I just finished doing the "KDP" and re torquing all the inner timing case bolts.

I was inspecting everything else and came across this....

My pic is of the crankshaft gear and to me it looks like the "key"?? is shearing.

Also this gear is sitting farther out that the gears it's meshing with.

As I don't really know what I'm looking at/for can someone let me know what is going on.

And more important, how to fix it!!

Is that "key/pin" supposed to be lined up and fitting into the "keyway"??

Thanks in advance.

 

I haven't payed attention when I had mine apart but that don't look right to me. Some one else will know for sure though.

 

That is a definite problem. The good part is that you found it.
The bad part:
From the Cummins service manual; Page 7-146
The crankshaft gear cannot be removed in-chassis. To remove crankshaft gear refer to B Series Engine Shop Manual, Bulletin No. 3810206.

I believe the gear is a press fit which requires heating the gear and possibly cooling the crankshaft itself.

 

WOAH!! That definitely does not look right!!!

That is only a matter of time before it shears and your left dead. Hope someone has a easy fix for that.

 

If it's not a very nice truck, weld it.

 

If it's loose enough to move to shear the key and side out on the crank, then maybe it could be loose enough to pull without heatin' and beatin'??? but then what would help hold it back on if you could get it off???Loctite??? Also, I would have to think that this is screwing up some engine timing, maybe not by much but could be a problem. Sorry to see that. Best of luck.

 

BigBully!

that ain't right

 

I agree with yorel, is there room enough to get some sort of gear puller in there?

 

I have about an 1/8 of and inch from the block where it is supposed to be.

I have to admit.

This one is stumping me........

I'm thinking some heat and gentle coaxing and see what I can get before I get aggressive.

Dunno... I'm also thinking I'm going to wait for some more suggestions.

 

It is just a pin, not a key, and is only supposed to align the gear during assembly, not transmit torque.

The manual specifies removing the gear with a puller, removing any burrs, and then heating the new gear for no more than 45 minutes in a 250 F oven for installation.

I can't find any specs for the diameter of the gear surface.

It seems to me that it will be almost impossible to heat the gear in place without heating the crank, too.

I wonder how common this problem is?

 

Gonna have to pull it.

Not gonna be very fun to do either

 

https://www.dieseltruckresource.com/...9&d=1283488067


This is right from the quick serve

The other option is not pretty Cummins saz to remove the Crank and use a Gear splitter

 

Thats a common result of a bolt or pin falling into the gearcase. The geartrain stops before the crank/ flywheel can. Heat the gear until it's loose enough to remove with an oxy/ ace torch, remove the gear, throw it away, get a new one. Getting the pin out is the hard part of the job.

 

Do you have an update? Curious what you decided to do, and how you fixed the problem.

 

As far as heating the gear, we heat ball bearings of all sizes to 325* before installing on the shaft so i can't imagine the the gear couldn't take that kind of heat, if you can get pullers on it get it of and throw it in the dirt and stomp it, then heat up a new one and install.

Dar