solved the jackhammer sound... I think

So after installing the new motor mounts and removing the spacers from my Transmission bracket I started noticing a vibrating sound coming from somewhere when I was idling in drive.
I crawled under the XJ, had the wife put it in drive to figure it out.

Turns out the rivets that hold the exhaust pipe bracket in place had all worn and stretched to the point that the exhaust was vibrating against the Transmission brace.

I tack welded two corners in place after using a jack to push the exhaust back up. No more vibrations and I am pretty sure the jack-hammering when offroading was from the same thing. I guess I'll find out.


trying to weld it in place was a real PITA. I couldnt do proper surface prep because there was no way to grind paint and dirt out so I cleaned it as much as I could and put in my welds. Thanks to the confined space I managed to flash myself three times and get slag burns on my arm when a dingleberry dropped down my sleeve. :gee:


hopefully the welds hold, I'll find out during hunting season.

Don't you just love welding exhaust parts lol!

You crawled under the car - while your wife put it in drive? Now that's real true love!

Dragonslayer said:

You crawled under the car - while your wife put it in drive? Now that's real true love!

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I'm out of the military and no longer worth $500k dead. :gee:

Dragonslayer said:

You crawled under the car - while your wife put it in drive? Now that's real true love!

Click to expand...

I can't count the number of times I've had to lay under my roomies k1500 while he tries to do a burnout (on 37's) so I can figure out wtf's going on with his driveline making the truck hop on acceleration. Fun/scary.

jackhammer not solved. but I think I know what it is.

My lift is a bastard pack of two S-10 leafs in between the XJ top and short bottom leaf.

I think the bottom leaf is smacking on the leaf above it, theres no rubber pad between the two and no metal strap around them. Now I need to figure out how to solve the problem.

I cant figure out how to edit, but was looking through a few of my older posts and realized I never updated this.

In case anyone has the same issues I was having I wanted to give an update that might help them.

The carrier leaf on my spring pack was missing the dampeners, I used chevy dampener pads that were plastic circles with a rubber pad under them. The post was too thick so I shaved it down and plugged them into the holes in my leaf spring. No more rattle

If you are having a jackhammer sound when hitting speed bumps then check your leaf springs.

Good to know, thanks for getting back to us with the cause and fix.

Makes me think about my leaf pack. The rear is kinda harsh on bumps. I might do a leaf pack rebuild soon since I have a few spring pack clamps laying around

http://www.bsfab.net/?p=65
Has anybody done this?

mtbxj87 said:

http://www.bsfab.net/?p=65
Has anybody done this?

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Bastard spring packs have always been popular.
Cutting the ends off a main leaf and using it under the pack's main leaf is a common mod.
I have used the plastic liner and it gives a smoother ride and last a lot longer than the graphite spray. As the layers of plastic are added, they do add to the overall lift, so take that into consideration.

Sounds good. I was just in Ace hardware. I noticed the garden edge divider strips looked a lot like the strips they used in that write up. I considered that too

mtbxj87 said:

Sounds good. I was just in Ace hardware. I noticed the garden edge divider strips looked a lot like the strips they used in that write up. I considered that too

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The plastic spring .strips, made for placing between the leaves, are "H" shaped, the sides keep the strips in place. Without them, the strips will get pushed out.
Garden border strips are made from recycled milk cartons, a much softer plastic than the spring strips. Might be interesting to try if you don't mind experimenting.

I have bought the stripping from Eaton springs, in Detroit. It doesn't show on the their website, you need to call or email them. Local spring shops should be able to order it.
https://www.eatondetroitspring.com