I need to add driveshaft safety loops to my 40 ford and was wondering if 1 or 2 should do the job? one at each end of the driveshaft or one centered between the trans and rear axle? Any pro's or con's?
Just my opinion... It's a big deal if the front of the shaft drops and digs in. Not such a big deal if the back drops. A single loop should be towards the front. C
Yeah, and it should be no more than 6" from any couplings. I think that is what NHRA says. It might be 12"... I'm sorry, I forget. But one up front is usually sufficient.
One near the front joint is all that is required, but one in back is nice to catch it from whipping. Only problem is it makes it harder to remove the shaft for repairs. Doc
And if you put a loop in back, make it oval, and kind of tall, both for suspension travel and to make the shaft eaiser to remove The odds of the driveshaft coming loose are pretty low, so you'll be safe with only one front loop.
From the NHRA rule book, "In place of a crossmember, in the vicinity of the front universal joint, all cars in competition using open drive shafts must have a retainer loop 360 degrees of enclosure, 1/4 inch minimum thickness and two inches wide, 7/8-inch x .065-inch welded steel tubing, securely mounted and located within 6 inches of the front universal joint for support of the driveshaft in case of a U-joint failure." In the illustration, the measurement appears to be made from the center of the U-joint to the closest edge of the drive shaft loop. There is more, but if you have already been told you need one, then this is what you need.
A rear joint failure might not be too dangerous on the dragstrip. On the street you need to worry more, if your car is powerful enough to make that a serious possibility. A failure at rear joint might well cause severe damage to underside of car and, worse, allows the shaft to slide out of the trans onto the road. On the highway, this could easily cause severe problems for the car behind you, causing injury, loss of control, lawsuit... I had a just plain worn out rear joint break once as I stupidly drove round and round the block trying to figure out the odd noise beneath the car, and it dropped right out on the ground. If I had been going 70 on the interstate, what would that thing have done behind me?? Thank goodness all my cars have torque tubes now...
Good point, maybe it would be better to do two to save the floor from taking a beating or launching the shaft out from under the car.
loop should also be as small around the shaft as you can make it to keepit from moving too much. the ones i have made all are an inch bigger then the shaft movement
I'd go with two if you're really worried about it. I was in a Bronco once that broke the front shaft u joint, it beat the shit out of the underside of the truck. Flatman
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