4.3L timing chain
butchsterling
03-06-2007, 05:21 AM
At what mileage should you change the timing chain on a 1991 4.3L Also is the 4.3 an interference motor or not.Thanks for any replies It's in a 1991 S-10
MT-2500
03-06-2007, 09:23 AM
There is no set mileage.
No interface on it.
With good regular oil changes and good oil the timing chain will outlast the engine.
To check for slack in it hook a breaker bar on the end of the crankshaft bolt and move back and forth to feel slack in the chain.
Let us know how many degrees slack it has.
No interface on it.
With good regular oil changes and good oil the timing chain will outlast the engine.
To check for slack in it hook a breaker bar on the end of the crankshaft bolt and move back and forth to feel slack in the chain.
Let us know how many degrees slack it has.
ericn1300
03-06-2007, 06:04 PM
i found this old post from Old Master, it's how i checked mine :
Timing chains stretch just like motorcycle chains and bicycle chains, but they are adjustable. A timing chain however, is not. You can check timing chain slack very easily. With a socket and breaker bar on the crankshaft bolt, slowly rotate the crankshaft in the normal direction of rotation until the timing mark lines up with TDC on the index. If you go past TDC, do not turn the crankshaft the opposite direction, go around again. The whole idea here is to keep the slack on one side of the gears. Remove the distributor cap and have an assistant hold the rotor tightly with their hand while you slowly rotate the crankshaft in the opposite direction. The instant the rotor begins to move, stop turning the crankshaft and read the degrees on the index. With any more than 12 degrees of slack, the chain can jump on the camshaft gear causing valve timing to retard.
Timing chains stretch just like motorcycle chains and bicycle chains, but they are adjustable. A timing chain however, is not. You can check timing chain slack very easily. With a socket and breaker bar on the crankshaft bolt, slowly rotate the crankshaft in the normal direction of rotation until the timing mark lines up with TDC on the index. If you go past TDC, do not turn the crankshaft the opposite direction, go around again. The whole idea here is to keep the slack on one side of the gears. Remove the distributor cap and have an assistant hold the rotor tightly with their hand while you slowly rotate the crankshaft in the opposite direction. The instant the rotor begins to move, stop turning the crankshaft and read the degrees on the index. With any more than 12 degrees of slack, the chain can jump on the camshaft gear causing valve timing to retard.
butchsterling
03-07-2007, 10:34 AM
Thanks very much for your replies.I will check degrees this weekend and see where I'm at. Thanks again this website is awsome
butchsterling
03-17-2007, 11:29 AM
Sorry it took a while to get back to you but I' m working in yard that is all mud. It finally dried out enough to get under truck.Pleased to say I had wife hold rotor as I turned crankshaft and it only moved 4 degrees till rotor moved so I take it must be ok. Thanks again
MT-2500
03-17-2007, 11:38 AM
Sorry it took a while to get back to you but I' m working in yard that is all mud. It finally dried out enough to get under truck.Pleased to say I had wife hold rotor as I turned crankshaft and it only moved 4 degrees till rotor moved so I take it must be ok. Thanks again
As long as you moved the crank back and forth clockwise and counter clockwise.
4 degrees sounds good.
As long as you moved the crank back and forth clockwise and counter clockwise.
4 degrees sounds good.
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