Your Tech Questions Answered!
Q I am considering a Total Chaos Gen2 Caddy suspension kit for on my ’87 Toyota 4x4 with the Total Chaos Gen2 Caddy. I understand it will widen the front track width 61⁄2 inches. What do I do about the rear? Is there a straight swap? What will work to match the front width? Or am I better off just planning on building a rear axle from scratch?
A A Toyota T100 rear axlehousing will match the front width after you add the Total Chaos Fabrication long-travel suspension (www.chaosfab.com).
Which Way YJ?
Q It’s been a year since I bought my dream vehicle, a ’92 Jeep YJ. Now I’m ready to start modifying it. I’ve been reading up and asking questions about lift kits. I thought I had a decent understanding of body and suspension kits, then along comes SOA (spring over axle) lift kits. I really like what I hear about them. What is the best economically priced 4-inch lift kit for a daily driver that will see an occasional off-road trip?
A For a YJ, if economy is your goal, the best 4-inch lift option is a basic spring-under suspension. Most lift kits for these Jeeps include everything you need, such as shocks, springs, and brake lines. You will still have the springs under the axles, which reduces axlewrap very well when under hard acceleration. You won’t need any cutting or welding to install these kits.
A body lift is fine for about an inch of tire-to-body clearance, but as you go up from there, you run into issues with brake lines from the master cylinder to the frame, as well as steering column and shifter length issues. I recommend keeping body lifts below 3 inches whenever possible.
The spring-over-axle suspension is a little more complicated than just moving the axles under the springs. Depending on the condition of your current springs, you may need to replace them with new stock springs or aftermarket lift springs, but this can result in a lift taller than 4 inches. SOA can also contribute to rear axlewrap, which requires some sort of traction bar. SOA does allow for a more flat spring and better ground clearance, but I do not think it is economical compared to a suspension kit because you will need welding tools.
One of my favorite suspension setups is spring-over up front and spring-under in the rear. This setup works well and helps reduce axlewrap, but requires parts from both a lift kit and a spring-over, so it isn’t very economical.
Ford x Four?
Q I have a ’77 F-150 with the 351M four-speed 2WD. I want to convert my truck to 4WD. I know people just say to buy a 4WD one, but this truck has extremely low miles and has been in the family since day one. I have taken it where 2WD shouldn’t go, and now it’s time to put a front axle in. I was wondering if you could help me with any information that you have or put me in the right direction. I would think it wouldn’t be too difficult on an older truck. Should I search out a parts truck?
A As a matter of fact, there is a project in our July-Sept. ’00 issues and on our website that you might be very interested in. In “Project Two-by-Four” (goo.gl/SUTxM, John Cappa shows how he transformed his two-wheel-drive ’79 F-150 into a 4x4. He used a divorced 205 transfer case from a Dodge and a Dana 44 from a Chevy. Then he built a linked suspension and ran coilover shocks.
Nuts, I’m Confused
I have an ’87 Suzuki Samurai that I’m building into a street and trail rig. This is my first build and I’m trying to do it the right way. I have invested in a spring-over axle kit, but I’m in a haze as to how to mount the shocks and what type. All over I see people running their rear shocks at inboard angles. Dose this add any benefits in handling? From what I’m told, each degree angled inward takes roughly a percentage off of the damping ability of the shock absorber. I read sources that support this method, saying that this follows the way that your solid axle will react to obstacles only applied to one wheel, very common in off-road situations. Others tell me that this is bad and puts the fame on a peak and gives the adverse affects of that like a seesaw. Should I go with gas shocks or oil-filled? What are the benefits of the two? I know that these are important parts of the suspension and I don’t want to screw it up.
I did a spring-over axle swap on a Samurai once, and I chose to mount the shocks as close to vertical as I could fit (see photo). The situation you’re getting into is that the more angle you put on the shocks the less effective the shock will be. A general rule is to keep the shock at 15 degrees or less off of vertical. Once you go past 15 degrees the shock loses efficiency exponentially. If you imagine that the shock is trying to control the movement between the axle and the frame, then the best way to control that is to be directly in line between the two, not at an angle. Yes, the shock may work under articulation, but you need shocks more often at high speeds than at low speeds, and at high speeds the axle is more likely to move up and down parallel to the frame, not at an angle.
Many people put shocks at an extreme angle to try and fit a longer shock for additional wheel travel, but this results in a shock that works poorly. The proper way would be to move the shock mounts and even come up through the bed floor if need be.
A gas-charged shock is a better option over a basic oil-filled shock because it helps reduce frothing in the oil as the shock works. By the way, both styles have oil in them; one just has a charge of nitrogen in with the oil to keep it under pressure. An even better option is a remote-reservoir shock that is gas-charged and has a separation between the gas charger and the oil.
If you are looking for shocks and shock mounts, you can find them at Poly Performance. Since your question is so helpful to many readers, you get this month’s Nuts, I’m Confused prize, a Poly Performance gift certificate. Poly Performance has a website with lots of off-road parts from complete suspension kits to builder/fabricator parts to shocks and seats. Check it out at http://www.poly performance.com, or call 805.783.2060.
To everyone else out there reading, we have lots of great prizes for upcoming Nuts & Bolts sections, so send in those letters.