'99 379 rear airbag height.

It'll just adjust to whatever its set at.

 

I run 11r 22.5 all the way around. Not sure if springs are factory. Something i just thought of...could it have car hauler axle on it? Whats the difference? Like much difference is the drop than a normal axle?

 

you can kinda tell how it dives in front. The back fender is parallel to the frame. Don't know if this helps.

 

Front end does look a little low.

 

Should've asked sooner, but did this just kinda suddenly start or did you change something that it started after?

 

No been trying to figure this vibration out for a while. This is my last thing that can possibly think of. Replaced tires, shocks,drums, transmission, both rears, complete driveline, all ujoints, carebearing, leveling valve. Just noticed other day about airbags not even close to the same. And frame setting on stops in front but not close to back stops. Front shocks bottom out on front rear end when deflated but back are still extended. This is why i was thinking that the front end needed to come up more..

 

Anybody tell me how to check if its a car hauler axle?

 

Hard to tell just from the picture and I know those fenders have bigger lip than stock, but even still, I think you're an inch or two lower in the front than I am. Mine is completely stock with the same rubber as yours.

 

Yeah those are the jones fenders. That's what I'm thinking about a couple inches more in the front end.

 

https://www.fleetowner.com/news/article/21667253/peterbilt-offers-car-carrier-axle