Never Use Gasoline to Clean Wheel Bearings???

In the process of annualing the Mooney my partner claims that you should never use fuel to clean wheel bearings. We used Varsol.

Of course ever the skeptic I said
"You dont really believe that do you? all the solvents basically do the same thing"
He said it was because gas washes the oil from the pores.
Is there any truth to all that? and why would it matter?
I suspect 90% of car bearings get washed in gas and they run 100,000 miles.

Of course its a fire hazard, and carcinogenic, and might cause my pet rat to have birth defects if he swims in it everday, who cares? I am flying experimental airplanes, riding motorcycles, drinking booze, eating steaks! ....I'll consider myself lucky to live to 85 then die of a rare cancer!

What do you guys use to clean your bearing?.....

RickS said:

I suspect 90% of car bearings get washed in gas and they run 100,000 miles.

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My toyota has 220K miles and I don't think the bearings have ever been touched ... ?

I wash the airplane bearings in whatever solvent the mechanic has in his parts washer (I do owner assisted annuals on the 170/172 - still building the -8) It sure smells like mineral spirits but I'm not sure.

T.

RickS said:

In the process of annualing the Mooney my partner claims that you should never use fuel to clean wheel bearings. We used Varsol.

Of course ever the skeptic I said
"You dont really believe that do you? all the solvents basically do the same thing"
He said it was because gas washes the oil from the pores.
Is there any truth to all that? and why would it matter?
I suspect 90% of car bearings get washed in gas and they run 100,000 miles.

Of course its a fire hazard, and carcinogenic, and might cause my pet rat to have birth defects if he swims in it everday, who cares? I am flying experimental airplanes, riding motorcycles, drinking booze, eating steaks! ....I'll consider myself lucky to live to 85 then die of a rare cancer!

What do you guys use to clean your bearing?.....

Click to expand...

The only reason that I know of to NOT use gas is becasue the fumes will BURN. It evaporates in an area with poor or no circulation and a spark ignites (explodes) the fuel air mixture. Some one gets hurt, the shop catches fire, or the airplane catches fire along with the fuel being used to clean the grease and the grease now burns as the gas got it hot enough.

I never wash out my bearings. (unless they fall in the dirt) I just REPACK them with new clean grease.

Should the question be, "How often do the bearings need to be cleaned?". Just how many miles do we put on our gear in, say, 100 hrs. or so annually? The bearings seem fairly substantial, and I know they need to take high shock loads. I also know the grease will get dirty or can break down with age, but I just feel silly cleaning bearings each year, especially since they look fine upon disassembly.

I know I'll hear the chorus, saying it's a little inconvenience, just go ahead and do it. Still, I'm...

Just wondering,

Mark

I use low odor mineral spirits, but wouldn't hesistate to use 100ll. Gasoline (reformulated) just stinks way too much to use, but would work well.

The point of cleaning the bearings, if necessary in the first place, is to get them totally and absolutely clean. Leave no residue whatsoever. Gasoline, a petroleum product, does a nice job of cleaning the conventional greases typically used in wheel bearings.

One point of cleaning the bearings is to visutally inspect for spalling or other damage. Otherwise, Gary's suggestion of just repacking is reasonable.

I used to clean and repack mine annually when based at a grass strip. But now that I'm on concrete 99.9% of the time, flying about 75 hrs a year, I'm rethinking this.

Speaking of an odd wheel bearing situation. I have two GM vehicles, both '02 models. The front left wheel bearing on both vehicles - pickup and Suburban - failed within a month of each other at about 80-90,000 miles. Never heard of a car wheel bearing failing for no reason before. These did. Both sealed type brgs and completed wiped out. That set me back about $450 apiece. But I can change that spindle assy out fast, now.

RickS said:

He said it was because gas washes the oil from the pores.
Is there any truth to all that? and why would it matter?
I suspect 90% of car bearings get washed in gas and they run 100,000 miles.

....

Click to expand...

wow how did they ever get them greased in the first place the flash point of gas is very low compared to varsol. kinda a diesel v/s gas thing but the whole point is to clean and inspect. fresh varsol will clean and dry very quickly. just wont explode on you. and make you smell like **** for a week.
my z28 has 229000 miles on the front wheel bearings and no issues however a rear axle brg is finally making some noise. clean it with what ever you want just use high quality grease that can withstand high temps generated by the rotor
if youve ever practiced short field landings at night youve seen a glowing red rotor.

note : the yukon is up to 120000 miles with not as much as an airfilter. still on its second set of tires. oops i lied i did install a battery guess its time for an annual.

Washing with gas

Ahhhhhh!!! DON"T DO IT, use varsol or any other parts cleaning solution.

I come from a small town and when I was a kid used to hang around the B/A garage....The old mechanic there always had a pail of gas sitting in the middle of the shop for washing parts,hands or anything else needing cleaning..He lived to a ripe old age...go figure !

I am also a firefighter and have gone to several calls where the person (one victim) were:
- cleaning motorcyle parts in the basement.... with gas
- cleaning oil off the floor of the shop....with gas
- kabooom

I know that a lot of people still use this practice for cleaning parts......why ? It ain't that much cheaper.....Is a LOT more dangerous......and WILL eventually ruin your day.

Safety should be a priority as we are building our RV's......we go through a lot of pains to Fly Safe......Lets "Build Safe" too.

stepping off the soapbox now...

Marc DeGirolamo said:

Ahhhhhh!!! DON"T DO IT, use varsol or any other parts cleaning solution.

I come from a small town and when I was a kid used to hang around the B/A garage....The old mechanic there always had a pail of gas sitting in the middle of the shop for washing parts,hands or anything else needing cleaning..He lived to a ripe old age...go figure !

I am also a firefighter and have gone to several calls where the person (one victim) were:
- cleaning motorcyle parts in the basement.... with gas
- cleaning oil off the floor of the shop....with gas
- kabooom

I know that a lot of people still use this practice for cleaning parts......why ? It ain't that much cheaper.....Is a LOT more dangerous......and WILL eventually ruin your day.

Safety should be a priority as we are building our RV's......we go through a lot of pains to Fly Safe......Lets "Build Safe" too.

stepping off the soapbox now...

Click to expand...

When I was a young man with my six year old 1950 Chevy, I dropped the U joints I was replacing in the dirt (yes, the garage had a dirt floor). I washed them in gas and repacked them in grease. Seemed to work...what's the funny growth on my hands?....

Anyway, I've been told that a good shop cleaning solution is one gallon of "Gunk" with five gallons of Mineral Spirits (this is for a typical shop parts washer). I've also been told that OSHA no longer allows this mix - which means it must work.
John

RickS said:

...He said it was because gas washes the oil from the pores.
.....

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There are good reasons not to use gasoline (already stated above) but THAT is not one of them! If the bearing used sintered balls or races that were porous (unlikely) the oil would be replaced by the fresh grease.

-mike

I used whatever the mechanic had.

Used to clean and repack the bearings every year but lately have skipped a year in between as I haven't been flying the 172 very much.

Paint thinner

Next time you're at Walmart, pick up a gallon jug of "Paint Thinner". Just make sure the fine print says "mineral spirits".

The correct solvent for anything petroleum based is mineral spirits. It costs half as much as gasoline, works better, and isn't an extreme health or safety hazard.

Do not wash bearings at all, as I was told

A very experience AI told me, DO NOT WASH wheel bearings at all, in gas, solvent or whatever.

The issue with solvent is you can never get it all out, or that is the theory. You can used compressed air, shake it and let it sit, but it's really hard to get all the solvent out. You add new grease after the cleaning but the solvent just dilutes the grease and keeps it from staying where needed. A little "dirty" grease is better than excess solvent remaining. As far as inspection? You can wipe the rollers off and look and look at the race as well. Wheel bearing last for ever. If there is any doubt about the condition replace them, but from my experience it will be obvious, like when one of them is missing or comes out in a chunk.

The method is just use fresh grease and pack it in until you push the old stuff out. Bearing greasers are great tools, but a little blob in the hand (with gloves of course, petroleum can cause health problems) and start working it thru. I use the slap method, where you smack the bearing into the grease to force it further in. Keep going until all the grease coming out is clean.

Its like greasing a Hartzell prop when you grease it. You don't fill the hub with solvent and than new grease, you just push in new grease and let it flow out the other side until its clean.

BTW, Gas is very dangerous and a fire hazard for one and should not be used for a solvent ever. Gas has vapors that of course will collect and go ka-boom as someone mentioned. It's just too old school.

Cheers