Merry Christmas and welcome to Packard Motor Car Information! If you're new here, please register for a free account.  
Login
Username:

Password:

Remember me



Lost Password?

Register now!
FAQ's
Main Menu
Recent Forum Topics
Who is Online
63 user(s) are online (47 user(s) are browsing Forums)

Members: 1
Guests: 62

George, more...
Helping out...
PackardInfo is a free resource for Packard Owners that is completely supported by user donations. If you can help out, that would be great!

Donate via PayPal
Video Content
Visit PackardInfo.com YouTube Playlist

Donate via PayPal

Forum Index


Board index » All Posts (DavidPackard)




Re: BigKev's 1937 115-C Convertible Coupe
#1
Home away from home
Home away from home

DavidPackard
As far as I know the Model A straps are available in at least three lengths, namely 6, 7, and 8 inches Some of the Model As used a steel door stop with a generous rubber bumper . . . meaning adding or reducing the bumper length would make it adjustable. If you step back to the Model T they used a woven web material nailed to the door frame. Lots of ‘non-leather’ options, but clearly some manufacture’s used leather, and since most of the time it only servers as a gentle reminder the life will likely out last most of us. The leather belts on the trunks, and hoods have an exceptionally long life.

dp

Posted on: 2022/12/1 18:46
 Top 


Re: Brake Noise & Fading
#2
Home away from home
Home away from home

DavidPackard
Marty;

I think you’re on the right path of identifying the differences in the primary v. secondary springs, and the secondary leaving the anchor at the beginning of the process. I’m at a loss what would sustain that activity to produce a pulsation. If both wheels suffer the same condition, and become out of phase, I suspect some pedal pulsation would be felt. I’ve never had a set of drum brakes cause a pulsating pedal, but when a set of disk brake rotors warped the pulsation was quite severe. I would think putting the drums on a lathe would prove or disprove whether the drums are warped.

My vote is the primary spring is too stiff, or the initial preload is excessive. Perhaps the difference in the two springs is quite subtle, and if the wire diameter is the same, as you reported, the difference is embraced in number of active coils, coil diameter, or perhaps the length of the hook ends.

Without knowing the coefficient of friction, I don’t know what to say about the length of the primary shoe friction surface. You would think with 15% more surface area the initial spring force should be reduced. Once the available wire diameters are known, and the winding mandrels have been made, I would think one of the few variables left is the length of the primary shoe. That’s the last ‘adjusting screw’ that’s turned.

The two part numbers for the friction material may be nothing more that the geometry of the shoe (thickness, width, arc diameter, and location & diameter of rivet holes), and given the known difference in shoe length having two different part numbers makes sense.
The sensation of fading could be the loss of a portion of the ‘self-energizing’ character of the brake . . . they just won’t stop as well, and the pedal force is increased.

Warning: I’m going to go full geek on this part of the posting:

The equation for the spring constant (k - force per unit deflection) for a coil spring is given by the relationship
K = Gd**4 / (8nD**3) where d**4 = d to the fourth power and D**3 = D to the third power
G is known as the Modulus of Rigidity, which is a property of the material, steel in this case, which would be the same for both retraction springs in a drum brake
d - wire diameter
n - number of active coils.
D – mean coil diameter which would be the outer diameter of the coils minus the wire diameter
A weaker spring will have more coils, all else being equal
A weaker spring will have a smaller wire diameter, all else being equal
A weaker spring will have a large coil diameter, all else being equal.

The shape, length, and configuration of both ends of the spring will not affect the spring constant, but will affect the initial hydraulic force required to initiate motion. That alone can also affect the initial motion of the primary shoe. It is my understanding the design intent is for the hydraulic end of the primary shoe to move first, which infers the static force of the primary shoe is less than the secondary shoe (with single diameter wheel cylinders). The initial static force is the combination of the spring constant and how far the spring is stretched.

With the wire diameter being raised to the fourth power small changes can become significant. In this case a 10% change in wire diameter suggested by Ross’s estimate of primary/secondary spring wire diameter difference will result in approximately a 46% change in spring constant (all else being equal). With the mean diameter being raised to the third power small changes can become significant. If the same 46% change is used the outer diameter of the coil would need to grow by 13%.

All of the variables can be changed simultaneously, and I’ve intentionally not included initial coil binding, which is another contributor to initial spring force to be overcome by hydraulic force.

dp

Posted on: 11/17 23:20
 Top 


Re: Stuck vent windows?
#3
Home away from home
Home away from home

DavidPackard
Humanpotatohybrid . . . HH56 is clearly a faster typist than I!

Referring to the picture you posted; for the frame and post to rotate one end of the coil spring must ‘slip’. Try some penetrating oil at both the top and bottom of the coil spring. If after a few applications the window doesn’t ‘frees-up’, then loosen the nut a bit and see if than gets things moving.

My vent windows open much more than 90 degrees. I guess you’re looking for smooth operation but with enough friction to keep the window from moving at speed. This particular window may have been adjusted years ago with some lubrication at the slipping interface. Perhaps 20 + years ago the lube left the scene, slowly being replace with rust. I would think the design would call for a washer at both ends of the spring, so either end participates in ‘lowest friction wins’ contest.

dp

Posted on: 11/6 17:23
 Top 


Re: Re-installing rear brake drums
#4
Home away from home
Home away from home

DavidPackard
ScottG

During the rear axle bearing clearance adjustment there are shims placed between the rear axle housing and the backing plate. The wisdom found in the various shop manuals suggest both sides should have about the same thickness of shims left to right. If the shims are all on one side there is the possibility that the thrust block masked the true bearing clearance. I would start by double/triple checking the bearing clearance check for A.) is the clearance is close to the correct value, and B.) is there anywhere near an equal amount of shims on each side. A wildly high amount of bearing clearance is likely to result in some interference. A drum with axial run-out could also result in rubbing. Your question about hold-down springs reminded me of the subject as to whether the brake drum is a cylinder or worn into a cone shape. If all of scoring and wear could not be ‘turned-out’, and that wear was favoring the out-board side the shoe could be (emphasis on vague) pulled out-board.

Would you say the noise appears when the car is going straight ahead, or are you in a shallow turn?

You wrote that ‘the rear hardware all looked to be in good shape . . . ‘, how far did you disassemble the rear-end?

dp

Posted on: 10/23 22:12
 Top 


Re: Mike's 53 Caribbean
#5
Home away from home
Home away from home

DavidPackard
Mike;

The process to R&R the axle seal is covered in the shop manual, but to answer your question, yep, the whole kit and caboodle needs to be removed to gain access to the seal. Actually, the seal replacement is somewhat an access convenience item to some larger job such as replacing the brakes or servicing the axle bearings. As long as you’re in there inspect both and replace as necessary.

dp

Posted on: 10/4 17:54
 Top 


Re: Zddp question
#6
Home away from home
Home away from home

DavidPackard
I recently read a paper on zddp, and in spite of hours looking for it again I’ve struck-out. The paper outlined the post war history of zddp, and went something like this, and remember the goal is to produce more power than the competitor:

1. Dependent relationship between power output, higher compression ratios, and higher-octane fuel
2. Higher octane fuel was achieved with an increased level of tetraethyl lead
3. Higher levels of tetraethyl lead could foul spark plugs
4. Boron based compounds were introduced/increased as a lead scavenger
5. Boron based compounds would also deplete zddp in the lubricating oil
6. To maintain acceptable engine wear protection during a reasonable oil change interval, the initial level of zddp was increased to anticipate accelerated deletion during use

As the public demand for more and more engine power occurred, steps 2 – 6 were repeated until the power output exceeded 1 hp/cuin, octane rating of the fuel was 100+, and initial zddp levels of 1200-1600 ppm were formulated . . . and then the cycle was broken by ‘out-lawing’ lead in gasoline, so out goes the zddp depleting boron compound. When the initial level of zddp was reduced in response to the new set of boundary conditions the gear-head’s hair caught fire!

If all of this has a factual basis then the ‘extra’ amount of zddp was to specifically have a sufficient amount during the entire service life of the oil . . . even with lots of zddp depleting ‘boron’ in ‘high-test’ gasoline. What I haven’t found is whether the oil change interval was decreased to accommodate higher load requirements imposed on the cam/lifters when those components were optimized for power output. That would be evidence that some engines did/do require elevated zddp levels, and the solution was merely to change the oil more frequently.

I would think without ‘leaded’ fuel the historic (pre muscle car) levels of zddp would be quite adequate. I’ve also read that below 3000 rpm this is an academic subject, even for flat tappet cams, so an over maintained Packard I8 engine, driven by a mature driver, may have herd immunity on this subject.

Posted on: 9/29 22:41
 Top 


Packard Plant Demolition Begins
#7
Home away from home
Home away from home

DavidPackard
https://www.bing.com/news/search?q=Packard+Plant+Demolition&qpvt=packard+plant+demolition&FORM=EWRE

Sad

Posted on: 9/29 22:30
 Top 


Re: 1951 wheel bearing
#8
Home away from home
Home away from home

DavidPackard
“Wheel off the ground” also means more tire to wheel well clearance, so you might remove the wheel and look for witness marks. The last forum member that had a one per rev noise in a rear wheel it ended-up a brake drum with a bend (repairable) in the diaphragm, so with the wheel off look for a ‘true-running’ drum. Actually, before you remove the wheel let’s go with your first instinct and grab onto the tire and try to feel any ‘slop’ in the bearing.

To answer your first question changing an outboard rear axle bearing is quite doable, but sometimes getting the hub to release from the axle can be challenging. R&R of the bearing itself requires a shop press. I believe the axle bearings are different junior to senior, and also believe both are available from Timken. Even a simple brake inspection requires the hub/drum to be removed. I suggest you use the ‘Advanced Search’ feature to read a few threads on the subject. If you find a failed bearing and replace it, you will become a student in the subject of ensuring the correct bearing clearance has been achieved. This site has a lot of documentation on the subject, and the job itself is quite straight forward.

dp

Posted on: 9/19 21:30
 Top 


Re: 1951 wheel bearing
#9
Home away from home
Home away from home

DavidPackard
Soybeanfarmer1:

Wheel bearings do not normally make a ‘metal to metal grinding sound”. There are several items associated with the drum brakes that may make such noises, but you need to do a bit of diagnostic investigations to figure out what’s going-on. Get the car on jack stands and start rotating the wheels trying to get more detail on what’s making the noise.

dp

Posted on: 9/19 19:07
 Top 


Re: 1952 200 deluxe with 327ci dies when warm
#10
Home away from home
Home away from home

DavidPackard
Mike52_200
Assuming there isn’t a haboob forming in your neighborhood why don’t you remove the air filter and take the car for a drive around the block . . . just to see if the symptoms change/go away.

IMO that filter is way too small (too much pressure drop) for a carburetor that is referenced to the atmosphere . . . it would surely be OK on a much smaller displacement engine, but not one of 300+ cubic inches.

Now if we return to the Carter overhaul literature, ever one of the ‘spec-sheets’ has a list of turn-up items that should be checked prior to condemning/messing with the carburetor. Have those items been looked at?

dp

Posted on: 9/15 17:21
 Top 



TopTop
(1) 2 3 4 ... 41 »



Search
Recent Photos
Boneyard 400 close up (11/30/2022)
Boneyard 400 close up
Boneyard 400 (11/30/2022)
Boneyard 400
1937 115c Touring (11/27/2022)
1937 115c Touring
Photo of the Day
1955 PACKARD DEALER POSTCARD
Recent Registry
Website Comments or Questions?? Click Here Copyright 2006-2021, PackardInfo.com All Rights Reserved