Poll related to 48RE final shift.

[Ken F]

Poll related to 48RE final shift and turbo bark.

I have been experiencing a grinding noise on the final shift. (around 50mph) I believe this is the turbo bark that results from the substantial RPM drop on the final shift. It seems like some trucks do it and some don't.



I would like to know if the amount of RPM drop varies from truck to truck, and if any variation correlates with the turbo bark.



So, here's my poll . . .

 

[Ken F]

So far 60% of trucks do this.



I probably should have included a catagory for stock vs. aftermarket exhaust.



Clearly some do and some don't. I would really like to know what is different in trucks that don't. I was thinking it may be related to a variation in the amount of torque converter slipage which goes away on the final shift. Perhaps trucks that experience a greater the RPM drop would be more prone to have the grinding noises. (turbo bark)



The noise itself doesn't bother me all that much. The thought of a snapped turbo shaft does.



I will make a few calls today to see what some of the aftermarket companies think of this.

 

[DFrank]

I don't tow enough to comment on your poll, but mine barks alot even when not towing. Unless I let off the pedal for the shift it is likely to bark. It does it even more if someone less familiar with thte truck is driving. No one thiks it sounds normal, except my service advisor. He says my 2G did it too you just couldn't hear it over the cummins.



I would love to stop or reduce the barking as well. Let us know what else you learn.