Flex plate bolt heads hitting mudguard!
10-05-2017, 11:25 PM
#47
Junior Member
Thread Starter
Join Date: Jul 2017
Posts: 63
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
Got it. Sorry.
Main Bearing Clearance 0.03 to 0.06 mm
(0.001 to 0.0025 in.)
Preferred 0.051 mm (0.002 in.)
Rod Bearing Clearance 0.025 to 0.076 mm
(0.001 to 0.003 in.)
Preferred 0.044 to 0.050 mm
(0.0015 to 0.0020 in.)
Shouldn't have asked for something I could easily find myself. My bad.
Main Bearing Clearance 0.03 to 0.06 mm
(0.001 to 0.0025 in.)
Preferred 0.051 mm (0.002 in.)
Rod Bearing Clearance 0.025 to 0.076 mm
(0.001 to 0.003 in.)
Preferred 0.044 to 0.050 mm
(0.0015 to 0.0020 in.)
Shouldn't have asked for something I could easily find myself. My bad.
10-05-2017, 11:29 PM
#48
CF Veteran
Join Date: May 2015
Location: Arizona
Posts: 4,481
Likes: 0
Received 18 Likes
on
14 Posts
Year: 97
Model: Cherokee
Engine: 4.0
Got it. Sorry.
Main Bearing Clearance 0.03 to 0.06 mm
(0.001 to 0.0025 in.)
Preferred 0.051 mm (0.002 in.)
Rod Bearing Clearance 0.025 to 0.076 mm
(0.001 to 0.003 in.)
Preferred 0.044 to 0.050 mm
(0.0015 to 0.0020 in.)
Shouldn't have asked for something I could easily find myself. My bad.
Main Bearing Clearance 0.03 to 0.06 mm
(0.001 to 0.0025 in.)
Preferred 0.051 mm (0.002 in.)
Rod Bearing Clearance 0.025 to 0.076 mm
(0.001 to 0.003 in.)
Preferred 0.044 to 0.050 mm
(0.0015 to 0.0020 in.)
Shouldn't have asked for something I could easily find myself. My bad.
Tell you what, the search on this site works better when you are logged out than when you are logged in. lol
10-05-2017, 11:32 PM
#49
CF Veteran
Join Date: May 2015
Location: Arizona
Posts: 4,481
Likes: 0
Received 18 Likes
on
14 Posts
Year: 97
Model: Cherokee
Engine: 4.0
Got it. Sorry.
Main Bearing Clearance 0.03 to 0.06 mm
(0.001 to 0.0025 in.)
Preferred 0.051 mm (0.002 in.)
Rod Bearing Clearance 0.025 to 0.076 mm
(0.001 to 0.003 in.)
Preferred 0.044 to 0.050 mm
(0.0015 to 0.0020 in.)
Shouldn't have asked for something I could easily find myself. My bad.
Main Bearing Clearance 0.03 to 0.06 mm
(0.001 to 0.0025 in.)
Preferred 0.051 mm (0.002 in.)
Rod Bearing Clearance 0.025 to 0.076 mm
(0.001 to 0.003 in.)
Preferred 0.044 to 0.050 mm
(0.0015 to 0.0020 in.)
Shouldn't have asked for something I could easily find myself. My bad.
10-05-2017, 11:55 PM
#50
CF Veteran
Join Date: May 2015
Location: Arizona
Posts: 4,481
Likes: 0
Received 18 Likes
on
14 Posts
Year: 97
Model: Cherokee
Engine: 4.0
Got it. Sorry.
Main Bearing Clearance 0.03 to 0.06 mm
(0.001 to 0.0025 in.)
Preferred 0.051 mm (0.002 in.)
Rod Bearing Clearance 0.025 to 0.076 mm
(0.001 to 0.003 in.)
Preferred 0.044 to 0.050 mm
(0.0015 to 0.0020 in.)
Shouldn't have asked for something I could easily find myself. My bad.
Main Bearing Clearance 0.03 to 0.06 mm
(0.001 to 0.0025 in.)
Preferred 0.051 mm (0.002 in.)
Rod Bearing Clearance 0.025 to 0.076 mm
(0.001 to 0.003 in.)
Preferred 0.044 to 0.050 mm
(0.0015 to 0.0020 in.)
Shouldn't have asked for something I could easily find myself. My bad.
10-06-2017, 07:01 PM
#52
CF Veteran
Join Date: May 2015
Location: Arizona
Posts: 4,481
Likes: 0
Received 18 Likes
on
14 Posts
Year: 97
Model: Cherokee
Engine: 4.0
I need to share this... If the clearance appears to be too much don't panic yet. They make odd sized bearings for these too. Takes a little homework to chase them down but they are available for about everything and this block and crank design has been around a long time as the AMC so I'm sure they can be had. They make them in like .003 and .005 under sizes to make up for minimal wear on a stock crank yet not enough to really needing to be turned a full .010 or .020 under. The reason we check these is just in case it might need this odd size option for bearings.
Or you could throw it together and fill it with 20-50 and run it with the knowledge it is temporary and that it will need be redone in the future at some point.
Or you could throw it together and fill it with 20-50 and run it with the knowledge it is temporary and that it will need be redone in the future at some point.
10-07-2017, 02:11 PM
#53
Junior Member
Thread Starter
Join Date: Jul 2017
Posts: 63
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
I need to share this... If the clearance appears to be too much don't panic yet. They make odd sized bearings for these too. Takes a little homework to chase them down but they are available for about everything and this block and crank design has been around a long time as the AMC so I'm sure they can be had. They make them in like .003 and .005 under sizes to make up for minimal wear on a stock crank yet not enough to really needing to be turned a full .010 or .020 under. The reason we check these is just in case it might need this odd size option for bearings.
Or you could throw it together and fill it with 20-50 and run it with the knowledge it is temporary and that it will need be redone in the future at some point.
Or you could throw it together and fill it with 20-50 and run it with the knowledge it is temporary and that it will need be redone in the future at some point.
Two questions: the clevite rod bearings came in 2-packs. each pack had a half with an "A-4" mark and the other half had an "A-3" mark. Neither said upper or lower like the mains did. I can't see any difference in size or dimension between the a-3's and a-4's... and they both seem to install exactly the same.
I did a little research and most say it doesn't matter which is upper or lower...
I ended up keeping them in the pairs they came in and installed all the a-4s as upper and a-3s as the lowers. Any thoughts?
I will be using plastigauge to ensure the mains and rod bearings are all in spec. I have read the service manual sections on Crankshaft, Main Bearings, Connecting Rod Bearings twice now, and can even point out the typos. I don't want to have to do this again for a LONG time.
Last edited by sambroom; 10-07-2017 at 02:13 PM.
10-07-2017, 02:21 PM
#54
Junior Member
Thread Starter
Join Date: Jul 2017
Posts: 63
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
One more thing. I did some reading on what could have hashed the thrust bearing and thrust face. Because had I just put the motor in, and it was only ever run under load for a matter of seconds, not even a minute, I assumed the thrust bearing was already bad.
However, I have read reports of too much pressure from the tranny pump hashing thrust bearings very quickly, so I wonder if it is even remotely possible that my tranny could have destroyed it? It sort of a long shot, since my tranny didn't damage the thrust bearing on the original motor, and the symptoms of the bad thrust bearing manifested INSTANTLY when it was put in gear, but I would really hate to go to all this trouble only to start it up and immediately eat another bearing.
However, I have read reports of too much pressure from the tranny pump hashing thrust bearings very quickly, so I wonder if it is even remotely possible that my tranny could have destroyed it? It sort of a long shot, since my tranny didn't damage the thrust bearing on the original motor, and the symptoms of the bad thrust bearing manifested INSTANTLY when it was put in gear, but I would really hate to go to all this trouble only to start it up and immediately eat another bearing.
10-08-2017, 12:27 AM
#55
Junior Member
Thread Starter
Join Date: Jul 2017
Posts: 63
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
Update:
The crank install went smooth as can be. No scratches or other bad-word-inducing mishaps. Having my dad there was key. He mainly lifted, and I aligned everything and bolted up two caps. It took less than a minute.
More good news: All the bearings were on the tight end of in spec, measured with green (the marks all ended up at the thickness of the .002 measurement or a bit bigger on the mains. A bit bigger spread (smaller gap) on the rod bearings. The crank rotates smooth. I tried to measure the thrust with a feeler gauge, but couldn't even get an 0.004 in, so that's good. I didn't realize the oil pump has a gasket, but I have gasket material laying around so I made a new one. I got the motor buttoned up, new seals in, the pan back on, oil in and all the accessories back on. All I have left is to drop in the radiators and bolt the tranny back up. I should be able to test the motor tomorrow. I sure hope it works.
I'm going to pull the fuel pump relay, and tap the starter for a while to get oil moving throughout the motor, then start it. I'll let it just idle long enough to fill up the coolant and warm up the motor, again, only idle. No revs or load. Then I'm immediately going to change the oil and filter.
If its running right after that, I'll drive it for a week, and change the oil and filter again.
The crank install went smooth as can be. No scratches or other bad-word-inducing mishaps. Having my dad there was key. He mainly lifted, and I aligned everything and bolted up two caps. It took less than a minute.
More good news: All the bearings were on the tight end of in spec, measured with green (the marks all ended up at the thickness of the .002 measurement or a bit bigger on the mains. A bit bigger spread (smaller gap) on the rod bearings. The crank rotates smooth. I tried to measure the thrust with a feeler gauge, but couldn't even get an 0.004 in, so that's good. I didn't realize the oil pump has a gasket, but I have gasket material laying around so I made a new one. I got the motor buttoned up, new seals in, the pan back on, oil in and all the accessories back on. All I have left is to drop in the radiators and bolt the tranny back up. I should be able to test the motor tomorrow. I sure hope it works.
I'm going to pull the fuel pump relay, and tap the starter for a while to get oil moving throughout the motor, then start it. I'll let it just idle long enough to fill up the coolant and warm up the motor, again, only idle. No revs or load. Then I'm immediately going to change the oil and filter.
If its running right after that, I'll drive it for a week, and change the oil and filter again.
Last edited by sambroom; 10-08-2017 at 12:31 AM.
10-08-2017, 07:59 AM
#56
Old fart with a wrench
Sounds like a plan. I'd pull the ASD relay and crank it until the oil gauge needle jumps up. The ASD relay controls spark and injectors. The fuel pump will only run for 2 or 3 seconds to charge the rail.
10-08-2017, 12:02 PM
#57
CF Veteran
Join Date: May 2015
Location: Arizona
Posts: 4,481
Likes: 0
Received 18 Likes
on
14 Posts
Year: 97
Model: Cherokee
Engine: 4.0
Update:
The crank install went smooth as can be. No scratches or other bad-word-inducing mishaps. Having my dad there was key. He mainly lifted, and I aligned everything and bolted up two caps. It took less than a minute.
More good news: All the bearings were on the tight end of in spec, measured with green (the marks all ended up at the thickness of the .002 measurement or a bit bigger on the mains. A bit bigger spread (smaller gap) on the rod bearings. The crank rotates smooth. I tried to measure the thrust with a feeler gauge, but couldn't even get an 0.004 in, so that's good. I didn't realize the oil pump has a gasket, but I have gasket material laying around so I made a new one. I got the motor buttoned up, new seals in, the pan back on, oil in and all the accessories back on. All I have left is to drop in the radiators and bolt the tranny back up. I should be able to test the motor tomorrow. I sure hope it works.
I'm going to pull the fuel pump relay, and tap the starter for a while to get oil moving throughout the motor, then start it. I'll let it just idle long enough to fill up the coolant and warm up the motor, again, only idle. No revs or load. Then I'm immediately going to change the oil and filter.
If its running right after that, I'll drive it for a week, and change the oil and filter again.
The crank install went smooth as can be. No scratches or other bad-word-inducing mishaps. Having my dad there was key. He mainly lifted, and I aligned everything and bolted up two caps. It took less than a minute.
More good news: All the bearings were on the tight end of in spec, measured with green (the marks all ended up at the thickness of the .002 measurement or a bit bigger on the mains. A bit bigger spread (smaller gap) on the rod bearings. The crank rotates smooth. I tried to measure the thrust with a feeler gauge, but couldn't even get an 0.004 in, so that's good. I didn't realize the oil pump has a gasket, but I have gasket material laying around so I made a new one. I got the motor buttoned up, new seals in, the pan back on, oil in and all the accessories back on. All I have left is to drop in the radiators and bolt the tranny back up. I should be able to test the motor tomorrow. I sure hope it works.
I'm going to pull the fuel pump relay, and tap the starter for a while to get oil moving throughout the motor, then start it. I'll let it just idle long enough to fill up the coolant and warm up the motor, again, only idle. No revs or load. Then I'm immediately going to change the oil and filter.
If its running right after that, I'll drive it for a week, and change the oil and filter again.
Sounds like it will be good to go! Looking forward to hear it is all well and sounds good!
10-08-2017, 01:28 PM
#58
Old fart with a wrench
Bugout, on the A3,A4 thing. I'm thinking usually one bearing shell of a pair is slightly longer than 1/2 so it crushes into the bore and holds tight. Am I correct on this? This would be a way if identifying them. Also on some engines, one has an oil hole and one doesn't. These are to feed lube for the piston pin or squirt jet for cylinder wall lube.
10-08-2017, 01:46 PM
#59
CF Veteran
Join Date: May 2015
Location: Arizona
Posts: 4,481
Likes: 0
Received 18 Likes
on
14 Posts
Year: 97
Model: Cherokee
Engine: 4.0
Bugout, on the A3,A4 thing. I'm thinking usually one bearing shell of a pair is slightly longer than 1/2 so it crushes into the bore and holds tight. Am I correct on this? This would be a way if identifying them. Also on some engines, one has an oil hole and one doesn't. These are to feed lube for the piston pin or squirt jet for cylinder wall lube.
But every bearing maker has a different code for this so it is maker and series specific.
So it has been bugging me all morning and I have been digging into it. But I need to ask him what series bearings those are first. Me second instinct was that it very well be to indicate that they are to be installed with the hole in the top shell because of the squirt hole most engines have even though these do not. If it's the squirt hole difference, like I think it is, he should be good to go...
But you are on the money, it is either or with these two gustions Dave and I now plan do re-educate myself on this for peace of mind! lol
10-08-2017, 04:37 PM
#60
Junior Member
Thread Starter
Join Date: Jul 2017
Posts: 63
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
Honestly I couldn't remember for sure, and my curiosity was exactly the same two questions as you have Dave. They can indeed can be asymmetric depending on the "series" of the Clevite bearings because rod journals do stretch and they compensate for the slight oval by making the top shell different enough to take this out.
But every bearing maker has a different code for this so it is maker and series specific.
So it has been bugging me all morning and I have been digging into it. But I need to ask him what series bearings those are first. Me second instinct was that it very well be to indicate that they are to be installed with the hole in the top shell because of the squirt hole most engines have even though these do not. If it's the squirt hole difference, like I think it is, he should be good to go...
But you are on the money, it is either or with these two gustions Dave and I now plan do re-educate myself on this for peace of mind! lol
But every bearing maker has a different code for this so it is maker and series specific.
So it has been bugging me all morning and I have been digging into it. But I need to ask him what series bearings those are first. Me second instinct was that it very well be to indicate that they are to be installed with the hole in the top shell because of the squirt hole most engines have even though these do not. If it's the squirt hole difference, like I think it is, he should be good to go...
But you are on the money, it is either or with these two gustions Dave and I now plan do re-educate myself on this for peace of mind! lol
In other news: She lives!
I took this video after the first warm up and the second oil/filter change. Its great to see it idling smooth, but I'm not counting my chicks before they hatch; the real test will be if the bottom end lasts for the next 80k miles.
Not all is well however, I noticed the CEL was on, so I checked the codes while it was warming up. It came back with a P0748, problem with the Gov pressure solenoid in the tranny. Dun dun DUN! I'm actually not too worried by that. I have some transmission building experience on Ford E40Ds my dad and I both had. These are very similar. I'm going to chase wires first and see if I can find an issue, but worst case scenario, I'll have to drop the tranny pan.
Per my earlier concern, I'm not going to go putting the Jeep in gear until I have the tranny issue resolved.
I do wonder about the tranny fluid level... I lost some when I first pulled the motor (tranny leaned back and spilled out the fill hole, I'm guessing a quart or two), and low fluid level could potentially cause the P0748 code... But I don't know how I would check the tranny fluid level without putting it in gear, which I'm scared to death of doing, for fear of wrecking my new thrust bearing and crank. Maybe I'm just safer to swap the solenoid out. It would be like $200 total for the Solenoid, sensor, tranny pan gasket, and fluid.
Thoughts?
Last edited by sambroom; 10-08-2017 at 05:04 PM.