Main bearing replacement in car?

Just curious, has anyone successfully spun in new main bearings in a block before?

I have done it on the stand, same principle applies because I took nothing else apart. Roll them out and roll them in. In the car it will be the same but just add oil dripping on you haha.

I've done it. Its' easiest to loosen all 5 main caps. The thrust is the toughest. I used a nylon trim stick and tapped on it with a hammer to get it started. The rest is easy.
Doug

The make a tool for that but it's kind of spendy. I've seen people do the same thing with a big cotter key but I have personally used neither.

Bearing Removal Tool

I did two of them the same way, one a big block Chrysler, and one straight six Jeep. DVW has the right idea here.

As an experienced engine builder that believes every bearing clearance is critical to the oil pressure and life of the engine. And the only way you can accurately check the clearance is to the measure the crank and bearing journals separately to find the proper clearance. I have to ask this question? Why would you ever need to change the main bearings without removing the crank? Just curious.

A very long time ago I saw something like this use successfully.

Not sure why the engine and crank were not removed.

https://tescotools.com/products/t68660-upper-main-bearing-shell-remover

I remember back in auto shop in the 70's they had a bit that would go in the oil journal of the crank and had a flat tee on the top of it and you would turn the crank and the T would catch the bearing and just roll it out. Install rotate opposite direction. Looks like the tool listed above.

I've installed them just like Doug said too.

Many years ago a friend and I changed the main bearings on a Ford engine in a one ton truck, wasn't any trouble at all.

Replacing number five main bearing is the bear due to the main seal.
I use a small flat narrow bladed screwdriver to start the push the main bearing out of the retainer from the other side of the retaining tang,
As already mentioned, that is with all main caps being loose and drop down a little bit from the block, remove the bolts for each one at a time and then put them back in when your done installing the new main bearings to help keep the crank a little loose so it doesn't press hard up against any of the upper main bearings until you're ready to torque all of them, make sure to check and have enough thrust clearances also .

Yep. I used a small screwdriver to tap it and just took my time. Changed out a severely worn thrust bearing in a 440. Long story, but it was a bandaid fix that worked for a while.

I've done it. Wouldn't do it on something good.

Small screw driver or flat scraper shaped tool. Tap on the edge of the bearing opposite the lock to get it moving around. It will only go so far with the tool.

I've used the small screwdriver type tool with the edge sharpened, and narrow enough to fit the lock tang slot, to use the slot and walk the thing around until it will come free.

Also used cotter pins with the head flattened, stuck in an oil hole and rotate the crank around to push it out.

Have to be careful not to ding the crank.

MoparBilly is smiling down on this post I’m sure if it needed to be done…. he did it. I’ve only done that with rods when we got silly with a nitrous tune (we couldn’t tune ). At least I see I was in good company

As you see a lot of ways to skin a cat..do it!

Curious as to why you're thinking about going this route. Doesn't take long to yank an engine.

My lower back and neck were telling me the same thing!

Done it many times on rb mopar engines . Flatten the top of a cotter pin and use it to rotate the bearing out and the new one in. Works very well,

Great meme, after pulling my Gen3 swap 3 times, I understand it’s not as easy as thought

Sure, people do it all the time. Not really a long term solution but sometimes you have to do what you have to do. Falls into the category of quick and dirty.

To those asking, happened to have the K-frame out of the car for front suspension work, super easy to take the oil pan off. Figured replace the slightly banged up oil pan, check some rod and main bearings. Already pulled a couple of rods, a little shinier than I'd hope to see at 30k miles so going to put a new set in, will pull 1 or 2 mains and see if it's the same deal.

Hmm I replaced 2 rods so far, got my ball adapter for my mic today and measured the 4 old shells and compared with the new… all the new shells are almost all around 2-3 tenths under per shell, which means 4-6 tenths larger in diameter…. Maybe I should just throw the old shells back in 😀.

Rod clearances with old shells when it was new below