Shimano PD-M731 Bearing Service - How To

[rjsdavis]

OK - once the axle is turning nicely and you've removed all of the play in the the adjustable cone. This is a bit trial and error, so be prepared to do this a few times whilst you find the right balance of tightness as you twist the axle round, against having no play at all when you try to push the axle laterally. There's nothing worse than having pedals with play when you're cycling.

Once you've found the right balance. Keep the adjustable cone in place, and really tighten up the securing nut - again, the last thing you want is for the pedals to come loose over time and damage the bearing surfaces by running loose or with play. I had to slightly over-tighten mine, as they were in such poor condition and the bearing surfaces were so pitted from being run loose, they are somewhat gritty and stiff, however, through use, this will ease up and the pitted surfaces will wear down a little over time.

Once this is done - refit the plastic end cap and cage - and the pedal is fully serviced. Just one more to do now! Below are some pics of finished pair that have both been completely cleaned and serviced. A good deal better than they were...

 

[regan_ev]

Fair flipping play to you this is a superb step-by-step & how-to thread - one of the best I've seen!!

I found it from your other post about what tool to use to get the plastic nut off, and wondered if they were the same on the PD-M735 I have in the cupboard, so went to take a look and I confirm they are.

So the pedal body design and I presume axle and bearings, too, will most likely be the same on the PD-M735, in case anyone's wondering.

And good old Raleigh, eh?! What a wonder-tool that turns out to be! (I had a Raleigh Burner, but sadly it and its multi tool, are long gone!)

Pic of my M735 showing the same plastic 4-notch fixing nut/cap:

 

[dyna-ti]

Well done all round on a great thread. I was following it waiting for the 'how do i tighten one nut while the other remains in place'


This is going to sound mad but im prepared to be shot down,flames trailing from my 4r5e.

What about using grinding paste for grease ? For a bit, just to help the bearings grind out the pitting .
Im sure faffing about will need to be entailed or mount it to a drill spin/tighten/spin/tighten till it feels a little less gritty :?

 

[rjsdavis]

Fair flipping play to you this is a superb step-by-step & how-to thread - one of the best I've seen!!

I found it from your other post about what tool to use to get the plastic nut off, and wondered if they were the same on the PD-M735 I have in the cupboard, so went to take a look and I confirm they are.

So the pedal body design and I presume axle and bearings, too, will most likely be the same on the PD-M735, in case anyone's wondering.

Thanks Regan

Yep the internal axle/bearing design is identical. The only real difference between the pedals I did, and yours, is the outer cage design as yours are the low profile wedge design that replaced mine (M731's).

However, having looked at yours, they look very clean and very low mileage indeed. Can't imagine that they need touching surely?

 

[rjsdavis]

Well done all round on a great thread. I was following it waiting for the 'how do i tighten one nut while the other remains in place'

What about using grinding paste for grease ? For a bit, just to help the bearings grind out the pitting .
Im sure faffing about will need to be entailed or mount it to a drill spin/tighten/spin/tighten till it feels a little less gritty :?

You probably could - but I can't be arsed with any of that malarchy!

If you stuck some grinding paste in there instead of grease, it probably would work, but you'd soon then need to strip the whole thing down again, clean it all again, and then grease and rebuild them for future use.

Letting them smooth off the pitting this way will be far slower and it will never "grind it smooth", but it will forge a new wear pattern characteristic in the bearing races over time. I'm happy to let it work through it over time.

 

[regan_ev]

Thanks Regan

Yep the internal axle/bearing design is identical. The only real difference between the pedals I did, and yours, is the outer cage design as yours are the low profile wedge design that replaced mine (M731's).

However, having looked at yours, they look very clean and very low mileage indeed. Can't imagine that they need touching surely?

Mine are NOS, never been fitted to a crank let alone ridden!

I put info up in case anyone else wondered if the 731 & 735 differed. I presume 730 are also the same, bar for the cage design again.

Top job you've done there

 

[rjsdavis]

Mine are NOS)

Fair enough. That's what you call quality remote diagnosis - told you they didn't need servicing!

 

[FMJ]

If you stuck some grinding paste in there instead of grease, it probably would work, but you'd soon then need to strip the whole thing down again, clean it all again, and then grease and rebuild them for future use.

Old roadie trick from BITD. Run a new BB with toothpaste in it for a few miles then clean it and grease it.

 

[Tsundere]

Great thread, very helpful.

 

[Peachy!]

Used this thread, cheers and here's a little finishing add on...

Backpedaling... (Shimano/Tioga pedal restoration)

Ok, so in the renovation sticky thread, a link to rjsdavis's excellent how to service thread was posted; https://www.retrobike.co.uk/threads/shimano-pd-m731-bearing-service-how-to.336402/ I initially said it was great but in the wrong place as it’s a service thread not a "renovation/restoration"...

www.retrobike.co.uk