Took the 90 Vert for its maiden voyage today! Just around the neighborhood, but got it above 2000 RPM's and it shifted great.

As you know, I've replaced shocks, brakes (complete overhaul), u-joints, axle bearings, new differential fluid, et al. But Ive got this loud creaking sound coming from the rear at low speeds when letting off the accelerator. Under acceleration or normal driving, all sounds fine. So, my assumption is, when the engine is driving the rear, no sound, but when the rear is driving the transmission (engine braking), I'm getting this creaking sound...it almost sounds like someone bouncing on a car with bad shocks.

Thoughts?

 

What is the frequency of the creaking, I mean, does it coincide with driveshaft speed (a dry u-joint, driveshaft rubbing on parking brake cable, pinion bearing), tire speed (brake drum rubbing on shoe or dislodged "anti-rattle" spring), or something else, like a leaf spring part?

Slow freq I might associate with a wheel, faster freq maybe driveshaft, trans, or diff noise. If it's more like a temporary noise that quickly goes away, then maybe suspension or a body part rubbing.

Noises like that can be a b****. I had a creak coming from the front end after I got my truck back on the road; turned out to be the left front fender bolts at the bottom of the fender - both loose. It was intermittent, but more noticeable on rougher roads.

 

I had a brake adjuster cable break inside of the drivers side drum. It would make a scraping squealing sound at times. It was at low speeds and more in reverse. If you dont see something obvious, I would jack it up and have someone put it in drive while you listen outside the vehicle.

 

One thing I think of that's frightening - is a, or more than one, loose U-bolt holding the springs to the axle.

Try what Ragged89 suggests, and 93_ragtop, to verify it's not something else.

I'd also check the torque on the U-bolts for your cousin, Justin Case. He's funny about things like that.

RwP

 

It's definitely at a slow wheel rate....So differential, axle, hubs or brakes I suppose. It goes away upon acceleration or normal driving...only seems to appear forward or reverse when releasing the accelerator.

 

Yes, I plan to put it on the lift and test again today...I did that the other day and heard nothing, but it was a quick test at low RPM. I'll try more thorough tests today.

 

Thanks for the suggestions Ralph....I didn't touch the spring U-bolts so I never checked them...good idea to give them a once over. A shop put the U-joints on the drive shaft for me, so something else to look at.

 

Well, I raised the truck a foot in the air and no noise, all the way up to 60 mph...Have to admit, even with the truck securely on my lift, I had visions of me sitting in the truck and it falling off the lift at 60 mph! Not fun!!

So, I raised her on up and started jerking on everything. I found one loose shock bolt, but then I found this...I think I found my squeak. Evidently, the drive shaft under deceleration and under load with the wheels on the ground shifts up enough just to rub the gas tank shield.

 

Nice racing stripe around the drive shaft! Better something like that than a differential problem I reckon'.