The Jalopy Journal
Discussion in 'The Hokey Ass Message Board' started by TANNERGANG, Apr 26, 2014.
Well put Donnie !!!!!!!!!!!!
As the pot calls the kettle black
What a F*ckin IDIOT
I gave you the correct answer, i assume you didnt read it since i didnt post a copy of a 32 title. I do design driveshafts 40 hours a week, but not for 32 fords, sorry i couldn't be of help.
Tannergang, First impressions are a real big deal on these forums.
If you go back and re-read your first post, it really sounds like you're putting a chip on your shoulder. You took an offensive position from the word go, and that's going to stir up chit. I guarantee it.
I understand that you would like to limit the annoyance of silly and irrelevant posts, but the way you start off accuses people of that before the fact, you see?
I believe that anyone who starts off posting something like, "I only want to hear from Eskimos and snake breeders," you've implicitly marginalized the contributions of everyone else on the forum.
That is to say, you've labeled their advice as worthless before it's even offered.
That kind of approach is just gonna raise hackles no matter where you go.
That's how he treats people he doesn't need.
And I know, I know, da34guy. I'm a fucking idiot.
Sometimes people just act strange when they're out of their comfort zone. I find that typical of most folks my age when confronted with computers, for instance.
Or perhaps he's a total misanthrope.
But I'm not gonna act on that assumption unless I get out of my comfort zone.
Is it safe to say when the vehicle (any vehicle with leaf springs) is under acceleration, the driveshaft should be parallel to the ground?
That brings up why some shafts could be level and many are not, while still being correct. And, those differences would be found on comparing many "32 Ford coupes".
The angle of the driveshaft to the ground is affected by the ride height of the chassis, rake, tire dia, how high the motor sits, etc etc. No two 32 "driveshaft angles" would be identical unless every detail in the build is matched.
And that makes the statements in post number one, totally invalid.
It's the working angles of the "cross-type" joints, not the angle of the shaft to the earth.
A cross type joint needs some working angle to keep the grease moving under the needles, but not too much angle to cause vibrations. Any amount of angle in a cross type joint, will cause the driveshaft to spin in a "non -constant" velocity.. the shaft actually speeds up and slows down during each rotation, and the difference in these speeds multiply with increasing angles.
But what the F do we know.....
No, some could be, but its not safe to say that.
Here's an exercise in understanding the concept .
If there were need of a drive shaft in outer space where there is no gravity, no levels and no ground, could you set it up?
What if the car was hanging by the left front wheel in a tree?
The angles are relative to each other, that's the concept. We use 5.00 gravity powered instruments to get there m
I see..... At least the thread is making more positive progress now.
Wait....wait...wait, me too, I got a 36, but I was at a car show where I saw a couple 32's, then some guy told me I couldn't respond. Relax pal, you asked a fair question, then set yourself up for some abuse, hope your question was answered to your satisfaction.
What do you mean by neither a '32 or a Ford?
He means it was not manufactured in 1932 or by Ford. It is a shot at the fact it is a fibreglass car.
Sticks and Stones.............it drives like my Steel '32...it looks like my Steel '32...most people think it's a '32.....the same parts that fit my Steel '32 will fit it.....I didn't think about putting it was Tupperware in my discription....lets see....I should have worded it...I have a fake car that has a vibration in it...the wheelbase is???...the engine is 350 Chevy..the transmission is Turbo 350..it has a REAL FORD 9" rearend......has anyone got any suggestion to what it might be other than the Tupperware vibrating when I go down the road?..........I'm just about over all these .....well I'll just stop there.
Yeah yeah whatever- let's fix your car then worry about the other shit.
My car probably had more Tupperware on than yours lmao!
is this a new problem? A new to you car? A new build?
Trying to establish some history here.
What tires are you rolling on ? What do you know about them? How do they look, feel, wear?
Does your car have any rake to it?
How much ? Angle finder on the bottom of frame rail but make sure the ground is fairly level.
What's the rear suspension set up/ style?
Now help me test drive your car-
Where do you feel the vibration? I. Your feet, in your butt, in the steering wheel?
Does the vibration change if brakes are applied?
At 60 lightly apply brakes and increase throttle to maintain speed- what happens
At 80 do the same - what happens.
Does it still vibrate on WOT acceleration from 0 up to 80
Drive up to 80 ( or where vibration stops ) and note Rpms.
Drop Trans to 2nd and engine to Rpms same as noted above- what happens?
Increase speed to 80 in second - what happens?
I do not currently have a 32 but I have owned and built more than one. I have set pinion angles.
4 pages, you need an answer.
This is how I would do it and it works. Raise the car so that the weight is on the springs as if it were setting on the ground. Pull the starter, take a magnetic protractor and attached it where the starter mounts to the block, note the degree and write it down. Go to the rear end yoke and some how take a reading and write that down. The pinion should be down anywhere from 2.5 to 5 degrees. I have read a lot of opinions on this and I do not know who is correct but if you are not close then change it. Maybe shim it or adjust it, drive it, and note if it gets better or worse. When you find the sweet spot, measure the angle, cut the pads off or adjust the rear, and set it to the angle that has fixed the problem.
This thread got stuck on the drive shaft thing for a minute haha. I have driven, repaired many and built one 32 roadster from scratch, chassis, body, suspension (new panels from brookville, rails from ASC ect.) So i guess I probably qualify better than some one that owns one. My thought was if you're not seeing any vibration until you hit 65, it's probably not the driveshaft. Have your tires checked and balanced its cheap and easy and the smartest place to start with slight vibration issues. If it was a driveshaft it would keep getting worse the faster you went. Could be loose suspension joints as well. Or get your driveshaft balanced. what ever floats your boat.
Plain and simple is that any car with suspension as previously mentioned needs some working angle to keep bearings happy but also very close angles where they will reside most of the time, at ride height. An out of balance or bent shaft will vibrate but the worst culprit tends to be unequal angles on each end or U joints out of phase.
The link provided by blowby should be required reading before anybody can post anymore drive shaft/pinion angle threads. http://www.youtube.com/watch?v=gmV4qwLfOMY
The angles should also be opposing each other so that they lose or gain angle at the same rate through movement of suspension. I know there are drag only cars and sky high 4 wheelers that oppose this but practicality and longevity may not be their main goal.
Other things to consider, angle is angle and if you happen end up with everything in a straight line front to rear but the rear yoke is off center you're U joints don't know the difference, it will still work. Too much angle wears U joints out faster and a link suspension behaves a little different that parallel leafs. A 4 link and long ladder bars see very little deflection at the pinion where a leaf spring may wind up a bit even with a light load so an extra degree down at the pinion might not be an issue.
Also a vibration could be as simple as an out of balance engine, tire or drum/rotor.
Ok...here's what info I could get between waiting on customers...
STARTER -2 DEGREES
DRIVESHAFT +1 DEGREES
PINION +2 DEGREES
FRAME CHECKED UNDER DOOR IS 4 DEGREE RAKE
VIBRATION SEEMS TO COME IN AROUND 60-65 AND STAYS TO ABOUT 75-80 DEPENDING ON ROAD SURFACE....IT'S MORE OF A HARMONIC SOUND
Hot rods with a rake are kind of special when it comes to measuring the drive line angles. You need to be very aware of what you are measuring exactly and what that means.
If you want the over regurgitated 3* Trans tail down
You want a 4* rake nose down chassis
You have a 7* discrepancy between the engine and fire wall.
This is aesthetically horrible.
So what do you do ?
You Gotta think on that to get it right both function and form.
Ok here's another hot rod oddity-
Your chassis is done , everything is fine but now you decide you want a change and throw a rubber rake on there.
So the nose goes down & the ass comes up on the chassis the same chassis the engine is bolted to. For example- the chassis rides about level and the engine is 3* Trans tail down. Now with a 4* rubber rake the Trans tail is actually 1* up put your pinion angle don't change much with the rubber rake. Now you have the makings of a vibration issue.
What do you do?
Dropping the Trans tail 4* down is likely to crash the engine into the fire wall someplace, torque up your exhaust pipes, maybe stress the relationship between the radiator and engine.
There is more hot rod oddities but these two are the biggest problem causers and the 3* up 3* down bullshit just don't fit into some of these packages.
Some say the carb flange must be level front to back. Please tell me why it MUST be level.
After you do I'm going to ask you to explain how your car can run up hill for hours on end, or how could you ever navigate a parking garage. I'm sure I might here the manifold is milled at 3* so the level carb flange and 3* down go together. Fine but now ill ask you what the guys running blowers are supposed to do because they can't get both level and 3* down and as far as I know no manufacture has ever made a blower carb plate that's wedged.
You can set your engine at 0 and set the pinion at 0 as long as one is above the other. Like a deep lowered car. The pinion is way above the Trans tail. You can set both at zero if the Trans tail and pinion are not both on center. Both of those situations induce a working angle into the u joint.
You can set the Trans Tail up and the pinion an equal amount up or down- equal is the important part. So what happens if you just can't get any of this to happen, you'd use a CV joint or double cardan or a 2 piece drive shaft.
Sound from harmonics will get weeded out in my test drive.
So far all above looks normal. Your 9" still have an offset pinion or was it centered ?
9" has offset pinion...........I also have Hoosier 31.5 x 12.50 tires on 15"x10" wheels.......next week I'm downsizing to 17"x9.5" with 265/70/17's.....I think some of it is the road surface patch being so wide......maybe a narrower tire will help
Usually not tire general tire noise if its 60-80 mph related. Could be shitty tire noise though.
The test drive will shake out if its rotational relative to wheel speed or related to Rpm, engine Trans or drive shaft
Engine is generally nose up on most cars possibly to help oil draining but more importantly to prevent air pockets in the heads, at least that's my philosophy. Also the frame angle/rake is completely irrelevant to U joint angles.
If I've got TANNERGANG's numbers right at engine down towards back at 2 deg., drive shaft up towards back at 1 deg. and pinion down at front 2 deg. he has working angles of 3 deg. front, 1 deg. rear. A difference of 2 degrees that may get worse once he and a passenger get in the car since his angles are not opposing each other to begin with. Sounds like the car may need the pinion rotated up in the front but it could cause the angles to be excessive unless the transmission can come up some?
Would the pinion up or down another one or two degrees help?......trans. can't be raised any more.
To be honest I'm not sure. The angles would be closer but still with the lines running in an arch and not the preferred Z. Guess what I'm saying is put one joint at an angle and the other end starts to cycle as in the demonstration. Put them at the same angle but in a Z and it cancels out. Take one and flip it the other way and does it still work or is it just compounded and off more? Even if it does help the car may change angles when loaded since the equalizing factor is lost with the U joints not in a Z configuration.
I've never seen such an easy chassis setup become so complicated so quickly. First, it doesn't matter what rake the car has, pull the driveshaft, put an angle finder on the end of the trans tailshaft, mark how many degrees it is pointing down, then put your angle finder on the rear yoke in the same method, it should point UP by the same degree. If the two are opposite and in a parralell plane, bingo bango, you're there. If not, make it so.
Too much difference will give your car a hum at speed you can feel in your ass, furthermore, it don't matter if this is a 32 ford, 59 Cadillac, a Yugo, hummer, the principle is the same.
All this info is widely available, its really difficult to diagnose symptoms without an actual ride, better yet, an actual drive, this could be a number of things, having a plastic car certainly isn't one of them. Good luck.
The trans tail shaft is -2 degrees and the pinion is +2 degrees..............
Separate names with a comma.