Steering Wheel feels like a Jackhammer...

[Waterloo]

At 63 MPH and above, nice new PA Turnpike pavement, steering wheel turns into a jackhammer. Bop, bop, bop, bop, very quick up and down. Will get worse when passed by a truck. This is loaded and bobtail.

2008 ProStar, 1,048,000 miles, regular old school original 12,000 lb two leaf suspension. No abnormal wear on any of the tires. Nothing noticeable on suspension in regards to loosey goosey, everything is tight. This started a few months ago and continues to worsen. I was thinking shocks, so I replaced, no difference. I lost a front wheel seal last week, replaced that on passenger side, spindle and bearings looked good, spindle was mic’d.

Rear suspension was rebuilt 300,000 miles ago, new bushings and torque rods. Historically I normally haul light loads. Rear looks good to my eye.

Michelin 16 ply steers have good tread depth, even wear, but are getting long in the tooth age wise, getting time to replace, another possibility? Going on four years with these babies. I high speed balance my tires, use external weights. No Centramatics, beads, etc.

I have an appointment this Friday at local PA International stealership... Hill International off I-70 just east of Pittsburg. Need to get this addressed ASAP.

I’m thinking King Pins... Your thoughts are greatly appreciated if any of you can help or have suggestions. I’m stuck in PA on a dedicated account.

[Chamberpains]

Check your steering shaft and joints. Ive seen trucks do this when there worn out or even seized up.

[marek4792]

brake drum out of round?

[Magard]

(11-25-2020 )marek4792 Wrote:  brake drum out of round?

Brake drum. Have you removed a front tire recently. Does the wheel wobble when you put on the brakes

[Waterloo]

(11-25-2020 )Magard Wrote:  

(11-25-2020 )marek4792 Wrote:  brake drum out of round?

Brake drum. Have you removed a front tire recently. Does the wheel wobble when you put on the brakes

I put new drums on, but it was doing that prior too... I think I am going to have the tires inspected first, before doing anything. Thinking one may be out of round. The more I think about it the more sense that makes. I forgot I had the same symptoms when I first bought the truck, had a bad tire, doing the same thing. My memory is not worth spit. LOL

[Waterloo]

(11-25-2020 )Chamberpains Wrote:  Check your steering shaft and joints. Ive seen trucks do this when there worn out or even seized up.

I replaced that around 200,000 miles or so ago, that was an issue that a new shaft fixed. I keep her greased too, thinking tire.

[DVT873]

Broken belt in tire or out of round. Broken belt can be hard to see. Your weights etc. may be able to compensate at lower speeds. Out of round easy to check. Get tire off ground. Put something in front of tire and spin it. .070 absolute max for radial runout. Less is better of course.

This everybody probably knows. The Pstars and all NAV's with that cab design have a u-joint in the steering column up by the firewall on the engine side. Can be hard to see but it does need greased.

[Rawze]

(11-26-2020 )Waterloo Wrote:  

(11-25-2020 )Magard Wrote:  

(11-25-2020 )marek4792 Wrote:  brake drum out of round?

Brake drum. Have you removed a front tire recently. Does the wheel wobble when you put on the brakes

I put new drums on, but it was doing that prior too... I think I am going to have the tires inspected first, before doing anything. Thinking one may be out of round. The more I think about it the more sense that makes. I forgot I had the same symptoms when I first bought the truck, had a bad tire, doing the same thing. My memory is not worth spit. LOL

jack one side at a time up and lift the tire off the ground. rotate it by hand fast and watch the thing for out of round, uneven height as it spins, etc. ... also look at the rim indication stripe stamped into the rubber close to the rim to see if it is even distance all the way around, check to see if tire was mounted funny.

get a dial indicator and check king pin and bushing lash using a dial indicator by following the maintenance manual for that model axle.

-- Every time my truck starts doing this, the tires have 150k+ miles or more on them (at end of life) and it is always simply the tires wearing out. - Anything past 100k miles on a set of steers, you have done well with them.

[Magard]

Like Rawze says. Also watch as the tire leaves the ground. I’ve seen them start moving. Especially if the oil is warm. Dead giveaway that there is a major out of balance going on.