I've got a 1985 bronco with a 300 I6 as a winter beater...last winter I had to replace the timing gear for the first time since I purchased the truck in '90. about 3000 miles later it stripped again, I've left it sit since then, but have decided that I want it to trudge through the NJ snows. I'm afraid to replace the gear again without knowing what caused its early demise...I do know that it gets oil, so what else could cause it to strip?

thanks in advance

 

I believe you are refering to the plastic type timing gear that has problems with this in cold weather on higher mileage engines.
When i was younger I was told this is due to the extra wear on the cam and lifters and the cold putting too much strain on the nylon gear teeth . We just always replaced them with high performance gears and since they don't have any plastic problem solved .

 

On one hand, I agree with 'blue. However, unless you are in the alaskan tundra trying to cold start an engine sitting for three years, I don't think you should be having this problem.
How easy does the engine turn? Do you notice a loss of power or does it just quit? Have you inspected the valvetrain? Look for a bound spring, a bent valve, a stuck lifter, a pushrod off the rocker & binding against the head, etc. It could also be foreign debris lodged against the cam, a cam bearing that's binding. I can't remember if the dist & oil pump are driven off the cam. They could be putting extra drag on the cam. But that's a remote possibility.

Tony

 

hey thanks for the input guys. When I pulled the cam out it did have some worn spots but the lobes seemed to be pretty close in size, no more then a few thous. each way. I noticed the lifters were a little tight when I took them out, I think that may just be some mushrooming in the bottom end, because when they're on the cam they move easily. In your opinion, is it worth replacing the cam and lifters on a 1985 beater? I don't care about performance, I've got a lightning!
I bought the steel gear this time...I think it should hold up better then that fiber gear...(why did ford do that anyway?) Whats your input, I'm not a mechanic,just know how to read my chiltons

BTW Tony...it just quit, I was doing 65 down a highway and it went "poof" and shut off. It turned over very easily after that which is what led me to believe it was the gear (again). It never had much power anyway
thanks

 

clean out the oil pan. When your first gearset went it probably threw crap into the pan. The oil pump picks this up and locks up momentarily, stripping the gears. Other times it strips oil pump drive gears or snaps drives off. Be sure that pan is spotless on the inside!

 

Hondahater - I believe the reason Ford used the composit gears is because they are quieter than metal.

 

thanks nomopar, I did already take the pan off and found that there was not only alot of teeth in the bottom, but some had sucked into the mesh of the pickup...I figured that while I have the pan off and the engine jacked up I'd replace the rear main...what a pain to do in a driveway, and it's getting colder in NJ!

 

Sorry for the 'grampa' story -- but this one seems on target.

When Pontiac first went to a nylon gear way back when rocks were soft -- they did it to keep the engine quiet. Spur gears make noise. This wasn't a spur gear -- was the next worst thing -- but it did have a stamped-steel link chain which I guess made too much noise for Pontiac (or the nylon gear was cheaper to make).

Well, they all lost their teeth around 50-75,000 miles (thank you, very much -- it paid my rent) -- and the 'fix' was to go back to a metal gear.

Sound familliar?

 

Y2K... just goes to show that those who fial to learn their history are doomed to repeat it! :-)
-Joe-


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98 Explorer (Lemon Law Case in Progress)

'00 F-150, X-cab, 4x4, Lariat, Off-road, Trailer Tow, Holandia Sunroof, built 11/99 picked up 10/00!
List of planned mods: Clear corners and tails, CB wiring, Stainless brush guard, at least 1 set of KCs (probably more!), custom radar detector mount, color matched trailer hitch with stainless steel ball, torsion bar tweak, bug deflector, spray in liner, and a tonneau of some sort...