Bad U-joints in DSS driveshaft?

[Tbone]

So last weekend I installed Freedom racing UCA (for lowered cars), freedom racing adj panhard bar, BMR LCA and relocation brackets and a DSS driveshaft with a dynotech adapter plate. Since the car was lowered I did everything I could think of to correct the suspension geometry changes.

Panhard bar to center the axles, LCA + relocation brackets to fix their angle (OEM LCA were facing up), and the UCA to fix the pinion angle for the new driveshaft.

Now, I have no vibrations at any speed while cruising. But if I tap the brakes and slow down, there is a noise just for a second, it sounds like running over a rumble strip when coming to a stop sign. If I give it just a touch of gas it does the same noise, but only for a second. After that it decels and accelerates perfect, no noise or vibrations.

I was thinking the only thing it could be is ujoints. This is a first gen dss driveshaft with ujoints at both ends and a slider. I called DSS and they said they use solid 1350 ujoints, part 2-0799 neapco brand or 5-1350 spicer brand.

Before I buy the joints and tear everything apart I wanted to see if anyone had any other opinions. Thanks!

 

[BadPiggy]

U-joints would be my guess.
Nothing else that you've done should create a clunk unless you didn't get the bolts tight?

When you pull that DS to install new U's...I'd highly recommend installing a BMR Driveshaft Safety Loop. Surely you know what can happen if that DS snaps and drops to the pavement. Look in the Classifieds section. I saw one for sale there just a few days ago. I think it was forum member "DiMora" selling it.

 

[o2sys]

Was your new driveshaft a different length than stock? Why do you need to change the pinion angle?

 

[Tbone]

Was your new driveshaft a different length than stock? Why do you need to change the pinion angle?

The car was lowered which throws off the pinion angle. The stock DS is 2 piece so it compensates for it. I used a UCA from freedom racing thats made for lowered cars so it corrects the pinion angle. The way I see it, Stock UCA is bolted to the body, so lowering the car moves the mounting point on the body down, which will clock the differential up. New UCA is shorter, so moves the differential back down to where it should be.

And yes I will definitely put a DS safety loop on. Dont like the idea of my car trying to pole vault!

 

[07 procharger]

First off. Get under the car and look for contact marks on the shaft, make sure it's not rubbing anywhere.