drive shaft angle question
 

While starting to change my differential, I noticed the drive shaft is at a 5 -7 degree (an estimate) angle from the transmission to the differential. This angle is from the left to right side of the car. This seems odd to me...Is this a normal on the BDR cars?

Do you mean side to side or up and down. Mine is up in the air now, I'll look at mine tomorrow.

Trueoo7,

It's side by side...not up and down. Let me know what yours looks like.

Thanks for the reply.

Bill

This web site has usefull information on driveshaft angles.
http://www.dennysdriveshaft.com/
hog

Bill
I would have to say thats normal based on mine. Driveshaft at the rear of the tunnel (Diff end) looking back to front, closest point on the driveshaft to side tunnel is 1" (right side) 2 1/2" (left side) It does not sit exactly in the middle of the tunnel. The front end of the driveshaft (tranny end) sits exactly in the middle, just shy of 1 3/4" each way to side of tunnel. So if your looking from front to back my driveshaft drifts to the left or passenger side of the car.

Just noticed that my driveshaft is missing the grease fitting for the back universal. Just an empty hole. Thanks for making me look.

I wonder if this could be caused by placement of the body on the chassis.

This is caused by the fact that the crown wheel in the diff causes the pinion to be of center.It is quite normal for the driveshaft to be at an angle,and to minimize any vibration the angles should be the same at both the tranny end and the diff end.

I noticed the mounting plate for bolting the driveshaft safety loop on is also off center. I figure this lines up with the diff driveshaft connection meaning the driveshaft is expected to be at an angle.

The diff is not made symetrical and the engine and trans are, but it is not off by much and nothing to worry about. A straight axle car goes way more out of center than our IRS setups. If this freaks you out take a hard look at your steering column geometry. :JEKYLHYDE

I agree 100%...what the heck is this all about? You can feel the steering wheel U joints...but the they are not rotating at 3000 rpm's with 300 ft# of torque!

The point is that the angles of a steering column are very extreme in comparison. And while the torque is not the same, neither is the importance. Think about the load on your front wheels and steering column doing 100mph around a series of turns. I would rather be pulled over to the side of the road rather than overshoot a turn and wind up in the trees.

I agree...but, are you saying this is a safety issue on the BDR car?

No...not at all. What I am saying is, since we were previously talking about shaft angles, that the steering of most any cobra has very extreme angle and work perfectly fine. In other words, don't worry about the drive shaft angle because there are others more severe. I am going to be glad to put all that through the test in just a few more weeks! :D

You would not believe the drive shaft angles that my Jeep goes through when flexing offroad. With a Klune-V 4X mutiplier that makes low-low at 10.88:1 (2.72:1 Low X 4) there is an unbelievable amount of torque being applied at even extremely low speeds.

U-joints and CV joints were invented to handle non-straightline driveshaft situations.

The angles that we are looking at on Backdrafts are so small as to be inconsequential.

Look at the pic below of my Cherokee, if you want to talk driveline extreme angles.

http://i45.photobucket.com/albums/f8...aGOODthing.jpg

Cheers!
Dave

Could the offset be the little "thump" I get in the seat of my pants on most upshifts? Visual inspection up in the air shows nothing hitting the tunnel, it seems. I have learned to live with it, but I still don't like it.

UT

uncltodd

That little thump you get is your wallet letting you know that you have an expensive cobra with a Kieth Craft motor. HA!HA!

DON

While esthetically more pleasing to be in a straight line the offset to the left/right depending on your perspective or the vertical offset from the transmission's output shaft has little significance for us. The important consideration is that the angles are equal at the trans end and the pinion. When the angles are not equal there is a nasty vibration that will ultimately lead to parts breakage.

If you are a scratch builder or motivated owner you can correct the "misalignment" by rehanging the center section to put the pinion shaft in "proper" alignment with the transmission output shaft. When you have completed the rehanging you will have to have a custom set of half shafts made to fit the new center section location.

From drawings and pictures I have researched it appears that the originals from the sixties had a similar "misalignment" however I have seen pictures of originals that appeared not to have the misalignment. Running change, photographic angle? I don't know. If there are any owners of originals out there I'd love to know how your driveshaft angle appears.

By the way the equal angle thing is easy to accomplish without space shuttle equipment. The equal angle means the center line of the pinion shaft is parrallel to the centerline of the transmission outputshaft. Although parrallel it can be offset either vertically or horizontally as long as its centerline is still parrallel to the centerline of the transmission output shaft.

For what its worth I was not a happy camper when I saw my driveshaft offset, but the cost to correct it and the benefits were tilted the wrong way towards the cost. Mine is still offset.

Ed