Rod/Main Bearing Recommendations

[howeitsdone]

There are so many different brands and types and for how inexpensive they are I just want to make sure I'm not buying crap. NAPA's are about $170 for Rod and Main while you can get same part numbers from Summit for under $100.

Part # Referenced:

4289M

63310CPA

 

Which honestly is sad because I always thought of NAPA as top dog, but when they price themselves out this badly it's hard to shop there.

 

Any other part numbers folks have used that work just fine? Those are the highest price points from what I can tell. There are lots of different ones for less $$$.

 

UPDATE:

Main are .001

After HOURS of searching it appears the new Mopar part # is 83507080AB - Unfortunately no aftermarket options. @eaglescout526 Is there an updated part number for the thrust bearing or does that not have a size variation? Can only find standard sizing.

Rod appear to be .001 as designated by the 'x'. Found that info on Rockauto

 

 

[ghetdjc320]

Clevite 77 or King bearings are my go to for engine builds

[eaglescout526]

I will take a look. 

[AZJeff]

When I put bearings in my MJ early in the summer, I found the mains were 0.001 undersized from the factory, and the only replacements I could get were Mopar branded.   None of the other big makers seemed to list that undersize.

 

The local dealer didn't have any, and said they were on national backorder.  However, Summit Racing had them in stock.

 

The rods were standard size, and I got Clevite's from Rock Auto.

 

I don't remember seeing anything on Rock Auto about the "X" marking indicating an undersize from the factory for the rods.   Then again, mine did not have those markings, so I wasn't searching out the meaning of such.

[howeitsdone]

Thanks guys. Ordering the Clevite rod bearings. Looks like the mains have no other option than Mopar.

 

@AZJeff I clicked the product info next to the Clevite brand. So I'm assuming the X on mine might mean that. Figured it would translate maybe. Unless I'm wrong? Did yours have that too? I just don't know how to decode that bearing in the photo above.

 

[howeitsdone]

Also, this was the stamped info on the thrust washer. No indication of size.

 

[eaglescout526]

So there’s 4 different sizes that were done for the 4.0L. 
 

 

All 4 of those number supersede you an AB. I can still readily get those. Any other parts for the engine you need to know?

[howeitsdone]

20 minutes ago, eaglescout526 said:

So there’s 4 different sizes that were done for the 4.0L. 
 

 

All 4 of those number supersede you an AB. I can still readily get those. Any other parts for the engine you need to know?

Thank you! 
 

I'm just having trouble identifying what sizes I have in the above photos. Only 1 had the .001 marking. I’m actually headed to the dealer now to ask them so I’ll keep you posted. 

[howeitsdone]

I’m assuming the bottom 7-digit is the P/N maybe

 

[howeitsdone]

Well, dealer here had no clue. Other than miking the crank doesn’t seem I can order the right parts. 

[eaglescout526]

Well I can assist. Those guys at the counter don’t know old stuff. Those 7 digits are old AMC numbers. Put a J in front of them and you’ll have a part number. AMC probably used the same parts in all their straight 6’s

[howeitsdone]

No kidding lol. Unfortunately those numbers yield nothing when searching other than people in the same boat. But they're doing an out of chassis replacement and can get a micrometer on it so they never report anything.

 

I know they would use .001 and STD together sometimes when they needed more like .0005 and that's apparent since I found a .001. I'm leaning toward the rest being STD even though they're not marked. That would make the most sense to me. Only concern is the rod bearings because I haven't found one with a size on it yet.

[eaglescout526]

Do you have the numbers on the block? I’ve got a 4.0L book that can help us decipher and see what your engine really is. But judging by the old AMC bearings, which are really damn cool by the way, are probably correct on the .001. But chances are unless those guys are expert Jeep engine rebuilders, they have no idea what they’re looking at. 

[howeitsdone]

Appears to be

 

EF8933002665CD

 

The site here decodes some of it, but in all honesty back then not every crank was the same hence mix-matching the bearings themselves.

 

This appears to be the worst of them all as most look like the other. So I'm thinking I can maybe get a little more time before pulling the motor. I just gotta drive it a few states over and then I can begin the teardown.

 

 

[howeitsdone]

I can at least put a micrometer on the rod surface just not the mains. And the one with most of the copper is a rod. I'll go to HF and buy their set since no one else in the area has one for sale.

[eaglescout526]

20 minutes ago, howeitsdone said:

EF8933002665CD

That’s a part number for the block. I’ll post a pic from my 4.0L book that shows a spot where there’s some numbers that look random. 

[ghetdjc320]

2 hours ago, howeitsdone said:

Well, dealer here had no clue. Other than miking the crank doesn’t seem I can order the right parts. 

Mic’ing the crank is the best policy. Using plastigauge or similar also yields great results to get what you need and ensure the best clearance.

[howeitsdone]

@ghetdjc320 Okay, so I just did a rod journal and got 2.0941" which is within the factory spec of 2.0934" to 2.0955". I'm struggling with how to determine the bearing size I should order though. How do I determine that? Do I just need to order multiple sizes and use plastigauge to get within the tolerances?

 

Since the motor is in-chassis I can't measure the rod bore.

 

I did find the below info on another forum but not sure how accurate

 

Rod journal = 2.0948-2.0955" -- standard inserts for both top and bottom
Rod journal = 2.0941-2.0948" -- standard inserts for top and 0.001 undersize insert for bottom
Rod journal = 2.0934-2.0941" -- 0.001 undersize inserts for both top and bottom

[howeitsdone]

I went ahead and called Oreillys and ordered a pair of each: STD, .001, .01, .02

They'll be in tomorrow AM. When I pick them up I'll grab Plastigauge (Green) as well.

[ghetdjc320]

1 hour ago, howeitsdone said:

I went ahead and called Oreillys and ordered a pair of each: STD, .001, .01, .02

They'll be in tomorrow AM. When I pick them up I'll grab Plastigauge (Green) as well.

That’s a good call. Was going to post the link for the clevite part you need for .001 undersized but your method will ensure the best result as there can be slight variations between each journal. 

[75sv1]

Also, there is a difference for the main bearings for the RENIX vs the HO's. I found out the hard way when or as I am doing a mini-Stroker. I bought a 238 crankshaft with bearings. The tabs are in a different location for the RENIX and earlier AMC blocks. I bought a set of Clevites. Also, I used ACL cam bearings. I think they are out of Australia.  I could not find a coated set of bearings for the 4.0L. 

[howeitsdone]

Great callout!

 

@eaglescout526 Any way you can post another picture of the main bearing parts and #s? The new part number 83507080AB says offset but it's only on the bottom and the Renix is offset on both pieces. Might be able to save the trouble using the Mopar parts diagram below?

 

 

You can see below the difference and that the newer are centered but the old ones are offset. To note though, this is only an issue for .001" bearings since the other sizes are available from aftermarket suppliers. But hope this helps someone. Definitely saved me from spending the money to only have the wrong parts so thanks @75sv1

 

 

 

 

[eaglescout526]

[75sv1]

Also, I suggest a new Harmonic balancer. I am checking into the Dayco one. I do have a Power Performance on my '98. I am building a 4.6 stroker that will get a Power Performance one I have. I am looking for one for a mini-stroker I am assembling.  I did use a NAPA one on my 2000 XJ. That will get the mini stroker. The MJ gets the 4.6.

[howeitsdone]

Thanks for the part numbers again!

 

Just measured the clearances with the STD and looks like I need to order standard size. Getting ~.002-.0025.

 

Last question then. The pair from Clevite that I bought CB960A was flat on both ends, while the ones I removed and the ones pictured in sets for sale have half circles on each piece. Does that matter? Oreillys can get me 5 pairs tomorrow but can't get me the set until next Friday.