I have a stock 1994 Bronco. When I Bought it 2.5 years ago it had 100,000 miles on it now I'm close to 125,000. I don't know the past history of the vehicle should I be concerned about changing the timing chain?:shrug
There's absolutely no reason not to replace the chain. The second one went out on my dad's Suburban at around 300k miles and totalled the engine. It cost something like $3k for a new engine plus installation. Better safe than sorry.
In my 1986 bronco I guess Ford used a Deleron gear, like a hard plastic. Plastic in a motor?!?!? :shrug I know.... What were they thinking.... I heard it was because it made the engine quieter.... Whatever...
If I recall you're supposed to replace it every 80K ..... Mine finally went at 160k (almost exactly). I spun the cam chain on startup and then spent two weeks trying to figure out what I did.... Once I found I spun the cam chain I went in to the front of the motor to find a very round cam gear..... It was easy to get to and easy to replace. I think I bought a kit that gave me the gaskets I needed for the timing cover and thermostat and oil pan etc as well as a new timing gear, chain and crank gear..... It was an afternoon project once I found out what I did....
so if you're talking preventative work... no big deal I guess... I got lucky with mine and it went on startup but if it were to go while running you'd probably bend some valves and ruin the motor..... ( maybe... I don't know the tolerances.... )
When i had to do my timing cover, i figured, since im in there, i may as well change the chain/gears. It was stretched to the limit (IIRC, ~1" deflection; according to the specs in my Helms manual). But mine was a double roller, with no plastic gears in sight. What years did they use the plastic ones on?
(Naturally i put another double roller on it.:thumbup)
Heres an easy way to see how sloppy your timeing chain is.
1 Pull the cap off the distributor.
2 Grab a wrench the size of the balancer bolt
3 Turn engine over clockwise until the rotor moves.
4 Turn engine over counter clockwise until the rotor moves in the other direction.
Its pretty easy to gauge how much slack there is in the chain.
Not all fords come with nylon gears on the chain as a matter of fact I havent seen any that come with nylon gears, Maybe its a diffrent story on the newer ones. Some even come with a double roller from the factory 84 and 85 351 h.o. 's do for sure. My 84 351 ho made it 300k miles befor I spun the balancer off and desided it was time for a rebuild. Never had the valve covers off and it was seriously abused.
As for the $30 double roller I wouldnt waste my money on something like that If your gonna do it, do it right get a comp cams high tech or something similar in the $80+ range. $30 timing chains are made in china if your lucky, even worse they could be factory seconds.
It will make a big diffrence In durabilty the week link becomes the chain not the gears. The only reasons auto makers use platic in there engines is cost and weight. Ive never seen an aftermarket timeing chain set come with plastic gears. Then again I dont go looking for the cheapest crap I can put on my vehicle.
if you never want to open it again look in to a gear set. they cost a lot more but they last a good long while. you should be able to swap it in to your next bullet that rests betwen the fram rails if you stay whith the same engine. but they make a lot more noise. kinda sound like a huffer wine'n
I bought the house brand double roller from Mancini or Summit 10 years ago for $22.00 and it's still going strong in my Mopar 360 (which also came with plastic cam gear teeth originally).
If you can afford better, buy better, at the very least go cheap double roller and toss that plastic stuff over the neighbour's fence...... wait a minute, you're in the states right ? forget that. Your neighbour may very well have a gun, put it out with the recyclibles.