VikingTrad3r

haggis how would it work? like order a set of bearings same size or slightly undersized? i have a lift so i could do this easily. and ive head stories about new bearings making engines last longer.

its new territory for me.

is it as easy as pulling a bearing cap and putting a new one on again?

confab

Oh yeah, I did rods and mains in mine. The biggest things you have to worry about are not scratching the journals on the crank while doing it, and getting the caps back on in the proper orientation. You can mark them with a punch or whatever before removal to help here. If you get a rod cap on backwards, it will do damage..

But, aside from that the bearings look like this:




They are inserts with a tang to locate them, and you simply slide the old ones out and the new ones in. Most of them (and the one in the pic does, as you can see the "std" marking) are marked for size right on the backs. If you want to double check (I did) you can put a strip of plastigauge in the bearing torque it, and it will compress and then you compare their scale with the width of the compressed strip, which gives you the oil clearance. It's real simple.

The mains, you have to lower the crank just a little. The rear main is the thrust, so you put it in and align it by gently prizing the crank back and forth and torque it down.

Nothing hard about any of it for a quick overhaul, as long as you get caps back on in the proper orientation and don't scratch crank journals. (Use some fuel hose on the rod bolts to prevent damage and take your time.)

I did rings, heads and a cam too.. Right in the car!

confab

Use wood or plastic to slide them.. Or bend up an old bearing to help..

VikingTrad3r

so just buy std? or buy them at .001 undersized to tighten them up a bit ?

or are you saying buy std and then a couple smaller ones and use plastigauge to put the right size in? like u need inventory of multiple sizes beforehand?

mtwoolford

to do the mains, assuming that the crank has never been ground, when the cap comes off, the bottom half of the bearing is right there. Pop it out of the main bearing cap and on its back you should see "std", "0005" (half thousandth oversize) or "001" (one thousandth oversize) ; all of which the factory uses to ensure proper clearances; the only problem is that sometimes the factory used a letter designation, which is a little mysterious.

Getting the upper half of the main bearing can be a little more difficult. rotate the crank shaft and sometimes it will roll right out; if not get a brass cotter key, hammer the head flat, insert the cotter key into the oil hole in the crank and now rotate the crank; the flattened head of the cotter key will rotate the bearing shell right out. Important; one side of the end of the bearing shell has a small tab rotate the crank so that the tab end rotates out first.

You should note that the #5 main bearing also serves as the crankshaft thrust bearing.

installing the new bearings is just the reverse.

The rod bearings are even easier. just do one rod at a time and make sure that the lower rod end cap goes back on in the same way as it came off.

confab

Install the size that is in it now.. Even if it did wear a bit? It didn't wear uniformly and you don't want too little oil clearance.

If you want to double check the clearance, use plastigauge..

mtwoolford

bearings are available individually; buy one "std" and one ."001" oversize; use them in the various positions to figure out which is gonna work best; then order your bearings accordingly. When you use plastigage on the mains (assuming you're working from below) place a jack under the crank to force the crank up; what the plastigage will then measure between the crank and the lower half of the main bearing is the total bearing clearance, which is what you're interested in...obviously, if the engine is on an engine stand, bottom side up, gravity is already pulling the crank down into the upper (block side) bearing shell.

similarly, on the rods, make sure that the crank is rotated so that its forcing the rod up.

VikingTrad3r

thanks for taking the time guys. i think ill go ahead and do this.

VikingTrad3r

So Guys, I suppose i need to do the whole cardboard box with holes drilled in it thing so i can stick the bearing caps and rod caps back exactly as they came out? same bolt goes back into the same hole? I'm going to pull the pan again (re-useable gasket, no worries) and pull the bearings off and order replacements. thnx for pushing me.

confab

Sort of.. You are going to want to mark them to return them to both the same position and the same orientation on the engine as they were.

The mains are honed to be aligned and they need to go back exactly as removed. The rods are worse, because the edge away from the common area of the journal has a chamfer turned on it, and the rod has a corresponding chamfer on one side to accommodate it.

Get that backwards and you will do damage.

So, number the mains front to back and side to side, and put the rod caps back on the same rod and in the same orientation as they were removed.

VikingTrad3r

^^ Thank you Dogs!!!

today i replaced the ujoints in the driveshaft and will be reinstalling the driveline.

then ill drop the pan and do the main and rod bearings.

ill be re-reading all the tips in this thread and it’ll take me a while but if i hit any snags ill post the questions here.