Packard Forum Index » Pre-War (1899-1942)

Phil, let me suggest that what DavidM has suggested, wheel "shimmy", is most likely the correct diagnosis. I had a hint of it on my 34 when I first bought it; it most often occurred if I hit something like a RR crossing at a diagonal where one front wheel hit the rail before the other. The front end, king pins, tie rod ends, drag link, steering gear box were all snug - the solution was a front end alignment and front wheel balance. For wheel balance I had it done dynamically by a truck shop that balanced the entire rotating assembly, tire/wheel and brake drum, as a unit, marking the position of the tire on the rim. Though it might not have been necessary I marked the position of the wheels on the drums with a daub on paint so should you get a flat or have to retire, you remount the wheel in the same position. I have replaced the tires since and through tens of thousands of miles of touring the shimmy never returned.

You might first want to check that the U-bolts that hold the axle to the springs are TIGHT and that if a tapered shim was inserted to adjust the king pin inclination, it's still in place and snug. I'd guess that worn shackle bolts from a non-functioning Bijur system could also contribute to shimmy but first and foremost, wheel balance followed by alignment.

Thanks for the advice Owen I will get the wheels checked for balance. Marking them is a good idea.

The shudder is quite violent. Mudguards moving up and down alternatively and the radiator motometer is probably moving 3 to 4 inches sideways as well as the radiator of course.

It is like the whole front chassis is twisting side to side. The only way to stop it is to brake and reduce speed.

I hope a wheel/tire balance job does it for you, let us know. But if you've got wear/slop in the kingpins, tie rod ends, drag link ends, steering gear box, and/or shackle bolts it may help but almost certainly won't completely eliminate the problem. With a nice tight front end in correct alignment and balance these cars, despite a beam axle, should have very nice road manners.

Does the wear pattern on your front tires give you any clues?

I wish I had some wear patterns to compare with but since I have had it on the road it would barely have done 500 miles. There seems to be a never ending line of things going wrong. Here is another question. With the front wheels off the ground I tried to pull the wheel to the right by hand rather than using the steering wheel. All that happened was the spring compressed in the rod that connects the steering knuckle and the steering box. Should that happen or is the spring too weak? Would this be the cause of the shudder?

I have borrowed an early alignment machine with two wheel pads, a gauge for checking camber/caster and a toe in rod. There are no instructions but my first measurement seemed to indicate about 2 deg of caster.
Does anyone have any figures for alignment apart from toe in of 1/8" to 1/4" depending on which instruction book or service manual is being read?

Phil,
Those springs in the drag link are extremely stiff almost solid, I don't believe you should feel any compression pulling the front wheels to the right. The spring sounds to be way to weak and that could be allowing the wheels to shimmy.

Does anyone have any figures for alignment apart from toe in of 1/8" to 1/4" depending on which instruction book or service manual is being read?

Sorry but the earliest I have is for the 6th Series and I don't know how relevant that might be:

Camber 1? 30'
Toe in 1/8" (also given elsewhere as 3/16".
Caster 1?

Phil,
Attached is the wheel alignment data that I have used on my projects. On all three of the Packards I restored, the front axle king pin inclination was well off spec and needed correction. In each case I had this done by facilities that do the same work on heavy trucks, using the attached data.

Also attached is a photo o one of the springs that fit behind the ball joints in the drag link.

Attach file:

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Phil,
I will try again to attach the wheel alignment data, if it doesn't transmit I will e-mail it to you

Attach file:

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David,
Thanks for the info, the link transmitted ok and I was able to print it off. First job tonight is to check the spring!!
The wedge under my axle is inserted from the front which should incline the king pin top forward. According to the sketch it should be inserted at the back of the axle to incline the king pin backwards 1 degree. Is that the way your wedge is fitted?

Phil,

None of mine had wedges either in the original wreck or the finished car. I would think wedges were added in a "trial & error" attempt to correct a steering problem.

Once you have checked the wheel alignment that should tell you if wedges are needed and how they should be fitted.

However I believe the best solution is to correct any problems with the axles so that all angles are correct relative to the horizontal axle pads that supports the springs. Once that is done wedges would be unnecessary.

Removal of the front axle is not a small job but not particularly difficult.