My '96 EB with 5.8 has 169K miles on it. Does anyone know how long the timing chain lasts? I had a '79 van with a 351 that jumped timing and a '81 van with a 302 that the chain wore so much the cam was slow. Mine is still great but I'm wondering about long trips. Thoughts?

 

there is no way to guess the life of your timing chain but with that many miles its a safe bet that it has alot of wear its insurance to change it but thats not to say that it MIGHT last as long as the rest of the drivetrain

 

I agree with 7fords, it's really hard to determine the life of it but be warned that IF it snaps, you would need more than a timing chain to get her back running. I replaced mine at about 200,000 miles and man, did it make a difference. Started, ran, shifted etc... better ! I did it myself and was the biggest thing I have ever done on a vehicle in my life. I'm no mechanic but decided while I was replaceing the water pump to try it. About 2 hours past the pump, you are done. I even had to go to the zone for a puller.

Good luck,

 

What parts did you replace? Did you have to drop the pan?

 

I would recommend replacing the water pump while you are at it. With that many miles it has to be close to its way out the door. It is not a fun job ripping all of the stuff apart twice.

 

I replaced my timing chain and sprokets and new gasket. Got them at the Zone since it was a spur of the moment replacement.

 

Thanks guys. Do I need special tool like maybe an air impact wrench and can I rent/borrow what I need from A.Z. ?

 

If you don't have a haynes manual get one of those, it explains the whole prosses, besides the timing chain and gears get a new front seal, you won't have to drop the oil pan but I believe on your motor the front oil pan bolts attach to the bottom of the timing chain cover, as far as tools go you really don't need air tools but they sure are nice, and you will need a puller for the harmonic balancer, you can also get tools for the front seal removable and install, but you can also do it without them (big sockets) the biggest tip I can give you is don't tighten down the timing chain cover bolts till you put the HB on there to line up the front seal, they make some fancy tools for that too...

 

I agree with what everybody said. I would just add, the cam bolt that holds the cam gear on, clean it and add a little lock-tite on it. Especially when it is so easy to swap in a killer cam at the same time and take that puppy to the next level, OK I'll stop! Get a double roller chain if you can. Not that expensive, and well worth it for strength. You MIGHT also find that the cam has a fuel pump eccentric on it, MIGHT, you can remove it.
Al

 

By chance I saw a friend today who is a mechanic and told him I was concerned about the milage on the timing chain. He suggested putting a socket on the crankshaft and turning it back and forth to see if I can feel chain slack before it tries to turn the cam. If no slack, don't worry about it. Duh! Now I remember a mechanic doing that and showing me the slack on a 302 years ago. He is guessing either 15/16 or 1 1/8 socket. I'll check it this weekend but suspect I'll use all of your great help. Thanks. His comment was that if it was his and the chain broke it would bend a valve but if it were mine it may not. He drives a chebby with 400k and has not changed his. You know the story about mechanics' cars, cobblers kids....

 

Hard to believe your buddy has a Chebby with 400k and the original timing set. I owned a 454 Chevy pickup, back in the 70's and the fiber timing gear went south at 103k.
You have received excellent advice from previous posters. I suggest using an air impact wrench for removing the crankshaft bolt ... you might be able to remove it with a breaking bar, but an impact will make it a cinch. I had 135K on my 351W, when I changed the timing set and the old chain had a lot of slop in it. Engine ran better and idled smoother after replacement.

 

Thanks. Haynes manual is coming via snail mail any day now (cheaper on eBay). I did put a socket on the crank today and rocked it back and forth to check the timing chain slack. It moved the belt pulley about 1/2 to 3/8 inch as the crank turns before feeling it starting to pull on the cam. What are your Bronco guru thoughts? Is this enough slack to be concerned?