My 29 roadster ch***is already has the T-5 and Frankland rearend installed. No driveshaft yet. I looked up diagrams and asked others what is the correct installation angle for the driveline to rear-end to transmission connection. Here’s the chart that expresses this issue. In other words angles A and be can be no more than 3 degrees or less. Is this correct? Any other caveats? Thanks.
Equal and opposite angles, at ride height, for a single drive shaft setup. If trans is pointing down, pinion points up at an equal angle. Imaginary lines drawn between the two should be parallel. Three degrees is a typical factory carb pad angle, allowing the carb to be level with the rear of the engine pointing down.
Please do a search here for past threads on driveline angles. You will get a lot of opinions and see why @Bandit Billy 's post is relevant.
If one is ever concerned about this matter, all one has to do is look at a stock 1960s Ford SWB F100. And yes….. Whatever you do is ……. Wrong.
Is there another subject that has been covered ad nauseum as much as this one? Search. Search. Search. (That's the little magnifying gl*** on the upper right.)
Who cares that a question has been asked several times. How many times has anyone asked a parent for something but didn't get what they want and went to the other parent to ask the same question? Has anyone used the search feature and got a lot of nothing that answers the question but they come up only because the answers contain a word that you're looking for an answer to so you need to sift thru the answers? It's frustrating, isn't it? "AIRBORNE!" Sarcasm intended.
This topic keeps popping up with the same answers. There is no "correct angle" for drivelines. The angles of around 3 degrees might be wonderful, but even 8 degrees wont hurt a darn thing. As mentioned above the critical, and most important part is the angle at the trans and rear pinion must match and cancel each other, and the angles can't be so great as to put the U joints in a bind under normal travel. That's it, nothing more.
Max operating angle for a single Cardan U joint is 13 degrees, a max difference of 0.5 degrees end to end.
This is what works, having the output shaft of the trans and the yoke and the pinion shaft parallel with each other .
You tube has videos of IMCA modifieds circle track race cars with cameras mounted to see rear end movement. Once you see one of these you’ll never worry about this subject again. The drawing above is all we need to know.
And there’s no law saying it has to look exactly like the pic. The rear can be higher than the engine/trans centerline. Thay can dang near point at each other Just keep the angles “parallel” rears mounted on parallel leafs will generally not have those parallel angles when parked. Not on the OE stuff I’ve measured anyway.
I've used this App on my phone to insure the correct driveline angles. https://tremec.com/aftermarket/tremec-toolbox-app/
If you guys are going to bark at each other, instead of constructive replies to ***ist I’m deleting the negative posts. If your post got deleted, don’t repost it. Thank you, Moderator
So ideally if the output shaft is pointing down 3 degrees the pinion should be pointing up 3 degrees so they running are parallel?? Many manifolds have about a 3 degree angle in them so if you want the carb level the engines angled down in the rear. .
I'm no expert nor did I stay at a Holiday Inn, but Anthony (and others!) above stating that the two imaginary lines from the engine/trans and rear yoke angles being identical is right. In addition I've seen stated that you also want no more than 3 degrees of driveshaft angle between those two points. Some angle is good for bearing rotation in the U joint caps but not too much. This is what gets guys who do cheap lifts on their trucks and push their driveshaft angle too far, eventually destroying stuff. One other thing I have seen stated is that with leaf springs you want the pinion angle to be a little less than the engine/trans angle to allow for spring wrap on hard acceleration with good traction. For example the numbers on my car with leafs are engine/trans: 2.7 degrees down, pinion yoke: 2.3 degrees up and driveshaft angle between the two points is 1.2 degrees. That gives me -.4 degrees for spring wrap. It all works nicely, no vibrations and smooth up to a quite a bit over the interstate speed limits here (for science, obviously!).
If your angle is p*** the recommend U joint working angle you will need To adjust . Tail shaft Or Add wedge deg's Or change spring mounting pads and Reweld on axle tube. Same with Triangular 4 Link or ect.
DOWN. The inclination of both the output shaft and the pinion shaft are as they slope from the front to the rear. It can quickly become a very confusing conversation when this is not described correctly. The diveshaft should make the same angle with the output and pinion shafts and the angle should stay within the operating limits of the uni joints.......when the suspension is at full compression and rebound. Somewhere around the 3 degree mark at ride height is seen as good. And don't forget to make sure your universal joints are phased correctly.
I’ve seen a video of a super mod as you mentioned, and it is amazing how far from parallel they get. But, I think they fail to mention the lifespan of the ujoints when they are used like that. We hope they last the lifetime of our hot rods. The racer hopes they last a few nights, or maybe a season at best.
The pinion is sometimes set at a negative angle relative to the transmission output shaft to compensate for pinion climb under hard acceleration. As the front of the differential rotates upwards, the pinion shaft becomes more parallel to the Output shaft. This gives better alignment when the system is under heavy load (eg: drag racing).
The Jalopy Journal
