Calling all strange noise detectives!

[jrchafin]

I have a Mahindra 7520 (75hp) 4WD tractor that has been making a noise in the right front for some time now. (I've posted this on the mahindra forum with very little response, hence the post here). It started a couple years ago as a subtle clunk which each rotation of the wheel, but it would only happen sometimes. It is not effected by 4WD or 2WD or pushing the brakes. It seemed to be mostly when I had weight on the FEL, and also when I was turning to the right. The noise has gotten louder but is still intermittent. most of the time it isn't there.

I think it is the universal joint, but I can't be certain. The joint doesn't have grease nipples. I think there is a tiny bit of play in the joint, seems more than on the opposite side. So I have 3 main questions.

1. Am I right? Does it sound like the U-joint?
2. Will it hurt anything if I just keep using it, assuming it is the U-joint? Obviously it would need to be replaced at some point, but would it cause additional damage to run it until failure?
3. How are these joints usually changed? The joint is surrounding by the axle housing and the bracket that the hub pivots on. I think if I took the tie rod off and rotated the hub maximum amount, I could get to the joint. Is this how they are usually changed?

Thanks in advance.

 

[banjodunn]

G'day is the noise worse if you are on full lock? It may be a wheel brg have you checked for brg play? If it is the uni and you suspect it bad then do not use until failure as you could be up for new shafts as well I have seen them get that bad that when they go they break the eyes out of the yoke. The way to replace it is to strip the front hub off and pull the shaft out of the diff I have never seen one that can be changed any other way.



Jon

 

[jrchafin]

Thanks for the info. No change in 4WD. There's no play in the bearings. So if it is the u-joint, when should I replace? Right now it seems excessive to strip the whole thing apart considering the intermittent symptoms, but as I said, I don't want to damage anything further.

 

[Baby Grand]

You've probably already checked these, but it never hurts to suggest:
Tie rod end in the steering gear wearing?
Lug nuts not tight?

 

[kencunningham]

If you have two piece rims, check the bolts to make sure they are tight. I have seen at least a few posts on here where that turned out to be the cause of that type of noise.

 

[jimmysisson]

Lug bolts like I have with no cone-type centering can get loose without it being easy to notice. I have had that a couple of times once front once rear. I thought I'd broken something very spendy but ten minutes with a torque wrench fixed it.
Jim

 

[jrchafin]

Thanks for the ideas. I do have 2 piece rims and Ill check them tomorrow. I've taken the wheels off and reinstalled multiple times with no change, so I'm sure it isn't the lugs.

 

[jrchafin]

Thanks Ken! Sure enough I had 2 loose bolts on the rims! Feel kinda stupid to miss something so simple, but what an easy fix. Haven't used the tractor much since, so I am not yet positive that it's a fix, but the bolts were really loose, and it fits the symptoms. Noise got worse with more weight on the loader, worse when wheel was turned vs straight, etc. I'm 99% that was the problem. Good call.

 

[RedNeckRacin]

I dont meant to thread jack an important question, BUT the title of the thread reminded me of a Bob & Tom show skit. (radio station personalities) It was the Mr. Obvious show skit called "the animal" i think? Anyways a caller phones in about a strange noise under his sink and he is looking for some help from Mr. Obvious. It only happens when he turns a light switch on and it starts growling like a critter is stuck under the sink. Anyways, long story short, it turned out to be a garbage disposal making those strange growling noises. I think its on youtube if anyone is curious. I am doing the story no justice by typing it out as the caller is pretty seriously stumped by this question.


As for the clunking noise, is it possible a wheel bearing may have failed? Have you picked up the front end with the loader and played with the wheel with the engine off to try and isolate a component making noise? Shake and giggle the tire and anything else to try and find something?