[03HeavyHalf]

I recently put a lift on my 03 1500HD, 3 inch blocks rear and cranked stock keys. When i accelerate fast the rear end starts shaking and wants to hop around, it doesnt do it when i go slow, and its stopped doing it as bad over the last few days, but it still does it on hills. My main concern is will this affect towing, and how long will it take to stop? apparently the driveshaft needs time to adjust?

 

[Crawdaddy]

No, that's not your driveshaft. Are you sure you torqued down the u-bolts for your block to the right amount? Sounds like they're loose. Double check your work. Also, how long have you had the blocks on? After something like 150-250 miles, you're supposed to re-torque the u-bolts. If you don't do it right you could lose a block from it slipping out and your axle will try to follow suit...

 

[03HeavyHalf]

well thats what i was afraid of it being. im going to check them today. and i only put the lift on monday.

 

[Rockstarrchevy81]

Yeah i have the same problem it's only at 40-45 mph though i have had my lift on for more than 2 or 3 months and havent got them retorqued but will be taking my truck to the dealership and my buddy who put the lift on for only $350 bucks is gonna retorque everything for me so hopefully that helps and also he's installing new boot's up front since they are cracked.. let me know if it helps or not buddy.

 

[silveradotrailblazer]

As mentioned most likely the rear U-bolts. We retorqued them after the first 150-200 miles and then again at 800-1,000 miles. They stretch when there new. My truck been lifted since '05 and every January I retorque all the nuts and bolts.

 

[Crawdaddy]

It's also helpful to know that having blocks will cause the rear axle to have more wheel hop. By putting blocks in, everything becomes one big lever that wants to load and unload on acceleration causing wheel hop. But still, definitely recheck your u-bolt torque.

 

[03HeavyHalf]

Thanks guys. What is the torque supposed to be on the rear end? I got the torque wrench and everything but im not sure what its supposed to be set at?

 

[Rockstarrchevy81]

Thanks i will make sure i get all my lift kit torqued to specs sometime end of next week since ill be busy until thursday afternoon i will let everyone know how it goes.

 

[silveradotrailblazer]

Yep as Crawdaddy said, block spromote wheel hop. The taller the block, the easier to get wheel hop. Back in '96 I had blocks and a add-a-leaf on my '96 'Burb and one time when I got on it to get threw some sand the rear end hopped and I broke my driveshaft. (crap). Fixed the driveshaft and installed new rear lift springs. No more wheel hop. If you run a tall block you should install traction bars. Now, a set of GOOD traction bars are almost/same cost of a set of lift springs so i went with the lift springs on my '05 silverado.

 

[2COR517]

Definitely sounds like axle wrap due to the blocks. And yes, it will affect towing. Also, U-joints in poor condition could be causing some problems too. If you will be towing heavy and/or mountains, you may want to bite the bullet and get some new springs.

 

[03HeavyHalf]

So basically unless i buy new springs i have to remove the blocks to make it stop doing the hopping? my friend did this same lift to his truck and it stopped doing that after awhile.

 

[silveradotrailblazer]

Have you retorqued the u-bolts yet? Start there.

---------- Post added at 06:29 PM ---------- Previous post was at 06:21 PM ----------

Also a older truck with miles on it will axle wrap easier than a new truck because the springs are worn/softer. If it was my truck I would take the 3" block out and install a add-a-leaf and a smaller block. Every truck is a little differant so you may only need a 1"-11/2" block with the add-a-leaf.

 

[Rockstarrchevy81]

I guess i will get my U Bolts tightened next week and if that doesn't work just get some Traction Bars like SILVERADOTRAILBLAZER said i found a pair of some from Tuff Country for $182 as a pair. This seem's like this would make it not hop or anything after u install them.!?

 

[03HeavyHalf]

well let me know if either of those work out.

 

[Bigg Ron]

You may also want to look at your drive shaft angle to make sure you have not exceeded the allowable angle, which will cause vibration and early u-joint failure.