How worn is my pinion ??

Is that a crack running from one tooth to the other or a piece of hair or something?

thats just a bit of hair or string or something mate.

yes matching gears is what i thought.
though Im not overly concerned with tearing it back down again as its only a days work should the pinion break a tooth.
what i am more concerned about is the amount of wear on it.
i haven seen a new pinion gear so its hard for me to work out the wear.

also , when looking at the bevel gear, i believe the alignment was out as the wear is on the edge of the teeth.....
this i guess would also reflect on the pinion gear.

also who is KUON ? as its stamped on the pinion. is this the original supplier or has the pinion been replaced with an aftermarket item
it has the original cat part number on it.
just a curiosity. also gives you another angle to inspect wear.

also one last thing in regards to wear jack , the pinion will not wear certain teeth of the bevel out as its contact pattern differs every rotation.
i.e pinion gear 12 tooth , bevel gear 53 tooth. for the first revolution the first tooth on the pinion gear will touch the 1st,13th,25th,37th and 49th tooth of the bevel gear
on the second revolution it will touch the 8th ,19th 31st and 43rd tooth.

see how it keeps rotating around the gear teeth. Gear manufacturers do this on purpose to promote an even wear rate.

To me that pinion doesn't look all that bad....seen a lot worse still operating. I don't see any chunks missing or severe wear but then I'm just looking at a picture.

Yes, pinions and bevel gears should be replaced in sets but in the bush that didn't always happen. For your limited use there seems to be plenty of life left, just do the best adjustment matching you can and don't go trying to push start any D8's.

My pinion is better than yours but like OLD MAGNET said you can reinstaled yours maybe for long time

I'm glad this has come up, I was concerned about my pinion shaft as well (also D4), but found the pinion bearings were shot, have replaced them but wonder whether the pinion has taken a worn "set", now with new bearings potentially the tooth engage pattern will be different.


[img]http://i16.photobucket.com/albums/b1/RichardJayW1/pinion.jpg[/img]

I showed your photo to one of the best field Cat Mechanics in Oz and he feels for what you want to do it should be OK as the hard facing is worn a bit, but you need to be sure that pinion shaft bearing is OK, the rust on the cage is one to look at carefully as there is enormous load there.

We just installed a "new" secondhand pinion shaft and crown wheel in my D4 7J yesterday, though be careful if you decide to replace that pinion bearing BL313, as I discovered our #1 aftermarket supplier of bearings here in Oz supplies lightweight bearings with only 8 balls, and not the original spec 12 balls found in my BL312 (P/N 1B4122), and no doubt your BL313. I just went out and bought a 12 ball bearing replacement bearing yesterday for the 8 ball replacement bearing I got from Qld., $192 thankyou very much. Those letters indicate it is a aftermarket pinion shaft. I got my pinion and crown wheel from Paul Moore in Toowoomba, he is a good guy to deal with and freight on heavy items is cheaper.
regards
Mike