Energy Suspension

 

Thanks for the compliment.
Once it is complete, it will be driven.

 

Engineering has come a long way in 50+ years.

 

Engineering has come a long way and the new poly is a great product especially with the self lubricating graphite infused in with the polyurethane.
This bushing failed and so can a rubber bushing.
I’m thinking that the reason for the failure could have something to do with the 70 ft lb torque specification placed on that bushing called out in the assembly instructions.
The AIM calls for 55-75 ft lbs torque, on an oem rubber bushing and I’m wondering if the 70 spec is too much on that poly bushing.

I’m thinking about running a little experiment with the new bushing they are sending me.
I might install it and torque it to the lower value of the factory specifications, maybe 55-60 and let it sit for a while, just to see what happens.

I was also wondering how the top of the new rubber bushing I have would work with the Delrin cushion installed between the frame and snubber.

Its little things like this that make our hot rodding hobby so cool 😎
Just imagine if the hot rodders in the 50’s had the internet.

I’m also thinking about sending this bushing back to Energy Suspension and maybe they can figure out why it failed and if needed make it better.

 

If anyone has installed solid mounts at all three diff mounts, have you seen any adverse effects?

 

I still have the VB&P polyurethane bushings they sold me on my Corvette and they are over 25 years old. I rebuilt the front end and replaced all the rubber parts that I could reach. A while later the dreaded Squeaking started and then I learned about how to get graphite into the joints and that quiets the noise down. I had just purchased a set when I learned about the Graphite infused joints hitting the market.

When they wear out or break I will be using RUBBER bushings!

 

On my 66 and 68 coupes, I installed aluminum solid pucks on the two differential crossmember mounts. I used rubber on the snubber mount. I really do not notice a difference, but I don't push the car(s) the way I used to. Jerry

 

I installed a new poly front differential bushing.
While I was torquing the bolt from 40 to 55 ft lbs I could feel the threads on the bolt strip.
I loosened and removed the nut and the entire bushing assembly.
As you can see in the pictures of the bushing assembly, the bolt stripped, the lock washer became disfigured and the thick flat washers bent.

I thought my torque wrench was off because it never clicked so I replaced it with my second torque wrench with the same results.

This is the second bushing I’ve had problems installing and need some help from the pro’s as to try and find the issue.
I just received a new rubber bushing to install instead of using poly.
The new rubber bushing cushion is thicker than the poly replacement and almost twice the thickness as the first Delrin bushing.

Could something be binding up the assembly?
The rear differential is bolted and torqued to spec to the differential crossmember.
The differential crossmember is bolted and torqued to the frame.
The front differential bracket (snubber bracket) is bolted and torqued to the differential.
Trailing arms and shims are installed, the bolts are not torqued.
Half shafts are installed and flange bolts are finger tight.
Strut rods are in and nothing is torqued.

I can move the front of the snubber bracket up about 1/2” easily by hand.

Does anything look off in the pictures or could the parts that I have torqued be causing a bind?

If all looks good, I’ll try installing the new rubber bushing and see if it torques up to spec without bending anything, breaking anything, or stripping the bolt threads.

Thanks for the help!

 

Is there any problem that there is as much space as there is between the snubber bracket and the frame or is it normal to have some space?
I’ve watched several videos and read threads where there is discussion about having to pry to two pieces apart just to install the cushion.

Could my problem be that the Derlin bushing is half the thickness of the other poly cushion and the rubber cushion?

I’m just trying to figure this out before I ruin another bushing assembly.

Thanks everyone!

 

I have the same setup, Van Steel Delrin crossmember bushings also right?
And I had no trouble. And I wound up installing it twice.

Only thing I can think of with your bolt stripping is maybe threads got galled? But at only 45 lbs? WOW

 

Thanks Leigh.
Van Steel said it could have been a poor batch of grade 8 hardware.
They also said the short cushion is needed to keep the driveling angle correct.

 

Kinda glad I stayed w/ rubber instead of poly. Moog is also what I used.

 

That type of bushing should have one part with a washer and sleeve inside and it gets installed with the other ring put over the sleeve then a big washer. It gets tightened until the washer is compressed to the sleeve. So, you should not be attempting to adjust the pinion angle by changing the amount of compression in the bushing.

your new failure looks like it was just a shitty low grade bolt. You also have the lock washer damaging the flat really badly.

 

I think you are correct about a poor quality grade 8 bolt.
When I reassembled the bushing to see where it failed, I found the threads stripped right where the assembly torques together against the frame bracket and the bolt wouldn’t take the applied torque of somewhere between 40 - 55 ft lbs.
Van Steel agreed and they are sending me a new set of hardware.
Those Delrin cushions don’t compress.
You could try all day and it would be like trying to compress aluminum.
If the shorter cushion is too thin I’ll call Tom’s and see what thicknesses they offer in aluminum or have one made the correct thickness to bring the driveshaft angles into proper alignment.
Other forum members have used this bushing kit from Van Steel and they report no problems with the supplied bushing thickness or hardware.

 

None that I can see, but I have gusseted the frame in various areas and I have a rust free frame. Wheel hop is very damaging. When I first installed my 5 speed I could induce wheel hop in second gear just by going in and out of WOT. So to get going you had to ease into the gas. I already had a 500+ pound rear spring, Smart struts with poly ends, 9/16th rear sway with spring end adjustable, and QA-1 dual adjust shocks. I have solid motor mounts, solid tranny mount with a thin rubber spacer. So my only movement was the differential.

 

Look at this picture. The two flats on these components are not parallel and never will be. All the clamping force you apply will be in the front region of whatever bushing you use. I would hypothesize that poly bushings want equal pressure all across the surfaces.

 

In the beginning of the thread, or some where in it, I posted that I could easily lift the front of the snubber bracket.
When I do the two surfaces appear to be more parallel to each other.
You make a good point and when I install the new bushing and start to tighten the bolt, I’ll see what happens.
Thanks!