Packard Forum Index » Post-War (1946-54)

Thought I'd start a separate thread for this question. For many years (15-20?) the clutch will slip a little if you floor it in 3rd gear going up a hill. We've always just been gentle with the throttle in top gear. I've read the service manual and searched for threads on the topic to see if there could be something simple. I have about 1.5" of travel at the pedal before enguagement, that seems ok. The way the rod is attached to the throwout lever looks a little suspect (nut being used as a shim, cone washer backwards?) but I the lever does have play when you wiggle it (not in constant tension w/ the bearing).

Before going down the road of new disc/pres plate I thought I'd ask if there could be an adjustment or other issue I should look at. Thanks.

Car has less then 3000 miles since the disc and press plate were replaced in 1997.

Did you check the parts book diagrams? Might have the answer as to whether it is put together properly.

packardinfo.com/xoops/html/modules/parts ... list.php?cat=16&partslist=1941-1947

About the only two clutch adjustments on the 47 are at that point with the extra nut and with the over center spring tension at the pedal. The extra nut should not be there so possibly something is bent or a piece from another year or model was swapped in and "made to fit". There are a few extra clutch troubleshooting suggestions toward the end of the training manual "Clutch and Electromatic Clutch" which covers the post war Electromatic. That manual might be worth a look if you haven't downloaded it already.

It looks like there is a problem with the disc or the pressure plate, or both. If you have free travel at the pedal, and the release lever is free with the pedal released, it must be an internal problem, most likely an improper installation or incompatible parts. I'd take the clutch housing cover off and look for anything unusual, like loose pressure plate to flywheel bolts or loose fragments of clutch disc lining.

Along with what TxGoat mentions, IF you take things apart and remove the clutch plate, assuming parts are the correct stock items for a 356 follow the instructions in the service manual about placing 3/8 nuts in a position to keep the fingers on the pressure plate depressed before unbolting it. You can tie them on a string if you want to eliminate the possibility one will fall inside and be difficult to fish out.

Because the fingers stick out the rear of the plate in their relaxed position, you will have a clearance issue and a more difficult time getting plate assy to pass out of the bell housing opening and then back in if you don't do this step. The nuts also keep pressure off the bolts when fastening the pressure plate back to the flywheel so there is no extra difficulty with that step.

I believe they also suggest marking the pressure plate and flywheel so it can go back in the same position and balance is kept unchanged.

I once had a similar problem on my 1952 Henney-Packard which weighed 6200 lbs and on steep mountain roads (yes, I drove it in obscure places) the clutch would slip. One time I had it loaded with parts from a rural guy in the Santa Cruz Mountains in California and got to a short but steep hill and not only slipped the clutch going forward but the brakes, which were freshly relined, wouldn't hold slipping backward! It turned out that the brakes were relined with too hard a material and the clutch was simply glazed from use. Once the brakes were re-relined, never a problem and once the clutch was also redone, no issues there either.

One other thought on the nut. On the carrier for the throwout bearing, on the passenger side there should be a short spring between the carrier and a clevis pin that just slides in a small hole in the bellhousing. Purpose is to put a bit of tension on the carrier when not in use so it retracts away from the fingers and sits snug against the fork so there is no vibration or noise. The spring can break or, since the clevis pin is just a loose fit in the hole and held in place by the transmission, it frequently falls out and can get lost when the transmission is removed to replace the clutch. That spring setup might be missing or ineffective.

If that happens and all pieces are correct I wonder if someone could have put the nut on to force the fork slightly forward at all times to keep the throwout bearing and carrier lightly forward touching the fingers. Without the spring there might have been vibration intermittently moving the bearing into contact with the fingers and making some noise. If the clevis pin is missing a standard 3/16 diameter x 1/2 inch long pin from the hardware store is a bit longer but will work. The spring might have to come from a vendor.

Have you eliminated the possibility that the slippage is the result of an oil-soaked clutch due to passage of oil from the rear main? I know that with only 3000 miles on the clutch and pressure plate since new that's unlikely, but perhaps worth a quick check if you haven't already done so.

Yes, as OD suggests, oil from a leaky rear main seal can get on the clutch. My ‘40 has a ‘47 356 that had the same problem. I removed the clutch cover, braced the clutch pedal down with a block of wood, then got under and and sprayed brake cleaner between clutch and flywheel. That cleaned enough to drive from Portland to San Francisco. I sprayed it again to get back , the the shop packed in a new rear main seal. I think I covered this issue in the Duchess Project blog. Just wear a professional mask when you spray that stuff under the car.

It’s here.packardinfo.com/xoops/html/modules/newbb ... ic_id=5878&order=ASC&status=&mode=0
Post 414-maybe 418. The video is gone, but there are pictures.