Bearing service

[Scott'n'Wendy]

I'm about to repack the bearings. I've seen a few posts where people just wipe off the old grease from the bearing and pump new grease through the rollers. No cleaning in varsol or whatever prior to pushing new grease through.
Thoughts?

[Jlawles2]

The idea of getting all the old grease out is so you can inspect the rollers for wear, feel the inner race (because you cannot see it) for anomalies, etc. Clearing the old grease also ensures there are no foreign particles in the grease to cause increased wear.

Also this is the perfect opportunity to ensure there is only one type of grease in the system and that there is no moisture in the grease. Grease can breakdown over time separating out into the various components that give it the lubricating properties needed.'

I say clean so you can do a proper inspection of the bearings. Those that just pump new grease through the rollers are either lucky or waiting on disaster.

[familytruckster4]

A thorough cleaning is important as Jlawles2 says. I second his thoughts on the matter. I usually give mine a bath in mineral spirits while I clean the hub up and inspect it and then wipe them clean and give them a good inspection before repacking. I finally broke down and bought a Lisle bearing packer last time. Although I had no issue packing them by hand the Lisle packer is less messy.

[Scott'n'Wendy]

I usually give mine a bath in mineral spirits while I clean the hub up and inspect it and then wipe them clean and give them a good inspection before repacking. I finally broke down and bought a Lisle bearing packer last time. Although I had no issue packing them by hand the Lisle packer is less messy.

Funny you should say. I just bought one of those packers after doing it the old fashioned way for the last 4 decades....

[Yoda]

When I had mine done before the Alaska trip the Tech was willing to teach me and was very particular at getting the old grease out of everything (including the EZ-Lube channel) as he was concerned about compatibility with the red&tacky grease I wanted. The OEM grease was also breaking down. Second he said do not use a solvent cleaner (brake cleaner, acetone, paint thinner. carb cleaner, etc) basically if it says wear gloves don't use it. He liked mineral spirits and said don't use air to blow things out (spin the clean bearings), Take the time with a paper towel and let them dry.. He was a by hand pack guy, but said a good packer was also good, if you kept it clean.

This Dexter video has some good information too
https://www.dexteraxle.com/Resources...ype=75&page=3# video on bearing maintenance.

Hope it helps
Keith

[TucsonJim]

Rhetorical questions....

For those of you who use solvents or mineral spirits to remove the grease, how do you know that you're not leaving behind residual cleaner that can break down the new grease?
Personally, I wipe the bearings down until I get them as mechanically clean as I can and then inspect and repack. When I repack, I see any residual grease pumped out of the bearings. As long as I'm using a compatible (NLGI #2) grease, I don't sweat it.


When you do an oil change on your engine, do you flush it with solvents to make sure there's no residual oil in the oil pan, bearings, pump, etc?

Jim

[COReflection]

Rhetorical questions....

For those of you who use solvents or mineral spirits to remove the grease, how do you know that you're not leaving behind residual cleaner that can break down the new grease?
Personally, I wipe the bearings down until I get them as mechanically clean as I can and then inspect and repack. When I repack, I see any residual grease pumped out of the bearings. As long as I'm using a compatible (NLGI #2) grease, I don't sweat it.


When you do an oil change on your engine, do you flush it with solvents to make sure there's no residual oil in the oil pan, bearings, pump, etc?

Jim

Jim----liked the post. I've had different experiences than others with the solvent and shop air. When I started working for GM dealerships and GM, I was taught to actually use brake cleaner and parts washer solvent to clean out the bearings on the front of cars. My dealership mechanics and I did that for thousands of bearing re-pack jobs through the years and I still follow the same practice today for my old muscle cars. We were sure the solvents were completely removed by blowing shop air via a blow gun through all the crevices of the bearings....with the caveat that we used eye protection when using the blow gun and that we did not spin dry bearings. Both givens in my mind. We then either repacked by hand or with our Snap-On bearing packers. I lost track of the hundreds and hundreds of those jobs that I did myself. If you ask ten people how they do the same service--you will likely get at least ten answers or variations of how it can be done and what's worked for them. Each can then decide. At the end of the day, inspecting the bearings and races for wear, repacking the bearings with your fav grease, and setting the bearing pre-load are the most important things no matter which method you follow IMHO.

Dave

[Lonestar]

Jim----liked the post. I've had different experiences than others with the solvent and shop air. When I started working for GM dealerships and GM, I was taught to actually use brake cleaner and parts washer solvent to clean out the bearings on the front of cars. My dealership mechanics and I did that for thousands of bearing re-pack jobs through the years and I still follow the same practice today for my old muscle cars. We were sure the solvents were completely removed by blowing shop air via a blow gun through all the crevices of the bearings....with the caveat that we used eye protection when using the blow gun and that we did not spin dry bearings. Both givens in my mind. We then either repacked by hand or with our Snap-On bearing packers. I lost track of the hundreds and hundreds of those jobs that I did myself. If you ask ten people how they do the same service--you will likely get at least ten answers or variations of how it can be done and what's worked for them. Each can then decide. At the end of the day, inspecting the bearings and races for wear, repacking the bearings with your fav grease, and setting the bearing pre-load are the most important things no matter which method you follow IMHO.

Dave

I do bearing service just like you. Wonder why the recommendation to not use brake cleaner? I also blow air through all the crevices of the bearings, but can sure understand why you would not want the bearing spinning without lube on it.

[Cate&Rob]

I use a varsol tub and a parts cleaning brush to clean most of the grease out of the bearings. Then a brake clean spray over clean paper towels for the final rinse. At this stage I am looking for any shards of metal. The brake clean solvent evaporates leaving clean dry bearings. I don’t think there is any solvent left to deteriorate the new grease. I use pressurized air very sparingly to assure that all crevices of the bearing cage are clean. I do think it is important to get the bearings “clean as new” before re-greasing. I have never found a bearing packer that worked as well as my gloved hands.

Rob

[Jlawles2]

The only reason I can see not to use spray cleaners is to avoid the chlorine which can get into the pores of the metals. At elevated temps they are released back into the grease the bearings are packed in.

I remember cleaning bearings with GASOLINE. We always blew the bearings dry but not letting them spin.

As for packing, never owned a packer other than the 2 I was born with. I was taught to pack them so tight you almost could not spin them. And Rob, NO GLOVES b/c they were just not a staple back in 1977 when I learned to pack bearings (this was long before I could drive).

[NoPeeking]

I've always used brake cleaner or similar solvent, a shot of compressed air and a few minutes in the sun to dry. I recently bought a cheap cone packer and it works fine, but still prefer the palm of the hand method... yeah, I know showing my age... I did graduate to using nitrile gloves, though.

Mike

[Scott'n'Wendy]

Rhetorical questions....

For those of you who use solvents or mineral spirits to remove the grease, how do you know that you're not leaving behind residual cleaner that can break down the new grease?
Personally, I wipe the bearings down until I get them as mechanically clean as I can and then inspect and repack. When I repack, I see any residual grease pumped out of the bearings. As long as I'm using a compatible (NLGI #2) grease, I don't sweat it.


When you do an oil change on your engine, do you flush it with solvents to make sure there's no residual oil in the oil pan, bearings, pump, etc?

Jim

What Jim says is why I posted this thread. I've ALWAYS done my bearings like Rob posted. Has served me well. On another automotive forum I frequent the no solvent, just push the old grease out with new grease thought was very popular. Made me wonder about leftover solvents and whether I was one of the few still doin' it the old school way.

[familytruckster4]

Rhetorical questions....

For those of you who use solvents or mineral spirits to remove the grease, how do you know that you're not leaving behind residual cleaner that can break down the new grease?
Personally, I wipe the bearings down until I get them as mechanically clean as I can and then inspect and repack. When I repack, I see any residual grease pumped out of the bearings. As long as I'm using a compatible (NLGI #2) grease, I don't sweat it.


When you do an oil change on your engine, do you flush it with solvents to make sure there's no residual oil in the oil pan, bearings, pump, etc?

Jim

I wipe mine down with lint free towels and then let them dry. This is exactly the reason I dont use Brakleen on differentials when servicing them.
https://www.dexteraxle.com/user_area...ice_manual.pdf
Note on page 50 it states to clean the bearings "with a suitable solvent" although it doesnt state what that is. It also says not to blow bearings out with compressed air.

Also Yoda concern about the R&T being compatible, its an NLGI#2 Lithium complex grease so compatibility wouldnt be an issue. The whole grease compatibility issue can really be a trip into the weeds. Any #2 Lithium based EP grease is acceptable and compatible with what Dexter uses. If your brand/flavor isnt on Dexters list it doesnt mean its not serviceable, it just means that all companies likely didnt pay Dexter to get on their list.

[TedS]

The Dexter manual does not say to not blow out with compressed air. It say not to spin the bearing with compressed air.

[Jlawles2]

The #1 reason they say not to spin the bearing with air has more to do with SPEED of the bearing. Remarkably air speed from an air blower can be remarkably high. If the rotational speed of the bearing gets too high without proper lubrication it can lead to the rollers contacting the cage, this can cause cage wear and possibly bearing heating (that leads to possibly changing the temper of the bearing).