Timing belt #3
Elder User
Joined: Dec 2007
Posts: 757
Likes: 1
If the woodruff key broke, they should be able to replace it without having to replace the crank as the crank has a slot that the key fits into. Woodruff keys do fail, typically if the device which they are driving (gear, flywheel, etc) comes loose and said devices starts backing off the key. Seen it on motorcycle flywheels a few times.
I don't think there is an actual keyway machined into the crank shaft that would accept keyway stock for the sprocket. I believe it is all machined into the shaft so if it sheared off there would be nothing to hold the sprocket in place.
Logistics Pro
Joined: Sep 2002
Posts: 4,410
Likes: 1,015
From: Central KY
That looks expensive. Dealers get $100/hour and they're going to have to pull the engine out of the truck to repair that. Would honestly cost less in labor to replace the engine. See if you can find one in a salvage yard.
Senior User
Joined: May 2009
Posts: 121
Likes: 1
A Woodruff key normally fits into a slot milled into the crank, but it looks like the EB35 was just using a hole milled into it, and when the key quit its post, it damaged the crank. As wallowed out as that one is, that crank very well could be shot. You would think that they could just replace the crankshaft, but I looked it up on Tasca's site, and it's shown as only being sold as part of a short block assembly. (It seems to be peculiar to the EB35; you can buy a crankshaft for a Coyote.)
I'm not sure about this particular application, but Woodruff keys like this are often only supposed to be there for alignment during assembly; the fit between the gear and shaft is supposed to be tight enough that friction keeps them together. That would lead me to suspect that there was either a defective part or something wasn't done right in the previous timing chain work, so if the dealership won't do anything to help, I'd suggest talking to an engine builder in your area to get a second opinion. It may be that they're telling you God's own truth on this, and it really was just bad luck, but I think I'd want to be sure.
I'm not sure about this particular application, but Woodruff keys like this are often only supposed to be there for alignment during assembly; the fit between the gear and shaft is supposed to be tight enough that friction keeps them together. That would lead me to suspect that there was either a defective part or something wasn't done right in the previous timing chain work, so if the dealership won't do anything to help, I'd suggest talking to an engine builder in your area to get a second opinion. It may be that they're telling you God's own truth on this, and it really was just bad luck, but I think I'd want to be sure.
Cross-Country
Joined: Nov 2014
Posts: 80
Likes: 15
Seems like the crank could be drilled for a pin the same size. If the shaft is too scored, there are machines that can grind them in place...pop in a sleeve and go to town. (same machine that can grind a crank when engine in vehicle. Not too much expense.
Elder User
Joined: Dec 2007
Posts: 757
Likes: 1
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Fleet Mechanic
Joined: Jul 2005
Posts: 1,800
Likes: 52
From: Southern Colorado
Agreed - horrible design. Much cheaper to engineer and install a pin than a Woodruff key, but the result is obvious. I'm sure that dozens are not failing, but there's not much headroom in this design for a failure. If labor were not a factor, a machine shop could drill through the entire crank and install a new pin that projected out just as the original did.
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