Hey guys Thinking of putting in a 8.8 (or maybe dana60) rear end into a 57 truck. I've see it discussed on numerous threads but curious to hear other real world examples. The pumpkin/carrier housing is offset on the rear by like 3" ... obviously creating a pinion/ offset angle. Seems like a lot of guys run it the way it is. I know you can shorten the longer side ... but then you have to shorten axle tubing and either get custom axle made or use a short side of another rear. In my case I'm pretty sure the 57 Chevy is around 60" WMS ... and so is the ford 8.8 ...... so cant really shorten anyway. Run it as is ?? Thoughts ?
I'd say run it as is. I think the only issue you may have offset is if your driveshaft starts hitting a driveshaft tunnel. I know the guys that run S10s like them. They practically bolt right in and there's no real issue with the offset for them. They are starting to get plentiful and I've seen them at Pick N Pull. Find one in later Explorer and they have disk brakes and a limited slip rear end.
I am amazed at the number of people who question the pinion offset when considering certain rear ends. Does it not occur to anyone that it was built that way, and run that way in whatever it was factory installed in, without any issues? For all practical purposes, the side to side offset is no different than the typical height difference between the trans output shaft and the pinion. The angle formed is just 'clocked' at about 5 instead of 6. Now you math wizards who like to argue about compound angles may be technically correct, but the world's major manufacturers seem to not be bothered about that. As mentioned, one place this offset might be a problem is an application with a very narrow driveshaft tunnel. If you have the clearance, set your pinion angle based on the center line of the eng/trans and enjoy your ride. Ray
I have built four projects using the Explorer rear end with offset pinion and had no problems. The driveshaft tunnel on one required a small tap with a BFH at the very rear. Since he is going into a truck there should be no clearance issues at all.
Funny myself and my colleague had same discussion at work. The part we couldn't answer/agree though ..... was is the offset (if any) of the front engine/transmission to counter the offset on the rear in the OEM setup ......... whereas in an aftermarket build that will probably not be. The other problem with the 'clocked' analogy which we also discussed is typically your only going against a 2degree down plane (from trans) with a matching 2 degree up plane (pinion) in a normal setup. Now your throwing in another plane with the offset. I was thinking to use a custom shaft (probably have to anyway) with a double cardan joint both sides to help.
I didn't have a custom axle made. I pulled another short side axle and cut the rear end to fit it. If I break one I can find another one anywhere.
Dont think I can do that. Length on the 8.8 is around 60.75" I think. Length on the 57 is 60" Nothing to shorten
8.8 Ford axle housing are available in widths ranging from approximately 56.5" to 65", depending on the vehicle line from which they are sourced. The narrowest being Ranger/Mazda pickups and the widest from the big sedans and full size pickups. The Explorer has been very popular because it is 59.75" (fits lots of apppications), plentiful, typically with disc brakes, often with posi and 3.73 gears. 3.55 and 4.10 are not too difficult to find. About the only thing missing from 'perfection' is not having a drop out style gear carrier. Ray
Correct. Explorer due to the posi and 31 spline and disc brakes. But nothing to shorten..for a 60" WMS Chevy 57 truck
I run a circa-1981 Ranger 8.8 in my Falcon. The pinion offset is even higher than that of the Explorer. Yes, I did have to re-work the floor/tunnel, but it is a low car. The driveshaft angles are not an issue.
Here's the answer from SPICER. http://65.170.161.218/~spicerpa/sites/default/files/pdf/driveshaft_installation.pdf Then, be sure to read this post and ALL the articles listed there in. http://www.jalopyjournal.com/forum/threads/a-different-driveshaft-angle-question.28436/ Especially read this one: http://www.drivetrain.com/parts_catalog/drivetrain/driveline_angles_and_phasing_problems.html
Still reading through all this 19Fordy. Thanks (except for my sore head). Im not sure if Im cherry picking - but the jist of what I am reading is that anywhere up to 7 degrees of offset is ok. 3 is recommended especially at race speeds. Anything over 3 you really want to make sure angles balance themselves out. eg +4,-4 ... +5,-5 The hard part is when working on two planes ......... how the heck to do that properly. I don't think most people are reinstalling the pinion to account for the horizontal plane offset (eg addressing the 3" physical left/right). Vertical seems easy enough ...... if engine/trans/driveline is 3 degrees down then pinion up 3 degrees. But not sure on the other. Will try the compound chart calculator (mixture of chart figure and actual figure).
The driveshaft is still working in a single plane, just not a vertical one. As long as the transmission and pinion are parallel, vertical and/or side offset doesn't matter. 2 parallel lines define a plane. Just think about the 2 yokes, forget how everything else is oriented. If you extended the yokes out long enough and set a piece of cardboard across them it should lay flat. That is your single working plane.
U joint working angles !!!! Study that . 2 dimensions visualized into 3 dimensions is a special aptitude that not everyone has. Side view degrees plus top view degrees will be close enough to get the u joint working angles equal.
Side to side offset, as installed in the original vehicle (like an Explorer) does indeed line up with a straight line from crank to rear u-joint. Eng/trans units began going to the right in many cars starting in the mid to late 60s. More room for controls, steering, etc. GM cars are 1", some Fords are 1 1/2", most Mopar cars are 1" but some are 1 1/2. Early stuff was just centered. Narrowed too many housings and tubbed too many cars to not pick this up as normal info. I don't like a driveshaft off to 1 side. It may work just fine but not for me. I'd probably look for 2 8.8 axles. 1 from a full size pickup, one from an Exploder, shag a short axle from the Explorer to put in my new narrowed-one-side full size housing with the pinion dead center. Narrowing is easier than it sounds. Get it clean, put a nice bevel in the housing end that's cut off (with enough tube left to butt weld), do a good hot MIG weld in stages, job done and likely dead straight if you pay attention. You could cheat too. Slide the axle in with the bearing in place (no seal) use it as a "fixture" to tack the end on in about 6 places but keep it cool, pull the axle and full weld. Too easy? Trust me, I won't rat you out...
The reason I brought up the subject of 'compound angles' is that in previous threads on this very subject of an offset pinion, a few HAMBERs brought up the subject with formulas and explanations. Personally, I don't know enough about the math and/or geometry to argue the issue in professional terms. I do have a reasonably sound grasp of inductive and decductive reasoning to believe their contentions are inconsequential in these applications. Ray
There is only one plane of function in a driveshaft, even if the pinion is offset. While the Human mind wants to break it up into two planes, down (or up) from the tailshaft to the pinion, and down (or up) from the tailshaft to the pinion, that is not how it works. Imagine this: You have the standard arrangement of a talishaft that is above the pinion, and a pinion that is offset to the passenger's side. Two planes? Nope. Put the car in a rotisserie and rotate it until the driveshaft no longer shows the offset to the passenger's side and you will see it. One plane. Rotate the car back to level and that does not become two planes, still just one. The drive shaft has no idea where it is in space, or where the ground is, and it does not care what you think about it. Now, you can use the two observed angles to compute the operating angles. Having an offset pinion does cause a higher rate of change in u-joint angles during suspension cycling, however, in most setups there is simply not enough travel in the suspension for that to be an issue. As long as there is parallelism between the transmission output shaft, and the pinion, and the u-joint operating angles are complimentary, and within reason, offset is irrelevant, in terms of function.
The more I think about this, the more I realize that we may be inadvertently be sowing confusion about driveshaft slope and u-joint angles, by the shorthand that we use to describe them. We all know the old advice: tailshaft 3º down, pinion 3º up (with some caveats). The trouble is, those two angles are just reference angles to make it easier for us Humans to understand. The both reference the horizon. We will skip the part that the horizon is not flat, but a curve. When you measure these using an angle finder, that tool is referencing the center of the Earth, via gravity. We will skip over the part that lines that are perpendicular to the center of the Earth are not parallel to each other. Neither the tailshaft angle, nor the pinion angle are actually the critical angles, per se. Imagine these two setups: Both setups assume engine and transmission parallel with chassis center-line, and axle square in the chassis. Passenger car: tailshaft down at 3º, pinion up at 3º, pinion 48" behind, and 3" below the tail shaft. 4x4 truck: tailshaft down at 3º, pinion up at 3º, pinion 48" behind, and 23" below the tail shaft. The angles are good, so all should be well with both, right? Nope. The first one will see 200+ at Bonneville, with no issue. The second will shake white off of rice at 55. Why? The angles of operation between the tailshaft, and the driveshaft, the driveshaft and the pinon are actually the critical angles here, and on these two setups, they are totally different. In the case of the passenger car, they are within the acceptable range. In the case of eh 4x4 truck, they are not. The smoothest operation would be tailshaft 0º, driveshaft horizontal, no pinion offset, and pinion 0º. There are some who would argue that this would lead to premature u-joint failure, due to lack of grease circulation, but I tend to doubt it, as most cars get driven on roads that are substantially less than perfect, and not operated stationary. The farther the angles get from 0º, the more each pattern of movement of each of the two planes of u-joint movement move from a perfect circle to an ellipse. Contrary to what many think, u-joints do not move at a constant velocity. Having complimentary angles at each end of the driveshaft helps cancel out that speeding up and slowing down of the shaft at each end, to an extent. Even in the aforementioned passenger car application, there is vibration, but it is dampened by the motor and transmission mounts, suspension bushings, tires, etc., so you don't feel it. Push the operating angles too far, the ellipse becomes too great, and you will shake your teeth out. And remember kids, your driveshaft is a dumb chunk of metal, and so are the u-joints. They don't know where the Earth is, where the horizon is. Slope and working angles are relational to the working components, and not external factors. Those are just external reference points to help us to comprehend what is going on. If you have a driveshaft that is horizontal when viewed from the side, but deviates off chassis center line, from tailshaft to pinion, at a 20º angle, it has a 20º slope.
Great post gimpy With As much info is out there on driveline angles it's easy to see why it's shrouded in confusion because a good portion is mis information another generous portion is mixed information from different applications and then there's the "short hand" which is missing infirmation. For example the famous " 3* up 3* down" . That statement is first off short hand because it eliminates the point of reference and indication that the observer trying to under stand it, the author writing it or the applicator trying to establish it is required to turn around and change the point of reference. The proper way to state that is to include tail shaft 3* down to the rear & pinion gear 3* up towards the front. Secondly that 3* up 3* down statement is mixed info as it pertains to a certain type of stockish OEM application and stock ride heights of mainstream vehicles - Not necessarily lowered vehicles Or rear huger rubber raked vehicles. Thirdly the statement is missing information. It completely ignores the idea of u joint working angles, drive shaft slope direction and again the change of reference point, as well as it will not the golden rule and will not be applicable to all drive lines is specialty cars. I do believe the majority of vehicles spoken of here are of some form of specialty. The golden rule is equal U joint working angles. In order to get that established the drive shaft slope needs to be used in the calculations.
I am at the point now where I don't talk about the drivetrain parameters in my Falcon to anyone but a select few. I have had people get angry with me, and tell me that my setup will not work, often while I am standing next to it, you know, somewhere I drove it to. The engine and transmission are at 0º. The pinion is at 0º. The pinion is 3/4" above the tailshaft. The pinion is 2" to the passenger's side. The driveshaft is 50". No vibration. No issues, no noting. SF-LA-SF, 800-miles round-trip, 82MPH average speed on I5, not a peep. Of course, these are often the same people who will not accept that I put a T56 in it, or that I could have 5.13:1 gears in the rear.
Sorry guys. Didn't get messaged on updated threas. Still weighing all this up. Some is over my head. Seems to be that the general consensus is if you can get the working angles to offset each other - then on standard vehicles (DD/street) then they should balance enough to not have a vibration issue. Currently I'm looking into a 31 spline 8.8 from a 94+ mustang ...... rather than the 8.8 from an explorer purely due to the pinion being more centered. At least I think they are - still trying to determine if true.
Yes. Your working angles should offset each other, and be as shallow as possible. This is basically what it breaks down to: Engine/trans straight in the chassis. Axle square to the chassis. Angles offset each other, and are not crazy-go-nuts. Make sure the width of the Mustang 8.8 will work for what you want to do with it.
http://www.toonutsracing.com/smf/index.php?topic=2121.0 Puts it at around 61" http://www.moddedmustangs.com/forums/5-0-mustangs/6621-8-8-rear-end-measurements.html 94 and newer Mustang 8.8 will bolt into a 79-93 Mustang but will require brake line adapters. Ted, 79-93 Mustangs use a 57 inch wide rear axle. 94-98 Mustangs use a 58.5 inch wide rear axle. 99 and newer Mustangs use a 59 7/8 inch wide rear axle. Lincoln Mark7 LSC, SVO Mustang and Fox Body Saleens use a 59.5 inch wide rear axle. Hope this helps. Looks close. I tape measured as a 60-61" WMS on current truck.
Even if the pinion is offset, given the length of the driveshaft, even on the short-wheelbase 1957, the angle change should not be of any major concern. As long as this is not a 4x4, and you are not dragging the oil pan while driving, you should be fine.
Thanks guys. If I dont go with an explorer/mustang rear ........ thinking I will go new. Best I have seen for price is speedway. http://www.speedwaymotors.com/Speedway-Ford-9-Inch-Posi-Traction-Third-Member-Assembly,6788.html $850 http://www.speedwaymotors.com/Bare-60-Inch-Centered-9-Inch-Ford-Housing-w-Axles,61973.html $649 http://www.speedwaymotors.com/Ford-9-Inch-Bolt-On-Rear-Disc-Brake-Kit,5336.html $349 $1850. Looks like it should hold 300-400HP. Obviously have to put together the axle bearing.
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