5.8l f350 1990
the reason I ask is because my mechanic told me my timing chain has stretched and/or the gear the timing chain runs on is to abused to catch chain
Has this happened to anyone

 

Mileage varies. I replaced the stock chain and gears around 120000 miles, and I have since replaced the timing set again around 170000 miles because I had a coolant leak and I found that it had stretched beyond spec.

 

Eric, how can you tell if it's been stretched? And what's spec?

 

Spec from Ford is .50". You can also put balancer at TDC mark, remove dizzy cap and rotate balancer. If their is more than 5 degress of crankshaft rotaion before the rotor starts to move the timing chain is probably stratched.

 

^ Right on.

When I got the timing cover off to replace the leaking gasket around the water ports, the replacement chain that I had installed 50000 miles ago had about 3/4"-1" of movement on the loose side, and as posted above, the spec is 1/2". Since I could see it and easily replace the chain again, I went ahead and replaced it again while I had the chance.

 

what about soaking the chain in fresh oil overnight before installing it. is that just a tall tale, or does it actually help keep it from stretching prematurely when you first install it and it's dry on initial startup. i've always done it cause it made sense for it to be well oiled for the first startup but am curious if any of you guru's know for sure.

 

I don't know about soaking it in oil, but I did pour fresh oil on the new chain before I put everything back together. Definitely seems like a good idea to me.

 

OEM chains generally seem to last 150K miles or so. Some 70's Fords had problems with nylon gear teeth breaking off. I think pretty much all those had already done so and been replaced or the vehicle junked by now.
With a rebuilt engine that might have had the mains line bored a new timing chain might have mariginally acceptable slack right off the bat.
All new chains I've ever had had some slack upon being installed. If the didn't they would be an awful job to get installed.
I've found the cheapo parts store chains may stretch unacceptably withing a few thousand miles. Pay extra for a "true roller" chain, they will last longer. Paying some extra for THE name brand of timing chains, Cloyes, never hurts.
Soaking I don't think is necessary. This was normal procedure for some new motorcycle drivechains years ago but I can't think of any currently available motorcycle chains that require soaking before use. I've never heard of soaking a timing chain. I can't see it being useful or necessary. I can't imagine any way it could hurt to do so though. I always just put some engine assembly lube on the gears and a few squirts of oil on the chain.