Mitsubishi 4g32 spun rod bearing

[PharmD]

Hi, I have the engine from my Bobcat 642B on a stand right now and have the oil pan off. The back rod bearing is completely gone. The crankshaft looks like it could be turned, there doesn't appear to be any deep scratches. My question is: should I have the whole engine rebuilt (this will cost about $2000)? Or pull the crankshaft, have it turned then reinstall it with new undersized rod bearings. Any suggestions? Thank you for the help.

 

[Tazza]

Its really hard to say.
Was it using oil? low on power? excessive blow-by?
If you don't use it heaps, i see no problem just doing the crank and big end bearing, check the others for damage and wear too. Check the bores for scratches, you could measure them to ensure they are still within the wear limits.

 

[jeepcreepcj]

Its really hard to say.
Was it using oil? low on power? excessive blow-by?
If you don't use it heaps, i see no problem just doing the crank and big end bearing, check the others for damage and wear too. Check the bores for scratches, you could measure them to ensure they are still within the wear limits.

If you are going to spend money on having the crank turned, you probably shouldn't cut corners on the rest. I would take the block, head, and rods to a machine shop and have them check everything. You know that you will at least need the crank refinished and one rod, but not checking the other rods, bores, journals etc could cost you twice as much if it fails and you have to do it again. I bought my 642b with a spun bearing, and the motor disassembled. To repair my crank (which needed welding on one journal) was going to be nearly $500. When looking for a different option, I found that auto-zone sells remanufactured cranks, and offers one for an 80s dodge colt, which had this motor. I don't know that they are the same for sure, but it might be something worth looking into, as it was under 200 with bearings. I ended up doing a diesel conversion, and never tried the auto-zone crank.

 

[PharmD]

If you are going to spend money on having the crank turned, you probably shouldn't cut corners on the rest. I would take the block, head, and rods to a machine shop and have them check everything. You know that you will at least need the crank refinished and one rod, but not checking the other rods, bores, journals etc could cost you twice as much if it fails and you have to do it again. I bought my 642b with a spun bearing, and the motor disassembled. To repair my crank (which needed welding on one journal) was going to be nearly $500. When looking for a different option, I found that auto-zone sells remanufactured cranks, and offers one for an 80s dodge colt, which had this motor. I don't know that they are the same for sure, but it might be something worth looking into, as it was under 200 with bearings. I ended up doing a diesel conversion, and never tried the auto-zone crank.

Thanks for the help. After much research and spending alot of time on some Mitsubishi boards, it looks like a crank from a 4g37 out of a 93 Mitsubishi Eclipse is a direct drop in for the 4G32 engine in the Bobcat. The 4G37 is the same block as the 4G32 with a larger bore. All of the Dodge Colts from the 80's use a G32B engine block which is slightly different. The only Dodge colt to use a 4G32 is the 76 and 77 and a crankshaft kit isn't offered for those. So I'm ordering a crankshaft kit for a 93 Mitsubishi Eclipse from Autozone for $150 with bearings. I'll let everyone know if its a direct fit. The cheapest I could find for a machine shop to cut my crank was $250 plus $100 for bearings. $350 total seemed kinda steep for crankshaft grinding, but maybe that's how much it costs nowadays.

 

[jeepcreepcj]

Thanks for the help. After much research and spending alot of time on some Mitsubishi boards, it looks like a crank from a 4g37 out of a 93 Mitsubishi Eclipse is a direct drop in for the 4G32 engine in the Bobcat. The 4G37 is the same block as the 4G32 with a larger bore. All of the Dodge Colts from the 80's use a G32B engine block which is slightly different. The only Dodge colt to use a 4G32 is the 76 and 77 and a crankshaft kit isn't offered for those. So I'm ordering a crankshaft kit for a 93 Mitsubishi Eclipse from Autozone for $150 with bearings. I'll let everyone know if its a direct fit. The cheapest I could find for a machine shop to cut my crank was $250 plus $100 for bearings. $350 total seemed kinda steep for crankshaft grinding, but maybe that's how much it costs nowadays.

Did you get this going yet? I am interested to know if the eclipse crank worked. Please let everyone know!

 

[PharmD]

Did you get this going yet? I am interested to know if the eclipse crank worked. Please let everyone know!

It did work. The kit is Part #13860 from Autozone. It's used in the early to mid 80's 1.6L Dodge Colts and also late 80's and early 90's 1.8L Mitsubishi Eclipse.