93 Shimmy

[TKirby]

I have a 93 extended cab 4x4 auto. I've noticed when I get to around 50-55mph I often feel the entire truck shimmy and wiggle some. It goes away if I speed up or slow down. I'm wondering if this is a front end problem and the body/suspension is so stiff that it's feeling like the entire truck is shaking, or whether it's possibly something else. It's nothing really bad, but it's definitely noticeable. It seems to be worse when I'm on a flat section of road or going down an incline, sort of coasting and not under a load. Is this a common issue, and if so what's the fix?

Thanks

Todd K.

 

[ARhine]

it is most likely an out of balance tire, or a loose component in the steering.



Check the tires. Then check for loose TREs, kingpin bushings, ect. .

 

[JLEONARD]

While you are checking the balance... look for a bent rim as well. Also inspect the chamfer on the holes... I had one rim that the nut couldn't tighten properly because of a worn out chamfer... . and that one drove me nuts for a long time.

Jay

 

[chunter]

I would also check to make sure the front wheel bearings are properly adjusted.

 

[Philip]

You didn't say what size $X$ you had. Look and see if it has the 6" lift blocks between the springs and rear axle assy. If it does there is a TSB out for vibration. Here is a link with the info.



http://dodgeram.info/tsb/1993/03-02-93.htm



My 93 did about the same thing till I did the tSB on it.

 

[TKirby]

Thanks for the suggestions. I figured it was something worn out on the front end since it has 200K miles on it, but a previous owner has at least installed a Borgeson steering shaft. It drives great except for this occasional, annoying shimmy problem.



Todd K.

 

[chunter]

FWIW - I just picked up a 93 WY250 with 199ka on it and the truck would occasionally shimmy between 50 and 60 mph. I jacked up the front end and found that the wheel bearings were not adjusted properly. They had plenty of fresh clean grease, so I adjusted them per the manual and so far so good.

 

[TKirby]

A front end shimmy should radiate up through my steering wheel though... this shimmy is a little different since it feels like the whole truck "wiggles". I gotta check that pinion angle TSB right away. Where do you get those shim kits, at the dealer?

 

[Philip]

Its just a piece of flat stock with two holes to match the carrier bearing mounting holes. MFG your own and save the money from the TSB kit.



That TSB applys if you have the 6" lift blocks. Some 4x4's had 3" blocks. If your is a w350 it should have 6" blocks.

 

[TKirby]

Mine is only a 250, but it has the 6" blocks. How do I tell if this TSB has already been performed? Why did some trucks come with 6" blocks and others only 3"? Also, my truck has overload springs... fairly hefty looking ones... are those stock? I'm guessing not.

Thanks again for the input.



Todd K.

 

[Philip]

To tell if the TSB has been done. Look at the carrier bearing. If there is a 1/2" steel plate between the bearing and the chassis mount it has been done.



Most W series had 6" blocks installed to level the truck out. D series had 3" most of the time.



The factory overloads are heavy. Most likely they are stock. Post how many leafs and someone with overloads can tell you if the pack has been beefed up. My truck doesn't have overloads.

 

[CLiberty]

This is one of my rear springs #ad
I count 6 plus the O/L spring, no carrier shim either.