apache

I have a question regarding removal which im not gonna do but a shop will soon. do you remove the oil fill tube, remove nut and pull out? Ill assume the gear stays put? it must be a buzzard to retime or what? I was hoping they had to pull the cover so they could do the KDP. But was told no they didnt so I KDPed it a few days ago. any links to the tricks? Im just curious how its done.

infidel

The cover can stay on, the bolts come from the outside, the two on top are a trick, you need a bent open end wrench.
As long as the timing pin on the pump is pushed in upon removal and reinstallation the timing will be the same as when it was taken out.

As you can see the timing gear (top one) doesn't have much room to move with the pump removed.

Jeremy Cusick

Infidel,
That pic gives me bad flashbacks of last winter when my dowel pin killed the case (luckily, that was all it took out). Worked on it for 1 1/2 weeks under the carport in 30* weather every evening after work.

To any who've never had the opportunity to replace the gear housing, consider yourself blessed! I still haven't re-charged the A/C. Everything in front of the engine HAS to come off to get the cam out. If it wasn't for that, it wouldn't have been nearly as bad.
I soldiered through it and got er done, though. After almost $500 in parts from my local Cummins dealer.....

apache

Thanks Infidel, Timing pin? would that lock the pump shaft at a given alignment point like the plastic pin for the valve adj`s?also allowing the 200+ftlb of nut torque. Isnt the gear on the pump just a taper fit and no key or? This is why it is possible to have the timing slip.

infidel

There are two timing pins, the plastic one on the back and a steel one on the side of the pump that can be locked down. The side one has a cap over it with a pin underneath, the pin is removed and turned around to lock the pump.

Taper fit, that's why it can slip and also the means of changing the timing.

apache

Infidel, when guys say the timing has "slipped" dont they mean the nut came loose or? and the gear rotated on the taper somewhat?
Also sounds like like you have done several KDP repairs. Do you typically see them sliped out some? mine was out 1/8 or so and had to be punched in to set the tab over correctly. Make me think I did something good here would ya

Paul Winey

I was able to get at the injection pump mounting nuts pretty easy with a 15 mm swivel socket and a long extension reaching in from behind. They aren't torqued very high (18 ft/lbs I think). The timing gear just floats against the other gears and really doesn't move. Be sure and have them put a new washer on the injection pump shaft when reassembling. By the way, can I ask why the pump's coming off?

Paul

infidel

When stock the gear slips on the shaft it's mainly because of the torque on it.
I've never seen any data on it but my bet is the injection pump takes at least 20 hp to turn.
When the timing slips after someone has had the gear off it's usually due to not cleaning the shaft and gear spotless. I've heard of just a felt tip mark on the shaft causing a slip that wouldn't go away. Reusing the old washer and not torqueing the nut correctly can also cause slip.

Most of the dowel pins I've seen are out a little bit, like 1/8".
My feeling is they were never in all the way from the factory because they are rather hard to pound all the way back in.
Once they are out more than a 1/4" they are easy to pound back in, these are the ones that would have most likely caused a problem.
Cummins first said that the problem came from variances of less than a thousandth of a inch in the pin diameter from the manufacturer. Not sure if they are just shifting blame but it certainly could be the root of the problem and explain why the pin will never be a problem on most trucks.