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OT: Question on press fitting a bearing

Randalthor

Cast Iron
Joined
Mar 7, 2018
Location
Kansas City
I've not fit this type of split race bearing before and seeking some advice please.

It's a thrust bearing with an interference fit. It's a throwout bearing which goes on a tractor. It has a split inner race. (pictures attached) The inner race where it fits on the housing measures 2.497". The other inner race (which doesn't contact the housing) is 0.080" larger. The O.D of the round part of the housing, where the bearing fits, measures 2.501"

The shop manual says to use a special tool to press fit the bearing, but the tool is not available. I've not been able to find any pictures of what the tool looks like. The book warns to use the tool, else it will "shorten the life of the bearing".

I'm assuming they don't want a regular drift used, rather I'm guessing their drift only has a 0.040" lip thickness to slip down inside the larger diameter inner race to make contact with the edge of the smaller diameter inner race?

What I'm wondering is a drift with a wall that thin, will it even make good contact and stay on the edge of the smaller diameter inner race, when pressing it on?

Also wondering if it's possible to fit the bearing without tools using a hot mount (i.e. heat the bearing to 150F and put the housing in the freezer)? Mounting the bearing to the housing with 0.004" interference seems like a lot of interference to overcome using no tools, even with a hot mount, but I again I don't have any experience with this type of bearing. Any thoughts?

Lastly, I'm wondering if using a bearing separator would work? There is a small gap between the two races of the bearing (on the outside of the bearing). I'm wondering if fixing a bearing separator in that gap and using it to press the bearing on (i.e. using the bearing separator to take the press force and deliver it to the correct inner race)? Thoughts?

Attached are the pics. The bearing is a Koyo bearing CTS54SA.

Thanks for any advice.

KIMG0760.jpg

KIMG0759.jpg

KIMG0758.jpg

KIMG0757.jpg

KIMG0756.jpg
 
I'm assuming they want a tool used that just slips into the bore by a couple thousandths but catches on the lip once it's in there. I'd use a little heat if you can but don't worry about the freezer. Make the press tool out of aluminum or brass so it doesn't damage the inside of the bearing. And use a press to do this. If you don't have one, take it to someone who does. Use engine oil as lubricant before pressing the bearing in.
 
Four thou on the diameter is a lot, what did the one that come off look like? Also, it's a bit tough to do measurements
on items like this, the bearing ID may be a bit irregular and if the surface finish on the iron casting is a bit rough or grooved
from turning, its OD may be a bit less than it looks.

The idea here is to not press the bearing on through the balls, which could brinell the races. If you had a lathe you could make
up the correct tool.
 
Thanks. You folks pretty much confirmed what I thought. I've just never installed a bearing like this, so I wanted to do it correctly.

It didn't make sense to me either to press on the face of the bearing (through the balls) but I've never made or used such a thin walled drift, so that it will catch only the lesser diameter of the split race.

I don't have a lathe, but have the tools to make the drift (Bridgeport, Criterion boring, Hardinge dividing head). I'll make it out alum or brass, something soft. I may even have some Delrin. I wonder if that would hold up to pressing forces with such a thin wall?

I haven't taken the old bearing off, since I got a new housing and new bearing.
 
I had a quick glance earlier and was mistakenly thinking that you were going to be pressing on the face where the rollers ran when I recommended aluminum or brass. Now that I've reread and looked at the pictures a little closer, if the area where the tool will contact isn't in the area where the rollers run, steel will be better.
 
OK thanks.

I'll skip the Delrin, since the wall has to be so thin. I'll just go ahead and make it out of Al. I don't have any 3" dia. steel rounds on hand.
 
That release bearing looks fairly similar to the one I fitted to my Fergie 135 a few weeks ago, certainly the same size. I ignored the 'special tool' command, simply pressed it on directly under my flypress, just being sure to use a nice square pressing tool. The thin wall of the 'housing' as you call it is the reason for the 'high' interference, the thin wall obviously collapses a fair bit. Yes I did consider the risk of Brinelling for a millisecond but recalled the relatively small force required to get the original bearing off the spigot ('housing'). I didn't bother measuring anything ... & I used to be an instrument maker in a former life (blush). You might be overthinking it.
 
You did not mention the brand of tractor. These days most brands will have an online group and if not there are many general tractor forums. I would post there as you may find others have already done the same job without the special tool.
 
That release bearing looks fairly similar to the one I fitted to my Fergie 135 a few weeks ago, certainly the same size. I ignored the 'special tool' command, simply pressed it on directly under my flypress, just being sure to use a nice square pressing tool. The thin wall of the 'housing' as you call it is the reason for the 'high' interference, the thin wall obviously collapses a fair bit. Yes I did consider the risk of Brinelling for a millisecond but recalled the relatively small force required to get the original bearing off the spigot ('housing'). I didn't bother measuring anything ... & I used to be an instrument maker in a former life (blush). You might be overthinking it.

I think this is correct, don't overthink it. But don't hammer the damn thing on, press it, and have it pressed squarely, don not cock it crooked or you will scrape away the metal on the spigot. The thing is a thrust bearing, so of course you can apply thrust to put it together. The balls and races are very well supported, and can take a hell of a load. It is quite unlike pressing a regular ball bearing on its side faces, in which case you are forcing the balls to wedge into the races with very high point contact. It should go on easy enough with a 5 ton press, otherwise check the amount of interference.
 
Hi, I'm not recanting BUT something that came to mind .. my situation was putting a new bearing on the ORIGINAL carrier so the only possibility of an error was with the bearing, Very unlikely. HOWEVER over the years I've had several badly made items from an aftermarket parts supplier here in Oz (USA origin). In one case a front axle pivot pin nominally 1.750 diam oversize to the tune of 0.020". Took it back & inspected the remainder of the stock .. all correct diameter but locating peg-hole near the middle of the pin instead of near an end. Went home & made my own. Since then I've had incorrect gaskets, & the worst, a brand new stub axle ruined when the supplied castellated nut, which LOOKED perfect completely stripped the axle thread. I'd been blissfully unaware, believing the bearing/stub axle fit to be a mite tight. SO this is not my place to rant, rather advise, if you can, measure the original carrier diameter. It should still be similar to your new one coz if plastic flow has occurred making it smaller, all the benefit of press fit was negated .. I think that unlikely. Only cause for concern is if the new carrier diameter is significantly bigger than the old, say more than a thou' or two.
 
That release bearing looks fairly similar to the one I fitted to my Fergie 135

Hi, I'm not recanting BUT something that came to mind .. my situation was putting a new bearing on the ORIGINAL carrier so the only possibility of an error was with the bearing, Very unlikely. HOWEVER over the years I've had several badly made items from an aftermarket parts supplier here in Oz (USA origin).

This tractor is also a Massey (4225 4X4). We must be reading the same shop manual. The new carrier is OEM. That doesn't of course guarantee it's built to specs, but I try to stay away from aftermarket parts, regardless of how temptingly cheap they are. I've pretty much learned my lesson that a lot of aftermarket parts (and rebuilt parts) don't last very long. A short list of such failed parts in my lifetime includes: two starters, at least one alternator, a torque converter.

I also purchased a new pilot bearing (where the nose of the main input shafts fits into the flywheel) There's a little metric bearing there. The dealer sort of screwed me on that little bearing. I had told the dealer I wanted all OEM parts (he tried to sell me an aftermarket clutch he had on hand). I said I don't risk aftermarket parts (unless they are very easy to replace). He said OK. So when they sent me the parts, the little pilot bearing was loose with no packaging (As you know AGCO puts every part in a bag/box and labels it with the part number.)

I looked at the bearing and it was made from a manufacturer I didn't recognize (Codex). I looked it up. As far as I could tell, the maker looked like some Chinese company. It may be a fine bearing, but I don't want to take a chance on this part because of the labor involved getting to it. So I spent the better part of the afternoon yesterday driving into the city to bearing supply to get a bearing from a maker I recognized.


Since it takes some time to split the tractor (this one especially) I'd rather not have to redo it, hence perhaps my over thinking things. Plus the shop manual's warning scared me a little bit.
 
I think this is correct, don't overthink it. But don't hammer the damn thing on, press it, and have it pressed squarely, don not cock it crooked or you will scrape away the metal on the spigot. The thing is a thrust bearing, so of course you can apply thrust to put it together. The balls and races are very well supported, and can take a hell of a load. It is quite unlike pressing a regular ball bearing on its side faces, in which case you are forcing the balls to wedge into the races with very high point contact. It should go on easy enough with a 5 ton press, otherwise check the amount of interference.

That brings up a question. How easy is it to brinell the races a regular ball bearing? Everywhere one reads, there are warnings to carefully install bearings (press on the correct races, etc.) to avoid damage to the bearing.

The reason I ask is that on this repair I'm working on, there is regular deep groove ball bearing that I tapped in with a rubber mallet, without using a drift. It was a light interference fit, which fit the outside of the race to the inside of the carrier. The bearing was a medium sized bearing (about 2.5" O.D.). I didn't place the carrier on anything, but just held it in my hand while I tapped the bearing in with the rubber mallet. It took several hits to get it in, but I wasn't wacking it hard, about the same force one would use to casually drive a nail with a hammer.

I've done this type of thing before on light press bearings, but maybe I'm making a mistake? I'd rather know now before I put the tractor back together, if there is any significant risk I damaged that bearing.

I had assumed a medium sized bearing is fairly tough, given the abuse they take in farm equipment. But I honestly don't know how little axial shock load it can take to damage a ball bearing? Will a rubber mallet do it?
 
That brings up a question. How easy is it to brinell the races a regular ball bearing? Everywhere one reads, there are warnings to carefully install bearings (press on the correct races, etc.) to avoid damage to the bearing.

The reason I ask is that on this repair I'm working on, there is regular deep groove ball bearing that I tapped in with a rubber mallet, without using a drift. It was a light interference fit, which fit the outside of the race to the inside of the carrier. The bearing was a medium sized bearing (about 2.5" O.D.). I didn't place the carrier on anything, but just held it in my hand while I tapped the bearing in with the rubber mallet. It took several hits to get it in, but I wasn't wacking it hard, about the same force one would use to casually drive a nail with a hammer.

I've done this type of thing before on light press bearings, but maybe I'm making a mistake? I'd rather know now before I put the tractor back together, if there is any significant risk I damaged that bearing.

I had assumed a medium sized bearing is fairly tough, given the abuse they take in farm equipment. But I honestly don't know how little axial shock load it can take to damage a ball bearing? Will a rubber mallet do it?

A rubber mallet doesn't provide the shock impact of a steel hammer. You can wail away with all your strength on a 3 lb rubber mallet and get absolutely nowhere, but a 2lb steel hammer will most likely keep things moving for quite some more distance where the other one gave up.

I try to apply the hammer force directly to the race being fitted, not transmitting from one race to the other. That also prevents caving in the bearing shields, if present. Well engineered assemblies should not require interference fits on both races of one bearing. For that purpose, timken taper roller bearings can be used because the races are fitted without the need to transmit installation forces through the rollers.
 
Hi Randalthor, had a chuckle about your story re spigot bearing. The issue that led to my tractor split was exactly THAT bearing, rusted up near solid & intermittently taking over drive when the clutch was released. Here I've never been offered an OEM part by a dealer, always one of two aftermarket mobs (not AGCO), 'course we ARE on a different planet down here. Tho' maybe it has something to do with age of the tractor, 48 years. As it happened the bearing was a very reputable make but not OEM, its failure brought about by wall-to-wall rust in the bell housing to a degree that led me to replace the entire clutch (fearing stress corrosion) despite little wear.
 
If didn’t read your manual I probably would have just press it on.
Good chance would put the carries in the freezer maybe warm the bearing up a bit.
Never really considered throwing bearings particularly fragile.

If you don’t have a press you could use a bolt and 2 plates, think gear puller in reverse
 
I ended up making the drift out of aluminum. I guess I'm paranoid and a little OCD when it comes to following the shop manual. The finish is terrible on the drift I made. (Pay no attention to the chatter marks.)

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If you don’t have a press you could use a bolt and 2 plates, think gear puller in reverse

I built a couple press racks a long time ago (a big one, and a little one). I have a 12 ton bottle jack. If that doesn't work, I have a 50 ton Enerpac jack, just enough to f... something up real good. Or I could always use the spindle of the B-port as an arbor press (just kidding). Seriously though, I prefer to use the 50 ton jack to press because the face of it is a large diameter, so it's easy to press bearings straight. The problem is that it's underneath the tractor, so I'm forced to use the little 12 ton bottle jack.

Hi Randalthor, had a chuckle about your story re spigot bearing. The issue that led to my tractor split was exactly THAT bearing, rusted up near solid & intermittently taking over drive when the clutch was released.

The clutch was slipping under load on this tractor. It was down in the rivets. It's enough work to split the tractor that I replaced anything which looks like it could fail in the near future: the clutch, pressure plate, throwout bearing, pilot bearing, ,seals in the input shaft, even some springs inside there. The parts are expensive, but not what it would cost if the dealer did the work. After I replace this drive clutch, I plan to replace the PTO clutch inside the rear differential. It's slipping too. I've never replaced one of those before.

I suppose as far as parts go, I've been lucky, so far. This tractor is 20 years old, and AGCO has carried all the OEM parts I've needed (so far).

My understanding is that your MF 135 is a great tractor. They just keep going and going and going.
 
Yes you replace anything that looks like it might need replacing when you have the split
Even take a look at the ring gear.
No need for a one use tool to look pretty all it has to do is work.

Only 20 years old that’s practically new plenty of life left in it
 








 
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