Shearing keys?

[cummins king]

I puled the IP off, and the key was sheared completely in half. Has anybody had this issue before?

The pump isn't seized or broken inside and it spins very nicely.
I checked the gear that the pump gets bolted to and theirs no wear, so i have no idea how this is possible. And also the nut was nice and tight.

CK

[sdstriper]

What prompted you to pull the IP? Was the engine running then stopped running etc?

Look for tell-tale sign if which direction it sheared from. Did you shear it off on install perhaps?

[CaptainChrysler]

If you have the pump locked and bolted tighly to the t-case, and then tighten the gear, it can fubar the key.

[JD730]

I puled the IP off, and the key was sheared completely in half. Has anybody had this issue before?

Which way in half? I broke one on install once.

[KTA]

Also you have to be sure there is no oil on the shaft or gear upon installation. Lots of no film brake clean usually takes care of that. What is the numerical torque value of "nice and tight"?

[sdstriper]

What is the numerical torque value of "nice and tight"?

That sounds like the American or in this case, Canadian equivalent of the German torque spec... Gootentight...

[cummins king]

Truck was running fine. Shaft was clean and free of oil. i took the pump off to check my high pressure seal. it split horizontally. I dont know what i tourque it to, i just do it till its tight and it hasnt faild me yet. and no the saft lock wasnt on.

Is it possible that the motor is making so much torque that it sheared it? And how does the p pumps stay on with out a key?

[sdstriper]

I think you should look at it close for which direction it sheared off. You will be able to tell... It could have been an install issue.

[cummins king]

oh ya, when you look at the front of the pump it sheared off to the left side. it was a very clean shear like a knife cutting a carrot or something like that.

[sdstriper]

My next question is this, how good was the key you had in there. You ever file on the thing or grind on it?

If you follow engineering or miltiary spec., a new key should be installed every time you remove one. I personally don't see anything wrong with reusing one as long as it is unmodified. Read that as, never filed on, sanded or ground... In fact I have been advised to use 1.5-2 thousandths shimstock to keep the damn thing in there if you R&R a pump according to the book. I like R&Ring with the key at the 12o'clock position instead though.

[bgilbert]

Operator/install error.

[cummins king]

My next question is this, how good was the key you had in there. You ever file on the thing or grind on it?

Well im not 100% on the condition of the key, but id never ground it or anything like that. But i order 2 new keys, and i will see what happens.

[Richie O]

Does the key just hold it in time until it gets seated on the tapered shaft, or does it also have some part of keeping it in time after things are tight?

[KTA]

The friction of the taper + the key are supposed to hold the gear to the shaft. As for making too much torque that isn't really an issue since your crankshaft does not drive anything through your injection pump. Therefore the only load on the pump gear is the load required to run the injection pump. You could have the pump driving soo hard that it would shear the key, but that would probably only happen if something was wrong. The key and taper should be more than enough to drive the pump. As a tip after torquing( I do 55FT-LB) the nut upon install. I always take a hammer and hit the socket to bang the gear on the shaft to help seat it. I then re-torque it and I find many times it moves. You could possibly have had a false lock.

[Ace]

I always take a hammer and hit the socket to bang the gear on the shaft to help seat it.

Now there's something you won't learn anywhere else.