When cab bushings are replaced with new ones, there tends to be a popping noise. I can't remember if I posted an inquiry about this already, so bear with me. I replaced my old bushings with a set of black energy suspensions awhile back. I have re tourqued those bolts 10 ft lbs past spec, and the right rear directly under the passenger side rear pops every time I make a left turn onto a driveway entrance, like with a slope. I've read this somewhere before that energy suspensions tend to possibly cause this, but why? Should I torque that one down a bit more? I guess I could, unless I'm missing something that could cause damage. Swear man, seems like for every 5 posts I put on,(and I don't post much) it seems 4 out of 5 are fix it posts. Seems like its always something. Truck is performing awsome, just little knick knack things seem to always pop up. Guess I really can't complain cause my troubles really aren't anything when compared to some. Anyway, if any has a suggestion I'm all ears. Thanks

 

I am going to surmise that you have something somewhere either fatigue-cracked or loose that the slack and sloppiness of the old cushions was not stressing.

With all that sloppiness taken away with nice new more solid mounts, whatever is amiss is now having to take up the slack.

It could be as simple as an exhaust tube now hitting something.

Years ago, when I still had the huge V-8 I-H engine in my truck, an exhaust clamp had worked itself to where it contacted the fire-wall under certain torque conditions and sounded like the crank-shaft was fixing to fly through the floor-board.

I about ran myself nuts before I found it, even cut short a money-making trip, listening to this knocking sound all the way home from central Oklahoma, expecting sparks to start flying any minute.

When I finally found it, it took about five minutes and no dollars to set things back to rights.

Hopefully, your situation is just as simple, but much easier to locate.

 

I had a truck once that did that, it was brand new, what I ended up doing to fix it was shorten the spacer inside the bushing 1/8" and torque it back down. All that did was squeeze the bushing a little more but it cured the problem.

 

I think polyurethane bushings are hard on a stock suspension unless it was built for it.
Fractures in the sheet metal can cause pops when it flexes, also loose rivets and cracks in the chassis.

Jim

 

Yeah, I'm betting he has sheetmetal cracks and the new bushings are bringing them to light.

 

I will look into that this evening. Thanks! The bushing spacers, the shafty deals, I remember someone suggested I trim some off the overall length to allow more room to tighten. Yeah, I already did that one. My last resort is to find that port under the carpet that houses the threaded portion that the thru bolt attaches to to see if anything is going on there.

 

polyurethane bushings will do that if they aren't lubed good between the poly bushing and the sleeve. that would be my guess.
But not on the points it contacts the frame mounts and the cab as Brian found out.

 

Yeah I added extra hardened washers under each of the bolts so I could torque them down properly. After removing all the grease...that I should not have put there...as Mark mentioned. I lubed up the bolts with never seize and slid them down through.

 

Why not on the points of contact? Curious. School me

 

Guess I should have said I put the washers under the nuts. I didn't want to add any washers under the points of contact with the body because it would have amounted to a small lift in the body.

Here is a pic with the washer installed.

 

Ok. Looks like mine. It's the grease why not lather up grease on the bushing contact point? Will this cause the popping also? Reason I ask is I slipped a swipe with the index finger on the bushing tops/ bottoms with Syl-Glyde

 

I don't think the Syl-Glyde would cause the popping. The noise from poly bushings is caused more from dry bushings sticking to the sleeves then breaking free. In a cab bushing it doesn't move as far so instead of a squeak you get a slight pop that is amplified by the sheet metal.

 

The popping might be your cab sliding from side to side? I know when I had mine all greased up the cab was slipping, and sliding. Although I did not have the mounts torqued down properly either...so that didn't help.