Possible Broken Flexplate: Increasing bottom end noise at idle and neutral throttle

[FnFilthy]

I think I might have a broken flexplate on my old girl (1992 7.3 E350 Ambulance). I've got 360K miles on her and the tranny rebuild I last put in has a tow package with a hard hitting 2nd and 3rd gear shift (which I suspect has hammered the flex plate)

Its been doing great. I don't have any decrease in power. There is nothing shiny in the oil. The only thing I've got is lots of noise near the rear bottom end/bell housing and it's increasing.

The only time the noise presents itself is during Idle and Neutral throttle (where the engine just keeps up with the forward motion). If I'm accelerating or decelerating, it's nice and quiet.

I'm going to pull the inspection plate this weekend and if that doesn't render any help, I'll slide the transmission back to take a look.

My questions are two-fold. Aside from $600+ billet flex plates, is there any preferred one I should go with? And is there a local chain (west coast) that can get me one in less than 10 days? I checked both Napa and O'Reilly online and neither appears to carry them in their warehouses. I hate to have to let it sit for a week after pulling the transmission.

I love this machine and want to keep it going for years to come.

 

[icanfixall]

I think any GOOD trans shop will get you one easily but.. You knew there was going to be a but.. What type flexplate do you have now? Is it the heavy cast iron plate thats actually a 3 piece unit. Or is it the simple stamped steel plate with the starter gear welded to it? You absolutely need to answer this question for more help. Now a little note about changing from the 3 piece heavy cast iron to the simple pressed steel plate. You will need the thick spacer the makes up the thickness lost when you change this. That heavy cast iron plate is very thick compared to the usual looking flexplate.

 

[FnFilthy]

Thanks for the heads up. I'll check it out. My assumption (yes, we know where assumptions lead us) is that its pressed steel or it would have grenaded.

 

[nj_m715]

make sure the flexplate to tc bolts are tight. they can rattle when not under load of they're lose.

 

[FnFilthy]

Yikes. I bet that really hogs the holes out.