King Pin Question

[Don Cavey]

I have a terrible shimmy in my truck if I hit a bump at 30 MPH or higher. I can sometimes turn the wheel back and forth and "regain control" but usually have to slow down or stop. I do admit that the tires are old and have not been balanced. Tire balance was a problem when I drove them in Germany and the motor pool put new re-capped tires on without balance. There is slop in the steering coupling that I have not addressed yet either. But the tires should not shake. I believe that the drag link and tie rod ends are tight.

It also has a GM type Power Steering gear that was installed and is going away. I have a NOS steering gear box and pitman arm. It will go on soon. I will also have to fabricate the rod that goes from the mounting bracket of the steering gear to the other side of the frame rail. It was torched off at some time in the past.

So, my question do you think that King Pins may be the problem and how much trouble is it to replace King Pins? Are there four (upper and lower per side) or just two. Reason for my question is that there is an auction on eBay that has two king pins for sale. I am the first bidder and I have dealt with Memphis before and they will often sell you more of the same at the winning bid if you just ask.

Here is the auction: http://www.ebay.com/itm/300621263266...84.m1431.l2649

Hope it is OK to link auctions here. I know that on another forum, they get upset if you even mention the name of the auctions company.

I really appreciate any help. I have not ever worked on a King Pin but am certainly willing. I really want to get this truck to be fun to drive and reliable.

[osut362]

i also want to know the answer . i hope someone will chime in soon...al

[Don Cavey]

i also want to know the answer . i hope someone will chime in soon...al

In its present state, I really can't drive the truck. We did have problems with trucks in Germany in 1970 when they put crap re-caps on the trucks. I was able to "requisition" some new tires and wheels from newly arrived trucks (just the spare tires, not one of the four!!).

Really appreciate any help. My truck is 100% stock, no suspension modifications etc.

[97XJSP]

To be honest, the part you bid on isn't really the wear part... Those are the lower king pins and there is a tapered roller bearing that goes onto the pin and seats into the knuckle ball on the axle. The top uses a bronze bushing, but could be replaced with a bearing. If there is slop in the king pin bearings/bushings, you can adjust them with a cheap shim kit, or if you're lucky just remove one or two from what's there now.
I had similar symptoms when I switched to the super swampers that I'm running now. I don't miss the Michelin XL's that were on it, but boy were they smooth and quiet! Anyway, I added a steering stabilizer this summer and that helped quite a bit, but after recently tearing it all down, I adjusted the wheel bearings and kings pins, as well as replaced the tie rod ends. Hopefully in the next couple weeks I can get it back on the road and see if it made any difference... I haven't found anyone yet that will try to balance the boggers, but I think I have a lead on a place that will. I'm guessing that'll help quite a bit, or at least for a couple weeks until they go square again
A poor alignment can also cause these issues. It's likely a combination of a few things listed above.

Wish I had taken some pictures, it would make the explanation much easier... There are some pictures in the manuals section, but it can still be hard to visualize. If you have any questions, just post up!

[hiker]

To help reduce shimmy, balanced tires are a big help. Rotate tires to see if that helps. Up the tire pressure slightly.

[Don Cavey]

Thanks for all of the advice. I will try them all. I have asked one place about balancing split ring tires and they said that they legally could not touch them. I am not so sure that is true, maybe they didn't want any liability. But I need to check all of this out.

Thanks again!

[brute4c]

Some places believe we use split rims...these are NOT split rims...they are split safety ring wheels and rarely ever come apart unless there is corrosion or something disfigured in the rim or ring...much safer than split rims.
I had mine balanced locally at a truck tire shop...no problem...someone should be able to do them.

Did you check the wheel bearings? Make sure they arent worn funny and are properly tightened...

[Don Cavey]

Some places believe we use split rims...these are NOT split rims...they are split safety ring wheels and rarely ever come apart unless there is corrosion or something disfigured in the rim or ring...much safer than split rims.
I had mine balanced locally at a truck tire shop...no problem...someone should be able to do them.

Did you check the wheel bearings? Make sure they arent worn funny and are properly tightened...

Thanks for the suggestions. I was hoping that you guys would know in which I should go. I will check this stuff out methodically and let you know what I find.

[hiker]

Also, Lock-out hubs help a lot. If you don't have them, look at your front drive shaft. My spinning front drive shaft induces slight shimmy just below 43 mph. Found that the driveshaft yokes were not in the same "plane". The drive shaft slip joint had been indexed incorrectly upon reassembley earlier in it's life.

[Don Cavey]

Also, Lock-out hubs help a lot. If you don't have them, look at your front drive shaft. My spinning front drive shaft induces slight shimmy just below 43 mph. Found that the driveshaft yokes were not in the same "plane". The drive shaft slip joint had been indexed incorrectly upon reassembley earlier in it's life.

I see that AB Linn has them for sale often for a little of nothing ($$$). I had thought it might be a good idea to get a long and a short for spares. Make sense or am I barking up the wrong tree?

Thanks guys,