74 Chieftain wheel wobble?

[dreib]

For whatever reason when i get up to 40mph i get a hellacious wheel wobble. After i get past 40 it goes away except for a little bit of vibration and again when i am slowing her back down it sometimes gets a little worse but again goes away after passing 40mpg. Anyone have any ideas what this could be?

The tires are good and have been balanced and the brakes are not dragging. When I rebuilt the brakes i gave the wheel a pretty good shake but couldnt seem find anything blantantly loose or bad. This is coming from the passenger side, almost forgot that point.
I need some advice on what to look for and what to do about it. For now im just gritting my teeth and holding on.
Thanks!

[Oz]

That does sound very indicative of an unbalanced tire.  I'm sure there are other possibilities, but you may want to pull that tire and balance it again.  Also, does it do it the very first time you go over 40, having driven it only a short distance, or after it has become warm?  Drive it until it wobbles, immediately pull over, and see and feel if you can find any bumps in the side walls.  Even a very small one.  There could be a manuafacturer defect.

[DaveVA78Chieftain]

Use the search feature and locate the post talking about king pins.  When checking these heavy tire/wheels, you need a pry bar.
Additionally, the king pins have to be greased.

Dave

[dreib]

Thanks guys I'll double check my tires and take a look at the king pin and see if its loose or needs greased.
I would think that if it were a mechanical problem though it would shake like hell all the time? Hmmmm. Im hoping its a unbalanced tire.

[JDxeper]

Shocks could also play apart in the shimmy shammy.

[dreib]

Shocks could also play apart in the shimmy shammy.

Im sure the shocks have never been replaced so i should replace them...is it that hard? it looks like it might be kinda easy other then getting past the rust. Also i used equal{sand} to balance the tires and was wondering if i might need more than one bag?
Thanks.

[Oz]

Very easy to replace the shocks.  Use PB Blaster or other rust dissolver a day before taking them off.

[Froggy1936]

Another possibility is (if you have a two piece driveshaft) the center driveshaft support bearing, Check for weak or broken rubber Also driveshaft (if 2 piece) can be out of phase. The rear & middle u joint must not be positioned the same way . Look up driveshafts on google   Frank

[salplmb]

when u say wobble do u mean side to side or up and down. i had a problem with a jumping of the front right wheel. part of the problem was a worn out shock mount bolt and belive it or not the tire preasure being low made the wheel hop alot at certain speeds. look under winne wanders i think. this has been coverd alot if u look in the files. hope this helps a little.
sal

[dreib]

Side to side for sure. gonna rebalance the tire and see what happens...I'll let you guys know.

[ClydesdaleKevin]

The sand is probably the problem.  I've never had luck with that method and don't know anyone who has.  The best and only proper way of balancing your tires is to take them to a shop and have them balanced on a machine using wheel weights where necessary.  This applies for bias tires and radial tires.  You are better off NOT balancing them than using the sand method.

Kev

[angrybreadbox73]

also on the rear duals there is a centering pin to locate the wheels correctly if both wheels arent in the pin the wheels will wobble side to side

[75Travco]

In tracking down a front end vibration problem, I found that the front wheels were not centered on the hub.  This was dramatically demonstrated by the folks at at Hagerstown Spring & Alignment when they spun the perfectly balanced wheel (while mounted on the front axle) up to speed!  The technican loosened the nuts, shifted the wheel slightly, and the vibration was eliminated.  The flange-type lug nuts on the RM350 chassis don't center the wheel as well as the older coned lug nuts.  My solution was to use three of the coned nuts to center the wheel, install five of the flanged nuts, and then replace the coned nuts.  My original post a few years back had more detail but I don't know if it is searchable.

[dreib]

Well have been busy and have not had the time yet to figure out what is goin on but hope to get looked at this week since the kids are off visiting their grand parents.

The rims are centered on the hubs, learned to do that the first time i had them off ..of course the hard way!

[dreib]

looks like i have a bad ball joint! Anyone have a part # handy? 1974 chieftan - custom, I think its a rm400 chasis...correct?

[Oz]

Use the VIN decoder.  That will tell you what chassis you have. All parts numbers are available in the Parts Manual available here.  The resources we have are very extensive.

[dreib]

ok so it turns out that it is a bad kingpin and of course no one can find a replacement. Ive ordered the parts cataloge but whatever reason i cant download it yet so,,,,,,,,,,,,,I REALLY NEED THAT PART NUMBER SO THEY CAN CROSS REFERENCE!!!!!!!!! 74 RM400 KINGPIN      RIGHTSIDE
dreistevens@hotmail.com      STAT!!!!

[DaveVA78Chieftain]

Dodge P/N is 4026848
I got mine at NAPA a few years ago.  They did have to order it in.  Check all parts in kit before leaving store.  First one I got had a broken plastic piece.

http://www.napaonline.com/Search/Results.aspx?Ntt=4026848&Ntk=Interchange%20Number&Nty=1&N=0

or

http://www.stemcokaiser.com/Catalog.pdf
pdf page 5, P/N K50D

Dave

[dreib]

THANK YOU!!!!!!

[dreib]

Ok got it ordered today from NAPA and it should be here wednesday or thursday and im praying that  after this repair i will be done messin with Wendy for awhile, aside from tinkering and finding out why my instrument fuse keeps blowing, because if i have to sink much  more money into her my wife will have me moving into it!

Wait a minute maybe that wouldnt be all that bad.............................hmmmmm.

[dreib]

Soooooooooooo, kingpin has been replaced and of course the tire wobble is still there! Im about to completly lose it!

Here is what we know for sure. Everything mechanically...kingpin, ty-rod etc, is sound. so what does that leave?....Tires? Im gonna have them sent to be balanced on a machine and also was told a steering dampener may help?  anyone ever hear of a steering dampener.  If this doesnt work im just gonna drive her as is and hope i dont end up killing myself. Any more ideas out there?

[JDxeper]

When I was going through rims to replace mine 9 out of 14 were not round( bent)
The only way I could tell is to spin them on a tire balance machine, they checked them for me at the tire shop.

[Jimco_W001]

Its almost always a bad tire or more that causes this problem in my 30 some years as a mechanic.

[Oz]

anyone ever hear of a steering dampener

Yes!  A few members installed them over the years to help eliminate the loose steering play syndrome (LSPS).  You can find info on that using the Message Search:  steering stabilizer.

But, it's not likely that will cure your problem.

Keep going with the basics.  Often, the simplest thing to look at is the problem.  Not that it wasn't a good idea to replace the kingpin, but, as mentioned, wheel balance, bent rims, and the tires themselves would be the first thing on the list.

[dreib]

Ok problem solved..........FINALLY!!! Turns out is was the tires the whole time!  Live and learn i guess.

She drives like a dream now, looking foward to camping this weekend.
Thank you everyone for your input!