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Clipper 6 cyl. with Electromatic clutch, 38k original miles. When letting off the gas in any gear there is often a grinding noise as if one were attempting to shift into gear without using a (standard) clutch. Yes, sounds like grinding transmission gears. Loud and disconcerting to the point where you want to pull over and stop. I'm pretty sure it IS the gearbox I'm hearing - it's much too dramatic to be just a pawl -, but can't wrap my head around what in the Electromatic system could possibly cause the drive train to force a shift; slipping OUT of gear would be a whole lot more understandable. Doesn't do this all the time, but often enough that it seems imprudent to drive until this is resolved. Again, all it takes to cause this is to let up on the accelerator pedal, we're not touching the shift lever here.

The only thing the Electromatic would do is engage the clutch. If turned on and below speed of approx 18-20 mph, letting off on accelerator would bring it in. On some cars, you would see the clutch pedal depress (don't remember on Clipper if it does). If the dash switch is off, then it should not come in at all. Once over the governor speed, it is normally locked out. If over that speed and it does try to come in, the direct speed switch on a stalk near power cylinder actuated by the 2-3 shift lever could be out of adjustment and staying closed or intermittently making or else a wire is shorting and a ground is being provided somewhere else in the wiring to energize the system. It is also possible if all is turned off, the vacuum supply on/off solenoid is leaking and system can not shut off. To rule that out, disconnect the input vacuum and plug the hose and try. In either case, all it would do is bring in the clutch--no different than depressing pedal-- and should not make any noise unless the throwout bearing is shot.

Thanks, I'll check all that today. Already have it up on the lift.

Howard -
Direct speed switch and vacuum supply on/off solenoid are OK. And as you say, the only noise associated with clutch activity would be throwout bearing, but that is definitely not what I'm hearing. Still, thanks for the input!

BTW, in case anyone's wondering, my screen name has NOTHING to do with transmissions; I'm a technical translator (German) !

Does the car have overdrive? Not sure on a 6 if many cars would but just a thought if it does and is the R9. There is a lockout collar in the OD operated by springs and the lockout lever or reverse plunger. If something is preventing that from being in the proper location -- either it's fully in or fully out position, it could cause a gear gnashing noise if it was creeping and met its mate already spinning.

Yes indeed, it does have OD (I just replaced the fluid). I'll check the lockout collar. There is an external lever attached to the OD housing which is connected to a fixed tab 12"-15" towards the front of the car by means of a length of baling wire (!). Just guessing here, but I'm pretty sure the baling wire isn't factory. Hard to tell how much further back the lever would be allowed to go without disconnecting the wire. I'll have to check my Warner Automotive (Overdrive) and Service Training manual for the transmission and see what that lever does internally.

Unless changed out in the 48-49 era when a retrofit program was available, the 47 should have the R9 OD and the Packard training manual is herehttps://www.packardinfo.com/xoops/html/downloads/EconoDriveTrainingBook.pdf If you have the later more common edition of the B-W book, that may be the later R11 unit Packard used from mid 48 on and also the one used by many other mfgs -- a considerably different system.

The lockout lever needs to move full swing -- stop to stop. One common problem is on the lockout cable at the inside end. Sometimes the cable housing loosens or even separates from the pot metal bracket assy and when moving the lockout knob, the entire cables moves slightly. In that case, instead of moving the working part downstairs the full amount, only a partial sweep happens.

G'day Transtech,
to PackardInfo. Sorry, can't help with your request but have a request of my own. It is inviting you to include your '47 6 Cylinder Clipper in the Packard Owners Registry here on PackardInfo.

Dear TransTech:

I have run into this problem before.

A sudden grinding noise that sounds like the transmission.

If it was the trans then the unit eventually would lock up and blow apart.

However, if there is a problem with the gas pedal start being triggered by a faulty overdrive relay then you can get a grinding noise because the starter motor is smashing on the flywheel ring gear.

Thus, I would go over the electrical system starting with disconnecting the gas pedal switch with the motor running and going for a test drive.

Good luck.

Tim,

That is a good catch. I wouldn't have though of that.