TAC Tech => Tires, Brakes & Suspension => Topic started by: NY81TTASE on February 03, 2021, 05:20:12 PM
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I was rebuilding some drill presses from the '40s and '50s and needed to pack some bearings so I ordered Magnalube G because it had some good reviews. I never bought or touched new wheel bearing grease so i dont know the consistency of it and I figured when I change my front rotors I'll use the Magnalube in the wheel bearings. So,,,i wrote them an email asking if I can use it for wheel bearings and they said definitely.
Searching online, I haven't read of anyone using it for wheel bearings. Maybe trailer bearings,gun parts, or atv's but nothing about a car.
It is NLGI grade 2 and a blend of PTFE
Am I over thinking this? You think I should use it?
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Should be able to get a quality bearing grease from a local auto parts store and be good to go. I'm using a synthetic.
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New stuff is very thick and will get on everything you touch if you don't wipe it off. I have no experience with the grease you're talking about but if they said you're good to go, and you have some, then I would use it. Get your palm ready with a blob of grease and start scraping it into the bearing!!
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I think it's regarded as perfectly fine to repack with a totally different grease (assuming it's good for wheel bearings) after you do a reasonable job of removing the old. That used to be a common occurrence years ago. People would repack bearings when they did a brake job.
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So grease.... a topic near and dear to a mechanical engineer's heart!
You apparently already have the Magnalube G. It looks like very good stuff from the mnfr's info and datasheet:
https://www.magnalube.com/g-product-info (https://www.magnalube.com/g-product-info)
https://13003da1-0d4f-0427-f0b8-57bfb235dd1b.filesusr.com/ugd/381112_65d2eebce0ee6c9b2e612273f514771f.pdf (https://13003da1-0d4f-0427-f0b8-57bfb235dd1b.filesusr.com/ugd/381112_65d2eebce0ee6c9b2e612273f514771f.pdf)
It's got an NLGI consistency of grade #2 - which is the usual for auto wheel bearing grease.
The thickener is polyurea/PTFE, which is fine if ALL the old grease is cleaned off everything - as anybody when doing any brake job / bearing re-pack. Most wheel bearing greases (including the old grease in yours in all likelihood) are lithium complex thickeners and generally not compatible for mixing with polyurea.
The base oil is mineral oil (not synthetic). Base oil viscosity is:
800 SSU at 100°F
76 SSU at 210°F
The Magnalube G is good for very high temperature service - partly attributable to the PTFE (Teflon) in the base I'd assume..
For comparison, the grease I like for wheel bearings is Penzoil 707L "red" - datasheet below:
https://torqueking.com/content/lubricants/specsheets/Pennzoil%20707L.pdf (https://torqueking.com/content/lubricants/specsheets/Pennzoil%20707L.pdf)
It's a lithium complex thickener.
The base oil is mineral oil (not synthetic). Base oil viscosity is "about" (converting from CentiStokes to SSU):
1070 SSU at 100°F
80 SSU at 210°F
So the oil in the grease is pretty close to the same viscosity in the two greases
In short, I would not buy the Magnalube G specifically for wheel bearings since I'm a creature of habit and have used the Pennzoil 707L many times, and it's easy to get. But since you have enough Magnalube G to do your bearings, I'm sure its fine (or possibly "better") to use. I'm guessing it's expensive? You can pretty much be sure that whatever grease you use - as long as it's intended for bearing service - is going to out-live the brake components.
Maybe it's obvious, but when I do front wheel bearings, I pack both bearings 100% (slathering the outside of bearing with grease is nowhere near a 100% pack) and fill the void between the two bearings about 50%.
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I'm a bit confused. I'm assuming that when I buy new front rotors,,I will need, or should change anyway, new wheel bearings. From what I read online new bearings come without grease in them...correct?
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On 2nd gen firebirds, the hub and rotor are made together as a single machined piece. Rotors do not include bearings. Each rotor has a larger inner bearing and smaller outer bearing. You can re-use the bearings you have if they are in good shape (no pits/ damage to any rollers, etc.) and you are re-using your original rotors. For new rotors, I would not re-use old bearings. I would replace all the bearings personally. Rotors also have a seal inboard of the inner bearing. You have to replace the seal whenever you pull the inner bearings, so you need two new seals if you are doing both front rotors.
If your bearings are original, or if the car sat for a long period, etc. there is a good chance they need to be replaced. Bearings do not come pre-greased. You have to pack them with grease.
When you buy wheel bearings, you may need a bearing (aka "cone") and a race (aka "cup") for each location. New rotors normally come with new races already installed in them, so you may need just the bearings. The wheel bearing and race may come as a set depending on who you buy them from. Some people don't like using the races that come in the hubs with another mnfr's bearing. The races can be driven out of the hubs with a drift punch and hammer and new ones installed that are the same brand as the new bearings. If you're not familiar with it it's probably better to just use the races that come in the new rotors.
(https://live.staticflickr.com/65535/50909561346_c9015fb1f6_w.jpg) (https://flic.kr/p/2kyGNVG)
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I like the idea of keeping the bearing and race a matched set from one manufacturer. My car sat basically since 2012 so I probably need new bearings.
Thanks
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some FYI....in swapping out bearing races.....once you remove the races from your NEW ROTORS...to install the race thaqt comes with the bearing....once everything is CLEAN and a tad bit of grease inside the rotor...put the new races in your freezer over night (few hrs) ... you will find you can almost PUSH them in by hand or wooden hammer handle....then only takes 1 light SMACK with a BRASS punch n hammer...to seat them.
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Good advice. I don't think I'd ever use the race that came in them, but I guess they at least make a clean spot.