This may help youhttps://play.google.com/store/apps/details?id=com.Tremec.tremec.app Sent from my Moto E (4) using The H.A.M.B. mobile app
In other words - Chassis (or body) rake is irrelevant of pinion angle Is that a fair rephrasing of what you said?
Design your drive train correctly. Use this tool. Very useful. https://spicerparts.com/calculators/driveline-operating-angle-calculator
The common rule is 3 degrees + or - the trans angle Sent from my iPhone using The H.A.M.B. mobile app
The most important item to be concerned with is the U joint Operating angle, not pinion angle or trans output yoke angles. You can have some severe pinion and trans output angles if the U joint operating angles are within spec.
Using the same measuring device on both the manifold and the will give you a more accurate though subjective even comparison. You’ve probably been run off by now but the manifold manufacturer had their parameters for machining, maybe it is at 5 and then did anyone add some more? MAybe the bubble level is not reading the same as the angle finder
The obviously incorrect narrative- (Regurgitated endlessly) Trans 3* down Pinion up 3* Drive shaft up toward the rear 2* The results - FAIL
Well let’s at least correct the “wording” of the narrative, that might help. Let’s see as I explain it correctly Parallel verbally. Trans down towards the rear 3* Pinion down towards the rear 3* Drive shaft up towards the rear 2* Plug in the values with slope correction. Ok!! Now we’re at least Equal. Just dont ever drive your hot rod over 3500 rpm according to spicer. FAIL AGAIN!!! And those drive line angle looks like this. That drive shaft may even be uphill to the Diff more that 3-4 degrees. Keep her under 2500 rpm You’ll be good.
If it’s at all possible,,, You guys would be way better off to get selection amnesias and forget that bullshit narrative of “must be” rules. At least quit repeating it and quit posting this image for Pete’s sake. ITS COMPLETELY FUCKING WRONG @mgtstumpy and innocent guys think it makes sense.
Alright, I'll wade in here. I have built a LOT of cars, I don't worry about driveline angles while I'm building the car, only after when the car is near done and all the weight is in it, in the meantime, clamp the rear end onto the springs as you would before you would weld the spring plates to the axle, but do not weld yet, just clamp the assembly tight, WHEN YOU'RE READY, the car is near done, I'll check the carb mounting base for level. Car on all four, then check the tranny tailshaft for angle. Then I'll set the rear yoke to the opposite angle as the tranny tailshaft, eg. tranny down 3 degrees, rear yoke up 3 degrees, clamp it all tight, weld spring plates to axle and drive off for the first time. It's the way I've always done it, my 36 is twenty years and 100,000 miles old, and has yet to have u joint hassles, out of the dozen cars I've built, no issues either. Do what you like, it works for me.
I’m guessing by the rake and stance I see here that your drive shaft is relatively level. I don’t imagine any large elevation difference between the rear end and the trans output shaft.
No need to rephrase my statement but please, can you explain how "body rake" contributes to a failed U-joint operating angle. The entire drivetrain are components of the chassis and the only effect the body will have on the equation is the weight it represents. That's why it is important to preload the total driven weight on to the chassis before setting the pinion angle. I have always relied on parallel placement with opposing angles between 2-4 degrees and correct phasing of the U-joints for street driven vehicles. Seems to work best for any expected compression or rebound. I never paid any attention to the chart posted and know that a chassis set up for strip use takes into account several other factors and is not an exact science. That's my take and I might add, I respect your opinion and persistence on educating those who need the advise.
Slope is always read left to right, Always and that’s a rule! Any two lines that are on the same slope are parallel. Also Parallel lines are on the same slope. Always and by definition that’s a rule too ! Since Mostly the goal with drive lines is to get the center line of the trans out put shaft and center line of the pinion gear parallel, we aim for the same slope. Slope always expressed left to right Engine down x degrees Pinion down x degrees This is a pinion gear It’s shown at 3* down slope This is a rear end housing holding the pinion gear and it’s slope is down. Slopes down This pinion gear is sloped up
That may fly with cars that only go a quarter of a mile at a time at full throttle but in the real world creates excess U joint wear and actually puts the driveshaft in a bind while cruising on the highway. Dragrace bench race stuff doesn't actually work on street rigs that you are going to try to make several hundred miles a day on road trips with. Only applies with the drag racer bench racing bunch. Not really applicable to normal street driving. If you trailer the car to the track and back and never street drive it you would have a traction setup on it so the springs didn't let the axle wrap anyhow. More spit and whittle club BS than fact .
Well that’s why I rephrased. “Body rake” could be established by shims. Shims between the body and chassis. Or by wedge channels and changing the angle of the body in relation to the ground and the chassis. Any of that would have no effect to the chassis. As soon as you tell me that chassis rake makes no difference to pinion angles that’s when I’ll tell you. You might need it. Btw - this is a highly conflicted statement. I have always relied on parallel placement with opposing angles. Opposing means opposite
First off, you can rephrase your statements, just not mine. Secondly, I never said this - "chassis rake makes no difference to pinion angles". Thirdly, when I say "opposing angles" that simply translates to + or - in relation to the centerline. It's beyond me how I can state it any clearer.
Yes Vick, the driveshaft in my 36 is just about level without hardly any deflection, as I said, nearly 100,000 miles on the u joints in it with no issues. Now, having said that, I chased a vibration till last year that turned out to be a slightly bent driveshaft that was custom made by a driveline shop, bolted in and never removed till last summer. Never thought to check it, because it was supposed to be perfect, but even still, that had no effect on u joint life. However, on my roadster, the driveshaft climbs uphill from the trans to the rear end, with several inches difference between the two, I set it as described, and have no issues, smooth as glass at hiway speeds.
Those people who make the U joints tell us what’s acceptable for their product. I went thru it above and screen shot the all the results. A result of 5* is good for 3500 drive shaft rpm. If the vehicle is built and geared for highway cruising speeds of 60 mph with a 2000 engine rpm target then you’ll need to be reaching road speeds of 100 before reaching the maximum manufacturer set limits of driveshaft rpm. Change the mix of gearing in a build and we could see easily 3000 rpm at highway speed and simply passing a truck will exceed the manufacturer set limits. Nobody in their right mind should be driving their hot rods on any American roadways at 100 Mph. The problem is that nobody who’s completely in their right mind owns a hot rod. My point is that the so called rules are not. And Strictly adhering to these “not rules” can actually cause problems. Lowered vehicles present unique situations. Even if those problematic issues are only 100% purely visual. We go thru a lot of efforts , spend stupid money and make compromises to get the looks. For instance vintage look tires. It’s way way way Cheaper than tires to have your intake milled to keep in compliance with the “not rule” of carb must be level and build a car without an engine that looks like it’s falling out and a on the edge Z shaped drive line.
that's how ive always did it ! cant see why to do it any other way ! and call it positive, negative, or make up a word . the u joints only cancel each other out one way .not talking brain surgery !!! and it looks to me like the a is probably close to perfect . cant see the angle of the pinion but it appears that the driven shaft is about as parallel as you could want !! but hey we could go on ...and on . traction bars might help the axle wrap to !! just sayin
now we have some OEs phasing driveshafts as much as 30* out of phase. just tossing that one in for the crap of it
Additional info please. What manufacturer is doing this, what vehicles, or photos? Doesn't make sense to do it at all to me.
I always build at ride height, stance and tire size it will have when completed the last one had 2* down for the engine, 0* driveshaft and 2* pinion angling downward or up at the yoke. I like stupid low stuff which usually means raising up the engine I like to save the rear end welding for last on finalizing the pinion. I also like 2 piece drive shafts with low stuff, solves problems I like to build with a 1/2 inch spacer under the trans mount and hanger bearing (if used) A little adjust ability never hurts
im checking into it our school just purchased some new buses, the mechanic showed me an out of phase steering shaft. he also said the first drive shaft was also out of phase. trying to look up why
see , I knew we could go on awhile more .! I think in a steering linkage iif you have a sliding yoke , you could get away with a bit more than something turning at 4000 rpms but wrong cant be right! right?
a google search had a lot of pics and 4x4 guys asking the same thing one guy had a pic of a driveshaft over 40* out of phase I was hoping you guys could enlighten on this phenomenon
I have seen people say that when you lift a 4x4 , 6 - 8+ inches you should point the pinion at the trans. tail housing .cant see u joints lasting long ! . I think they do it because otherwise the shaft needs to be lengthened . but sure cant be vibration free !!
as far as the steering shaft out of phase, it doesn't turn fast enough to have any issues with vibration and shouldn't bind. It does have a slip yoke our diesel instructor is also trying to figure why the drive shaft would be.
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