Broken Set Screws on Main Drive Sprockets

[tbone9]

Try a little cutting fluid or tap and drill oil and run your drill real slow. Quarter trigger or less. Set screws are hardened and will overheat and dull that small tip on the drill in no time. A left hand bit is best. The trick is to keep the bit cool and it will cut. Hope this helps. Good luck.

[phabib]

You might also hit the setscrew with the torch, get it red hot, then let it cool naturally, before you drill to soften it up.

[Sherman802]

Hi Eldon, I seem to have the same trouble with my 02 max iv. What I did was heat the stripped out hole in the set screw with propane torch, Then I drove a torx T-20 (star bit) in the stripped out hole and used it in the manner of an easy out. If you try this use a craftsman 3/8 square drive bit with a 6 inch extension use the extension as a drift to drive the bit in the hole, six inch gives you a lot of room for purchase with a hammer to drive the little sucker. Imo splined axles with the set screw are not the best design. with my axles removed if I slide a the sprocket on them there is some forward rearward movement . If there was not the sprockets would not slide on and off they are obviously not press fit. when the set screws are tightened there is no movement , so what binds the axles to the sprocket the splines or the set screw??? Facts are the axles were upgraded to snap ring style and my screws break every season. Good luck

[msafi65]

I purchased some drill bits at the state fair last year when I saw the demo guy drilling bearing races. We're called Bad Dog drills. I use don't to drill through an easy out first time I used them. They are a carbide tipped drill sharpened like regular bit. Broke one after drilling through but was replaced for $3. When you get the axle out have it grooved if you can for snap rings and put a grease zirk in the set screw hole. I have the locations for the grooves if you need them. I couldn't find a torque speck on the 1/4 inch set screws but Argo wants the 5/16 set at 144 inch lb. I believe the max screws weren't set very tight so the tip only got side thrust. I've seen quite a few of the 1/4 inch ones fail. Do you have room for split collars? They will hold it if you can get them in. Good luck

[liflod]

After I fought the set screw battle with my machine, I redrilled all the set screw holes to 3/8 and used bigger set screws. At least I can use a 3/16 allen wrench to remove them now. The little 1/8 heads don't take much torque to strip them.

[Eldon]

I sure do appreciate all the valuable input from you folks. First few years I had the Max, I tracked every winter and never broke a screw. Then about three years ago I felt ambitious and changed out all the bearings. I broke two screws on the middle sprocket last winter and one this winter. I'm thinking that perhaps RI used a better screw but maybe the spline just wore a few thousands. I like the snap ring idea and I think it would work by having the outer in place before inserting axle. I really like the idea of a bigger set screw for two reasons, more strength and a bigger allen head.Mine are 5/32" and looking at them wrong strips them. I am in the process of acquiring some carbide bits and reverse drills. I'm reading all your info folks carefully so as to incorporate these ideas into a permanent fix. Your info is greatly appreciated.

[Sherman802]

Well I just called RR to get 2 new upgraded axles for my max 4 . $150 for six bearings,max4 3 bearings per axle , and $150 per axle. the set screws that keep breaking in mine are the rear drive axles (pain in the but ones) I really did not want to buy two new sprockets but I suppose any job worth doing is worth doing well... after all it is my max and I did give it a name. I also have a dog and I gave him a name as well MAX...

[tbone9]

NICE. at least you got a maxcot to help you lol

[Eldon]

Well my set screw dilemma turned very dark yesterday. I have been working away at it in my spare time for these past weeks to utterly no avail. I broke off an extractor yesterday and believe I am now into cutting the axle. I have randomly drilled holes around the extractor trying to cut off whatever is holding the sprocket but absolutely nothing works. I have had the Max for five years. The last one has been pure hell.I'll definitely be in the market for a new sprocket and a new axle most likely. I'm trying to decide if its worth it,its an 03 and has 400 hours on it.

[Sherman802]

sorry to hear about that. Listen I know cash is not a abundant resource for many ,and certainly not me, but I paid 150 a piece for upgraded axles, 130 per sprocket , 6 for the snap rings , and 25 a piece for the bearings , and 3 bucks for the strip caulk. I did both rear axles in mine with shipping my total was $751.00 . But I did not shop around as I posted earlier I went to RR. The upgraded axles are a lot nicer then the set screw style they give me a sense of confidence in knowing that there is no damn set screw to break. If you take care of your machine I would not be concerned with the year and hours. Im sure I may have a slight feeling just how frustrated you may be inside the tub of a iv with broken set screws.

[phabib]

Maybe instead of cutting the axle you can cut the sprocket/sleeve lengthwise most of the way through with an angle grinder (or a torch if you're good and protect the tub first) then kind of peel off the tube off the axle and save the axle. Either that, or there are service that have portable EDM machines that will come to where you are and burn out pretty much anything. Don't know how much those cost but I'd figure on an hour or two at whatever the labor rate is where you live.

All 6 of my axles had to come out with a Sawzall and I can confirm that it is to be avoided if at all possible.

[MaxRules]

The snap rings work well but I am updating a Max IV now by cutting a piece of tubing to go on each side of the sprocket. It's easy to do when the axle is out, just get very accurate measurements and cut tubing to go on each side of the sprocket between the bearings. If you can't get the set screw out and your only task is to secure the sprocket from walking left or right, I think you could use the same idea with the tubing. Instead of sliding it onto the axle when removed, simply cut the tubing in half lengthwise and install it on the axle with a few welds without needing to remove the axle. It's like using the two piece lock collar only much stronger.

[Eldon]

I have thought about sleeves Brandon and I believe the snap rings are most likely a good idea as well. I also like Shermans idea of new axles and sprockets. The price you paid Sherman wouldn't faze me if I thought it would cure it. I'll get it fixed building up my courage to tackle it again as we are have a winter storm today.I have received a lot of great support in this dilemma and I'll "Max" again. My Machinist thinks changing the set screws from 5/16" NC thread to 3/8" NF thread would cure it too. Not sure if there is enough room on the splines. Its pretty lonely up here with a Max,they are very rare. How thick is the lower body material in a Max II ? I have some scars from the sprocket inside in the trough as a result of battling with the axle etc. not real deep but I think I'd like to plastic weld it. How big a deal is this? Thanks to all who have kindly responded with advice and their experiences.