Engine Woes - Rod Bearings?

[CruisinGA]

That crank is toast! It needs a lot more than polishing.

I wouldn't bother reassembling.

On the oil pans- Toyota Black FIPG is the stuff for the job, but if you reassemble with that crank, you might as well use bubble gum...

 

[SBFJ60FIG]

I just use Toyota FIPG...it's good stuff. But I'm sure any ole-liqua gasket will do.

Hell, give it a whirl...I'll be coming out west this winter for a snowmobile trip...you can pay me to build you an engine and I'll drop it off!

Good luck man...make sure you plastigauge that thing when putting it back together...not that it will matter, if you can't get the clearance right Clarance, you're fxxxed! But hell, button it up and see what happens. You should get some Slick 50 to drop in that bad dog while you're at it!

Anyway, sorry I'm kinda pokin fun at ya, best of luck and sorry about that. Motor work is tough stuff, a lot of effort but in the end you'd be pretty proud of yourself once you've built your first engine. And over $3k for a short block is a lot of green, that'll get you a supercharger!

 

[Cruiserdrew]

Crank looks bad in my unprofessional opinion.

However, in the 2F world, I've seen worse, polished with emory cloth and run for years afterwards.

As long as you would not mind re-doing it in 8 miles it might be worth a try. I would reassemble with very cheap oil and filter!

 

[Snowtire]

I will polish the rod and the crank to a mirror finish and also go over it carefully with my Starrett 721. Don't worry, I will for sure let you know how many miles or how much run time I get before it spins again. Then you can all say, I TOLD YOU SO!

Maybe we should start a wager on how long it will run before it happens again. I'm giving my polishing skills a confident 50 miles. Winner gets this crankshaft...

I'll be encouraging here. I think the very fact that you have a Starrett 721 raises my estimate of the miles you will get out of the job. You are probably going to be more careful than the average dude in your honing/polishing activities. Since I am the first one to make a guess, I will make a split guess: you will either get VERY low miles out of it (5-10 miles) or this will last thousands of miles--let's say 20,000 just for fun.

If I were doing what you are doing (and I probably would, notwithstanding my previous comment), here are some points I would keep in mind:

1. Since you have access to bearings, you should be able to go under size if necessary, so don't be bashful about getting down to a very polished surface. Don't stop until you do. It shouldn't be mirror finish, but almost. And circumferential lines or sanding marks are probably better than ones that run perpendicular to the journal surface, but it would be hard to make those anyway.

2. Hook up a little flexible hose to a shop vac and try to suck oil and gunk out of the oil galleries in the crankshaft. You'd hate to have some piece of sand or iron come through and wreck your new bearing. Also vacuum out the oil pump pickup.

3. Make sure you get a uniform journal circumference across the bearing surface--don't let it "cone" by using your emory cloth too much on one side over the other.

4. Make sure your work does not result in an out of round condition for the journal. In other words, go slowly, and make sure you are taking off the same amount the whole way around the journal. An egg-shaped journal will let oil out too quickly because it has low spots.

5. If someone put a gun to my head and forced me to choose only certain parts of the journal to really polish well, I'd say in the side that takes the load from the connecting rod on the power stroke.

6. Wouldn't worry too much about the surfaces of the connecting rod--they'll be covered by the bearing shell.

7. As mentioned before, use plastigauge, maybe even a few times around the whole journal to make sure you haven't left high/low spots. THIS IS PROBABLY THE MOST VITAL STEP. You can probably get to something approximating a good regrind if you take your time and measure a lot, and don't button it up until it is good.

8. Use lots of assembly lube, the good stuff, to make sure you don't spin the new bearing on startup.

9. Clean all of the crap out of the oilpan, change the filter, change the oil.

10. Before starting the motor for the first time, pull the coil wire and turn the motor for 30 seconds or a minute using the starter. You really want to get good oil pressure on that bearing right away, and this will get oil into the system before you start it and give it load.

If you are careful, I actually think you have a decent chance. Good Luck!

 

[alia176]

I've done this particular band aid on an older vehicle of mine and unfortunately, that rod knock didn't go away. I sold the vehicle as is and the next owner had to get a new c-shaft. BTW, other journals were affected too, just not as bad.

My concern is if #5 is toast, how are the other journals? There's a good chance that you have more than one bad journal due to contaminants in the oil.

I polished my C-shaft on the floor, between my knees as I was kneeling over it and it was in a constant motion (left - right -left). I'm having a difficult time visualizing this process lying on your back while someone rotates the engine with a breaker bar on the front C-shaft nut. This will take a huge amount of patience and time.

It may be time to consider pulling the engine out, and swapping out the block for an used one. Or, take the C-shaft to a machine shop and have them weld and ground back to spec. I'm trying to think, if you remove the whole thing, including the ECU harness, place it on an engine stand, then rotate it upside down, would you be able to remove the C-shaft? Hmm, I think it may be doable!

Here's a pic of the C-shaft being polished: https://forum.ih8mud.com/nm-high-de...-anti-1fzfe-freak-same-place.html#post4127887

I wish you the best of luck with this.

 

[HarleyHetz]

After having a look at that crank, I'd say you ain't got a prayer. But, if you're gonna do it anyway, on #10 above, maybe pull the plugs first so it'll spin good and fast with no back pressure. Should allow the oil pump rpms to go a little higher and give you that much better of a shot.
Good luck man!!

Oh, put me down for 25 minutes after startup, or 25 miles, whichever comes first.

 

[hsiaoer]

Thanks for the encouragement. I'll let the 721 be my eyes and try and get it as perfect as possible.

Alia, that is quite the polish job. Why didn't the knock go away? Was your crank out of spec/round? Or bearing too small? It won't be too bad from underneath. with the crank all the way down, I can easily reach up and over it. I have seen that build thread, I also followed your a/c one closely. I'm starting to see a trend...

Dang, I thought the crank looked pretty good! Just shows how much of a noob I am. I'll try pulling plugs to release back pressure. So what is the consensus for the oil pan gasket? And what is quality assembly lube? Edumicate me here.

Have I mentioned this forum is the greatest thing on earth? In Utah a lot of people think its snow but its really MUD. I keep MUD open on one of my firefox tabs all day long.

 

[EricG]

Pardon my ignorance - people are suggesting a short block or new engine. Why isn't it feasible to just replace the crankshaft itself?

 

[alia176]

Thanks for the encouragement. I'll let the 721 be my eyes and try and get it as perfect as possible.

Alia, that is quite the polish job. Why didn't the knock go away? Was your crank out of spec/round? Or bearing too small? It won't be too bad from underneath. with the crank all the way down, I can easily reach up and over it. I have seen that build thread, I also followed your a/c one closely. I'm starting to see a trend...

Dang, I thought the crank looked pretty good! Just shows how much of a noob I am. I'll try pulling plugs to release back pressure. So what is the consensus for the oil pan gasket? And what is quality assembly lube? Edumicate me here..

Sorry if I confused you, I spoke of two diff vehicles earlier. The pic shows the crank out of the '97 80 and it was fine. I simply polished the minor grooves to accept new ConRod bearings. As far as the "other" vehicle; I suspect that the knock didn't go away because I didn't polish the crank before slapping on a new set of bearings. IIRC, I replaced four set of bearings and the knock was still there. It was a patch job to get the vehicle out of my driveway and the next owner knew about the temp fix.

Can you actually order an undersized bearing from CDan? I didn't know you could do that, cool.

Pardon my ignorance - people are suggesting a short block or new engine. Why isn't it feasible to just replace the crankshaft itself?

It is feasible but the engine will need to come out. Given that scenario, I wonder which route would be more cost effective: used crank that may be out of spec or just have mine welded and re-ground to spec.

 

[AJP]

I am reasonably certain the crank journals are hardened after machining and you may be fortunate and find that most of the material on the journal is babbit/bearing deposits. Thats what we need to hope for -- and with luck you may get it off with the crocus cloth. If there are grooves in the journal ... your are not going to be able to substitute crocus cloth for a machining (but I am pretty sure you are well aware of that anyway) .. someone mentions welding and regrinding ... that used to be unsatisfactory but maybe welding material/technique has improved. If you have to remove the crankshaft to replace or machine ... ensure that has been hardened after machining fwiw. Lots of sites give fairly good idea of the direction to give the final polish on the journal and what you should be checking for wrt journal taper.

FWIW - I did this once on a 221 Ford V8 with several "dirty" looking con rod journals and the engine ran fine for another 18k before I sold it. Course it might have run the same if I hadn't touched the crank. In your case you definitely need to see if that ugly stuff comes off or not. Good news is - it is amazing how long an internal combustion engine can last/run even when it looks like it shouldn't

 

[Snowtire]

I think the hardening is thick enough that it surface grinding will leave it intact. Normal crank grinding is not followed by hardening.

Any update on your work? I am looking forward to seeing pictures.

 

[AJP]

I think the hardening is thick enough that it surface grinding will leave it intact

probably as it is likely induction hardened but it depends on the process and how much is taken off ... nitrided and tuftrided surfaces usually should be rehardened

Normal crank grinding is not followed by hardening

that is very likely the case - not necessarily right though - again it depends on the original treatment, the depth removed during resurfacing and what the owner expects after R&R

In any event .. I think the initial intent is to see what can be done with the crank in the block ...eg polishing

 

[hsiaoer]

No real update yet. I've been in Moab all weekend in a Sienna (I saw about 8 land cruisers and cried a little every time). I have been reading up on my crank polishing. I have the bearings, a #3 set and a #4 set. I will be polishing with 320 grit to get everything smooth and in spec going in the unfavorable direction. From what I read, if I'm underneath looking up at the front of the crank, unfavorable is counterclockwise. Then I'm going to go back with 2000 grit wet/dry soaked in 3 in 1 oil and polish in the favorable direction. When I'm done I'll take measurements and see if I took off enough to warrant the #4 bearings. I'll vacuum everything out as best I can, and double check my measurements with plastigauge. This should all be taking place in the next day or two.

Questions: What type of lube should I use for reassembly?

 

[AJP]

lubriplate (apparently now designated "105") was the preferred assy lube.

I have also used STP ... but not sure how wise that was.

 

[jlg32281]

I've used Valvoline, Amsoil, Costal, etc. I don't think it makes a big difference on brand since it is washed away so quickly. Just be generous with whatever lube you use.

 

[hsiaoer]

Hahaha, well, y'all were right, I am screwed. According to the 721, which probably isn't the best device for checking round in the first place, I have a very egg shaped journal. It measures 56.26mm from top to bottom and 56.80 from side to side. Slight balloon to the right side as well. Spec is 57.00mm all around. I pulled a couple other bearings to check, and they all check out.

I'll probably attempt pulling everything from the bottom just for the heck of it. SBFJ if you were serious about helping out with a rebuild, PM me. Shoot, if anyone with rebuild experience wants to make some money on the side in SLC, PM me.

In the meantime I will find a way to get the crankshaft pulley off and try not to lose any bolts...

It looks like the smallest the journal can be is 56.98. Is welding up and regrinding an accepted repair? Or am I looking for a completely new crank?

 

[HarleyHetz]

I'll probably attempt pulling everything from the bottom just for the heck of it.

Remember, you have the flywheel bolted to the back side of the crankshaft. You will have to remove your transmission to get to these bolts...I think I'd pull the motor from the top if it were me...

It looks like the smallest the journal can be is 56.98. Is welding up and regrinding an accepted repair? Or am I looking for a completely new crank?

I think I'd shop around the junk yards and see if you can find a used one that is not in bad shape first, then, if not, go with new...a "GOOD" machine shop should be able to weld up your old one and regrind it...but not a "fair" one...maybe someone in your area will recommend someone to you, I wouldn't try it without talking to someone who has used them though. I've only been in this end of the country for a couple of years, so I won't be much help there...best of luck, and sorry to hear it turned out this way...if it helps, we are pulling for you!!

 

[Snowtire]

I am going back to my old post above on this one. I really think you will have an easier time swapping in a used motor. But hey, if you really want to do this, we will support you.

 

[Dave 2000]

I think you are showing you have the skills to pull this motor. IMHO I would pull it and turn it over and pull the crank leaving all the rods pushed up towarss the valves (carefully). Get the crank reground with new main/rod bearings and refit it. How much is a grind and a set of shells where you are?

You know the rest of the engine is ok, how will you know if you get one from a junk yard that it will not expire in six months with BEB failure again?


regards

Dave

 

[SBFJ60FIG]

Hahaha, well, y'all were right, I am screwed. According to the 721, which probably isn't the best device for checking round in the first place, I have a very egg shaped journal. It measures 56.26mm from top to bottom and 56.80 from side to side. Slight balloon to the right side as well. Spec is 57.00mm all around. I pulled a couple other bearings to check, and they all check out.

I'll probably attempt pulling everything from the bottom just for the heck of it. SBFJ if you were serious about helping out with a rebuild, PM me. Shoot, if anyone with rebuild experience wants to make some money on the side in SLC, PM me.

In the meantime I will find a way to get the crankshaft pulley off and try not to lose any bolts...

It looks like the smallest the journal can be is 56.98. Is welding up and regrinding an accepted repair? Or am I looking for a completely new crank?

I'm always serious brother! However, it really is not at all viable for me to help. However, with what you've done already in your career of car repairs, I really really feel this is within your ability. Just go slowly and read all you can before getting in over your head.

You can really surprise yourself with what you can do, and it's a wonderful feeling! At the very worst your machine shop might say the crankshaft is junk and then you gotta go the used motor route, or a new short block.

Word to the wise...you WILL NOT BE ABLE TO GET THE CRANK PULLEY OFF NOW! Just leave it on and keep going if you're going to do a rebuild. I would contact a machine shop and see what they have to say given the circumstances of the crankshaft before you really get too deep into it, a good idea to have a clue as to what direction it might go.

I think you are showing you have the skills to pull this motor. IMHO I would pull it and turn it over and pull the crank leaving all the rods pushed up towarss the valves (carefully). Get the crank reground with new main/rod bearings and refit it. How much is a grind and a set of shells where you are?

Dave

I agree with Dave that you can get it done...I disagree with Dave in that just grinding the crank is the route to do...you could save some $$ by not pulling the head and re-ringing the motor, but you're almost there. So go all the way, re-ring, hone, all new gaskets, maybe a new oil pump (frankly I almost never replace oil pumps, just check them and roll with it, but that's just me).

I sure the block is fine, and rings probably good, but to have a nice clean motor, no oil leaks, fresh paint, everything new, is a really pretty sight, and you will then have years of trouble-free service from the new power plant.

DO IT...make us proud, s*** make your wife proud!

As I've recently learned from Bob the Builder:

Can we fix it?

Yes we can!