IFS shimmy at 50mph or so???

[DanS HJ-45]

Nope, the faux-lux drives perfectly straight, clean and true.

This is dealing with a 1990 IFS 4x4 that is developing a shimmy in the wheel (the whole truck is not shaking, just the steering wheel) between about 50mph and 55mph.

I'm 99% sure it's the fact that it has three BFG A/T tires, and one Cooper something or other on the other corner, but wanted to see if anyone knew of anything else to check.

The ball joints all seem tight, the wheel bearings all check out, and the steering system seems nice and tight. This truck has not had the relay rod recall done on it yet (or may not be affected, I need to check up on that), so my hope is that we can get the tires "fixed" by getting another BFG A/T or two and then take it in for the relay rod recall--just to get the alignment out of the deal too.

Anything else I should be checking? They are all 235/75R15 tires, so the only issue there *should* be the fact that they are different brands and therefor have different rotating masses.

This is a vehicle for a youth camp I used to work at, and have been working at for most of the summer (while avoiding the airline job), so we're totally trying to keep the repairs on the cheap.

Dan

 

[2ndGenToyotaFan]

Are there 2 BFG's on the front? If not, I'd start by swapping the 2 most like tires up front. Sure sounds like a tire problem...

 

[DanS HJ-45]

Yep. the BFGs are on the front, and left rear. The BFGs on the truck were all purchased as a set, so they have virtually identical wear on them.

I think next week *someone* will be busy shopping for two cheap BFG A/T KOs in 235/75R15 flavor (two for the rear, and then swap one to the spare--the different size spare is what started this whole mess).

Dan

 

[Downey]

I'm not real sure what the Toyota Steering Recall is suppose to accomplish, but I do know that a bad Birfield Joint can produce similar problems (but generally at lower speeds).

 

[raydouble]

I'm not real sure what the Toyota Steering Recall is suppose to accomplish, but I do know that a bad Birfield Joint can produce similar problems (but generally at lower speeds).

Safety
-SSC 50N-
ON CERTAIN PICKUP TRUCKS AND SPORT UTILITY VEHICLES, IF THE STEERING WHEEL IS REPEATEDLY TURNED UNDER CERTAIN CONDITIONS WHERE HIGH STEERING EFFORT AND POWER ASSIST ARE REQUIRED, FOR INSTANCE, WHEN FULLY TURNING THE WHEEL WHILE THE VEHICLE IS STOPPED, A FATIGUE CRACK MAY DEVELOP IN THE STEERING RELAY ROD.

1990 has no birfields.

It does sound like a tire issue, but what about worn tierod ends, how about worn idler arm/pitman arm?