Broken CAMShaft in 91

[JCockerill]

I have a 1991 5. 9 truck that has about 200K on it. It stopped running, took the front cover off and turns out it has a broken cam. I was wondering how bad of a job it is to change this and if I should use a stock replacement, or aftermarket cam. the engine is otherwise stock. Are there any special tools requried to do the swap? the other thing i was wondering was what would have caused the cam to break like this? it seems snaped close to the front. thanks

 

[Mikey-KE7LBB]

I'm afraid that you have far worse problems than JUST the cam... Sounds like the KDP strikes again!! :{



I ended up installing a 93 engine from a junkyard in a 90 that had the exact same thing happen. The truck was given to a friend of mine and had the original engine in the bed that was torn completely down by the dealer.



The cam was in 3 pieces and the valves and pushrods were all bent as well as some damage to 5 of the 6 pistons!!! The starter was about the only thing that didn't get damaged.

 

[JCockerill]

the dowel pin looked to be still intact. think it's not worth fixing?

 

[dodgenstein]

Check all your case to block bolts. These "killer case bolts" are as much of a problem or worse than the dowel pins.

 

[mweiman]

I have a 91 torn down with the cam broken in the same way by a case bolt. I pulled the head to have it checked for bent valves and I think all were OK. I had several bent push tubes and broken lifters. Also check the crank gear dowel pin, mine was slipped by about a 1/4 inch. I never found any cracks in the gear case. It should be repairable, it is just time consuming.

Good luck,

Matt

 

[JCockerill]

so a loose bolt or dowl pin fall out and causes the cam to break? how dose it not chew up the drive gears in front?

 

[mweiman]

There was hardly a scratch I could find on the teeth of my gears, the crank gear was ruined from twisting over the key on the crank. There was a gear case bolt missing though. I agree, you would think there would be broken teeth.

Matt

 

[Ncostello]

If the dowel pin and bolts are all still there... it is possible the cam simply broke from fatigue due to something like a casting flaw. It is not outside the realm of possibilities.

 

[mysteryman]

Case bolts , broken cam

This just happened to one of my friends last month. It was a case bolt that fell out and jammed the gears. . Be sure to clean all traces of oil from the case bolt threads. Then apply loctite # 262 to the threads and torque to specs upon reassembly. .

There was hardly a scratch I could find on the teeth of my gears, the crank gear was ruined from twisting over the key on the crank. There was a gear case bolt missing though. I agree, you would think there would be broken teeth.

Matt