Cat 236 chain, bearing noise?

[18nascar18]

I have a customer with a Cat 236 skid loader with approx. 500 hrs on the machine. It has a noise coming from the right front chain case area when the machine travels at a decent speed forward and reverse. At first it sounds like a chain rattle or hiss. I raised the right side of the machine up and checked the chain tension and oil level and it was within specs. My next guess would be a bearing chattering, but I wanted to get some feedback from some of you who are more familiar with the Cat machine than I am. The noise does not sound ominous right now but I know it's not supposed to be there. Any help or "been there befores" would greatly be appreciated.

 

[Swannny]

Same issues with a friend's machine. His is a 246 Cat with 75 hrs. YES....75 hrs. Very loud...sounds like marbles/hissing in the drive motor area when cold...less audible when hot.

Did you check underneath the seat to tighten up clamps on the hydro suction or return hoses? This machine had tight clamps. Air in the system can cause noise.

I was also guessing possible water in the hydro fluid since this machine sat unused for 10 years. Going to change it out and send a sample to get it tested just for kicks.

I've had a lot of Cat machines...both the a and b series the seem to develop the hissing/ticking noise in the drive motor area.

Different machine, but had a Gehl 4840sxt with only 45 hrs. last year that had a clicking noise in the drive chain area. Took off the inspection cover and found the arm that has a gear attached to it that puts tension on the chain was slapping back and forth laterally. Welded a shim inside the pivot arm and was good to go. Was surprised how much tolerance was in the mechanism from the factory. Noise was really irritating to say the least.

 

[18nascar18]

Thanks for your reply Swannny,
I had talked to a couple of Cat dealer mechanics and they said to check under the cab for any loose bolt and it possibly could be a bearing. As hard as it is for us independant mechanics to turn away any business, I had to tell my customer that he should take it to the Cat dealer at least to let them hear it. I didn't want to tear the whole thing apart and put it back together and still have the noise(I don't charge for what I don't fix)! So, he did and the mechanic said not to worry about it, that some of those machines were noisier than others after so many hours. If the customer still wanted something done it would cost about $3500.00. It worked out good, I didn't let my fix it ego lose me money and the customer said I was his mechanic from now on for being honest. Thanks for your input, I really enjoy this forum for us construction gearheads!
Rob

 

[Swannny]

Well, at least you're on to something else (good for you)....I opened the chain case covers on the 246 this afternoon, jacked it up and got my youngest to drive it. Noise is coming right from the drive sprocket area (both sides). Chain case oil looks new, up to level. Chains are properly tensioned. Almost sounds like the oil is the wrong viscosity or something....sure does sound like marbles being tossed around. Ran out of time, but will look into it tomorrow.

 

[18nascar18]

When you find it let me know for future diagnosis
Thanks
Rob

 

[03hdrk]

I know this is old - but what happened to the noise?

 

[Nige]

We had the same issues with a Cat skid steer when the Ops people took it swimming and never told us. It took the axle bearings out in short order. We opted to upgrade to the Heavy Duty axle setup with (IIRC) triple lip seals and heavier bearings at the same time as we did the repair. I make a point of recommending this option (if available) whenever we buy new skid steers. Saves a lot of grief down the road if the machine is going to be working cab-deep in water ..........

 

[03hdrk]

It is the motor in this case. Cat 236B. Just a slight noise when not under a load. I pulled the suction screen - small amount of metal on the screen. Now how much flushing do I do? I recently repaired a leak on the suction screen fitting and replaced the seals in the joysticks. Replaced the hyd filter and fluid. Now I wonder if the owner is going to blame me. I always cover open lines when working on hyd systems and am sure that I did not allow anything to get in the system, …
This owner likes to use the cheapest hyd fluid he can find...
Only 1200 hours on the machine...
Frustrating and does not seem right that it would go out even with cheap fluid. But the leak I fixed was a blemish in the sealing surface of the oring, so I am sure it was leaking since it was new and has likely had cheap fluid in it all of its life and may have been run empty at some point.