Creating a firm foundation
|"Houston, the Teardrop has landed"|
I reviewed all the Teardrop plans that are available and spoke with local utility and horse trailer manufacturers before deciding on how to build the chassis. We also researched state & federal regulations because we not only wanted our Teardrop legal but safe too. A typical "street" Teardrop chassis can be built with less material and different construction techniques, which can be much less weight. We needed a firm chassis and didn't want any flexing in the frame, which would add just that much more stress on the body. The plans for the basic chassis are available in the Hot Rod Mechanix Magazine Vol 5 #2 1991 issue, c/o Tex Smith Publishing, P.O. Box 726, Driggs, ID 83422, cost $5.00. This is an updated version of the original plans in the September, 1947 issue of Mechanix Illustrated Magazine. This article called "Trailer For Two" can be purchased from Grant and Lisa Whipp of Tales and Trails and it helped us get some better ideas. Even if you are not building your own Teardrop from scratch, I suggest you purchase all the plans from Tales and Trails just for a better understanding and appreciation on how the originals were built. Click on the buttons to view a sample of the original plans and the modified version that we came up with.
The difference in ours is a larger 3"x3" tongue, the tongue terminates mid way instead of full length, center length wise cross member (not required), the gusset plates on the tongue, corners, and spring hangers. We added a bumper interrogated into the frame with a receiver hitch. Click on the thumbnail images to view the larger image.
HITCH is a Atwood Class II, 3500# capacity, 2" ball, bolt on straight tongue type attached with 1/2" grade 8 bolts. It can be replaced easily if warn prematurely by dirt. I used a 1/4"x2"x6" strap welded under the tongue for the safety chain. Your safety chain should be attached in an "X" configuration so the tongue will land on the chain instead of the ground.
TONGUE The distance from the frame to the ball is 34". I arrived at this figure by subtracting 1/2 of the tow vehicle's width and adding 2". The straight tongue is short enough so the Teardrop tracks right behind the vehicle and jack knifes over a 90 degree angle and will make it easy to maneuver around off-road obstacles. Ever try a "U" turn on a narrow dirt road? While camping, our vehicle can be at a right angle to the Teardrop with the tail gate opened up over the tongue for those "tailgate" parties. The tongue stops at the center cross member and is welded underneath the frame and cross members. There are (2) .120"x6" rectangle gussets inside the front rail attached to the tongue. The 6 conductor wiring cable will run inside the tongue and then to the kitchen bulkhead where it will terminate into a circuit breaker junction box. The middle cross member that is going the length of the chassis is for the plywood/insulation floor seam, otherwise this cross member wouldn't be required for a standard 4' wide Teardrop. More will be explained in the BODY PAGE.
BUMPER is actually the .120"x2" rear main frame rail and has a cross member welded inside it to terminate the Teardrop body. The seam between the (2) square tubes is caulked so the rear bumper looks like it's a 2"x4". A 2"x6" receiver hitch is welded on under the (3) cross members and will carry a heavy duty home made mountain bike rack. The outside frame rails are welded miter joints in the corners. At each inside corner I welded a .120"x6" square gusset plate with (2) 3/8" bolts tack welded to mount the (4) Atwood folding and extendable (15"-21") stabilizer jacks (cap. 1000# ea). Outback camping locations are not actually level so this option will come in handy. No tongue jack is required since I'll use the (2) front stabilizer jacks to hold up the Teardrop for now.
AXLE is a round 2000# capacity, 67" track length, 55" spring centers with (5) lug 4 1/2" bolt circle high speed hubs. We purchased this Reliable brand axle kit from Northern Tool & Equipment for $119.95 and is part number 124351-C151. They have many axles & kits available. Some of your lesser capacity axles have smaller wheel bearings. Good idea to carry some spares. The springs are 25 1/4" double eye (3) leaf. I may remove one leaf after experimenting with the ride. Lower capacity replacement springs are only $25.00 per set. Rubber torsion axles are nice but I couldn't experiment with adjusting the capacity. The front spring hanger has a 2" triangular gusset welded to the center cross member. The small rear shackle spring hanger has a 3/16"x2"x4" fish plate welded between it and the .120"x2" frame rail. The axle's center is located 42" from the rear bumper. This formula is from a fellow Teardropper, William Adkins, who uses a measurement of 34 1/2" for a 8' body and add 6" for each additional foot in body length. I have an additional 2" with the bumper. You'll notice that most Teardrops have their axles placed at the rear third of the body. This axle position should keep the tongue weight at the suggested 10-15% of the trailer's GVW, which this figure is from manufacturer and federal agency suggestions. We'll add shocks later.
WHEELS are white modular 15"x5" with "0" offset. This offset is important because you should have 2" of clearance between your tire and body for suspension and tire sway.
Let's build a tough body for the Outback.