replace grease in a sealed wheel bearing

simonfraser

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boat is on a trailer, gets run for about 2 mins in the yard behind a tractor to the slipway and back out again, salt water
trailer is never going to be used on the road
have blown 2 sets of bearings b4 i figured out i needed to rinse them out, i now have rinse lines
but am looking forward to, not, to the next set of AL-KO 2051 bearings to be replaced
in preparation for this bit of 'fun'
i am plan to remove the seal in the new bearings with a small pick and then take out the existing grease with a brake part cleaner / methylated spirit
get a grease Injector Needle and inject Marine Grease into the bearings
any one done this ?
good / bad idea ?
 
boat is on a trailer, gets run for about 2 mins in the yard behind a tractor to the slipway and back out again, salt water
trailer is never going to be used on the road
have blown 2 sets of bearings b4 i figured out i needed to rinse them out, i now have rinse lines
but am looking forward to, not, to the next set of AL-KO 2051 bearings to be replaced
in preparation for this bit of 'fun'
i am plan to remove the seal in the new bearings with a small pick and then take out the existing grease with a brake part cleaner / methylated spirit
get a grease Injector Needle and inject Marine Grease into the bearings
any one done this ?
good / bad idea ?
FIT stainless bearings .
 
At low speeds it is often possible to drill the hub and fit a grease nipple, you may need to drill the opposite side to make a drain and tap this and fit a tiny grub screw, you can then remove the grub screw to allow excess to drain while you pump new grease in.
 
At low speeds it is often possible to drill the hub and fit a grease nipple, you may need to drill the opposite side to make a drain and tap this and fit a tiny grub screw, you can then remove the grub screw to allow excess to drain while you pump new grease in.
I can see how that works for taper roller bearings, but not for sealed as the inner bearing surface is continuous from one face to the other?
 
boat is on a trailer, gets run for about 2 mins in the yard behind a tractor to the slipway and back out again, salt water
trailer is never going to be used on the road
have blown 2 sets of bearings b4 i figured out i needed to rinse them out, i now have rinse lines
but am looking forward to, not, to the next set of AL-KO 2051 bearings to be replaced
in preparation for this bit of 'fun'
i am plan to remove the seal in the new bearings with a small pick and then take out the existing grease with a brake part cleaner / methylated spirit
get a grease Injector Needle and inject Marine Grease into the bearings
any one done this ?
good / bad idea ?

I thought that the grease in these was hydrophobic anyway, at least those supplied by ALKO are.
I am surprised to learn that with your use that the bearings fail at all, unless the 2 minutes is at a high enough speed for the bearings to warm up and the trailer is then put in the water straight away?
 
No such thing as a sealed bearing as the inner and outer race move seperately, the seals they use are poor quality and only run on the moving race and don't really stand any pressure, you prise out the inner seal of each bearing so the fresh grease gets inside it and if the hub assembly is full of grease then there is no room for water.
 
I thought that the grease in these was hydrophobic anyway, at least those supplied by ALKO are.
I am surprised to learn that with your use that the bearings fail at all, unless the 2 minutes is at a high enough speed for the bearings to warm up and the trailer is then put in the water straight away?

without rinsing out the bearings have lasted one year before the wheels started to wobble, yes the nuts were tight

the last set, rinsed after every use, are coming up for 13 months ok so far, planning ahead :unsure:
 
First Mate and I were in the Motorcycle business for 40 years. I still have perhaps 30 wheel bearings for motorcycles in the workshop left over from when we sold the premises.

IIRC, the correct term is 'Shielded', not sealed.

Some have metal shields, some rubber.

I replaced a 56 quid plus VAT main bearing in a Johnson outboard with a 3 quid Honda 125 front wheel bearing. I just dug out the crankcase side rubber shield to allow the lube in and used a dab of loctite to keep it still instead of the roll pin of the expensive OE Johnson one.

Ten years later, still working.

Trailer bearings that are regularly immersed are a nightmare.

In NZ long distance trailed boat trailers use waterproof grease and are regularly greased and serviced. Trailers there require an annual WOF - Warrant of Fitness, so are kept in good nick.
 
No wheel bearings are really sealed against salt water corrosion so "sealed" bearings in my experience are bad news as it usually means a nightmare to replace.
Best bet I've found over the years is fit the cheapest bearings and plan to replace them every year and use in combination with bearing savers (aka bearing buddies). I've had this combination used like yours last 4 years. No rinsing.
 
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