Hi, this is my first post so don’t flame me if this is posted in the wrong place.
I recently removed my head to replace the head gasket, following the repair manual’s steps to a T. Reinstalled the head & torqued down & proceeded to reinstall the cam sprocket & chain which is when I realized the sprocket now will not slip over the cam. Tensioner & cassette have been removed & I am confident nothing has fallen into the gear train & the engine has not moved. PLEASE HELP ME.
Side view of chain over sprocket at max height

:(

 

Welcome to the forum

Should also include the year of Ranger, 2010?
4.0l SOHC engine(2001-2011 Rangers)

Is that the front drivers side chain?
Can you see its other end, it often comes off a bit and doesn't sit back on its jack shaft gear
Looks like this with head off: https://i.ytimg.com/vi/dJMtFNcLHmQ/maxresdefault.jpg

If you don't have the front cover off turn the crank back and forth a few times, mark the starting spot so you can return to it, and see if the chain settles back onto the lower gear

 

[QUOTE=RonD;2223800]

You are correct, 2010, 4.0L SOHC Ranger Sport.

Front, driver’s side head is pictured.

i do not have the timing cover off, likely will come off in the next week if I can’t resolve this otherwise. I can see part of the lower gear and it appears to be engaged.

i tried slowly revolving the engine a few degrees both ways while a partner held the chain, this made no difference.

if I get that cover off I will most likely replace that cassette, feels like there may be some unnecessary forward-backward movement in it, are there other parts I should buy with that cover removed?

 

Yes, there is another tensioner and a guide in there, seen here: https://i.ytimg.com/vi/e1P5c8qEO8Y/h...ZSSRFngEQMmNbw

If you have a 2WD you won't have the lower chain seen in the pictures, its for a balancer shaft added in 4WDs only when the front drive shaft was switched to always locked, it was to prevent vibrations

 

The later 4WD Rangers did not have the balance shaft. I am not sure any of them did. I know my 02 does not have one. Maybe the 2001 models did.

There is a tensioner on the main chain that drives the jack shaft from the crank. However, it should have nothing to do with the chain that drives the driver side cam.

My guess is your chain probably dropped off of the sprocket on the jack shaft and may be slightly fore of aft, and not dropping into the sprocket. It could also be caught on something else.

Do you have the tool to time your cam? Timing your cam should require removing the timing chain cover. I had to remove the pan when I rebuilt the timing chain system. The tool too time the cam must set up against the bottom of the block. There may be some way, but I don't know how you can do that without removing the pan.

 

UPDATE: I took sick leave off of work, checked all of my bases and researched until I had pulling hair out, and then, I just shook the chain and pulled on it hard as **** and it popped into place. I think one chain link was skipped on a gear tooth. Thank god I don’t need to pull that timing cover.

 

Ahhh...the old, "show it who's boss" move.