Thread: Another driveshaft question. Side to side angles?

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With the trans centered in the car, and the pinion offset to the right side, how much do these angles (left to right) affect the driveshaft?

I have heard that the drive shaft doesnt mind these sideways angles, but my specific question is does this minimize the importance of the up and down angles of the trans and pinion?

Thanks

On a street car, a line extended through the crankshaft and a line extended through the pinion should be parallel. The pinion or the engine (or both) need to be offset horizontally or vertically (or both) enough to give about a 3 degree angle between those centerlines and the driveshaft.

I guess you're asking whether you need any vertical angle if you have a good 3* angle to the side. The answer is no.

Originally Posted by Henry Rifle

I guess you're asking whether you need any vertical angle if you have a good 3* angle to the side. The answer is no.

So tell me this-
Can the trans point down a few deg. and instead of the pinion pointing up (parallel), can it point down a couple deg.?

This is an absoulte no no normally.

Dont ask , I was just wondering.

No is the right answer.

Don

Well Itoldyouso, you told me so!!

You getting of my dumb questions yet?

I am making good progress.

Thanks for your help

The answer to your next question is also no.

Got this off of Denny's Driveshaft site!

Angle
How much driveline angle is right for my application?

Thats a loaded question. The best answer is....the least amount of driveline or u-joint angle is the best amount of angle. Try to achieve the least amount of u-joint angle but don't make it less than 1 degree. A little known fact about u-joints is that they require about 1 degree of operating angle to get the needle bearings rotating. If they do not rotate they will fail. Too much angle will also cause them to fail. The type of rear suspension also plays a big part in setting the angles as well as the engine/transmission angle. Leaf spring cars have a need for more downward pinion angle due to spring wrap-up while coil spring cars control the situation better. Hard acceleration as in the case of a drag race car requires a different setting than a street driven car. Traction bars, ladder bars, 4 links, independent rears all have special needs and requirements

http://www.dennysdriveshaft.com/freq....html#faq_id25

I told you so is right. The centerlines for the transmission output shaft and pinion should be parrallel. I was told by a GM design engineer best to keep a 0.5 degrees difference for my application. My rear doesnt move. IRS. Also dont forget to put 2-3 degree angle on the tranny and pinion.....to allow the ujoints to cycle. Got most of those answers from these guys on here though!


EDIT: LOL's. Sorry Jack. You already answered. I'm going to have to tone down on the coffee. It doesnt mix with my speed reading. LOL's.

Dave G

More coffee, more answers, its all good.
Thanks

I've done a bunch of drag race only cars with a level engine and 3* down on the pinion, both 4 bar and ladder bar.... Probably not reccomended for the street, or whatcha think????

Dave, by level, do you mean that the carb flange is level? If so, doesn't that give a 2* or 3* down angle on the crank centerline?

That being the case, the line from the pinion and the line from the crank would intersect instead of being parallel. This is what most driveline shops recommend against.

However, it's hard to argue success.

Yup, I always make the carb flange level and let the crank centerline fall where it will.... I usually build in some height adjustment for the engine to change the chassis weight around a bit.

Don't think I'd do a street car the same way, but it sure works slick on a drag car..... With the chassis lift, things change on the angles, going to plot all that out someday. Big thing I suppose is that it's only 1/4 mile at a time and wear over an extended period is irrelevant---I replace the U-joints every 100 passes on an automatic, and 75 passes with a stick car........

On street machines and street driven Hot Rods, I do apply the more accepted angles on the driveline.

Don't know why it all works, but it works......

Well Gents, take a look at these drawings and tell me what you think.

This is just about what I have.

Wow! A 15 degree angle between trans output and driveshaft is at the ragged edge of any recommendation I've seen. Universal joints are generally designed to operate at 5* or less for maximum life.

Any prediciton on this one is outside my range of experience - or comfort. However, I don't think you have much choice.

More info here:

http://www.iedls.com/IEDL_PTS_LGL_091008_Secure.pdf

I raised the motor up 2 inches and the working angle changed to 8 degrees.

Any higher and I wont be able to see over the bellhousing.

Any other comments or suggestions?

Thanks everyone, its real comforting to be able to talk this over with all of you.

It would be even more comforting if someone said "Oh, that simple, just ...."

Originally Posted by maddddog

I raised the motor up 2 inches and the working angle changed to 8 degrees.

Any higher and I wont be able to see over the bellhousing.

Any other comments or suggestions?

Thanks everyone, its real comforting to be able to talk this over with all of you.

It would be even more comforting if someone said "Oh, that simple, just ...."

Wow. Thats darn near what I had to start with. LOL's. I decided to raise my engine/transmission more as well. Really wanted to keep a flat floor. Oh well. Its permanent now. Finally getting the floor welded in.

Here's another place I found usefull. A buddy uses it to work on semi-trucks. You can download the trial version....use it for your application.....and delete it from computer. I did a few months ago. No problems....no spam email.

http://www.vibratesoftware.com/

Of coarse....you dont have to have the software....but I found it to be a good teaching tool. Allows you to change things around for different scenarios.
Dave G