hey guys i just had a quick question. Is it a big of task to replace a timing chain? not sure on what motor and never have done one.. guy wants to trade a 76 f250 4x4 but he says it needs a timing chain. any help would be great thanks guys!

 

Really not that big a job. Would help to know what engine. Are you sure that is all it needs?

 

IF its original it should be a 360. Timing chain? No big deal, fairly easy with basic tools.

 

You're going to have to remove enough stuff to get to the front of the motor easily. The timing chain cover is behind the fan, water pump, harmonic balancer, etc. Drain the oil and remove the timing chain cover. Bring the motor to TDC on the compression stroke of the #1 cylinder and take a picture of the timing marks on the crankshaft and camshaft sprockets. They have to be in this same relationship when you put it back together or your valve timing will be off, and the truck either won't run, or it will run badly. You may need a pin spanner wrench to be able to turn the camshaft to get the marks lined up right as you put the chain back on.

 

Fairly easy to do labor wise, just a little time consuming. Should replace the water pump at the same time since it's off. Pull all the plugs out to make it easier to turn over.

 

thanks for the info and help guys!! helps alot!

 

just out of curiosity what are the symptoms of a bad timing chain?

 

That's a good question. I'm not sure there would be any outward symptoms per se. If the engine was running normally but you suspected cam chain issues, you could rotate the crankshaft back and forth while watching the valves. You shouldn't be able to rotate the crankshaft back and forth without causing valve movement.

I've replaced several cam belts and chains, but the symptom was the engine wouldn't run because the camshaft and the crankshaft were no longer connected. If the chain and sprockets were badly worn the chain might skip teeth and get the camshaft and crankshaft out of their proper timing alignment, but then the engine would run poorly, if at all. I've seen a camshaft off by one tooth and the engine still ran, but not very well.

 

You rotate the engine back and forth while watching the distributor rotor.

As for FE engines, they are fairly straightforward. One of the most difficult parts can be getting the crankshaft sleeve off.

Some are fairly loose, but it should be an interference fit. Which makes it tough getting off just by hand, and with nothing for a 2 or 3 jaw puller to grasp some are left frustrated. That's where slapping an exhaust clamp on the sleeve can make life much easier. Just install the clamp and then your puller has something to grasp onto.

Also, replace the timing cover seal.

And before you remove the chain and sprockets line up the dots so you don't have to mess with trying to rotate anything later.

Josh

 

I did my timing chain - twice - last summer. Once because the engine wouldn't run right, and then again because my engine still didn't run right (to check my work).

I was a total newb, so if you fall into that category, here's my 2c:

1. The crankshaft main nut is a pain to get off and - worse yet- back on. When you put the timing set on the first time - to get it lined up right - you need to have a way to turn the motor over a couple times. If your starter isn't still operable, the only way I know of is to turn the crankshaft... Remember, it's a lot easier to turn that nut towards "tight" than towards "loose". Going towards loose, you'll overrun TDC when it comes loose.

2. Sealant, sealant, sealant... When taking the front cover off, figure out some way to keep the old stuff out of the oil pan when you break out your brush/scraper. I used plastic wrap bc I was in a hurry, but would fashion a better shield out of cardboard & duct tape if I did it again. On the way back together, have everything in place so that the sealant can be put on and then pushed into place. Don't know if it matters all that much, but I remember dropping an f-bomb or two while fumbling for the right bolts (my 390 came with 2-3 different sizes for the front cover).

3. Don't spend any $ on "3-way" timing sets: they just add to confusion. If you think you're gonna want to advance your timing from factory retarded, it'll be easier to do w/ vacuum advance or just turning your distributor.

Ymmv

 

Yeah, you're right. I guess I meant to say "valvetrain", but if the distributor is driven from the camshaft, that's going to be the better place to sight any play.

 

To the OP...I sent you a PM with a link to to a good step by step write-up. Dunno site policy on posting links to other sites or I woulda posted publicly.