Case 1845 wheel bearing nut torque I have one wheel bearing apart and am waiting for the new bearings and seals from Motion. I don't have a rebuild manual. My question is what should the bearing preload or endplay be? What is the procedure for torquing the castle nut at the sprocket? It is a Case 1845, but I believe the 1845C is no different on this part. Thanks!
Most bearing preloads on wheel hubs are in the .010-.030 or so range. I usually assemble the hub, with greased bearings if that is what they call for, then tighten the nut slowly while rotating the hub forward and reverse until the hub stops moving. Then loosen the hub nut and rotate the hub until I can just "feel" the end play, but not quite see it. This has served me well for my vehicle for decades now, but saying that this has been on motor on road vehicles....these construction machine may be different.
Seem to think you tighten the nut to 20-25 ft lbs, then install the cotter pin at the nearest hole.
That sounds too tight to me. I agree with thrashingcows, tighten it up while rotating to seat it, then loosen up till you can just feel the play. Maybe the 25 ft lbs is what it's tightened to for seating? Apparently, bearings last longest with a slight preload. Too tight destroys them much faster than too loose though. And if you put them loose enough to play, then the seals leak.
I think the manual says there is no end play. torque is 75lbs. chain is suppose to have 1/2 inch drop. If you leave it with end play it will destroy your seal and if oil gets in there is will loose all the grease in the bearings. The bearing needs to be greased before you put them in and grease them every 50 hours with couple shots of grease. your drive is by the large sprocket by a chain. It puts a lot of torque on it when you operate it especially turning. If you have any end play your seal wont last long. Wheel bearings usually do have end play. I just had to replace my seas on the front left sidel due to them leaking. put new bearings in also. it had just a little end play but inner seal was destroyed. But its your machine so its your call. norm
I got it done. Not really a bad job to do. It is just that you have to work blind with one hand in the chain case. I torqued the castle nut to 75 ft-lb and it felt right. These bearings are never at high speed. Thanks for all your advice.
It isn't a bad job at all. Someone had replaced the bearings on it before I got it. I think about 3 months before. I noticed the seal leaked a little. I greased it and it pretty well stopped but didn't last long. so I ordered the bearings and seals to fix it. I bought a manual for mine. I noticed it had a small amount of endplay and the large nut inside was just hand tight. I looked at the manual and it said it was to be torgued at 75 lbs and cotter installed to the next hole. I had also noticed the chain was tight. book says its suppose to have a little lag in it or drop. who ever fixed it didn't know what they were doing. I think two important issues on these is to remember they support a lot of weight and the force is greater when you go from forward or backward when working. puts a lot off stress on the bearings and seals. I do believe that's why the torgue on the nut. just remember to give it a coupke shots of grease once in a while. I did put new bearings in mine but the old bearings were fine. hadnt ran it enough to hurt them just the seals especially the inside seal was cremated. Good job is always worth a pat on the back. good job norm
Is this bearing set up like an adjustable wheel bearing where the nut tightens up the tapered roller bearing? or something more like a sealed hub?
Yes they are more or less like a normal wheel bearing on say a front wheel of a two wheel drive pick-up. The nut is inside the chain-case and also holds the sprocket that drives the wheel. Tapered rollers with seals on both sides of the bearings, one to keep the dirt and water from the outside of the case out and one on the inside to protect the bearings from the nasty stuff that almost always is in the chain-case. It was rare, when I was working on these at the quarry, to open one up to replace a broken chain to find nice clean oil. Most of the time it was some nasty white foamy stuff, combination of water and oil with the chains and sprockets whipping it up like whipped cream. That said I always figure those chains and sprockets had it better than the chains on my motorcycles!
The hub itself is fastened by 6 studs. They have to be lossened to adjust chain tension. the bearings are supposed to be packed with grease before installed. there is a large flat like bushing that goes between the drive gear and bearing so when you tighten it it goes up solid to the bearing. basically becomes solid to the axle. tightening the large nut also keeps makes the drive gear solid. with the strain on the drive gear you don't want any play at all. do have to have some slack in your chain or it will wear out quickly or break. There is a grease zert to grease the hub every so often. the housing have a plastic cover on top that you have to remove to get to everything. poor deisgn due to when age catches up to the rubber seal on the platsic cover dust/dirt gets in. My housing on the right side was way over full. I think the books says 5 quarts. must have been 3 gallons at least in there. you just need enough to cover part of the chain on the bottom as it is all oil sling lubricated. the biggest difference between these and a tractor or truck wheel bearing is the speed of which It travels and the amount of torgue that is put on them when you turn the machine and reverse it which is a common operating practice on skid loaders.