Project COBRA'33 Project COBRA'33
Installing the Rear Suspension
Rear Frame section is ready for the addition of the Rear Suspension. There is much more work to do then meets the eye, as you will soon find out. The Winters Rear Quick Change makes an average Rear Suspension installation, into a complicated one, that takes twice as long and requires much more work.
4-Bar Installation
Heidt's Triangulated 4-Bar Set-up
Set the Frame
First and foremost, make sure the frame is still level and clamped there so nothing moves while you work on the rear section. I actually Tack Welded the frame to the positioners, so it could not move side to side or front to back. Maintaining the frames position is not something you should have to worry about once you start working on the rear suspension.
Position the Rear end Housing
Winters Championship Quick Change
This Street Rod Quick Change Rear uses stock appearing Ford® flanged 31 spline axles, and will accommodate after-market disc or stock Ford® brakes.
You now can slide the rear end housing under the rear section of the frame, and support it with jack stands or something similar that will offer safe support. The wheel base should be laid out and marked clearly on the frame. The instructions that came with the 4-bar set-up show the rear axle position both from the front or rear of the frame. We had already laid out the wheel base using the information supplied with our Heidt's Super Ride IFS instructions, it's 112" from center line of front spindle to center line of rear axle. We needed this information when we relieved a section of the rear frame so the axle would not hit it upon full suspension compression, so our frame had already been laid out. Center the rear housing under the frame, making sure you have the same distance on both sides from front to rear and side to side. Our rear end was 4-3/8" past the outside edge of the frame on both sides when it was centered. To make sure the housing was square to the frame, I used one of the mounting holes on top of the frame, to measure back to the front edge of the rear end housing, to make sure it was square. It takes some patience, and several reposition's to get it where it needs to be, so take your time and do it right. This is one reason the frame had to be clamped down so well, it would drive you nuts trying to get the rear end set if you had to constantly re-set the frame.
Picture shows the modified rear cross-member that the Rear Coil-Over Shocks attach too. The center section of the Cross Member had to be raised to allow room for the Rear End under full compression.
Setting the Pinion Angle
With the Heidt Triangulated 4-Bar Set-up and using their Coil-Over Shocks, when our car is at Ride-Height, the rear shocks will be depressed about 1-1/2". So we know the eye-to-eye extended length is 15", and the eye-to-eye compressed length is 10-1/4", while our eye-to-eye ride height length is 13-1/2". So with this new information we can set the rear end housing square to the frame and centered, with a shock mounting bracket to bracket length of 13-1/2". We can use this information as soon as the rear housing 4-bar brackets are installed. The instructions spell-out the mounting location of the 4-bar brackets, mark this location for future reference when we will Tack Weld the brackets to the rear end housing. Before anything gets Welded, we must first set the rear end housing's pinion angle. This is the angle in relation to the transmissions tail-shaft, for our project we will set it at positive 2.5°. Use a digital angle finder and place it against the front surface of the rear ends yoke (the place the drive-shaft attachés to). With the yoke positioned straight up and down, lay the angle finder against it and adjust the rear end housing till you have 87.5°. Lock the housing in at this angle. Now place the lower 4-Bar brackets back on the marks you laid out, and while holding them plumb with a level, Tack Weld the brackets in place. With the brackets now attached to the rear end housing, we can set the height of the rear end so there is 13-1/2" between the middle shock mounting hole on the 4-Bar brackets and the mounting hole of the top shock mount. You can figure the top shock mounting bracket, which is really a cross-member with the shock mounting eye welded into it, setting level with the top of the frame. Since we choose to run a Winters Quick-Change rear end in Project COBRA'33 , we had to section the middle out of the cross member and relieve it enough to clear the rear housing on full compression. This was done by mitering pieces of the same type and size of square tubing, so the middle raises up 3" more then the two ends.
What would have been a cut and dry installation, gets complicated due to the Quick-Change Rear End. The bottom 4-bar brackets work just fine, but the Upper 4-bar brackets don't. Because the Center Section of the Quick-Change is so wide, the top 4-bar brackets don't fit. We had to modify the axle brackets and completely build new Upper frame brackets to get the 4-bar set-up to fit. Shown are the Upper 4-Bar Brackets, Custom Upper 4-Bar Mount, and Modified Axle Brackets. The actual Control bars and Center Section of the Quick Change are wrapped to help protect them while the mounting process takes place.
Mounting the Lower 4-Bar Brackets
Hopefully at this time the rear end housing is centered in the frame, and setting square to the side rails. The pinion angle is set at 87.5° or up 2.5°, and the hole to hole measurement of the shock brackets is 13-1/2". If so we can now start to mount the bottom 4-Bar bracket to the frame. The first thing we need to do is set the control bars so that the two long and two short bars are the same length. Take one of the longer control bars and unscrew the adjuster so you have 7-8 threads showing. Now do the same to the other long control bar so they are both the same length, you should be able to push a 5/8" bolt thru both top and bottom mounting points when set properly. Position the bars as shown in the instructions, with the adjuster end to the frame. Secure the control bar to the rear housing with a 5/8" bolt and secure the frame mounting bracket to the other end of the control bar. Mark the frame where the top of the mounting bracket should be, and position the bracket there while Tack Welding it in place. Do the same on the other side, making sure the control bars are oriented correctly. Tack Weld the brackets in 4-5 spots so they don't move when the full weight of the rear end is upon them.
Drivers side of frame....showing the Upper and Lower 4-Bar control bars and Brackets. Tab mounted over the relief cut into the frame was removed, and another mount was fashioned for the bump stop. Picture shows the reinforcement welded into the rear cross member.
Mounting the Upper 4-Bar Brackets
The top brackets go on like the bottom ones, first set the two control arms so they are the same length then 7-8 threads are exposed at the adjusters. Mount the non-adjustable end to the top axle brackets and the other end to the frame brackets, position the control bar as directed from the top of the rear housing to the side of the frame. You may need some help holding everything in place and tying to mark the side rail where the instructions indicate. Once everything is set, Tack Weld the rear housing brackets to the top of the housing, then position the control arms out to the side of the frame rails and Tack Weld them in place. Re-check your measurements and make sure everything is still square and level with the frame, it's easy to accidentally hit something and move it out of position. If everything checks out, place several good Tack Welds on both brackets to insure they will not move. Because of our choice of Rear End, we had to deviate from the instructions. First problem was the center section of the Quick-Change was way wider then a normal Rear-End. This caused the Upper bars to be at a much narrower angle then called for in the instructions. The reason the upper bars are at an angle in the first place is to position the rear housing so there is no side to side movement. This side to side movement would be controlled by a pan-hard bar in a parallel 4-bar arrangement, but is eliminated in the Triangulated 4-Bar set-up.
Custom top frame mounts had to be made, since the supplied mounts would not work with the shallow angle we now had to work with. We installed an extra tube type cross-member to secure the upper 4-Bar brackets to. We simply had to come up with a mounting system that would allow as much angle as possible in the upper 4-Bar mounts so the rear end stayed put, yet make them strong enough to last, while fitting the chassis and staying below the floor line. I used 1-3/4" x .120 wall round tubing for the cross-Members, and 1/4" plate for the mounting brackets, which were placed in double-sheer for maximum strength. The brackets on the axle were positioned as close to the center section as possible for the most angle, and tacked in place. This arrangement made for a very strong and complete rear 4-bar mount. Looking back, it would be considerably easier to use a parallel 4-bar mounting system, and the conventional pan-hard bar to place the rear end in the chassis. I would recommend this system over the one we choose.
Cycle the Rear Suspension
With the some help, you should be able to lift the rear end housing and remove the supports and cycle the suspension up and down. Check that nothing is binding when the rear end is moving thru it's arch, and that there is no side to side movement.
Bump Stops
Reposition the axle supports under the rear end housing and install the rear axle Bump Stops. You should position it so it makes contact with the axle tube about 1/2" before the suspension runs out of travel or before it hits the rear cross member. These Bump Stops marks the absolute limit of the rear suspension's compression. The mounting bracket needs to be a healthy one, for it will have all the cars weight on it when in use. The Bump Stop should be positioned on each side of the frame, centered over the axle tube, and to the inside of the frame rail. We used a piece of 3" long piece of 3/4" square tubing welded to the inside of the frame rail with a 3/8" nut welded in one side. This made for a simple yet very strong bracket, and the Bump Stop simply screwed into the bottom of it, making any future replacements a snap. If you decide to use a different type bracket, make sure it is substantial enough to do the job with a minimal amount of length. The longer the bracket the more the leverage. When looking for a axle stubbier it might mean looking in other then hot rod type shops. I have found, the best assortment at chassis or off-road type stores. Both Energy Suspension and Pro-Thane are excellent sources.
The Anti-Roll Bar
We decided to use a Anti-Roll Bar on Project COBRA'33 because of the heavy engine and relatively tall roof height of the sedan. We purchased ours from Jeg's and the kit came with everything needed for the installation. We mounted the torsion bar to the shock cross member, and the control arms to the lower 4-Bar brackets on the rear end housing. The Triangulated 4-Bar made it much more difficult to mount then if we would have just used a simple parallel 4-Bar mounting system, but it fit with a little thought. Make sure if you mount one on your chassis that the control arms for the suspension don't come in contact with the arms from the torsion bar. Also you will have to fashion a mount to locate the torsion bar mounting bracket to the chassis, we used the shock cross member, but you can use other methods so long as they will hold up to the stresses applied to them when cornering. Adjust the arms as stated in the instructional booklet.
Picture clearly shows the step in the rear cross Member we made for the Quick Change Rear end. Also shown is the bracket we used to space the rear suspension at ride height. This bracket is drilled at 13-1/2" center to center, which takes the place of the coil over shocks, so they don't get messed up while fabrication continues, but positions the rear end at ride height so we can continue on with the process.
Now you can see the completed Anti-Roll Bar...While the rear end center section and control arms are still covered for protection, you can see how all the parts will work together.
This shot shows the relationship between the control arms for the rear suspension and the control rods for the Anti-Roll Bar.
Fuel Tank
This is a shot of our 1933 Ford Fuel tank we used on Project COBRA'33. Notice the two 5-hole openings, these would later cause some fit issues.
Our next problem is the Fuel Tank, Since we decided to use the Quick Change Rear End, the fuel tank will need major modification to clear the rear end. I'll mount the tank and take some measurements to see how much has to be cut out and to see weather or not I can use the stock fuel tank or if we need to have a custom tank made.
OK, so heres the troblems....I set the rear suspension to Ride Height (the setting most closely conforming to the actual height of the car after everything is finished), and put the fuel tank in place. I would have bolted it in place, but it would not go....it was hitting the the back of the quick change rear end. I knew there would be some problems when I decided to run the Winters Quick Change over a stock Ford 9" rear-end, but I guess I didn't know just how many problems I would have. Rookie mistake I guess??
I lowered the rear-end housing till the fuel tank fit in the frame, and bolted it there. Then I took a magic marker and outlined around the rear-end marking on the fuel tank there it hit. This was my starting point, for I now know the minimum it would take to clear the rear-End housing. To this I added a safety factor of four (4) inches on each side and six (6) inches across the back. Now I have the basic shape the relief should be. For the depth, I measured how much the rear-end still had to come up, which was about three (3) inches. Since the tank is only about seven (7) inches to the middle seam, I just had the relief come down as far as it could, which gave me about one (1) inch from the middle seam.
Here you see how we relieved the fuel tank, so it would not interfere with the Winter Quick-Change rear end.
I think this shot shows the depth of the relief the best. You can see what was involved in the process and how much of the tank volume was lost.
The tank only hit on the very back portion of the rear-end housing, which was my saving grace, had it hit more in the middle my relief would have been more complicated and would have severely limited my fuel capacity. As it is now, I would estimate I lost at least two(2) gallons out of my tanks original capacity of roughly 15 gallons. The tricky part was getting enough room to cut the 4-1/2" hole in the tank for the in tank fuel pump. These tanks come with Three (3) baffles, they are tack welded in place with eight (8) tack welds, two (2) on each side and four (4) across the bottom. These fuel tanks are assembled in two (2) half's, the bottom portion they assemble the baffles in, then the top is put in place and the seams welded together. So there are no tack welds holding the baffles at the top. When the middle section was cut out of the tank, we ran into the middle baffle. This wasn't to much of a problem, since the opening was fairly large and you could easily get in and cut back the baffle. It would have been much easier to just remove it, but I wanted to keep as much of the baffling in place. Our tank already had two (2) openings when we purchased it, both were the common 5-bolt round openings like the ones they use when mounting the fuel level sender, because of these openings it made placing the new 4-1/2" in-tank fuel pump opening very dicey. We were extremely limited, and had to plan on using on of the 5-bolt openings for our fuel level sensor. We made it work, but it was very close. We kept both 5-bolt openings, one we will just blank off the other will be used for the fuel sensor. Any closer and we would have been forced to cut out one of the openings and weld it shut,, when make our 4-1/2" opening. I wish I would have gotten some pictures when the tank was all cut open, but things just didn't work out, so I'm left with the few that I did get.
This shot shows the 4-1/2" round opening that was cut into the fuel tank to mount the in-tank electric fuel pump. here you can see the limited amount of room present. Notice how the tank comes in at the corner, which makes for even less room, and how lose our hole is to the 5-bolt hole. The baffle was right there in-between the 4-1/2" hole and the 5-bolt hole.
When we cut the 4-1/2" opening for the fuel pump, we of-coarse ran into a portion of the baffle on that side. This one was a bear, the limited opening size coupled with the fact that the surrounding metal was as share as a knife made for some interesting times. I reached in with a saws all and made a few cuts, but I was not able to get very close to the bottom of the baffle for fear of cutting a hole in the bottom of the tank. I finally had to resort to a cold chisel and a hammer for finish the cuts, then I used a pair of Channel lock pliers to wiggle back and forth the baffle till the tack welds broke. On thin gage metal like this, it's pretty common for the tack welds to pull thru, putting a small hole in the tank where the tack weld was. And this is just what we had to deal with, six (6) small holes that we brazed shut with our gas torch, not a big problem. I was very pleased to see just how clean and UN-rusted the fuel tank was on the inside, I had been expecting some rust since the tank was sent to us UN-plugged.
For good measure, we sealed the inside of the fuel tank with Red Coat tank sealant. I just thought it was good insurance with a vehicle that isn't driven all the time and what with all the alcohol they put in the fuel now days. I ask a local tank maker, and he recommended not only sealing the tank but using the Red Coat sealant. He said he used it all the time and it worked great, so I went with the man that had the plan and the experience to back it up and sealed our tank.
Sealing the tank was pretty simple, since our tank was clean and new there wasn't much to the prep work. I vacuumed the tank to remove any metal particles left behind when we sawed it, and wiped it down the best I could. The application was simple, just tape shut all the openings but one and work it around the tank by constantly turning the tank, letting it set for a few minuets then repeat. It took roughly 45 minuets to coat the tank and then another 2-3 hours to let the excess run out. I did add about 2 cups of ac-atone to the quart of Red Coat, just to thin it down a bit. We recovered about 3/4 of the quart, which is good for the next job, so I put it back in the original can and sealed it up. We ended up with a very even thin coat, this stuff runs out very nice, now just give it a couple days and I can install the fuel pump and all it's hardware. I figure will be the guys that make everyone else stop early on the rod runs, what with the blown V-8 and the small fuel tank, we will be lucky to get 200 miles between fill-ups.
Was it worth it? Sure. But I was total UN-prepared for the lack of knowledge, product and support for guy's like myself that decided to run a rear-end like this in a 1933-34 Ford. I searched everywhere and called all the top fuel tank sellers I could find, not one of them had a product that would deal with this problem, and all but one had no ideal what I was talking about. You got a be kidding! But unfortunately I'm not, most referred me to a custom tank that they or another outfit sold or made. What was the cost of there way around this problem ? well lets just say it started at $1000 and went up from there. That meant I would have to eat the tank I already bought, plus the grand or higher price they wanted for the custom tank. In all fairness, they were quoting me for a Stainless Steel fuel tank, not the steel tank like I have.
So what would it cost someone that needed this same work done? I would figure about $240.00. Two hundred for the welding and tank modification and forty for the Red Coat sealant. Not bad in my book, and it's alot cheaper then what they wanted. If you had them build you a special one off tank, that included the pump opening, sender opening, shipping and everything else needed I would not be surprised if the total was over $1500. Just another thing to remember when going with something as non-standard as the Quick-Change is, it's these hidden expenses that really add up. Just like deciding to run a Ford engine and not the standard Chevrolet 350 V-8, it's full of many hidden extra expenses.