I read on here or somewhere else that someone had experienced main bearing damage or play as a result of vibrations from a failing dual mass flywheel. any truth to this? this concerns me because mine has been failing for 30,000 miles, yet still held together. a new clutch and flywheel is my #1 priority, but could there already be adverse affects? the truck bounces up and down at idle from the vibration. any way to check for play with the flywheel removed or does the pan have to come off? thanks gentlemen.

 

yes, we run a fleet of 06's, the dmf uses a pilot bushing and the imbalance of the spinning junk in the dmf causes high stress on the bushing and front bearing. the southbend conofe kit has a real ball bearing and very precise balance of the flywheel. when you remove the g56 you will find the front seal will have wept some tran fluid. if there is substantial fluid the bearing had enough play to do it. you have a 50-50 chance of it hurting the housing. unless you see fluid drip from the bottom of the bell housing, you will be ok. there is a red rubber boot seal on top of the g56 that is also poor quality and will crack and leak down the sides of the g56, do not mistake this oil for the seal leak. the dmf was to keep the aluminum case g56 design quiet, but it was a horrible design. the new one piece flywheel is going to be very noisey but will never give any more trouble. all of our dmf's failed between 35,000 and 65,000 miles. after we had already replaced the last one, we figured out what we should have done on all of them. we tow very heavy and the g56 will hold up very well if you do a few things. the g56 must have one quart over full to lube and cool that front bearing. we have temp probes on ours and spotted this immediately. a lot of times i gross 44,000 to 46,000 lbs and there some 9% grades here. you do not need to go to the extremes we do to keep the g56 cool. so i will give what you should do. first replace the dmf with the southbend conofe kit. it is complete with new hydraulics, next replace the front seal and the rubber boot, use Dorman #614-002 universal fit, silicon rubber CV boot. mix one gallon sae 50 synthetic syncromesh transmission fluid with one gallon 5w-30 synthetic syncromesh transmission fluid while the g56 is on the ground you can tilt it on it's side and fill 7 quarts. once the g56 is back in there is another boot that goes over the shifter connection point. in between this boot and the leather boot add a layer of high density foam. also consider a fluidamper in the future if the noise is still a little aggravating.

 

Carl48,
How's backing up with that ConOFE? I read differing reports. I have to back under my cabover and don't have free spin hubs that would enable me to use low range.

I'm hedging on the new sbc 3250 dual disc,an OFE or the new Con OHD.
Thanks

 

Mine is real grabby backing in high range up a slight slope with the 5th whel on the back. Have to pop into Low range. Thinking an engine brace might do the trick to stop it all from jumping around. Worked on my 600HP 73 Chally.

 

it is grabby. look at the last pix, we installed the dynatrac free spin hubs. this gives you the best two wheel drive low range reverse you ever seen and gives two more consecutive forward gears. i grossed out 39,600 lbs with that line truck and can back it up on steep inclines with no problem