I have an 04 single cab it is supercharged not crazy high boost between 4 and 7 psi is my guess I don't know much about superchargers. when taking off from a stop the rear axle feels like it moves. like the drive shaft is taking the "play" out of the rear axle before it engages to move itself forward. is it axle wrap or am I way off? I'd imagine I'm in for other driveline issues if I don't get it figured out.

 

It's also lifted 4" with 315 70x17's

 

My stock 4x4 97 was doing that on acceleration and I had the clunk as well. Tried just about everything then I changed my rear shocks to stiffer ones and the problem is gone...

 

Trying hard to understand what your trying to say. Not following the part about the driveshaft taking the play out. But axle wrap can be a problem with all the extra power.

You mentioned being lifted. Have you checked your driveshaft angles? If these are off it can cause vibration, binding, and eventually wear out the u joints. It can also cause axle wrap. At the very least any binding os costing hp at the wheels.

Axle wrap occurs when torque and traction combine to twist the axle (pushing the nose of the differential up going forward and down going backward). When the pinion angle changes it distorts the leaf springs. A certain amount of this is normal and expected. Pinion angles can change +or- 1-4 degrees without causing issues a d sometimes even more. A prime example of this is when you load the truck down and haul stuff or simply driving over bumps and dips in the road. Lifting or lowering a truck can change pinion angles drastically causing axle wrap and as the effect becomes more pronounced so do the results. Even to the point of wheel hop which can do some serious damage very quick. Axle hop is almost a guarantee when you have the power your making and get traction.

My suggestion would be to check out those pinion angles and if the issue persist look in to traction bars. I have aligned my driveshaft and pinion angle to within 1 degree. I have installed Caltrecs on mine and they work great to keep it that way under hard acceleration. No more axle wrap no more wheel hop.

 

what "traction" bars / anti-wrap bars are you using??


did ya'll check the pinion angle after the lift was installed???

 

Heres a great manual for checking pinion angles. http://65.170.161.218/~spicerpa/site...stallation.pdf. Page 13 on was what I used as I have a 2 piece shaft. Being a single cab you likely have a one piece shaft so start on page 5. However the entire manual is beneficial.

With the added power/torque you have the ideal setup will be for your rear end pinion angle to be point down 1 degree from the the transmission angle. This way when the force hits the rear end and twist it upwards she will be close to perfect.

 

That spicer pdf is very helpful. Ill definitely refer back to it. so you have the caltracs on your truck and Im guessing the picture you have on your post is the truck you have them on. anywhere I look for them they're always for a lightning. I don't know if those would work on my truck or not. Also would they limit suspension travel much or at all?

Ill have to measure the pinion angles and see what I can do to lessen the angle. the angles don't look to severe but that's just me eyeballing it. I found something similar to the caltracs, its Roadmaster active suspension have you heard anything about those?

I haven't run into any wheel hop but I haven't really hot-rodded around. once I could tell there was issues with axle wrap I really dialed it down but Im sure if I gave it some go axle hop would be present. one last question (sorry about all my neediness) is there anything that will need to be replaced because I haven't corrected the axle wrap issue yet like bushings or u joints (which could probably stand changing anyway)?

 

The Caltracs don't seem to limit suspension travel at all. And the way they are designed I don't think they could. Also Caltrec doesn't have them listed. You just have to call them and they will get you what you need based upon your model and how much your lifted. I love mine. They are the only thing that allow me to drive this truck like I want and drag race it without issue. I think once you check your angles you will and correct them if needed a lot of your issues will go away. As far as any bearings or bushings needing to be replaced...I don't know what condition yours are in but if your angles are off yes the u joints will suffer.

 

I really appreciate all your input it was incredibly helpful. I wish Id of got on here a long time ago. one last question. Shims between the leafsprings and the blocks used with the lift kit to raise the rear would be the correction to too steep of pinion angles correct?