Broken Camshaft

[henryfw]

My 91 just quit. The fuel pump doesn't pump fuel. When you take the fuel pump off and look in the hole at the cam it does not turn when the motor is cranked. I took the timing cover off and the cam gear wobbles. The cam is broken right behind the front bearing. One of the bolts with 10mm head had come out and broke two teeth on the cam gear. It also spun the gear that is on the crankshaft. I called Cummins and the person I talked to said he had seen several of these happen. He also said it probably bent the push rods as I was going down the road when it happened. I hadn't seen anything of this nature posted on the TDR site. Was wondering if anyone had this problem. It might be something to check when the KDP problem is corrected. There are 5 of these bolts behind the cam gear.

 

[BushWakr - RIP]

As a result of the KDP fixes over the last while, it did come to light, that the bolt(s) you refer too can back out... .

When the jig is used to repair the dowel pin it is fairly easy and quick to do... what has been overlooked is the problem you are having... . this is a good wake up ... . unfortunately, at your expense...





Bob.

 

[J DeMaio]

Yep henryfw... Just happened to me this past winter. The guy that bought it off of me said that the cam was snapped, lifters exploded and found in oil pan, all pushrods bent, and a few other things. I was going down the road and it came to a halt in a hurry. Took me a long time and a lot of money to figure out what happened. Sorry to hear this.



John

 

[Tim1]

kdp jig

Hey bob, did I miss something here? I think he is referring to the bolts that hold the inner timing cover on. If the jig is used, I was under the impression that the outer timing cover wasn't even taken off? Did I misread this? My bolts were finger tight when I did this fix. Tim

 

[BushWakr - RIP]

No, you have it right Tim... . I'm saying the jig for the KDP is so quick and easy that the cover doesn't have to come off to do the pin fix. Initially the cover came off and the pin was tabbed inside... while that was going on, the bolts got checked cause occasionally there was one that looked loose. Sure enough it was. Then along came the jig, and no more cover removal, and no more tightening of inside bolts...



I really shouldn't talk myself... . I haven't done either yet... and I'm starting to push the ole girl a bit hard..... Our Lady Of Acceleration don't fail me now... .



Pastor Bob.

 

[RGT]

Since were on the subject I plan on removing my cover this coming week and tabbing the pin and loctitiing the bolts. Does the radiator have to come out? or is there enough room to pull the lower pulley/balancer and work with the radiator left in place? anyone have the part numbers for the cover gasket and seal kit?

 

[Tim1]

part numbers

Hey bud, here are the numbers for my 92, but a word of caution, have you cpl and ser. number with you when you go for parts, they made two gaskets. Gasket 3914385@15. 68 and seal kit 3804899@25. 63. These are at least a year old prices, so adjust. You don't have to pull the radiator or hoses,however, before you start working in ther cut a piece of cardboard a place in front of the fan to protect the fins on the radiator until done. It's an easy chore to install the seal in the housing when its off, it goes on the crank dry********. The tab on our truck has a small offset to it, no big deal, though. You can use a large punch to get the fan started when loosening, the size is 1 7/16". Good wrenchin! Tim

 

[R.E. Miller]

BTW Folks,

I have been working on cummins stuff for over a year, have seen and fixed quite a few gear housings. Little secret, not really, but FWIW, I always clean and blow out the holes that hold the housing to the block and install the bolts with lock-tite and torque them to 20-25 ft/lbs. I know, spec is 18, but yes, 20-25 is nice.



Russell

 

[RGT]

thanks for the info. any special care needed on the harmonic balancer? Standard puller ok for this? I put an old Ford script adjustable wrench on the fan today and managed to loosen it in preparation for next weeks project.....

 

[nascar mark]

No puller needed for harmonic. Just make sure you have cover gasket and front crank seal for reinstall. Rad stays in also.

 

[RGT]

How do you guys who have done this allign the cover, do you follow the directions in the manual and loosely install cover, use allignment tool, tighten bolts and then install the seal? or do you do like the guy at local Cummins recommended and install the seal in the cover while it's off the truck and let the seal line up the cover, by virtue of it being on there when you put the cover back up?????

 

[Joe G.]

I installed the seal in the cover when it was on my work bench. I made two alignment pins for the upper most screws by cutting the heads off some longer screws. Then used the seal guide tool to align the lower end of the cover while the upper end was supported by the guide pins. Tightened all screws. Replaced guide pins with the proper screws and tightened those. Pretty easy to do.