imagineero
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Would appreciate it if this post can hang here a couple days, then it can be moved to heavy equipment or whatever. That way people can see it and chime n with comments then follow it to the dark back corner of the shed.
My chipper started dripping oil a few days ago and it was coming out of the bell housing which is never a good sign. I figured it was probably the seal on the main shaft, so I put aside a couple days to deal with it. I thought I'd post up how I went because it might be useful to someone else. Mine's a 250XP but a lot of the bandits are probably similar.
Start by removing the cover off the main drive belts. Slack the tension off the belts by loosening the engine mount bolts, then sliding the whole engine over with the adjuster bolts. Remove the belts. If their worn, you might want to replace them at the same time.
The pulley fitted to the PTO has 3 bolts. undo them completely, and screw them into the 3 threaded holes in the pulley. Do them up progressively to break the pulley loose. Tap a flat head screwdriver in the split in the centre housing, and it will open up enough you can slide it back and forth. If the shaft is clean it should slide right off. If someone has painted it you may have to slide it towards the engine then clean the shaft up with emery tape. Put it aside somewhere it won't fall off the chipper. The ground is good.
Then undo one of the link arms for the clutch handle. Undo the 2 bolts holding the clutch handle onto the bell housing, and remove it, and the other two bolts holding the PTO shaft onto the bell housing. Getting the PTO out can be a bugger, the end of the shaft goes into a bearing which is inside the flywheel. It can be seized/rusted, and there's no good place to fit a puller. If you rotate it 90 degrees though, you can get a plastic falling wedge on each side. Tap away at both and have someone with a hand on the shaft to catch it so you dont damage it. It's heavy. You'll probably destroy the bearing (if it isn't already destroyed) but don't sweat it. You need to replace anyway, and it's only about $6. The one on mine was sealed ball bearing, 1" ID 2" OD.
Removing the bell housing, it's pretty straight forward. Just don't drop the thrust bearing. The 2 bolts on the clutch arm mount bracket are longer than the rest. A rattle gun will help with removing the clutch bolts, if you don't have one you'll need to find some way of stopping the engine rotating. There's probably a bolt on the end of the crank but I didn't check. Rattle gun will also help removing the flywheel bolts.
Hopefully your clutch is in good order. Mine wasn't. The seal on the main output shaft had been dripping probably for years. The dripping had got flung out onto the bell housing with dirt, grit and clutch material in it, and formed a thick paste about 1/2" thick on everything. The friction plate was fried. The thrust bearing was wobbly.
You'll probably be looking at getting a seal for your end shaft, the small bearing for the PTO, a new pressure plate, new friction plate, and probably a new thrust bearing. You may want to machine your flywheel. I didn't. You can get exchange pressure plates and new friction plates easily. Alternatively, some clutch places will rebuild yours, and can rebuild your thrust bearing too. They will supply new friction plate. A good clutch shop can turn that around in a couple hours no worries. Seal/bearing shops will stock the end seal, and the small bearing. Pickup some anti seize if you havent got some already. The main end seal on my machine (120 perkins turbo diesel) is 5.250"ID 6.250"OD and 1/2" thick. It's a standard nitrile double lipped seal and only costs a few bucks. Get about 4. You'll need them.
Clean the hell out of your bell housing and the engine, flywheel etc. I started with a spatula on mine, and filled a bucket with crap. Then degreaser, scrubbing brushes and a hose. Then compressed air, and finally some brake cleaner. You want the whole area squeaky clean. Don't skimp here, or you'll be doing this job again soon.
Now for the hardest part; changing the end seal. Getting it out is easy. Drill a small hole in it, screw in a self tapping screw, then pull it out with a claw hammer. Don't try using a screwdriver to get it out, you'll scratch the mating surface. Getting the new one in is difficult. There is no seat for the seal, it just floats there. So there's nothing to drive it onto. Normally with this kind of seal there is a seat. You push it in until it's seated then you're done, in about 4 seconds. Because of the lack of seat, and the awkward size of the seal, you're going to have a bad time. If you try driving one side, then the other, you'll soon find the seal is out of square, and that driving the 'high' side just pushes the whole thing further in, still out of square. If you keep driving it, it just falls into the engine. You can only get it out again with the drill/screw method. If you push it in too far, you can't reverse it, so you have to drill and screw which destroys the seal. It has to be driven flush with the exterior face of the engine and cannot be out of square or it won't seal.
The only way I found that worked was by using another seal to drive the first. Get everything spotless. Spray a light coating of WD40 or similar on the shaft and seal. Put the first seal on, squarely, by hand. Don't push it in. Now, put a second seal on the shaft. Now, put a block of wood across the second seal and gently drive it. Rotate the block around, go slow. When the second seal is flush with the end of the shaft, the first seal will be exactly flush with the face of the engine. Pull the second seal off. Check for squareness with the face carefully, with a straight edge. You're done.
The rest is pretty straightforward. Drive the old bearing out of the flywheel with a drift. Rest the flywheel on some wood while you're doing this, you don't want to damage the teeth. Give the inside ring of the flywheel a very good cleanup with emery tape. Spend 5 min on it and get it nice. Drive the new bearing in using the outer race of the old one to drive it, or socket the right size if you have one. Only drive the outer race.
Try the shaft of the PTO in the new bearing. It probably wont fit. Back to the emery cloth. It should be a smooth slide in fit. Once it slides in nice, put it aside, and bolt the flywheel back on. Fit the friction plate and pressure plate up, the 'snout' side of the splined inner on the friction plate faces towards the pressure plate, not the engine. Put the bolts into the pressure plate only a few turns, you need to align the friction plate. With all the bolts of the pressure plate in only a few turns, pickup the PTO and slide the shaft into the friction plate, then into the bearing. You will never be able to do this unless you already cleaned up the shaft perfectly for a smooth slide fit earlier. Push it all the way in. The fiction plate is now aligned. Leave the PTO hanging there, and do all the bolts on the pressure plate up, tight. Remove the PTO.
The rest is all very straightforward and really needs no explanation. Make sure you put the right bolts in the clutch bracket, not the short ones. The PTO will slide in smoothly once the bellhousing is on, because the shaft, bearing and friction plate are all aligned. Once you have the pulley back on, and all tightened up, adjust your clutch. You should have at least an nch of arm travel remaining once the clutch is engaged, or you'll wear your clutch prematurely.
Tighten up everything. Refit belts. Re-tension with engine bolts. Don't forget to tighten the engine mount bolts, tight! Refit guard. Congratulate yourself.
The whole job takes about 3-4 hours if you have all the parts on hand, and a rattle gun. The electric ones are just fine.
Shaun
My chipper started dripping oil a few days ago and it was coming out of the bell housing which is never a good sign. I figured it was probably the seal on the main shaft, so I put aside a couple days to deal with it. I thought I'd post up how I went because it might be useful to someone else. Mine's a 250XP but a lot of the bandits are probably similar.
Start by removing the cover off the main drive belts. Slack the tension off the belts by loosening the engine mount bolts, then sliding the whole engine over with the adjuster bolts. Remove the belts. If their worn, you might want to replace them at the same time.
The pulley fitted to the PTO has 3 bolts. undo them completely, and screw them into the 3 threaded holes in the pulley. Do them up progressively to break the pulley loose. Tap a flat head screwdriver in the split in the centre housing, and it will open up enough you can slide it back and forth. If the shaft is clean it should slide right off. If someone has painted it you may have to slide it towards the engine then clean the shaft up with emery tape. Put it aside somewhere it won't fall off the chipper. The ground is good.
Then undo one of the link arms for the clutch handle. Undo the 2 bolts holding the clutch handle onto the bell housing, and remove it, and the other two bolts holding the PTO shaft onto the bell housing. Getting the PTO out can be a bugger, the end of the shaft goes into a bearing which is inside the flywheel. It can be seized/rusted, and there's no good place to fit a puller. If you rotate it 90 degrees though, you can get a plastic falling wedge on each side. Tap away at both and have someone with a hand on the shaft to catch it so you dont damage it. It's heavy. You'll probably destroy the bearing (if it isn't already destroyed) but don't sweat it. You need to replace anyway, and it's only about $6. The one on mine was sealed ball bearing, 1" ID 2" OD.
Removing the bell housing, it's pretty straight forward. Just don't drop the thrust bearing. The 2 bolts on the clutch arm mount bracket are longer than the rest. A rattle gun will help with removing the clutch bolts, if you don't have one you'll need to find some way of stopping the engine rotating. There's probably a bolt on the end of the crank but I didn't check. Rattle gun will also help removing the flywheel bolts.
Hopefully your clutch is in good order. Mine wasn't. The seal on the main output shaft had been dripping probably for years. The dripping had got flung out onto the bell housing with dirt, grit and clutch material in it, and formed a thick paste about 1/2" thick on everything. The friction plate was fried. The thrust bearing was wobbly.
You'll probably be looking at getting a seal for your end shaft, the small bearing for the PTO, a new pressure plate, new friction plate, and probably a new thrust bearing. You may want to machine your flywheel. I didn't. You can get exchange pressure plates and new friction plates easily. Alternatively, some clutch places will rebuild yours, and can rebuild your thrust bearing too. They will supply new friction plate. A good clutch shop can turn that around in a couple hours no worries. Seal/bearing shops will stock the end seal, and the small bearing. Pickup some anti seize if you havent got some already. The main end seal on my machine (120 perkins turbo diesel) is 5.250"ID 6.250"OD and 1/2" thick. It's a standard nitrile double lipped seal and only costs a few bucks. Get about 4. You'll need them.
Clean the hell out of your bell housing and the engine, flywheel etc. I started with a spatula on mine, and filled a bucket with crap. Then degreaser, scrubbing brushes and a hose. Then compressed air, and finally some brake cleaner. You want the whole area squeaky clean. Don't skimp here, or you'll be doing this job again soon.
Now for the hardest part; changing the end seal. Getting it out is easy. Drill a small hole in it, screw in a self tapping screw, then pull it out with a claw hammer. Don't try using a screwdriver to get it out, you'll scratch the mating surface. Getting the new one in is difficult. There is no seat for the seal, it just floats there. So there's nothing to drive it onto. Normally with this kind of seal there is a seat. You push it in until it's seated then you're done, in about 4 seconds. Because of the lack of seat, and the awkward size of the seal, you're going to have a bad time. If you try driving one side, then the other, you'll soon find the seal is out of square, and that driving the 'high' side just pushes the whole thing further in, still out of square. If you keep driving it, it just falls into the engine. You can only get it out again with the drill/screw method. If you push it in too far, you can't reverse it, so you have to drill and screw which destroys the seal. It has to be driven flush with the exterior face of the engine and cannot be out of square or it won't seal.
The only way I found that worked was by using another seal to drive the first. Get everything spotless. Spray a light coating of WD40 or similar on the shaft and seal. Put the first seal on, squarely, by hand. Don't push it in. Now, put a second seal on the shaft. Now, put a block of wood across the second seal and gently drive it. Rotate the block around, go slow. When the second seal is flush with the end of the shaft, the first seal will be exactly flush with the face of the engine. Pull the second seal off. Check for squareness with the face carefully, with a straight edge. You're done.
The rest is pretty straightforward. Drive the old bearing out of the flywheel with a drift. Rest the flywheel on some wood while you're doing this, you don't want to damage the teeth. Give the inside ring of the flywheel a very good cleanup with emery tape. Spend 5 min on it and get it nice. Drive the new bearing in using the outer race of the old one to drive it, or socket the right size if you have one. Only drive the outer race.
Try the shaft of the PTO in the new bearing. It probably wont fit. Back to the emery cloth. It should be a smooth slide in fit. Once it slides in nice, put it aside, and bolt the flywheel back on. Fit the friction plate and pressure plate up, the 'snout' side of the splined inner on the friction plate faces towards the pressure plate, not the engine. Put the bolts into the pressure plate only a few turns, you need to align the friction plate. With all the bolts of the pressure plate in only a few turns, pickup the PTO and slide the shaft into the friction plate, then into the bearing. You will never be able to do this unless you already cleaned up the shaft perfectly for a smooth slide fit earlier. Push it all the way in. The fiction plate is now aligned. Leave the PTO hanging there, and do all the bolts on the pressure plate up, tight. Remove the PTO.
The rest is all very straightforward and really needs no explanation. Make sure you put the right bolts in the clutch bracket, not the short ones. The PTO will slide in smoothly once the bellhousing is on, because the shaft, bearing and friction plate are all aligned. Once you have the pulley back on, and all tightened up, adjust your clutch. You should have at least an nch of arm travel remaining once the clutch is engaged, or you'll wear your clutch prematurely.
Tighten up everything. Refit belts. Re-tension with engine bolts. Don't forget to tighten the engine mount bolts, tight! Refit guard. Congratulate yourself.
The whole job takes about 3-4 hours if you have all the parts on hand, and a rattle gun. The electric ones are just fine.
Shaun
