Design for a DIY frame spreader
- Thread starter alexiskai
- Start date
Brentwood Bob
Well-known member
Like the second prototype. Should do the job.
BRENT in 10-uh-C
Well-known member
Colin, help me understand what you are doing. It appears the torque tube & driveshaft are still in the vehicle, so when you use your spreader design, how do you install the transmission??
alexiskai
Well-known member
Sure, so both prototypes 1 and 2 were "proof-of-concept" that I did after I had removed the engine/transmission *without* a frame spreader. The lengths of some of the elements wouldn't work in practice, with the engine, transmission, and tailpipe in place. I'm working on getting these lengths right and will update the post.
I did test-fit some components on a car with the engine in, and the design will work. The hinged section fits against the frame just behind the rear motor mounts and passes under, or just behind, the radius rod ball. The vertical section on the passenger side fits around the outside of the tailpipe just before the muffler.
So the answer to your question is that prototype 3 will show the V-angle made by the hinged section as being large enough for the transmission to pass through it on the way in or out.
BRENT in 10-uh-C
Well-known member
Ohh, OK. I understand now.
I can tell you from experience that it really does not need to move the frame rail much. Generally speaking, maybe 0.030" or so.??. When you think that a 1/32 of an inch is about what a Model-A spark Plug gap is, moving it that far is really nothing.
alexiskai
Well-known member
Oh yeah, absolutely. One reason I decided to work on this project was from reading accounts of people saying "I tried to order a frame spreader but it didn't arrive in time," or "... I thought I could just brute-force it instead of paying $100 for a one-time tool." (And in fact frame spreaders are out of stock right this moment at all the major vendors.)
I thought "I bet I can design a crude-but-effective frame spreader that you could make out of spare parts or $40 of stuff from Home Depot." It really only needs to wedge the frame open a tiny amount, so optimizing mechanical force isn't a big concern.
alexiskai
Well-known member
You will need:
- 1" or greater square tube, 24-30" long, perforated
- Angle iron to match above tube, two lengths of 12", perforated
- 3-4 short bolts and nuts for dowels
- Two lengths of 1" square tube, exactly 20.5" long, ideally perforated
- Two lengths of flat steel or aluminum, 20" long and 1/8" thick
- 6 thick washers, 5/16" ID, 1.5" OD
- 8 5/16"x2" bolts with nuts; try to get some with a 1/2" shoulder at least
- 1 5/16"x3" bolt with nut, 2" shoulder
- 1 flat washer, 5/16" ID, 1" OD
- Scissor jack
- Bolt the two lengths of angle iron to either side of the long square tube, in the middle, so that it forms a platform for the scissor jack to rest on without tipping over.
- Set the short bolts and nuts in the horizontal face of the angle iron, poking up, to form dowels that will keep the scissor jack from sliding around.
- Locate or drill three 5/16" holes through each 21" square tube as follows: a hole at each end with center 1/2" from the end; 1 hole with center 3" from one end. All holes should be on the same face.
- Mark and drill 5/16" holes on the 20" lengths of flat steel/aluminum as follows: 1 hole 1/2" from one end; several closely-spaced holes going from 18.5"-19.5" from that end.
- On each 21" square tube, place a bolt & nut through the hole that's 1/2" from one end and is closest to the 3" hole; place thick washers on either side. It should look like a pair of wheels on the end of the tube.
- Use a 2" bolt & nut to attach each flat steel to one square tube; use the hole 3" from the end of the square tube and one of the closely-spaced holes in the flat steel.
- You should now have three assemblies – a square tube base with a 12" platform and two identical hinged pieces consisting of a piece of flat steel/aluminum attached off-center to a piece of square tube with small wheels on one end – a scissor jack, and some additional fasteners.
- Take all the pieces and get under the car, along with two 1/2" wrenches.
- Place the base assembly, with the scissor jack on top of it, centered under the front radius rod ball cap.
- Take one hinged assembly and place it so that the thick washers at the end of the square tube are pressed against the inside of the chassis frame on the driver's side, with the other end of the square tube resting diagonally on the saddle of the scissor jack. It should be somewhere between the rear motor mount and the battery platform.
- The flat steel should hang down vertically in such a way that you can use one 2" bolt to attach it to the square tube base using the hole drilled at the end. If the flat steel is too long or too short, re-attach it to the upper square tube using a different one of those closely-spaced holes you drilled.
- Once you sort out the first hinged assembly, move to the other side of the car and place the second hinged assembly. This one is tricky because you have to slide one end of the assembly around the tailpipe. You should be able to place it so that the hinged pieces go on either side of the tailpipe while it's still thin, before it bulges out at the muffler.
- Get the bolts sorted out on the flat steel so that it fits properly and attaches to the square tube base at the bottom. Make sure you attach one flat steel to one side of the base and the other to the other side, so that when they pull on it, they're not both pulling on the same side.
- Finally, use the 3" bolt to attach the two hinged square tube pieces where they meet on the saddle of the scissor jack. Place the flat washer between the two square tubes and the remaining two thick washers on either side of the bolted joint. These will help keep the joint from sliding off the saddle.
- Your frame spreader should look like the one in the picture from the previous post. If not, go back through the instructions and look for errors.
- Tighten down all the bolts one more time. Make sure the two ends of the square tubes are squared up to the chassis, not cocked at an angle. Make sure the hinged joint is securely on the saddle of the scissor jack.
- When it's time to spread the frame, begin cranking up the scissor jack with the handle. You may find that the spreader lifts itself slightly off the ground. This is normal, but if it happens, try to shim under it with some thin pieces of wood – otherwise it will wobble around as you crank the handle.
- It should only take 3-4 turns of the handle to spread the frame enough to let the engine in or out.
- When done, relax the scissor jack and disassemble the spreader in the reverse sequence you used to assemble it. Fold the pieces up and stow them away until next time.
Last edited:
Smokedtires
Senior Member
This is great, thank you. This may be this week's project in the garage. If you have any other views of #3, that would be great @alexiskai.
alexiskai
Well-known member
Smokedtires
Senior Member
Thank you very much for this!