I got my 85 SR5 pickup today and on the ride home (200miles) I noticed the steering was shaky, I did have a 600 pound motorcycle in the back and it was pretty windy, but it seemed to be alot more movement than my steering, the truck is on a 5" lift and 35s, the front end isnt geared, only the back, I was thinking maybe the tires werent balanced, they were purchased at some place called "budget tire" (they are BFGs) It happened more at the 80mph range than in the 60s, anyone have a clue, is it bad or just been too long since i drove a toy?

 

Could be any number of things.

The weight in the back will make the rear end ride lower and each inch it is lower than the front adds about 1 degree of caster angle to the steering, so you may have gone out of the stable steering range. Try driving a similar speed with the bed empty.

Could be a tire flat spotted from sitting a long time, but that is uncommon with radials and usually the tire will round out again once it warms up.

Could be a tire has gone out of balance (weight fell off for example) or had a belt break. You might try putting the front tires in the air and spin each tire and watch for any runout in the tread pattern as it rolls by. Look for any side-side wobble in the tread or any up-down motion in the surface or sidewalls of the tire.

 

Does it still have a steering stabilizer? Alot of the solid axle trucks I've ridden in and drove kind of have the tendency to "chase rabbits". Could this be what you are referring to?

 

check your steering joints for wear

 

Could be a bent rim. When I first got my truck, the steering wheel would vibrate a lot at 50 mph. Took it to the tire shop to have the wheels rebalanced and the shop found one of the front rims bent. Rotated the bent rim to the rear and the steering wheel vibrations stopped.

 

Thats exactly it, I am not very mechanically inclined with the truck yet, only been 1 day, but while I was driving that would be the best way to explain it, chasing rabbits, it would just swerve on its own seemingly. How do I check for a stabilizer?

 

23 year old truck. Worn tie rods end, sloppy steering box, wheel bearings, etc.
A steering stablizer is going to look like a shock mounted to your axle housing and tie rod.
My truck with 33's is sometimes affected by ruts in older road surfaces...

 

Look for something like a small shock absorber attached to the tie rod on the front axle. The one below is after market, the stock one is smaller in diameter and usually black.




http://www.4crawler.com/4x4/CheapTri...ringStabilizer

 

Yea I have one, it does look old as hell though, same with my shocks =x where can I find cheap stuff for my truck ?

 

whatever you do... dont use 4 wheel drive if only the rear is re geared. I replaced the stabilizer on my truck with an oem type replacement from NAPA auto parts and it made a big difference. just get the tires balanced and look over your steering system. Are you running stock steering with that 5 inch lift? You need at least a drop drag link for that much lift. if its all suspension lift.

 

On a side note you probably weren't really going 80mph. The speedometer will read quite a bit more than you are really going with the 35's. Unless you already factored that in when you said 80mph.

Rob

 

if you really were goin 80, and it dosent shake in the 60 and 70 ranges i wouldnt worry to much about it because 80mph in an 85 pickup with 35" mud tires with a 600 pound bike in the back is pushing it, my truck vibrates right when it hits 80 but up till 80 its smooth. also try goin 80 with out the bike and see if theres a difference

 

well if it was me after my experience, i wouldnt buy a "new" truck and hop on the freeway and go 80,
that just askin for trouble

 

Not sure if the steering is stock, I forgot about the ofset for the speedo, what is it for 35s usually?

 

See:
- http://www.4crawler.com/4x4/4LoCalc....peedoConverter

 

You sure your calculations are right there? It says when my spedo reads 80 im going 96, and I know I wasnt going 96 up hills with my bike in the back, and while people passed me =x

 

Pretty simple: NewTireSize/OriginalTireSize * SpeedometerReading = ActualSpeed.

This is assuming you have not regeared the axles or recalibrated the speedometer for the tire size change. Also assumes that the speedo was accurate before the tire size change.

 

That sounds like it's backwards. With larger tires than stock size your speedo is going to be reading faster than you are actually traveling.

Rob

 

No, it's correct. Giv e it a little thought. For each turn of the hub, you are now covering more distance because the circumference of the tire is greater.

 

In the Toyota, the speedometer actually reads the rotations of the rear driveshaft (or actually the transfer case output shaft). So for every rotation of that, a taller tire will roll farther. Thus for a given speedometer reading (i.e. rear driveshaft speed) a taller tire will roll farther in a given time. Moving farther in a given time = faster.