Thread: 4 link rear

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hello all,
i decided to fab my own paralell 4 link rear mount, i see some that have both bars below the axle tube and some that have a bar below and one above any advice on which is better and why, also what pinion angle do i use before i weld mounts to the tube, and i should be able to adjust pinion somewhat with adjusters is that correct, thanks for any advice i am kind of new to this and appreciate the help so much

Buy the brackets from someone and just do the application to your rear-----------and use one tube below and one above


http://chassisengineering.com/index....tegory&path=18

The brackets Jerry linked to are all parallel bar setups, and if you choose to use that approach you'll have to add a panhard bar or watts link to keep the rear end centered. The other approach is to go with a triangulated four link, where you have the two lower bars parallel to the frame from the axle tubes, and the two up top running from the housing/tube interface area out to the frame, keeping the rear centered. You might look at Paul Horton's site. His brackets are stout and well engineered - Rear Suspension Parts | Welder Series Inc.

Looking back, I see that you have a 1928 Tudor sedan. Also, you have five separate threads with frame/suspension questions. In one, you wanted a triangulated 4-bar. In this one, a parallel 4-link. Could I suggest that you stick with one thread on your frame project? Otherwise, it's hard to keep track and to give you reasonable advice. 0

If your plan is to build a solid street rod, I personally believe that the Chassis Engineering 4-link is overkill for street use, and takes up way too much space. (No disrespect to Jerry intended, just my opinion.) A triangulated 4-link is a time-tested, proven, simple rear-end suspension when coupled with coil-overs or air bags. Frankly, I wish I had used one on my '34.

http://www.progressiveautomotive.com.../TRB-CG-03.jpg

Originally Posted by Henry Rifle

A triangulated 4-link is a time-tested, proven, simple rear-end suspension when coupled with coil-overs or air bags.

I agree. Further, the use of factory-style rubber doughnuts will result in the best ride quality in my opinion.

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You can get a whole Mustang rear end with all the brackets for a triangulated 4 bar cheaper than you can buy the materials to build them yourselve

thanks for the advice, sorry for the multiple threads i guess i am kind of new at this forum thing as well as this first build, i built this frame and my original plan was to use a triangulated 4 link, but the rearend i have is a 8.8 ford with disk brakes and limited slip unfortunately it is a cast center so can't weld there, so i don't think i can get enough angle on the upper bars due to the narrow frame width so am looking at using the bars from the triangulated kit and making my own axle mounts, the forward end i already have mounts for that fit into my frame z, just looking for opinions on what is the best option at this point, thanks again

There's nothing sacred about the angle of the triangulated bars, only that they form a triangle to keep the differential centered. Weld your upper brackets to the axle tubes, close to their inner ends. Or get one from a Mustang like Jerry suggested? Had you told us up front you were dealing with an 8.8" rear the answers would have been specific to your situation, not related to generics, i.e. mine is a Ford 9" so my answer to you about my installation, and the angles was specific to a 9" housing type.

On the multiple posts, if you copy links to the threads that you'd like to see merged and PM them to Bill (mrmustang) with a concise, clear request he might work them together for you,

i hope this is the proper way to continue this thread about the 4 link rear end, i decided to go parallel and ordered the axle tube mounts and the panhard bar kit, my question is about the pinion angle, before i weld on the tube mounts what angle to set pinion at in relation to axle mount brackets, thanks for any info

Originally Posted by demano

i hope this is the proper way to continue this thread about the 4 link rear end, i decided to go parallel and ordered the axle tube mounts and the panhard bar kit, my question is about the pinion angle, before i weld on the tube mounts what angle to set pinion at in relation to axle mount brackets, thanks for any info

You want your pinion to tilt up at an angle equal to the downward tilt of the transmission output shaft. If you project lines on the centerline of the tranny output, and the pinion shaft they will be parallel with the driveshaft forming the diagonal of a between the two, with equal triangles above & below that diagonal.
http://i725.photobucket.com/albums/w...line_angle.jpg

thank you for the link and info, do i try to get the rear end angle at this point when welding on the axle tube mounts or do i set the pinion angle at 0 degrees in relation to the face of the bracket and then adjust after engine and rear are in with the rod ends. If my thinking is off on this is there a certain angle that is a good starting point to set for a street driven car with a 460 ford engine and c6 trans, weight around 2500 pounds, thanks for the help on this i am a little nervous to start melting metal on these brackets

I could be wrong here, but I believe 3*-4* pinion pointing up is pretty good for a street car. I'm going to be welding up my triangulated 4 link next week and I have to try to set mine with no power train either. I'm half tempted to just tack the brackets and make sure it all jives when I reassemble the car.

The angle needed can vary, depending on the frame and body clearance. On my '37 Oze, the engine is set dead level. You couldn't get the engine up more than a degree or so without the bell housing hitting the trans tunnel. My frame was supplied with the trans mounting plate welded on, so it wasn't practical to drop the tail of the transmission to get more angle.

To figure out how much rod adjustment is needed for 3 degrees, just multiply the vertical distance between the rod ends by .052 ( the sine of 3 degrees). For a 6 inch spacing, that's only 5/16 inch. Each rod end could move half that ( one in and the other out).

Demano, there's a lot of confusion on pinion angle. With a carbureted engine it's ideal to have the carb base dead level with the vehicle at ride height, and it was common for intakes to be machined with a nominal three degree forward tilt, meaning the tranny mount was dropped relative to the motor mounts to level the carb base. Now you consider a street rod running bigs & littles, and that three degree manifold tilt may still have the carb sitting back end high, messing with float levels. With EFI the engine doesn't care about the angles, but it's still common to have that nominal three to four degree downward tilt at the tailshaft. If you can, it would be prudent for you to get your engine & tranny mounted before you melt in the 4 link mounts, or like Ryan says maybe tack them good, then go back and weld them solid later. As was pointed out, the amount of linear adjustment to achieve a degree of tilt is not that big, but why not get it set pretty close to right as your zero point?

thanks again for the advice, i will set up as close as i can, then tack well and final weld after motor and trans are also set. It seems the farther i get with this project the more questions i have but it sure is a fun and addicting adventure.