Crankshaft Seized at TDC - Not Budging at all....

188k 2005 tundra 4.7L V8 double cab.

I was doing a timing belt replacement, water pump, etc and didn't verify the bottom mark on the crankshaft. Put it all together and realized I was off by ONE tooth.

Tore it down again. Turned the crankshaft bolt to realign the cams and crankshaft with TDC. Got the cams aligned and the crankshaft required a full rotation to get in proper alignment.

Began turning the crankshaft bolt and then suddenly it locked up and I can't budge the crankshaft at all. It's not moving. I have a big breaker bar on it. No success.

So I pulled all of the spark plugs to release compression but that had no change at all.

I'm at a loss on what to do next.... I'm turning to yall for help and support. Please guide me on how I can get my truck running again.

 

Easiest would be to probe down the spark plug holes with a small camera. Probably second easiest step would be to drop the pan and see if you can make out anything that has slipped out, or hanging or struck some forbidden glitter gold. @shifty` should come out and help save the day though..

 

I think you have a couple of options to try:

1. Set the cam timing to the big "T". This mark should set the valves so that there is no interference with with pistons. Try the crank bolt again to see if it will move. If so, move the crank to TDC. Once the crank is set to TDC, move the cams back to the TDC timing mark.

2. Set cams to TDC. Put a strap wrench on the crank pully and try to turn it backwards to TDC.

Did you start the truck with the belt incorrectly timed? In any case, being 1 tooth off on the timing belt probably had no detrimental effect. My truck was running (poorly) with the belt off 1 or 2 teeth advanced on the crank before I did the timing belt.

 

@87warrior
you were spot on! I was off TDC on one of the cams.

I moved it back into position and the crankshaft could spin again! Problem solved.

Thank you so much for the help.

Yall are the best. I appreciate this community so much.

 

That is great new @nbruno. Make sure you get the cams and crank aligned correctly before putting the belt on. Slip the belt on and make sure the timing marks on the belt line up with the timing marks on the crank and cams. It is pretty fool proof, but you have to make sure everything is lined up correctly.