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Discussion Starter · #1 ·
Okay Guys,

I've searched around but haven't found a good solution to this.

I bought a 1979 CJ7 a little over a year ago. It was in good shape and not driven much when I bought it.

It has a swing arm tire carrier cantilevered off the rear bumper. I can't determine the manufacturer nor the model but it looks pretty close to the Warn bumper/tire carrier combo.

I have 33" tires with steel wheels on the Jeep, the spare is the same combo.

Within a few hundred miles of getting it, I noticed that the tire carrier was flopping around. After inspection, I found that the mount on one side of the bumper had cracked and it was being held on by a thread. I also noticed that both the heads of the bolts that hold the bumper to the frame through the rear spring mounts had sheared off.

I welded the mount back together and added a 3/16" steel plate on the inside of the mounts to strengthen them. I drilled out the damaged bolts and re-tapped them 3/8-16. When I reassembled this, there was still a lot of flex in the rear bumper cross member so I took off the tire carrier.

My next trick was to cut a piece of 1/4" steel to bolt to the rear cross member to reduce the flex. I bolted the bumper and tire carrier to this and it was remarkably rigid. Thinking that I had this licked, I hit the road.

After about 50 miles, it was flexing again and it had sheared off the head of the lower bolt through the rear spring mount on the passenger side.

Any suggestions?

I know that the wheel & tire combination adds a lot of weight to the bumper. I also know that adding the reinforcing plate to the cross member increased the moment on the bolts. I'm using 316 stainless steel fasteners. I need to go check the strength of these. Tougher bolts may be part of the solution.

I'm not beyond getting a different bumper / tire carrier combo. Any recommendations would be greatly appreciated.

Also, what about going back to something more like the stock tire carrier?

I appreciate any input.

Jay
 

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I had a similar issue with my 85. Added a bumper on the carrier to add some stability to the carrier.

Seemed to have stopped the rattling.
 

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Kinda confused with your description but keep in mind the stock rear cross member isn't all that stout. There's a few offerings of replacement pieces made out of 3/16. Could even fab your own easily.

When I did my rear bumper/carrier I made "L" shaped brakets that bolted to frame and basically sandwich the crossmember between them and bumper. Then bolted bumper through crossmember and to these.

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