Export thread

One of the idler pulley's (part# 5101794) bearing disintegrated, taking the drive belt with it.

This deck uses two of these pulleys, so I'm replacing both (these can't be lubricated), even though the second one seems fine.

Anyway, is there published torque specs for the securing nut? I've checked the operator manual, parts catalog, and a search on the 'Net, with no luck.

The stud is 1/2", with a spacer, then pulley, then bearing cover washer, then securing nut.

Or do I need to reference a general SAE torque spec chart? I assume stud is SAE 2 course thread, which wants 37 lb/ft?

Probably
Do it up till it stops the 1/4 turn or put a high tensile split washer on it and do it up till it is flat.

bertsmobile1 said:

Probably
Do it up till it stops the 1/4 turn or put a high tensile split washer on it and do it up till it is flat.

Click to expand...

Thanks for your prompt reply.

I should have mentioned the nut is a self locking shoulder nut, so think the split washer is not required. (Sorry, I get a bit retentive, being a software engineer and have been wrenching on autos and motorcycles for fifty years )

Idler pulley are usually mounted using smooth flange nuts. In this case they are 1/2-13 nylon flange lock nuts and should be torque to 30 ft-lbs minimum per screw torque charts. I can't tell what grade they are from the images so I would go with the grade 2 specs to be safe. They use flange as the built-in catches the inner bearing hub making for an additional washer unnecessary. Also a spilt washer might damage the bearing seal if too large of one is used. Besides these pulley should have a pulley shield install which is modified flat washer.

I use flange nuts and screws where ever space allows as there is no need a separate washer. They come both smooth flange and serrated (lock style) , although the serrated vesion damage the mating surface which why nylon lock version is preferred over the serrated except extreme vibration areas.

StarTech said:

Idler pulley are usually mounted using smooth flange nuts. In this case they are 1/2-13 nylon flange lock nuts and should be torque to 30 ft-lbs minimum per screw torque charts.

Click to expand...

StarTech said:

Besides these pulley should have a pulley shield install which is modified flat washer.

View attachment 58287

Click to expand...

Thanks for the info ... and yes, Ferris does call for the "pulley shield" washer, then the nut (Ferris calls them "bearing cover washer" ) ...

There we go - two new bright-n-shiny idler pulleys installed to 37 lb/ft, in 30 mins.

Need to clean the deck, then tomorrow, belt arrives, and should be back mowing

One parting shot, if anyone lurks back here ...

I wonder why they don't use a bearing cover washer on the underside of the pulley??