Alignment specs
 

Anyone lowered their 1989 gmc 3500 dually and have any specs on it ???
Had mine done and they went by original height specs , something in the handling doesn't seem right , feels like it's skating a bit .
I didn't lower it so I don't know how much
Here's a picture maybe you can tell by it

Re: Alignment specs
 

There are several factors that need to be studied. First, Did the shop provide you a print-out of where the suspension is at this point...the "after" specs? If so, post them up.
Second, looking at the picture you posted, that front wheel is noticeably "back in the hole" of the Fender. Id think its every bit an inch off of where it belongs. Are both sides looking the same?
3 things (or a combination of) can create that. (1) The frame is bent in the curved, kick-up area between the suspension & the firewall (2) The upper ball joint is back (thus likely creating more positive caster as a result (3) The lower ball joint is back (thus likely creating a more negative caster than desired) which could give a "darty" and less proper feel of going straight as speed increases. The other thing to study is the angle on the tie rods from center link to the knuckles. That should keep you buzy for a few moments, HaHa, Lorne

Re: Alignment specs
 

No print out
Must be the way of picture it's not back in the hole
Frame not bent
The rest all seems to be good
I think I will take it back to the alignment center and see what they can come up with

Re: Alignment specs
 

You might also try posting in the 88-98 section for the GMT400 audience.

You've got this in the squarebody section.

K

Re: Alignment specs
 

Agreed.
That being said, here are decent specs to follow:

Camber: Street: -.5 degrees
Caster: Street: +3.0 to + 5.0 degrees
Toe: Street: 1/16” to 1/8” toe in

The Caster on my '99 3/4 ton obs ended up @ 4.1/4.2 when targeting the -.5 Camber. Drives like a Sport Truck vs a work truck.

Re: Alignment specs
 

Thanks I will give that a try