Dura Ace 7800 Rear Derailleur Issue

[Spinner]

In the process of cleaning my drive train, I removed the jockey pulleys from the derailleur cage as they were caked-up with grease and dirt. I did not identify which pulley was in what position, assuming that they were both the same as in other derailleurs that I have dis-assembled. Well, they are different (holly crap).

One pulley has chain direction arrows and normal flat-type washers outside the bearing that are approximately 15 mm in diameter. The other pulley has caps outside the bearing and are approximately 18 mm in diameter. The construntion of both bearings are different too.

So, which pulley goes in the bottom of the cage?

Also, I noticed that the pulleys are imprinted with "sealed bearings." What should I do if anything when re-assembling?

Thanks.

[nrs5000]

The one with the direction marking is the lower, tension pulley.

[oldpotatoe]

In the process of cleaning my drive train, I removed the jockey pulleys from the derailleur cage as they were caked-up with grease and dirt. I did not identify which pulley was in what position, assuming that they were both the same as in other derailleurs that I have dis-assembled. Well, they are different (holly crap).

One pulley has chain direction arrows and normal flat-type washers outside the bearing that are approximately 15 mm in diameter. The other pulley has caps outside the bearing and are approximately 18 mm in diameter. The construntion of both bearings are different too.

So, which pulley goes in the bottom of the cage?

Also, I noticed that the pulleys are imprinted with "sealed bearings." What should I do if anything when re-assembling?

Thanks.

The one with the smaller wee cart bearing is the upper one. Pry the seals off and squirt some grease in both of them, seals back on.

The top one isn't directional, the lower one should have the arrow facing you(toward the RH side of the bike) as you install.

[AgilisMerlin]

when holding each, when put back together, the upper rocks side to side (floats) when you spin - and so this is the upper pulley.

just a thought

[Spinner]

It's back together ... I didn't know about the floating pulley

[dgauthier]

Good to hear everything is fine now. For the future, keep in mind that Shimano has extensive technical documentation online (you can even see the arrow on the lower pulley in the pdf below):

http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/RD/EV-RD-7800-2254A_v1_m56577569830609123.pdf

[Spinner]

For the link to the tech site; very cool

[GregL]

Pry the seals off and squirt some grease in both of them, seals back on.

What grease do you recommend for Shimano's sealed bearings (e.g., derailleur pullies, bottom brackets)? I would like to know what greases are compatible with the OEM grease when adding to the original grease fill. Shimano grease is not usually available at my LBS. I've been using Finish Line grease.

Thanks,
Greg

[oldpotatoe]

What grease do you recommend for Shimano's sealed bearings (e.g., derailleur pullies, bottom brackets)? I would like to know what greases are compatible with the OEM grease when adding to the original grease fill. Shimano grease is not usually available at my LBS. I've been using Finish Line grease.

Thanks,
Greg

Grease is oil in 'soap', doesn't really matter, all are intercompatible. I use Park, ProLink, Miche, some stuff from the hardware store-white lithium, my employee uses some green stuff....