Truck Jerks from side to side?

[Blind Driver]

One thing that might help is this:

1) drain all fluid from the power steering system
2) fill to capacity with POWER-STEERING FLUID (not engine oil)
3) bleed the air from the system

I just did it on my truck and steering has considerably improved. Evidently a lot of shops/mechanics use ENGINE OIL instead of POWER STEERING FLUID when topping the reservoir!

Also, you might have air in the system and that causes "shimmying and oscillation" while driving, according to my International truck manual.

Many trucks do use engine oil in the power steering system. Always best to check and make sure the correct fluid is being used

What may appear to be engine oil, may actually be dirty power steering fluid.

[bob h]

Many trucks do use engine oil in the power steering system. Always best to check and make sure the correct fluid is being used

Engine oil and Power Steering fluid are both similar in color, but the two smell differently. Also, P/S fluid has a thinner texture. Either is usually acceptable for your P/S system, but DON'T mix fluids!


...I would doubt very much this shimmy/vibration problem is related to fluid type. Vibration and jerking during static steering might be related to fluid.

[RRaccoon]

Don't suppose you stay under the same trailer all the time and don't grease the 5th wheel every couple weeks? This will cause the jerking you describe but it's usually more noticeable loaded.