How tight are bearings supposed to be? On a John Deere pull pan is has bearings on each end of the axle and I have asked Deere how tight they are supposed to be and they looked it up and said there is no spec on what deere says it is supposed to be and it seems like they come loose fairly easy is it because we are not making them tight enough or what? Jerry
I tighten them very tight while spinning the wheel, back off a couple turns, tighten to about 50 or so foot pounds, (just guessing, no torque wrench), back off about 1/6 turn, and lock them. This is an adaptation of Mack's alternate procedure, and it works well for most stuff. When most manufacturers give a spec they give it in thousandths of freeplay, measured with a dial indicator. Keep in mind that it is better to be a little loose than too tight.
Thanks for that info these bearings in question have a bearing on each end of the hub and axle and the distance btween the bearings is about a foot and a half also these are packed with grease so does the same specs apply? wouldn't that spec for mack be with oil bath? The reason for the question is in the past I would rebuild bearings and it seems like 200-300 hrs later they would be loose so we would have to tighten them back up wud that be bcuz they are to loose or that they just wearing in?
I have used that general procedure for anything that uses opposed tapered roller bearings for years, wether it's grease packed trailer and equipment wheel bearings or anything else. You kinda have to modify your torque values to fit the size of the spindle you are working with. I think the most important points are the initial high torque while turning to seat everything, and the backing off, snugging up, and then backing off a little. When I do my initial tightening, I tighten, turn, tighten, turn, tighten until it doesn't tighten anymore when I tighten it. This helps to ensure everything is seated all the way. If a race is a few thousandths from seated when you put it in service everything will loosen quickly. If I do find something has loosened soon after being placed in service I usually try tightening it once.
I do it the same way
Thanks for the input I will have to do that next time I have to redo bearings! Jerry
I ALWAYS use a torque wrench when adjusting wheel bearings. I then check the the end play by feel. After a while you'll know the .001-.005 end play. This is from the TMC RP 618: http://www.conmet.com/pdfs/blue-product-service-card.pdf
I'm with all the others. Use a high torque initially to seat the bearings, then slack it off, then tighten to a much lower torque. The torque value will depend on the size of the bearing and the spindle and the amount of load on it. Usually loosening by one flat of the retaining nut/60 degrees if the nut is locked by a cotter pin is about right. If the bearings are "loosening" in the first few hours of service then there are 2 possibilities IMHO: - 1. If the bearings are simply looser than your intuition tells you they should be and are not showing any signs of wear on rollers/raceways then they were either not seated or not adjusted correctly in the first place. Bearings do not "break in". If they are correctly installed and adjusted initially the only way the bearing play will increase after that is when the bearings finally start to wear out. That should be years later. 2. If there are major signs of wear on the rollers/raceways and/or metal particles floating around in the wheel then they were initially set too tight.
How do you quantify a high torque,to slack it off and a much lower torque? A wheel bearing is a precision machined part. Why not treat it as such. How much longer do you have into using a torque wrench to KNOW that the bearings are seated and pre loaded properly. Do you torque your heads on your engines? Imagine this. A wheel comes off and hurts somebody. You go to court to defend yourself and your company and you are asked this very question, what is too tight and what is backing off.
I can think of other things. The race not seated. Wrong bearings. Worn out spindle. Wrong hub assy. Wrong bearings. Worn or no lock nut.
When the hubs loose after it's been run, what do the rollers and cups look like, brand new or chewed up somewhat, we had issues with import or cheap wheel bearings doing this, after we put good quality back in, it solved the problem. Also when you put new bearings in, do you do the cups as well new, or just bearings, reason I ask, I've seen some use old cups with new bearings and after x number of hours, the bearing wears in to fit the old cup and causes slack. I adjust wheel bearings the same way most here do it, have been doing it for over 30 years and never had one go bad yet, unless its a lube issue, or flat out worn out from use. Last question, what type of lube do you use on these that get excess wear or end up loose?
Maybe I should have set out by saying "as a generic procedure" wheel bearings are tightened in 3 basic steps. It's always been that way and AFAIK not much is going to change going forward. Not knowing the exact model of machine the OP is working on makes it impossible to give an opinion what each torque should be. Maybe I should also have said that after each torque application the wheel should be rotated a minimum of 2 revolutions and the torque re-checked. If it has reduced then re-torque, spin 2 revolutions, and check again. Repeat the process until the torque stablises at the specified value.
Whoop de ******g doop. I'm sure I could too. The OP was asking about installation and adjustment of new wheel bearings. The 2 possibilities I quoted are IMHO the top of the likely causes list. Maybe with some more detailed information such as photos from the OP we could go into specifics and forget the generalizing.
How do you teach your younger tech's. How do you teach them "not to tight" but "just tight enough"?. Also, just because its been done that way for 30 years and there hasnt been any problems doesnt really make it the right way. I run the stop sign by my house for the last 5 years and I have not hit anybody yet and received no tickets from law enforcement. However, one day I may not be so lucky.
lol...........
The machine would be a John Deere 2112E Pull Pan! And I have never cleaned up used bearings and regreased and installed old bearings if I am going to go to all the work to pull it apart it is going to get new bearings and cups! The grease I use when installing new bearings is the John Deere SD Poly Urea grease! The last scraper I did bearings on, the rollers had chips in the corners where they run in the race way or whatever there called what the rollers set down in! Also I use National seals or packings and Timken bearings! I don't have any pictures of the actual hub and spindle but here is the parts diagram of it!
FMD, I guess I wasn't aware tightening down wheel bearings by feel and like's been mentioned here by many except you was illegal and there's a legal way to do it, around here I figured the way the local heavy equipment dealerships do it, it must be acceptable and good enough for me. By the way what is the torque spec on the project here, I"m curious, you haven't mentioned the exact specs as of yet, not generalized but exact would be nice. I'd call the deere shop but doubtful if they'd know it, or could probably even find it, but that's just a hunch.
Yair . . . Crikey fellers, I don't think this is rocket science. I seat as described here then back of and retighten. If it's locked with a split pin or locktab its better to go one flat or castellation loose to begin with, take the thing for a run and readjust and you may gain one . . . they can run warm but not hot. Cheers
I never said it was illegal not using the manufactuer recommended way. I also sent the RP practice in a link, so I did give some info on doing it right on different nut sizes et el. At the time of my posting, we didnt know the make and model in question. I got NO IDEA on what the proper spec should be JD 2112 for I have none in my fleet. But I can assure you that I do know the spec's (or have access) to the spec's of my entire fleet on wheel bearing adjustments. My point is, why not use a torque wrench? What is a little tight or a lot tight? I am sure nobody is going to have the bearing police knocking on your door if you elect not to use a torque wrench. I am not going to put anybody in a head lock for not using a torque wrench. It is your equipment and do as you wish with it. All I am conveying is that when it comes to wheel bearings and chancing a wheel seperation, why not follow the OEM recommended practices and IF something were to happened where someone got hurt, you can show that you are following the suggested way of "doing it correctly"
The bearing cup od is 4.8125 and the bore is 2.6250! My question is it has a nut on it with the notches in it not a hex nut and the axle shaft sticks out about 3 or 4 inches beyond the nut so do they make a socket for a situation like that or how do you use a torque wrench without a socket for it? Jerry
A crowfoot open-ended wrench installed on a torque wrench would work. How does the nut lock in position if it doesn't have a cotter pin or some other sort of positive locking mechanism..? Can you post a photo of the nut installed on the axle shaft..?
I was always under the impression that torque with regard to bearings is the torque to rotate the component or shaft after installation. I was taught to tighten bearing to a snug fit place in service under load for a minimum of 50 rotations than reset the bearing while rotating and tighten until the last roller starts turning. Not always possible to do it like that in critical rotating parts a rotating torque or end play is specified. I dont consider a scraper wheel bearing critical get it close make a round snug it up once and you should be fine. To loose is much better than to tight.
Not in Cat manuals, it's the torque applied to the hardware that secures the wheel bearing retainer plate.
There is a thread somewhere on HEF about posting photos. It's an easy process, you can even post them from your mobile phone if necessary. I for one would love to see a photo of how everything goes together (your parts manual photo is a bit small for my old eyes I'm afraid) so that we can see exactly what we're dealing with.
The nut has four slots in it like a hydraulic cylinder gland, so you'd use a spanner just like the cylinder. This axle is fixed at both ends when mounted, right? The axle comes off with the hub so it's gonna be tricky to adjust with the procedure for a standard hub. If there was a bearing preload spec available that might be easiest to set with. JD uses this for some bearings, wrap a string around the shaft and pull with a spring scale to measure "preload". In this case maybe tighten as tight as you can within reason while turning the axle, back off and retighten until you start to feel the resistance to turning the axle. Or do you tighten these mounted on the machine, that nut looks like it's outside the seal?
Yair . . . As I mentioned up thread I don't believe this all that complicated and opposed tapered bearings (in my experience) are pretty forgiving and allow a little leeway. I mean to say you can often grab a wheel and wobble it get a little clunk but the bearings are okay with a tighten . . . or do I live in a different world? Precision spring scale adjustment as outlined by Delmer is mostly restricted to components such as pinions and cross-shafts adjusted with shim packs and I wouldn't imagine would be applicable to a basic wheel bearing assembly. One thing that hasn't been mentioned is the seating of cones and cups. The only way to ensure they are seated is to install them with a drift. The rebound and sound of the hammer will tell you when they're home . . . little bit of swarf or grit in there and any torque wrench settings after a few hours will go for naught. I have seen on a couple of occasions where the inner cone was bottoming on the radius rather than the shoulder. Again very easy to pick up by whacking with a drift and was fixed by machining up a washer. Cheers.
Here is some pictures of the scraper hub and also the parts diagram in bigger print the reason the first one was so small I read that is had to be resized so that's what I did and that's how it come out but anyway live and learn! Yes delmer is rite it has 4 slots in it like you can kinda see in the parts diagram! btw that is a 1814E in the pictures but they are all the same as far as the wheel hubs and axles go! And the pictures are just some I had on my computer I wasn't around any scrapers today so I couldn't take better pictures but it gives a better idea anyway! One thing I was wondering about is what happens with the torqueing if there is some dirt and grease in the threads this is a fine thread nut (yes I try to clean them up when I am rebuilding like taking wire wheel on grinder but if just retorqueing is what Im wondering)
When I seat the cups I have been using a punch but when I feel the hammer bouncing on the punch I know it is seated good and I can also pretty much see that! The last ones I rebuilt I took a medium sized ball pein hammer and a chisel and basically tightened it till it wouldn't turn anymore with not a lot of force with the hammer and I couldn't turn the axle by hand but with a pipe wrench on axle it turned just fine! Jerry
The two things that cause a bearing failure: 1) Improper tightening. 2) Lack of Lubrication. The guys here including myself have used this same method for over thirty years as well. Tighten, tighten, spin, spin, back off, tighten spin, spin...back off a little and lock it down. As for running a stop sign and waiting for that one time you lose...I'd consider the 30 years of NO bearing failures to be a good judge of the law of averages on that issue. There's "tech's", and there's mechanics...one claims he knows more than the other, one simply does. :naughty As a matter of fact, I just got done doing one about an hour ago, used this very same method, and I don't foresee nor expect to lose that wheel one ioda. Even found upon removal that there was not a locking tab ring behind the locknut...but it has a brand new one now.
I'd suggest using a brass drift rather than a steel punch simply to avoid bruising the bearing cup. Have you tried putting the cups in a freezer to shrink them a tad and make them easier to install..? We use liquid nitrogen on bearing cups but that's just because we can get it really easy. Dry ice is also another option to shrink the cups and avoid having to beat on them too much. To check if a cup is fully seated try installing the thinnest feeler gauge you have (usually 0.0015") between the underneath of the cup and the housing. If it won't go in there's a good chance the cup is well seated. That test does not remove the need to heave on the adjusting nut and spin the wheel a few times just to make sure, but it's a good guide.
Thanks for the input guys and Nige I havnt tried putting them in the freezer yet but I will have to! And uh Nige I am still trying to get practical experience but tryn to learn without as many mistakes by asking you guys that are smart! Thanks Jerry
Only two things you have to remember............ 1. The man who never made a mistake never made anything...!! 2. If you're not still learning you're probably dead..!!
just try and figure out the mistakes that will get someone injured or killed, and avoid those most. Only way to learn how to fix things is to get your hands dirty.
I installed a lot of wheel bearings in Clark Loaders, dozers, and skidders. In the manual, it says Install the planetary and snug up the bearings too 500 ft.lbs , roll the hub around a couple of times, then re snug it, next shock the bearings to line them up, 2X4 and a 21/2 lb sledge, give the hub a good whack at 12, 3, 6, and 9 o'clock close to the bearing, roll it again, repeat untill you don't gain any more then tighten then back off to spec, we used rolling resistance to set the bearing preload to 12 to 20 lbf. foot lbs with new bearings and 4 to 7 lbf. foot lbs with used bearings. This spec was for a 175 C Michigan loader, you have to compare the size to your machine. John Deere should have a rolling risistance spec for the machine that you have. They probably don't have a torque spec, just rolling resistance spec.