Oil pump carnage - RD350

[SoCal250]

My '73 RD350 that I purchased recently has a few issues that I've been wanting to remedy before I do any riding on it. Finally made some time to start digging in...
One is a top end rattle in the fresh rebuild (50-60 miles) that the PO had done at a local shop. Pretty sure they used the wrong clearance for the forged Wossner pistons. That one I'll get to soon.

The other is the oil pump which I discovered had a frozen priming wheel and the plunger did not move with the engine running.
It looked clean like it had been freshly rebuilt when the engine was done, and my suspicion was that someone didn't reassemble it correctly. I was correct!
Pulled the pump today and found this. The gear is destroyed! So I'm in need of a new pump (or the parts to rebuild one). I was able to recover the small pins and springs inside, and the other parts look OK.

Check this out!

[m in sc]

how does that even happen? thats a new one. 

i probably, heck, i know i have an internal gear for one. PM me i can mail you one.

[rodneya]

Wow. That one for the hall of fame.

[pdxjim]

There's that mechanical drag we were talking about a couple weeks ago.

[SoCal250]

i probably, heck, i know i have an internal gear for one. PM me i can mail you one.

Thanks Mark! I just sent you a message.

Heading out to garage to double check the parts after running through the ultrasonic. Need to make sure the pump bore is OK. On initial inspection it looked like only the gear was sacrificed and the housing was unscathed.

[m in sc]

There's that mechanical drag we were talking about a couple weeks ago.

^ epic. 

[SoCal250]

I'd be interested to hear Arrow's thoughts on this. I wonder if this is the result of putting the gear in backwards?

[busa1300]

Sounds like the (local shop) should stick to maybe lawn mowers...
I would be a bit concerned about any work that was done after seeing that and having a rattle too....

[m in sc]

gear in backwards just will freewheel since its a one way clutch.

going out USPS tomorrow.

[SoCal250]

Awesome, thanks Mark! 

Either something was assembled wrong inside and then stuffed back together causing a lock-up, or maybe a worm gear mismatch issue? The pump is the "old style" so it should be paired with a "coarse" 6-thread 278- worm shaft.
Need to double-check that and make sure they didn't get new style fine 9-thread 214- one in there.

The inside of the pump body looks OK. The gear took all the abuse.

[rodneya]

Is the plastic drive gear still intact?

[Striker1423]

wow. Well, good thing it was easily sorted!

[m in sc]

im guessing here, but i would bet one of the clutching pins popped out, got between the worm and the ring gear and went crunch. only thing i can think of that would do that.

there was a discussion somewhere where instead of using the spring loaded pins, which are a fiddly pia, they just used a regular roll pin or section of hardened wire in there, which removes the clutching feature, but really, who cares? they eliminated it later for a reason. 

when i did the one on the r5 last year, thats how i did it.  been fine. 

[automan]

Aren't the later pumps without those pin springs?

cliff

[Arrow]

Hi, it looks like the gear has been put on the wrong way which is why no movement when the engine running and the 'seized' priming wheel. The broken teeth look like it's been momentarily fitted to the wrong shaft at sometime in the past, but not this time.

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