Wheel Bearing Grease Intervals

[N999BT]

Does anyone know how often the wheel bearings should be greased? Is there a regulation that addresses this? Annually, every 100 hours, every 250 landings? I downloaded the maintenance manual from Cleveland but I can't find a reference to the timing.

[John Clark]

Originally Posted by N999BT

Does anyone know how often the wheel bearings should be greased? Is there a regulation that addresses this? Annually, every 100 hours, every 250 landings? I downloaded the maintenance manual from Cleveland but I can't find a reference to the timing.

FAR Part 43 Appendix D (e) 7 states:

(7) Wheels- for cracks, defects, and condition of bearings

So, I suppose that it depends on how you determine the condition of bearings. could be that you take the bearings out, inspect, and repack them, the usual procedure. Or, give the wheel a spin and pronounce them inspected Seriously, I have always done, and will continue to do, the real inspection but I suspect that annually is bit of overkill in most cases.

John Clark
RV8 N18U "Sunshine"
KSBA

[kentb]

I inspect every year and replace the grease every other year.

If I flew more then maybe it would need it more often.

Kent

[allbee]

actually, I'm interested in what people find as experience for usage. Because I fly about 300hrs a year. So a once a year might not be good for me, may need sooner.

[RV6_flyer]

Originally Posted by allbee

actually, I'm interested in what people find as experience for usage. Because I fly about 300hrs a year. So a once a year might not be good for me, may need sooner.

After 2,225 hobbs hours over almost 12 years (1st flight Sept 1997), I only repack my bearings when I change tires. I DO NOT solvent clean them just repack with clean grease. IMHO, the once a year bearing inspection can be done without solvent cleaning. Others will have different opinions. Yes if there is something that I question during the inspection, I will solvent clean them to get a better look. So far, I have only solvent cleaned them once after sitting outside in the rain over a two-week period. They had spots on them and were replaced. I could see the spots without solvent cleaning but solvent cleaned them to get a better look. They looked usable but were not good enough for me. Bearings are cheap compared to the entire airplane.

[allbee]

thanks gary. I would think things should go a long time, after all, we should be in the air more than taxi on the ground.

[John Clark]

The wheel bearing service issue is all about the sealing (or lack of) in the usual Cleveland wheels. Most cars, with modern seals almost never need, or get, service because the seals effectively keep the grease in, and more importantly, the crud out . So when did you last service the wheel bearings in your car? Anyway, we need to look now and then because of the stone-age felt seals.

John Clark
RV8 N18U "Sunshine"
KSBA

[randylervold]

Originally Posted by kentb

I inspect every year and replace the grease every other year.

This is my routine as well. When I do my every-other-year repack I like to clean them with solvent first for a thorough inspection first, just makes me feel better.

[az_gila]

...might be of interest here....

http://www.bomar.biz/download.php?view.1376

Note that the new expen$ive grease they now recommend is Exxon Mobil SHC 100

[Christopher Murphy]

20 plus years ago I worked in the wheel and tire shop at O'hare for the "then largest airline in the world" Tires were good for about 30 to50 landings and the bearings got cleaned, inspected, repacked with each tire change. I think we tore down and built up about 150 per week.

tidbit...almost every tire in the fleet was a retread. 747 all wheels&tires the same( including nose gear) 737-300 main gear tires wheels same as 757 only 1/2 as many

I clean and inspect and repack every other year or if I change the tires. I fly out of a high hot airport and the little wheels spin up pretty good. If you do alot of T/O and Landings you should adjust your mx schedule.

cm