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ok im building a 32 as some of you guys already know , my question is i got a winters quickchange and a muncie trans , the driveshaft seems to have to go on a big angle to connect to the rear since the yokeis located low on quickies , what is a good way to set pinion angle when the drive shaft has to dive down pretty far ......
3 degrees down works for me...
what about the driveshaft pointing down a bunch of degrees is that normal ?
Well, with the low pinion on a quickie, has to be that way. Look at the driveshaft angle on some of the 4WD stuff......
Dave, most of the severe driveline angles on 4x4's have a CV (constant velocity) type driveshaft.
Godspeed32, Is their anyway to rotate the rearend housing (pinion snout) up? Thereby decreasing driveline angle? If not, you can look into a CV type drivleshaft.
I am not really sur ewho could give you all of the information that you would need, or where you can get one.
I set the car on the ground - or at least mock it up at ride height, with the pinion yoke set at 0*. Then I measure the down angle at the transmission yoke, and bring the nose of the pinion yoke up until I have the same angle.
If you really want to dial it in, measure the angle between the output shaft of the trans and the driveshaft, then between the driveshaft and the input shaft of the pinion. Both angles should be equal, and between one and three degrees.
It's important to have the angles equal because U-joints are not constant velocity. They actually slow down and speed up as they rotate. Making the angles equal causes them to change velocity at the same time and it eliminates vibration. If the angles are unequal, you're looking for trouble, vibration and wear.
Take a look at this: http://www.iedls.com/ptsetup.html
Generally, you want the pinion pointing up about 3 degrees, and the tailshaft pointing down 3 degrees. They don't need to be aimed at each other, and in fact it is preferable if they don't. You want the u joints to "work" as they rotate.
Don
me to:D it works good on chevys to dave:whacked:Quote:
Originally Posted by Dave Severson
Like Don sez, the joints must '"work" as they rotate. A driveshaft that runs straight will eat u-joints in no time. the rollers wear into the cross in one spot, and there's no movement to spread the grease around.
All good advice -
Another item to consider is to make sure your driveshaft builder times it correctly - I recommend someone like Denny's in Syracuse, NY to manufacture it to take your engine power.
They had an internet special on the HD's when I bought mine and it was enough to pay my NY sales tax and shipping and then some. Their aluminum pieces are pretty but I'm not convinced they are worth the extra $100+.
Dave,Quote:
Originally Posted by Dave Severson
You point both the tail of the trans and the nose of the pinion down?
Here is Tom Woods' Driveshaft 101 link.
http://www.4xshaft.com/index.html
go to "tech info" and choose "Geometry 101"
The info applies regardless of the type of car/truck.
Tom also builds really nice driveshafts.
mike in tucson
Quote:
Originally Posted by Henry Rifle
The trans should point down 3 Deg and the pinion should point up 3 Deg, cancelling each other out for smooth stop-start mechanical transitions. Pointing them both down is an invitation to U-joint failures thru bind.
With the car level and the crank down 3*, I try for 2* up on the pinion. That way when you're cruising, I figure the engine torque will pull the pinion up another degree or so and you'll be flush. If you lay 'em both in a 3* down/up, then you're gonna be way out when the car is under power. At least that's the way my feable mind sees it.
Compensating for under load conditions sounds like a good idea to me. I would want to dial it in dead nut at common cruising speed and hopefully still be within tolerance coasting and under full load.
There's a few painfull ways to do this. Inductive proximeters or optics come to mind quickly. Cheaper would be to strap on a dial level and have the neighbor or brother in law open the door and stick his head under the rod while we're going! :LOL:
You guys do that and I'll just use my $1 dial level and scab mine in and run her 'till she shakes or breaks! :LOL:
Kitz
It's funny that you should mention that Kitz. I've thought about mounting a video camera under there to see what's happening.
Please read this in a positive manner - :LOL: :LOL: :LOL:
General specs are +/- a degree but the preferred angles by most "experts" in the field is 3* as I noted above. In cruise mode, my guess is that the road's surface makes any laser/machinists angle finder a moot point. But if anyone really feels that universal joint wear will be minimized by taking it to a small part of an angle, I'd like to see the final results. :HMMM:
Obviously, to run these tests, among many variables, you would need to take assembly tolerences(bolting, welding, etc), tire pressure and diameter differences, spring/shock assembly compression and rebound rates, differential weight patterns for other drivers and passengers plus the fuel in the tank into consideration.
As the price of a U joint is so very inexpensive ($15 - $20), and the fact that they will tolerate a lot of abuse, going to extremes, IMHO, is fun to consider as an engineering problem but really not worth my time:3dSMILE: .
(Though I would like to see a video of what is happening under there)
you do not want the pinion up you want it down .it will climb up and if it runs up bad things will happen on leaf spring cars . the leafs springs whined up pinion climbs up
Pat,
I'll agree if we're talking aabout high horsepower cars with a lot of bite and leaf springs. However, the car in question here is a street rod with ladder bars. Not much - if any - wrap on the rear axle under power with this setup.
Also, if you have the pinion down and the trans down and are not under power, just cruising, I don't think that's a good thing.
Just my opinion.
OK boys, it' all gonna be OK.
I think the parameters have been set here for a successful adventiure.
Peeace out, Kitz
It's all good . . . discussin without cussin
sorry i only work on hi HP cars? i will now pickup my marbles and go home the street ligths are on:whacked:
Pat,Quote:
Originally Posted by pat mccarthy
No, I think you're one of the most knowledgable folks on this board. I said it was just my opinion, and based on my knowledge and experience about the particular type of car he asked about.
i have been thru this i think its a very intersting post .i have seen stuff you would think ? no way in hell will that work and it will how long??the 4 wheel drive guys have proved it to me. i was just having some fun. now Henry please put the rifle down:3dSMILE:
he guys , thanks for the posts . to keep on track as henry said the car in question has ladder bars , 4 spd . 500 hp engine and a 3/4 quick change . the pic henry posted is dead nuts on what im dealing with . will that angle work is the question . to add im also using lakewood non greaseable u joints for strenth . if we can get this resolved peacfully that would be cool ...thanks so much for the efforts and input this is my first street rod build so i do have questions . all my other experience is with muscle cars ...
i hear crickets........henry putthe rifle away i need more info ....:LOL:
A rule of thumb that I have been told is to get them close to parallel, then test drive. If you get a vibration under acceleration then tilt the pnion down a couple degrees and retry. If you get vibration on deceleration then tilt the pinion up a couple degrees and retry. Repeat until vibrations are gone. With a ladder bar or 3-4 link suspension you should be able to make adjustments pretty easily. With leaf springs you can use wedges between the housing mount pads and the springs. If with the leaf springs you can't eliminate the vibration under both of the conditions, something to control the axle wrap must be installed. Please correct me if I'm wrong.
Pat
Damn it guys-----this gets argued about once every 2 months. For a street driven car, tilt the pinion angle up 3 degrees to match the down angle of the tranny tailstock. No, they don't have to be in the same plane, just close to parallel at normal ride height. If it is a drag car that will mostly see constant acceleration while going down the 1320, then set it up with the pinion pointing down 3 degrees. The wrap up in the springs, and frame torsion, will bring it up into line with the tranny tailstock while under acceleration. If you do much street driving with a dragstrip set-up, the universal life will be shortened, and you could have vibration issues.---Brian
Yep, short and sweet, what he said. I've had them close to ideal, and sometimes way off, and never encountered a problem. My Jeep with the 302 is a perfect example, I had to wedge it in there on a pretty steep angle to get the engine to clear the front suspension........no vibrations whatsoever.
Main thing is get a quality driveshaft built, with new components, and you will be fine.
Don
Brian,
Exactly.
Phew - I was beginning to question my sanity**)
Ya' know a nice high volume pump and a couple hydrostatic drive units would eliminate the whole problem :D :3dSMILE: :D :3dSMILE: :LOL: :LOL: :LOL: :LOL: :LOL: