is in this photo. Once wedged in there, a good slow powerful twist will coerce the bearing to come out and downward. Keep wrestling with it, it'll come. Now pull it all the way down and out. You'll notice immediatly the steering column shaft will flop loosely as it has nothing to support it now. Now get your new bearing (it'll be green) and slob it up with some good heavy grease. I coated the entire thing in anti-seize for it's extremly thick and will absorb shock well. Here comes the fun part now. put it back on like the other one came off, but immediatly you'll notice it's extremly hard to get the new one on. (this is a good thing) Pound it back on with your palm and back into the tube making sure it's going in straight. Also there's a notch cut in the steering column housing, make sure the keyed piece on the new bearing retainer lines up with this notch or it won't seat fully. I had to use a series of big screwdrivers and some long files to press the new bearing into the housing but finally got it. (remember, this part is supposed to be serviced out of the truck on a bench as per the factory manual so some creativity is needed). Now hook up your ISS and go for a drive. You will notice an immediate difference when you back up out of your driveway. I took the truck for a drive last night and this morning and I don't recall my steering ever being this nice or smooth since the truck was new. Also my "dash rattle" or what I thought was that is completely gone. Nice job Brian!

Cliff notes: If your steering clunks or rattles even with the new shaft, you need your lower steering column bearing replaced. New bearing fits TONS tighter than original one. Rattle was caused by bearing retainer sleeve being too loose within column tube. This took about an hour to do and a $22 part.


More reading about this topic can be found in a 14 page thread I found at the diesel place. You'll see the pic I used is from their site. A lot of guys are using exhaust clamps to remedy this problem or a radiator clamp. This I believe is a bad idea as I tend to think this would distort the steering column tube. I would recommend AGAINST this method. Anyways hope this thread is informative and helps at least 1 person out.


http://www.dieselplace.com/forum/sho...d.php?t=167683

truckmann

iTrader: (8)

Hmmm I wonder if that will solve my steering problem? It doesn't rattle (replace the steering shaft for that) but it makes an annoying noise mostly when I am turning slowly to the left and I can feel the vibration in the steering wheel. Kind of a feeling like a dry bearing or something. Guess I'll have to try it and see.

hirdlej

iTrader: (31)

If there's any slop whatsoever where your ISS goes into that retainer, the plastic bearing inside is shot.

jknox

iTrader: (2)

Ditto, truckmann. I just replaced my intermediate shaft yesterday. Had a ton of caked-up grease inside the boot where the dealer had lubed the original shaft. When I cleaned all of that out I hoped I had gotten rid of my other problem - nope (clunk is sure gone tho).

The other problem? A loud groaning noise when turning the wheel - far worse when turning to the left. More annoying, it is now worse since I swapped the shaft. It's embarrassingly loud - people liken it to a dog groaning. Anybody think this bushing/bearing is the issue here?

hirdlej

iTrader: (31)

I would bet on it. Get on your knees and get under there. Grab ahold of the steering shaft where it goes into the retainer. If you can wiggle it ANY direction, it is shot. Mine had only a few thousandths only of play and it was enough to cause my "bb rattle". A lot of guys with the new shaft or even the borgeson units are saying the rattle is worse with the new shaft than ever. It's because the problem is not in the shaft, since everything is more rigid with the new parts, the bearing slop is more drastic.

jknox

iTrader: (2)

There was definitely slop - I checked while I was changing the shaft. I just had no way of knowing how much was too much. That was a real read over on dieselplace. After digesting all of that I think that both parts are the problem.

My current theory: The original iss binds up and is allowing too much impact force through to the bushing, which then starts deforming. The new shaft should correct the binding issue, but the damage to the bushing is already done.

Hooray - a dealer gets more money from me!

lerbud1

iTrader: (2)

I had my shaft replaced last week and they also replaced the top bearing and now the rattle is worse than ever. Atleast before I could stroke the shaft and the noise would go away. This design really suxs!!

Grumpy5.3

iTrader: (14)

I am glad it helped, That is an awsome write up by the way!!!

truckmann

iTrader: (8)

Well doing some more investigation on my problem I don't think that bearing is it. While it probably could stand to be replaced my problem is really noisy fluid flow in the PS system. I think this is also a common problem. I hope to verify this with a GM tech and I fear that I need a new steering gearbox to fix the problem. The noise and vibration is very load and apparent near my steering gearbox.

Grumpy5.3

iTrader: (14)

there are bulletins for the gear box and the p/s pump... If it does it in 1 direction, its the box. Both directions, its the pump...