Not sure what all the arguing is about, the way I see "equal but opposite" is both working angles at either end being same-equal and opposing angles-opposite. The "absolutely not" pic is piss poor as both ends would not gain and lose angle at equal rates through changes in height, just the opposite would happen. Also feel that "perfect" in the pics is anything but, except in a dedicated drag car. Little friction, though brinnelling of the bearing surfaces would occur with extended use.
Actually it would be the second from the top diagram. You have the angles that I used in my statement used incorrectly. Read what I posted again and I think that you will understand.
Great , hope they help. I sent yours to your shrink - Now as far as using angle finders go - Lets say a guy is going for a parallel set up on his drive shaft angles . The car is on level surface & at ride height The trans and crank center line would usually be around 3* down to the rear. The pinion shaft is also 3 * down to the rear since its parallel . For some reason this is repeated over and over 3* down and 3* up .... With no mention of the reference or more importantly the change of reference. I believe this is where your radio comment comes from . Some how magically when the guy turns around and flips the angle finder around from the trans to the pinion all of a sudden it's 3* up . Just for grins lets say he wants equal and opposite set up - We have an engine/trans CL at 3* down to the rear The pinion goes which way ? He's got one drive shaft on a jacked up 4x4 and one drive shaft on a lowered slammed custom
I copied this from Currie. According to Currie, “a street driven vehicle should strive for between 1 and 3 degrees between the transmission and driveshaft, and 1 to 3 degrees between the driveshaft and pinion. Furthermore, the two angles should be nearly equal (between 1 and 3 degrees), but always opposite.” Otherwise stated, ideally, the angles between the transmission output shaft and driveshaft, and between the driveshaft and the pinion will be equal and opposite and 3 degrees or less. See the example below.
Im just trying to make people understand that these relationships are based on the driveshaft only, not the vehicle at ride height or sitting on level ground.
Yep I understand perfectly You measure off the radio and perform magic while stating the importance of not doing exactly what you did. ( btw another contradiction - ahem) Didn't mention your reference. And the center pic is not equal but opposite Now I'm just busting your balls But if you want to start a post with the kind of wording , make sure your on the money not FOS. The important thing with drive shafts is "equal working angles" Parallel or opposite isn't that important
In your example, you mention nothing of the driveshaft angle to the trans. If that angle is +3 degrees, then the ds to pinion angle should be -3 degrees it doesnt matter if the truck is upside down, low, high , or under water. Its the same.
Yes, the pinion and trans are parallel, but what about them in relation to the driveshaft? Equal, but opposite.
A guy can set his drive shaft angles up with his car hanging 50' in the air by one wheel with the right equipment. Most use a $5.00 angle finder that works off a pendulum weight and gravity. If a guys only way of measuring angle is the 5.00 gizmo then it the car needs to be on level ground and at ride height It's the limits of that particular tool
Speaking of contradiction---if the angles are equal as in my last diagram, then the pinion and trans lines will ALWAYS be parallel. Am I right or wrong?
since driveshaft angle is so important, what about the trucks with pinion off-centered from the factory?
If that drawing is to scale , and I noticed this on second a look (and i edited my post but you quoted it before the edit ) the u joint working angles are equal but the pinion and trans aren't parallel Think about a slammed vehicle where the trans output shaft is lower than the pinion. To get equal angles the pinion would have to be rotated up to the rear or in other words down to the front.
Takes some imagination or a cad program but if you capture the angles and at***udes of the drive shaft and both ends and rotate that around you will see that although on compound angles in the vehicle they are in a perfectly straight line with equal or nearly working angles
If the angles are equal ( and opposite like I said earlier) like in the pic, then the trans and pinion lines will remain parallel. Again, in your example, you left out information. What relationship does the driveshaft and trans have? the driveshaft and pinion would be equal and opposite.
You guys need to get a grip, or get laid, or something. You're both saying the same damned thing! The angle that matters is the angle relative to the driveshaft, not level ground. The angle relative to level ground lets you determine that, but you also need to know the angle of the driveshaft to calculate whether you have proper angles. The guys oversimplifying and saying "3* down on the trans and 3* up on the pinion" are ignoring the relative heights of the trans output and pinion, which can drastically affect driveshaft and u-joint working angles (i.e., slammed vs lifted vehicles). http://www.4crawler.com/4x4/CheapTricks/Driveline-101.shtml
Sounds like the OP got his information. I'd like to ask; if one is using radius rods instead of leafs, and has the proper matching angles at ride height, will not the angles become non-matching with suspension travel? What I'm envisioning is hitting a series of ripples on the highway and having that annoying wwamp wwamp over each one. I seem to recall this happening on my old jacked up cars in the '70s.
Yes I already knew about running the parallel working angles and usually set them up that way already. Your question is in theory what I was asking too. I seriously doubt many 60's and 70's cars were that close from the factory. I think that while the ideal matching angles would be what you would like to have all the time. There probably is a range of movement that occurs for various reasons ( suspension travel, spring sag, axle wrap from acceleration, cargo etc...) and as long as it stays within (I'm guessing 2-3*) I think will be fine. I could be completely wrong though?
Pinion angle posts always bring a little controversy don't they! Maybe we should order up some Popcorn!
Just my non-professional opinion (so take that for what it cost ya), but it seems like you'd be better off setting them up parallel and doing what you need to do to control axle wrap. You said youre going to take it to the strip a lot. Why are you going to put a bunch of effort into getting the car set up to drag, and then continue using ****ty, old springs?
Umm... They are brand new springs from CE. Pretty much everything on the car is new exept for the ch***is(which I added x member and boxing plates to) and the body. I also checked the pinion angle as the suspension loaded, the pinion angle increased upward with suspension load, so as the springs settle in (which new springs usually do) the pinion angle would now be off from parallel. If I would have set it up parallel to start with.
Oh ok sorry. Sounded like you were using old springs. Still seems like you should set them up pretty much parallel (how long will it take new springs to settle appreciably?). Setting them up to account for axle wrap ahead of time means they'll be out of whack where most time driving is spent - cruising/not accelerating. Anyway, good luck! I'm dealing with my own pinion angle issues and can't do anything about it because I'm a long way from having the car sitting at ride height.
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