I have a 1988 F-250 4x4 with 460 motor. It has original motor with 103000 miles on it first question is if the chain breaks will the pistons hit the valves?

How long is the service life of a timing chain on a 460 with a five speed stick?

Is there a way to check sloop on a timing chain?

This truck I believe has sealed front wheel bearings how long do they last? Should one do preventive maintenance and replace them at certain mileage?

Any help would be great

Brett

 

You should have standard roller cone wheel bearings. I dont think I have ever heard of a timing chain failue on a ford pickup. They usually last as long as the rest of the engine. I do not know if the 460 is an interference engine though
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I don't know what the failure rate on the timing chain is, but theoretically [and realistically for that matter] yes it is possible for the pistons to hit the valves if the timing chain were to break.

Having trouble with that lately?

And I'm not sure what all you need to remove to access the timing chain cover, but once it's removed, this the procedure you use according to my Chilton service manual:

1. Rotate the CRANKSHAFT clockwise to take up slack on the left side of the chain
2. Choose a reference point [a line drawing shows one being used on the gasket surface of the chain cover] and measure the distance from this point and the chain
3. Rotate the crankshaft in the opposite direction to take up slack on the right side of the chain
4. Force the left side of the chain OUT and measure the distance between the chain and reference point- the difference in the two measurements is the deflection [sloop]

The book says if the difference is more than 1/2" the chain needs replacement.

Hope this helps.

 

I'm not sure about whether or not the 460 is an interference engine. You can check slop by taking off the distributor cap, turning the crankshaft with a wrench clockwise until you reach the TDC mark. Then turn the crank counter clockwise while watching the distributor rotor. Stop turning the crankshaft as soon as the rotor begins to move, then look at how many degrees the crankshaft turned. If it is anything more than 4 or 5 degrees, the chain has too much slop. I don't think you'll have to worry about one breaking, but it would affect performance slightly from the slack.

 

Normal wheel bearing? Because according to my diff book that it is a sealed unit on a dana 53 ttb front suspension.

 

I didnt think Ford used a unit bearing until the super dutys came out. My Haynes manual shows them as tapered roller bearings.

 

I quoted the wrong front axle model it is a dana 50 front according to wiki-pedia.

 

Have never heard of a timing chain break on these motors, they stretch and get sloppy enough to rattle against the timing cover but that's pretty obvious and it takes hundreds of thousands of miles to get that bad.

And as far as I know the D50 uses caged roller bearings like the D44 and D44HD. These too should last the life of the vehicle if maintained regularly.

 

just replace the timing chain if you're worried about it it only takes like 3-4hrs it's not a big deal at all to do, and the wheel bearings don't like to be underwater/undermud i have had 2 sets fail on me in the past 3 years

 

Thanks guys I reread my differential manual and I miss read it the mono beam dana 50 has the sealed bearing again according to the book.

Are these twin i-beam 4x4 axles stout enough for 460 big block 4x4 over rough terrain and pulling trailers off road?

I have a dana 60 ford front axle I could have installed but would rather not do all that monkey business.