Shimano pedal maintenance question
 

I have XTR trail pedals that have spindles that look like what is pictured below:

https://www.universalcycles.com/imag...rge/197317.jpg

The rubber O-ring (second from left) seems to come loose after every ride, leading me to believe I don't have it in there properly. I am kind of at a loss for how to deal with this. I put it back, but it keeps doing this during every ride, so obviously I am doing something wrong.

Too much grease in the pedal is (probably) forcing it out. There is a small groove in the axle sleeve that it fits in, but it is not a super secure fit. Grease purging will often displace it, if you are not deliberate about installing the pedal body.

Thanks. That definitely was what caused the problem, but even after removing as much grease as I could manage, the O-ring still seems to slip out. I was hoping I was just overlooking something obvious.

I remove the axle assembly on mine about every 5k miles, clean out the housing and fill it with new grease. When I reinstall the axle dirty grease is through the cartridge of the pedal and through the seal. I carefully push the seal back in with a small screwdriver. I have not had the seal come out while riding between overhauls.

I push the seal back every day, and then it comes out again. This only happens on the left-hand side, for whatever reason. It is driving me nuts.

This type of seal, not rapped by a outer sleeve or groove, is often found to travel as it stretches/expands with wear. One more reason that the marketing term "sealed" is not what many find is the real result. I see a lot of pedals and other bearing units with drifting/expanding seals often.


I disagree with the suggestion of too much grease being a wrong thing. Seals are about keeping stuff out of a bearing, not about keeping grease in. I feel one should grease a bearing so some grease gets squeezed out in initial use.


Again I think the failure here is the belief that the "seals" referenced are a positive and reliable barrier to stuff getting in. Andy

Thanks, Andy.

Any suggestions on how to deal with it? New O-ring?

It was not my intention to imply that there was too much grease, simply that the purging is the likely culprit. Shimano specifies a 1/3 fill inside the pedal body, which would, as you noted, purge grease during the initial use.

For my pedals, I've often noted a displaced seal that refuses to stay in place; the grease inside does not seem terribly different from the other pedal during my 6-12 month checkup period.

FWIW, OP, you can take that part number on the exploded view to any bike shop with a Shimano account, and order a replacement part.

The classic way to create a bearing seal where none is was to slip over the axle a number of industrial "o" rings such that the one contacting the dust cap/ cup/body is sung enough on the axle to grip it well and of a large enough section to plug the gap between the axle and the dust cap/cup/body. Additional "O" rings butted up against this "sealing" one will keep the "sealing" one in place.


The best example of this is the Stein Zerk BB grease injection/seal kit. The same approach might also work with your pedal to keep the OEM seal in place. Andy.

Thanks very much. I will give it a try.

Sorry if I miss understood your earlier post. About the part availability- Shimano does a great job at providing product info/replacement part numbers. However info is not always an indicator of a part being in stock. Like any business Shimano makes choices as to what to actually make available in the after market chain WRT what will sell. Without actually checking I wouldn't assume the seal is available, hopefully yes but... Andy.

I definitely popped it out with grease.

Andy's suggestion inspired me to push it in more aggressively with a better screwdriver. So far (34 miles) it has stayed put. I seem to have the same problem when installing computer memory.

Why worry
 

This hearing design came out in the Late 80's if you can believe that. It's a little on the lower quality side I always felt but is very bomb proof.
I think your overthinking it.
The seals get too big. Harbor freight sells hundreds of o- rings for a few bucks.
The beauty of the bushing with an outside ball contained roller is that the bushing is also a type of seal because it's not a tight fit. Dura ace used a roller bearings in the middle and ball bearings both sides but Dura ace required a lot of work and this system you take the axle off by using the little plastic tool and squirt grease in the bottom of the pedal inside about half a ribbon of tooth paste and tighten back up. The good grease poops the bad grease out and you overhauled your pedal in one minute. I've rebuilt dozens of Brands of pedals, and they are a total pain to replace bearings. On the Shimano a 10mm wrench can adj. the roller if it's got play.
Bushings have no place on bicycles IMO, but on mountain bikes the pedal is great. If you trashed that o- ring and once a month squirted a little grease it last so long you'd be sick of SPD. Don't let a tiny seal bother you, as long as grease goes out now and then ... your set. Also performance has a $33 price on Shimano mtn. Double sided without the pathetic seal issue. O-ring. But if you want to get perfectionist ( good god they are mountain bikes) like the man says drill and tap a zerk and grease guard it with synthetic- that's the stuff us road guys did which of course is justifiable!

I glued mine in with Goop.

Some days, the internet just makes my head hurt.

In reality they are just dust seals. To keep liquid out you need a labyrinth seal as in heavy machinery.

I remove
 

I faced same issue with mine. I removed it and keep pedals always clean and greased. Try to avoid too much water and mud. If it happens, so clean and grease it again.

Add an O Ring and maybe a zip tie?