low speed wobble
 

Hello all,

V2500, 2 inch lift, 37 falkins.

Anyone have a odd source of the a wobble that took a while to find?

Truck rides smooth as silk, but a few month ago i had the wobble bad after crossing one of those concrete dips in the road to channel water while going ~15mph.

Startled me because my truck has 600k miles and never a wobble. Caster correct alignment perfect. Got it again the other day, but if let go, it could get violent enough for concern.

That said, the only play in my front end is the travel of the pitman arm from the steering gear, the normal play during teeth engagement. Any possible way this is causing it? It is a Lares Gear and i have them on multiple builds. This truck steers great, no play.


I am installing new SX8000 nitrogen shocks and the 9000 stabilizer tomorrow. All the shocks i removed looks okay. They still positive pressure but maybe not as much as new,.


Thanks,
Chris

Re: low speed wobble
 

I'm assuming tires are all balanced and 100%, oddly, mine was a transmission mount.

Re: low speed wobble
 

That is odd,, Mine is `100% front end. like the negative caster death wobble.

The new shocks came today,, will run through everything again. I can not get any discernible play from any ball joint or rod end but i have my body weight strength to move it.

Chris

Re: low speed wobble
 

If you have a helper. Dry streer test.

Tires on ground. I prefer engine off. Have helper steer back and forth. Crawl under and feel every joint that moves.

You will feel any clunk. Play. Slop.

Re: low speed wobble
 

Did that,, only tiniest of movement is the Pitman Shaft. maybe a few thousands.

No leak, steers great,, wasn't going to attempt to snug it up just yet

Re: low speed wobble
 

Happened after a tire hit? Maybe one of the tires developed a problem. Might switch the front and back tires. Check for recently missing tire weight.

Re: low speed wobble
 

When it happened the first time, I had just rotated the tires. I Rotated again it still happened.

I will have the shock installed this morning. Hopefully that fixes it

Re: low speed wobble
 

Update, sort of,,

Installed new nitrogen sx8000s and a skyjacker satabizer. No wobble but only a few miles of test.

I took it to Les Schwab today to have the guys put eyes on it.. Nothing looked a miss except a tiny movement in my pitman shaft. ( few thous, no leak) and the from leaf bushing tiny movement.


I tightened the leaf bolt to 100 lbs,, it was a little loose. and i put a 100 on the through bolt of the pitman,, i now read it only to be 45?

Anyway,,, take a look at the picture. This is not my wobble source but am i missing some type of spacer bushing? the bracket is angled and torquing it to 100 moved it more.

Should i have, am i missing something to stop the bend? should it be plumb, perpendicular to the bushing?

they are Tough Country springs.

Chris

Re: low speed wobble
 

update,

For future readers troubleshooting;


I put a few hundred miles of highway driving on the truck and it was a mess. I was getting a high speed bounce over 60mph. like the ball and paddle game as a kid. Turned around at Salt Lake and decided to go home.

Twin Falls Les Schwab slid me in for a quick balance check.. My just recently balanced tires were 2oz (driver) and 3 oz(pass) out of balance. I just had this done as a first step chasing the wobble.

Anyway, Installing the new SX8000 shocks made it worse. I think the Quad nitro shocks are too much for the old school leaf springs on the highway. They are strong enough to push against the spring and then the spring recovers and forces against the shock? They get in that harmonic phase and can't stop.


I am going to go back to hyd shocks.

Chris

Re: low speed wobble
 

did they road force balance the tires? it sounds like a separated tire, especially since it started after an impact