Max II Chain/T-20 Noise

[Eldon]

Since April I have been whenever I get the chance trying to repair my MaxII 850T. When I removed the tracks from winter and re-installed the front chains it appeared I was getting a noise like a chain rubbing. I determined it was on the right side and it appeared to be in the area of the chain adjuster. For a time I blamed it on worn tires of different diameters so I changed to new AT101's,still had noise. Then I believed it was the chain adjuster not locking on the rear ratchet assembly so I put new RI adjusters on both sides of front,still have racket. Everything appears to be in alignment. Bearings were changed about 120 hours ago and seems good. Chains are good and lubed. When running with floor out I can't see anything to indicate the chain rubbing yet it sounds like dragging the side of the chain by metal. I tried to night full speed reverse,no noise. Tried pulling right lateral when going forward noise immediately stops. There is absolutely no noise when jacked up holding full throttle .Question,could the T-20 be causing this noise? I am at wits end to locate this disturbing nerve wracking noise. Machine has 382 hours on it all by be for last 350 hours. Other than running tracks in snow and sensibly at that,the machine has had a very easy life. Could the T-20 be gone already? The machine always was so quiet you would think there were no moving parts under the floor. I have tried front chains off,left front chain off,right front chain off.It doesn't seem to be the chains but sure sounds like it. I sure would appreciate any help you guys can give.

[Mike]

Is your front right brake dragging for some reason? If you get moving forward and pull the laterals back just enough to get the T20 into neutral without activating the brakes, does it make the noise then while you are still rolling forward? Can you push the machine back and forth on the ground and get it to make the noise?

[Eldon]

Mike I appreciate your response.The brakes are running free and I can spin each side freely when jacked up.No noise with the laterals pulled and rolling even at a fair speed.In fact pulling the right lateral only does away with the noise.Definitely no noise when pushing back and forth on the ground and no noise even when jacked up and running at full speed. I am getting suspicious of the T-20 thinking pehaps a bad/ band drum on the forward right side is causing a rapid slipping/gripping when under load maybe causing torque on and off the chains quickly enough to cause a chain whipping but no sign of it when running without the floorboard. LOL just grasping at straws. By the way I called RI to buy the new adjusters and found their service superb and also thought that given the complexity of the adjuster that they were priced very reasonably. Thanks a lot Mike.

[ARGOJIM]

Seeing as you're thinking back that far, are the jack shafts even? An uneven jack shaft will cause a side load on the chain, more pressure more load. If you think they are even, you may want to back the tension off and check the bushings for excessive wear/play in the bushings.

[msafi65]

I've had track vehicles with strange clicking noises but only with the tracks on. Both were fixed by breaking the 2 outboard bearing collars loose and relock in the opposite direction. From your diagnosis I suspect a bearing in a planet unit right side????
Just for grins does it make the noise with right front chain out?
This may be a tough one,good luck

[thebuggyman1]

I seriously doubt the problem is in the T-20, but with 382 hours it might be wise to crack it open and take a look anyway. It sounds like you drive very sensibly, so I'm guessing the band lining material in your trans will far outlast that in mine.... Any problems with the bands should show up as driveability/ turning anyway.

I'm with Jim here, double check the jackshafts. Look at the sprockets on them for chain wear on the sides, this is very common.

[msafi65]

I had another thought, your machine should have set screw sprockets?? I have seen several maxIV that have had the tip on setscrews fail letting the rear sprockets wander to the side. Is there any chance the center sprocket has moved? Hope you find this one.

[Eldon]

I really appreciate the input from all of you folks,Mike,ArgoJim,msafi65 and thebuggyman1. The input on the jackshaft I will check out thoroughly as the sound seems to be around there or forward of there. The problem is of course no problem with a test jacked up only under moderate load does it occur. The suggestion of a bad planetary bearing is frightening (lol) but it is a sound like that would make and appearing in the general location.I did check the front sprockets for side movement but not the triple center sprockets. All of the points mentioned here are very valid and it will help me concentrate on these areas to either eliminate or focus on. I'm not sure whether valid/noteworthy or not but even under load when starting out I go 100-250 feet before it makes any sound. I am going to do another thorough test this time with front right chain off and put it through its paces and see if there is any noise. I did a run with a stethoscope as best I could and put the source on the right side at either front adjuster,jackshaft or center sprocket with it possibly just rearward of the adjuster,with telegraphing its hard to be certain. Thanks a lot for your help,it is really appreciated.

[Mike]

When you remove the front chain again, try removing the front tire too. That will completely eliminate the front bearing as the source of the issue as well.

[Eldon]

That is a really good idea Mike I sometimes forget that a 6x6 can do without a wheel for some applications. Further investigation has led me to believe that indeed the front right chain is making the noise though I don't believe that by itself it is at fault. When driving I clearly see that to the rear of the chain adjuster the chain moves out of alignment causing noise as it runs through the adjuster slightly out of alignment at rest it is perfectly aligned. I am thinking that either the center sprocket or possibly the entire axle is slightly moving inboard when under load/torque. It doesn't seem to move when tried but the investigation continues. Your advice is much appreciated.

[Eldon]

I am really appreciative of all you folks who helped me find this perplexing problem. Special thanks to msafi65 on his afterthought.........broken tip on set screw on center right sprocket,you were right on the money. Rolled up my sleeves at noon and just got it all back together. Looking forward to some silent running.The damned thing would self align after the torque left it and the chain sound was actually the rear chain rubbing just aft of the center sprocket. Thanks to All.

[Eldon]

Max II Sprocket Set Screws

I have experienced a double failure with sprocket set screws. On the right middle sprocket I found the end had sheared off the set screw and on the left middle sprocket I believe the set screw had never been securely seated. Not a factory defect as I re-did the bearings a couple of years ago and replaced the set screws. What is the proper size and type set screw for the Max II with solid splines axles. I believe an ordinary set screw doesn't have a defined enough end to seat properly and is there an extra good grade. In short,what does RI install in them as I never had any troble with the originals. Any input would be greatly appreciated.