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big end bearings and thrust washer

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RobSelina

RobSelina

Jedi Warrior
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Okay, I lied, more questions /ubbthreads/images/graemlins/wink.gif

It's my understanding that the big end rod bearings and the trust washer are weak links on the 1500. I also think I can hear/feel the wear of these components. My engine has 46k miles on it. I'm thinking I should replace these things. I was looking in the VB catalog and the thrust washer and big end bearings are available in different sizes. Like I said, the engine has 46k miles on it, has never been rebuilt, so I'm assuming I should go with the standard thrust washer and rod bearings? should i replace anything else? rod bolts and dowels? Any general tips for this install? I'll probably borrow my mechanic's lift (we're on good terms, he sees me frequently LOL) incase that has some imporance...
Thanks again,
Rob
 
Hello Rob,
the mileage quoted is not particularly high, as long as the car has been serviced regularly. What is the hot running oil pressure?, if around 40 to 50lbs\sqinch then the crank bearings are probably OK. If the thrust washers are badly worn it will be possible to detect that by levering the crank back and forward, any more than the slightest movement (and I mean just a few thousands of an inch) then change them as soon as possible. You will not be able to determine what size you need until you strip the engine and assess the wear. The crank may need a grind, etc. One little point, you can mix thrust washer sizes to get the correct clearance, i.e. one standard one plus 10.

Alec /ubbthreads/images/graemlins/thirsty.gif
 
idle oil pressure around 25-30, pull up the rpms and it's 60psi. this good? should i not worry about the big end bearings then? what about the thrust washer? when would be a good mileage to replace either of these items?
 
Hello Rob,
that oil pressure sounds fine, and in which case the bottom end is probably in good state. I wouldn't put a mileage on wear, rather do a check on crankshaft end float. If there is only barely perceptible movement I would forget it. If there is more drop the sump and have a look.

Alec /ubbthreads/images/graemlins/cheers.gif
 
okay, follow up question. I was assuming I would check crank end play by dropping the sump, no really a small task. Are you saing it can be determined from the front of the engine, I'm assuming fiddling with the fan mount?
thanks again,
rob
 
Rob, you don't have to disassemble anything to check crank end float.
Using a suitable pry bar, working from the front of the engine, nudge the crank pulley rearward until it stops.. Pick a convenient spot between the pulley and the timing cover, and, using feeler gauges, measure the clearance between the rear of the pulley and the timing cover. Now, gently pry the pulley forward until it stops, and measure again at the same point. The difference between the first measurement and the second is what is meant by "Crank Float". On a 1500, this should be between .004" and .008". If you are within this range, you have nothing to worry about, and with that kind of mileage, you are probably OK to go . If the end float is even .008" to .010" I would probably not be too concerned.
But, if you notice a sharp drop in RPM when you are stopped and push the clutch in,watch out.
Remember, there are no stupid questions!
Jeff
 
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