Side Spare Tire Carrier Tearing/breaking Is It The Tire Weight?

I have had two issues with the side tire carrier, and I think it may be the weight of the spare tire, 7.50-16 BFG KM3 (PO installed) is listed as 50lbs minus rim weight. Of course with a bumpy ride, the weight is torsional.

1st issue last year was a tear of the mount at the seam, cheap reproduction I assume the PO replaced. I had it welded, seems more rigid in that area now and no further tearing.

2nd/new issue is the right upper mount bolt/nut/washer is beginning to tear the rear fender skin. I need to deal with this now to minimize further damage.

What I am asking of the seasoned vets/old timers, any idea what the rated weight is for the mount/sub/inner mount? Could the heavier tire indeed be the culprit, seems logical to me. An extra 20 lbs acting in a torsional manner adds up in force.

I do like the KM3's (not to mention 7.50-16 are getting hard to find), but, a bit overkill for my needs as I daily my CJ5, they're heavy which plays into the un-sprung weight thus impacting acceleration, MPG etc.

I am looking at the Firestone NDCC| 700-16| 34 lbs to give more balanced performance of 70% road/30% off-road, mostly gravel, not a fan of mud, mostly trail riding on gravel and of course pavement. Mixed reviews on NDT's,/NDCC's even when siped, but still a contender.

It's difficult to talk tire performance with a modern tire shop as the needs and designs are FAR different than a modern vehicle. I prefer bias ply, I bought my vintage Jeep for the pure tactile operation, and I am ok with it riding and driving like a 1961 CJ5, so not interested in radial tires.

 

I will check further, I think I do see the backer plate intact but will inspect further to confirm. No to the anti-vibration block, not seeing part# 6711157 in Group 31 of Parts Manual listed via Google or KW

 

Great info, thanks Howard.

 

X2 on the vibration damping block, absolutely there for a reason! That, and tires have grown bigger and heavier that what was used off the assembly line.
-Donny

 

They all break eventually. If not fatigue, then trees and mailboxes.

 

I went with the Firestone NDCC 7.00-16 at 34 lbs, got a deal and 0% APR with my Amazon Prime. Now, IS it possible to mount them at home with spoons. I know it will be a chore if so, my moto's aren't easy, not afraid of sweat equity, I can repaint the rims after. Don't laugh, solid question.

I LOATH paying the tire place their stupid fees nickle and dime enviro made up fees, easier to have them balanced after the fact.

 

Do you have any local shops that sell used tires? They're a little more forgiving about fees and regulations, and usually cheaper than the big stores.

 

Good idea and worth checking.

 

Yes. If you are determined enough.

 

I bought a replacement dampener wooden block from Walck's, but now you need to get from Kaiser Willys. My side spare is 235 75R15 on stock steel rim.

 

thanks for the up close shot, I have plenty of wood and poly, I can make my own going by the photo and the 3B thread.

 

Or the gate post to the cows pen….

don’t ask about this….

 

Parking meters too, for the less adept suburban drivers. Just a guess.

 

Thats why I don't have a spare mount on my Jeep. I have a jack, compressor and tire plug kit in my toolbox, never needed it yet. I have a spare I can throw a spare in the back if I think I might need it.