# NAA Tire Failure



## Ed Williams (Jun 13, 2019)

I reported a tire blowout on the NAA in a previous post and thought I would give an update. I finally got the NAA on stands and got the tire/wheel comb off. During inspection of the tire, I could not find signs of a tire blowout. I do know I heard a loud pot and the tractor quickly tilted to one side. On closer inspection I saw a 16" hairline cracks in the rim inside the bead seat. I gave it a pretty good shot of air to help find the leak and you could physically see the cracks open up. This was on the back side of the rim and could not be seen until the tire was off the tractor. What I had was a catastrophic rim failure. The rim actually looked pretty good until air was applied. Evidently the only thing holding the rim together was the 6 coats of paint I applied to prevent rust. I rebuilt this rim 37 years ago, and thought I did everything right. I had a machine shop cut a piece of 10 gauge plate to the inside rim width, then roll the plate to the internal diameter of the rim. It was a real bear to install. Did a complete circumference weld on both sides and a butt weld on t plate ends. Then split the plate in the middle and hammered in a bead groove and then welded that back together. Looked like a pretty good repair. Lesson learned, a repair is just that, a repair and will not last forever. It did give a pretty good run though. Also, always be prepared for the unexpected while operating a tractor. Attached are pics of the extensive internal rim damage, although the outside still looked good.


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## pogobill (Jan 31, 2012)

Wow, that is some blow out! I'm surprised it didn't go flat prior to the failure.


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## Ed Williams (Jun 13, 2019)

I know. I was in shock for a few minutes after I got the tire off. I don't know how it stayed inflated, or why it suddenly popped. I have never seen a rim in such bad shape and still hold inflation. Paint must be a lot stronger than I imagined.


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## Ed Williams (Jun 13, 2019)

Update. New rim, new tube, new hub. Back in business. Another day with a tractor and deeper in debt. Overkill again, the tire shows a lot of dryrot, so while it was off the rim I plated the inside of the tire with an old tube that had a pinhole leak I couldn't get to stop leaking. A one piece liner by slitting inside dia on old tube and trimmed to fit. Tube is 1/8 in thick rubber, so should give a little added protection to prolong life of tire. Also, applied powder to inside of tube liner and outside of new tube. Should prevent any friction problems between 2 layers of rubber. Biggest job was removing and reinstalling the chains. Tire job very simple with a new rim. Not used to that.


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## Ed Williams (Jun 13, 2019)

Another update. New rim, new tube, new hub, new blowout. My luck is still holding out. Different field. LR tire blew after mowing about 1 hour. Made good decision not to ballast til had some time. Otherwise would have lost ballast also. Tire blew out just above bead. Noting the heavy dryrot, should not have been surprised. New tire ordered and due in 10/09. Tractor still in field went to get 4000, boom pole, jack, Jack stands, cribbling, etc to get tire and wheel back to house. 4000 gearshift had locked up on Jerry while dumping a load from the scoop. (YES, Jerry got a very nice 4 hour turn on the Big Boy tractor. I guess I will now have to hide the keys to have enough fuel for my work ) Tractor would move with H/L in L position and gearshift in N. Pick any gear on gearshift and everything locked up and killed motor. My normal run of LUCK still going strong and building steam. Now looking at teardown on 4000. I happened to remember a post on this forum about a locked up shifter being caused by misalignment of the guides. Jerry and I popped top cover and sure enough, the shifter guides were miss-aligned and locked up. H/L was OK. Realigned shifter guides and H/L position. Bolted on top cover to test. Everything appeared to function normally. Worked it for 2 more hours using 2,3,4,R gears with many, many shifts. Everything working fine now. This forum saved me many hours of checking and testing to find the problem. Still don't know the cause of the shifter guides locking up, but everything is working fine now. Just waiting on new tire to arrive.


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