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Crank super hard to rotate by hand

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boxfullofyertoys

boxfullofyertoys

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I'm hoping someone can provide me with some insight on this one, as I'm now officially worried:

I was in the process of replacing the connecting rod bearings, and I had to rotate the crank by hand in order to get to the rods for cylinders 1 and 4 after completing cyls 2 and 3. When I went to do it, the crank was unbelieveably hard to rotate...even moreso than when I rotated it at the onset to start working. Whereas before I used both hands, this time it was 2 hands plus bracing my legs against something solid.

The spark plugs are pulled, the new bearings were lubed with assembly lube, and everything was torqued to spec (50ft-lbs on the rods, 65ft-lbs on the center main (pulled it to check for wear). The new bearings were a direct replacement (old ones were standard sized, new ones are as well).

Granted, I was on my back/under the car when I was turning the crank, and was probably a bit tired, but it seems to be <span style="font-weight: bold">a lot</span> harder than it was. Was it possible my uber-low oil pressure was being caused by loosened bottom end bits? Of the bearings I replaced, only 1 of the 4 I considered to really need replacing. The rest were in good shape, as was the crank.

Any input would be great, as I'm worried about trying to start the engine with it being as tight as it seems...

Thanks!
 
Somethings not right, you gotta go back and check the bearings and caps. Something is reversed! Should turn over by hand easily.
 
Check to see if a cap is on backwards. I've done this before and the engine would not turn. The locating tangs of the bearing will put marks on the rod parting surface where they line up. This will help tell you if a cap is on backwards if the rod is not marked for orientation.

Also double check the markings on the backside of the new bearing shell. I have had one wrong sized bearing show up in a package many years ago.

HTH,
Mike Miller
 
Besides what's already been mentioned you should get some plastigauge and check clearances that way. It's possible you could have an undersized or mismarked shell and the only way to be sure is to check the fit dry.
 
Doh!

Well, this is a bit embarrassing...but I think I've already solved my problem without even knowing it...

I did the initial swap on Sat/Sun, and after re-reading the instructions Sunday night, I realized that there was a possibility I had put some of the caps on backwards. Yesterday I got under the car and checked them. I double checked cyls 2 and 3 first because they were easier to get to, and then rotated it to do 1 and 4. That's when I noticed the rotation issue. The only one that was installed incorrectly was cyl 1, which I then fixed. Once everything was torqued down, I cleaned up and quit for the evening, not even considering the backwards cap was the culprit.

The only other possibility is that I reinstalled the center main backwards, however I'm 99.9% sure that it came straight down, got looked at, and went straight back in the way it was. It was off for all of 2.5 minutes. I'm also pretty sure the bearings were all the same size, as I cleaned the h3ll out of them before they went in, and didn't see any odd size markings that caught my eye....but who knows right?

I guess when I get home tonight I'll get a wrench on the crank bolt and see if that was the culprit.

Looking back, I probably should have made that connection :wall:

The more I learn, the less I seem to know...

Thanks for your help guys!
 
Sounds like you might be on the right track. If it's still hard to crank, some plastigage will tell you if bearings & caps are to spec.
 
Same thing goes for the main caps, the bearing keeper tangs go on the same side. Also did you by any chance repalce the thrust washers, sometimes new thurst washers come of the box too thick and can cause a crank to bind and A series engines hardly ever wear the thrust bearings.
 
I haven't done the thrust washers yet. They're next up, along with a new oil pump. The issue with the crank was so blatant that I couldn't consciously move on without making sure I was good to go with the rod bearings.

I'll definitely keep an eye out for fat thrust washers when I put them in. I know they're a weak spot on the 1500, so I figured I'd do them with the rod bearings to ensure everything was kosher :smile:
 
Plasti-gauge is your friend.
 
Just thought I'd update everyone:

I'm an idiot. I guess my frustration blinded me a bit. I went home the other night, got under the car, and sure enough I still had the cap on cylinder 3 reversed.

Flipped it around, and now she spins properly.

Thrust washers, oil pump, and a cleaning/repaint of the oil pan are on tap for this weekend. Just knowing that I've personally seen/repaired the the bottom end takes a huge weight off my shoulders.

I'm hoping now I can relax a bit and turn the radio up when I finally go for a drive this weekend :smile:

Thanks again for all the help!
 
Always seems to take a few trys to get it right. In my garage anyway.
 
Just curious, since im still having a bit of the same problem. How exactly do you know in which direction do the caps for the bearings face. What ever markings there were on the bearing caps and piston connecting rods are gone and the only ones that still exist are the numbers stamped into the sides of the caps and bottom of the rods.
 
That should work, numbers on the same side. Should also be (maybe) a mark or set of marks cut into the rod and the rod cap. like I, II, III, IIII
 
Well i do have all the numbers facing the same direction. And when i did try to turn the pistons around to face the numbers the other direction it wouldn't even fit back in. So i know the rods and pistons are facing the correct direction, rings are properly gaped, numbers in the correct order and direction, and the correct bearing sizes. Other than that i don't know what else it could be. The engine does turn easily but with a small wrench on the end, it just doesn't turn easily by hand. Maybe its just the fact that there are so many new pieces in it and they have yet to be worn in.
 
On an 8 cylinder, once all together with 32 rings (4 per slug) and bored/honed, takes at least an 18" breaker bar to rotate it at first.
Small wrench to turn it should be fine.
 
Falkon said:
Just curious, since im still having a bit of the same problem. How exactly do you know in which direction do the caps for the bearings face. What ever markings there were on the bearing caps and piston connecting rods are gone and the only ones that still exist are the numbers stamped into the sides of the caps and bottom of the rods.
Click to expand...

It's already been mentioned in this thread, but here goes again, in these engines (almost all engines for that matter) on the connecting rods and mains, they are always orientated in direction by the bearing retaining tangs always being on the same side of the parting line, if you got a retainer tang on each side, you've got it in wrong.
 
Same here Jack. I think it's my brain just making sure I remember stuff for the next time :smile:

Falkon -
I realized what I had done when I discovered that the edges of the rod caps near the bolts are different (on a stock 1500 anyway). One edge of the cap has a much wider squared lip on it, while the opposite side is more rounded and narrow. 3 of the 4 were oriented with a particular end facing downward at the sump, the other wasn't. I flipped odd one it and sure enough everything started to move.

I've been taking some photos of this whole ordeal, and I'm hoping to augment the directions I've been using with them. They're great, but having photos would have been a massive help...

I've been using these directions:
https://users.wowway.com/~kottage/tech/1500_bearings.html

I'd be happy to combine the photos/instructions for the wiki, if need be...is there a wiki around here...right?
 
Sounds like you are ready to move on to other things.

Of course it should need a small wrench. And if you had new rings and pistons in new cylinders you would need a large wrench.

All sounds fine, seems you have done a good job.
 
Went back over all that stuff and it all checks out so i guess im good.
Thanks guys!
 
Boxfullofyourtoys,

I would be very interested in seeing your photos. If you would want to go to the effort of putting something into the wiki it would be great.

Charlie
 
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