Rod and Main Bearing Clearances?

[mitch1204]

Can some please help me with some manual info?
I bought a 1997 Explorer XLT 4.0 OHV. I installed a mystery junkyard motor and I am now 450 miles from home and now have a lower end knock.

My plans are to drop the oil pan for an emergency repair just so I can make it home. I have tools and plastigage with me. I stopped by 3 parts stores and every one was sold out of my particular Haynes manual. I searched the forum and Google with no luck. In fact on my android phone when I do a forum search here my keyboard disappears before I can type anything. No problems anywhere else.

Anyways I need the oil clearances on the rod and mains so I can do some bearing swapping. Torque would be helpful too.

I'll order a manual off the internet for when I get home. I have a good block at home I'm going to rebuild so I don't want to do more than I have to with this current mystery motor.

Maybe someone can throw me some insight there. I was pulling a 1500 lb camper to where I am now. I messed up and tried my cruise out. When I hit small rolling hills the cruise decided to drop two gears and tach 5000 briefly. That's when I noticed the knocking. I still have great oil pressure. I'm dropping the oil pan today and hopefully find the problem. I think I spun a bearing. If I'm lucky maybe a TC nut backed out because I didn't use any thread lock.

 

[2000StreetRod]

clearance & torque

According to my Haynes Manual:

Connecting rod journal allowable bearing oil clearance .0005 to .0022 inch
Main bearing allowable oil clearance .0005 to .0019 inch

Main bearing cap bolts step 1: 25 Ft-lbs, step 2: 72 Ft-lbs
Connecting rod cap bolts step 1: 15 Ft-lbs, step 2: plus 90 degrees

From what I've read lugging the engine is the most common cause of main bearing failure.

 

[mitch1204]

According to my Haynes Manual:

Connecting rod journal allowable bearing oil clearance .0005 to .0022 inch
Main bearing allowable oil clearance .0005 to .0019 inch

Main bearing cap bolts step 1: 25 Ft-lbs, step 2: 72 Ft-lbs
Connecting rod cap bolts step 1: 15 Ft-lbs, step 2: plus 90 degrees

From what I've read lugging the engine is the most common cause of main bearing failure.

Thank you so much. Hopefully it ain't a main but I think you are correct. I'll post tonight what I find.
Is it possible to install a main from underneath? I never tried that before.

 

[2000StreetRod]

replacing main bearings

If the main bearing is badly worn you may be able to slip it out by tapping on the end without the tab.

I don't know if you can install a new one without removing the crankshaft. However, you can replace the half in the cap which should help.

 

[Flash]

I hope you have a 2wd.

I've been reading that the OHV has a rev limiter at 4900, I wonder what the SOHC has that allows a 6250 redline.

I'm in the middle of reading about how a guy in Sweden put Cosworth DOHC heads on his OHC.
I wonder what he'll do about the bottom end.