Timekeeper explosion in P400

[CursedH1]

Figured I'd go ahead and post here as a warning to others.

Timekeeper set installed in a brand new P400 in 2022. 20k miles on the motor and Timekeeper set. Around Thanksgiving I noticed a knock coming from the engine, then found glitter in the oil.



Thankfully the pieces of the exploded dogbone were found and the engine is being rebuilt. This time with the standard timing chain.

 

[DieselCash]

Wow, that is wild! How bad did it mess up the engine?

 

[SnowDrift]

Has the cause been determined?

My set was purchased around the same timeframe for my engine, so I guess it will sit until this is resolved.

 

[CursedH1]

Wow, that is wild! How bad did it mess up the engine?

Thankfully the engine itself appears to be as unscathed as possible. The pieces of the broken dogbone are accounted for in the oil pan but there still was glitter. On Monday we order all new bearings/gaskets/seals/gapless rings. Already have all new ARP hardware ready to go. Also taking the opportunity to change to the P400 DS4 IP.

Has the cause been determined?

Not sure we'll ever really know - but I know that there was a thicker gasket put on the water pump / backing plate to make sure that the "dowels" didn't interface with something they shouldn't have when they were installed.

 

[SnowDrift]

Those teeth appear peened so it makes me wonder if they are either soft or if the tooth spacing in inconsistent, possibly causing the dog bone to fatigue.

 

[Big T]

Looks like the dog bone heated up on the side it broke. Regardless, this is not a good thing. Never had a timing change break and they aren’t hard to change.

 

[CursedH1]

Note that this was with the "thicc" gasket.

 

[Big T]

View attachment 97364

Note that this was with the "thicc" gasket.

Well there’s your source of heat and your answer. Seems like these time keeper gears were not compatible with your timing cover or they were not installed properly.

 

[Twisted Steel Performance]

@CursedH1

There is no gasket from the factory, I don't use gaskets, the idler gears are supposed to be put in place and the clearance of the shafts checked so they will float.... I use clay for measuring the clearance, I go for .050" clearance... This is after the fact your gears bound up and things went to crap, those marks could very well be from the gear being pushed around... no true way of pointing fingers as to root cause now.

 

[Will L.]

The gm and first navistars had gaskets, butas Chris mentioned the p400 didn’t. I am wondering if there is s depth difference in the timing cover mounting face to the block on p400 vs gm.

I’m convinced the axles were pinched.
The axles have to float freely, if they get pinched the axle binds ever so slightly and will sideload them into the gear. Thats what causes the axle to spin with the gear. See the rotational marks on the timing covers?

The one side could be argued it spun after the dogbone failed & thats the cause of the spin on that side. But obviously both spun.

My gears are spinning in my head. In racing these were the common upgrade the whole time I was in that scene. Seen a few fail but never like this. Hmm…

 

[CursedH1]

There is no gasket from the factory, I don't use gaskets, the idler gears are supposed to be put in place and the clearance of the shafts checked so they will float....

When the water pump was replaced back in September - my mechanic said he had to use a "thicker" gasket in order for the dowels/shafts to not interface with the timing cover. So he did notice them touching the cover but perhaps it wasn't enough.

 

[Twisted Steel Performance]

When the water pump was replaced back in September - my mechanic said he had to use a "thicker" gasket in order for the dowels/shafts to not interface with the timing cover. So he did notice them touching the cover but perhaps it wasn't enough.

Obviously it wasn't, the directions say to grind the shafts for clearance.... those gaskets that can be purchased aren't anywhere close enough to get .050" clearance unless a person uses 8-10 of them....