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Discussion Starter #1
Hey guys,
Trying to identify a vibration issue with my OM617 swap. Vibration increases with RPM, and is very noticeable/worrying starting around 2,500 rpm - enough to make me hesitate to drive over 2,500 rpm. When I did the swap I had the flywheel (22lb stock Toyota flywheel) match-balanced to the Mercedes flexplate. The shop owner said he was able to accomplish the balance, and the Merc plate was around 10 grams off. I'm now wondering if said shop didn't balance correctly, it did take some explaining to get them to understand what i want. My questions are as follows -
1) For those who did not have their flywheels match balanced, is there excessive vibration over 3k?
2) Would upgrading to a 38 lb flywheel smooth out the normal OM617 idle vibrations? My Toyota wheel is only 22 lbs vs the ~ 40 lb Mercedes torque converter.

Thanks guys!
 

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Discussion Starter #3
Yeah driveline is solid, at highway speeds if I push in the clutch vibration goes away. Same vibration is present in neutral if I rev it up.
 

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If I remember correctly on one of the other builds he was having clutch issues and had lots of pics and one of them showed the flywheel rubbing in one spot. That led me to believe that the flywheel adapter was not bolted up true to the crank or it wasn't made true. Not sure if that could be you're issue, but it's worth checking out.
 

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If that is the case , it could be way out of ballance . but having it ground should clean it up mostly .

should be able to get a dial indicator on the ring gear via service cover and turn engine over slowly and see how much it moves .
 

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I just went through this with a nissan FD35T. Nasty vibration got worse with more RPM's. I worried it was my backyard transmission adapter. I checked EVERYTHING by removing one thing at a time and running it. Had the injectors checked and rebuilt, then ordered new nozzles (never installed). Adjusted valves (and checked like three times). Pulled the transmission, pulled the pressure plate, ran it with the flywheel off. Nothing changed. Last check was compression - #4 cylinder shot. The last thing I checked should have been the first thing I checked.

I did take temperatures with a laser temp thingy. The number 4 cylinder lagged in temperatures through all operating ranges. The injector itself was cold as was the cylinder head in that area and the closest cylinder head bolt.

Probably not what you want to hear, but if you don't know the history of the engine (I didn't) then check the stuff you can check without spending any money on it.

Oh I eventually pulled the #4 piston and found the ring end gaps ALL lined up - like perfectly. Ahh that's it I thought. So I decided to to rod bearings and rings at this point. So when I pulled the other cylinders the gaps were lined up TOO! Not as exactly like #4 but pretty close. Had the head check and #4 was cracked between valves and from each valve into injector tube assembly.

I had 390 psi across #1, #2, and #3. #4 was reading about 220 psi. Other than the vibration I was perfectly happy with the performance.

Good Luck,
Jeff
 

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From what I understand about the Toyota/OM617 and Ford/OM617 set ups it is strongly recommended to have the fly wheel and adapter plate balanced together as a set.
 
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