Driveshaft safety loops

Most of us know that with upgraded engines and tires etc, that we should be running a drive shaft safety loop.

Many people, myself included buy the universal style and bolt them to our floor pans.

I'm here to encourage you to invest in something more substantial!

I recently sheared the ears off a u joint on a 1-2 shift.

My safety loop worked, but just barely! One of the four mounting bolts was pulled through the seat riser. Two more bolts were almost pulled through, washers and all. Two of the four bolts that hold the lower half in place were stretched badly and one was gone.

If this had happened on a 2-3 shift I am certain that the driveshaft would have torn out my exhaust system rather than just partially flattening my H pipe. It might well have dug into the pavement and caused a loss of control, or come through the floorboards and caused serious injury.

a driveshaft safety loop should be strong enough to prevent all of this and should be mounted to something more substantial such as the subframe connectors that many of us have added.



I've gone to great expense to upgrade my slip joint, my driveshaft my pinion yoke and pinion support to try and avoid a failure of this type in the future.

Stock driveshafts aren't meant to handle 500 ft pounds of torque. They aren't really meant to handle 400 ft pounds of torque.

If you are going to build a hot engine, please remember that the weak links will show up. 1330 U joints aren't up to the task for some of you. It will cost you close to a grand to put a top quality shaft u joints and yokes in your car, plus labor if you don't do it yourself.

Invest the money to be safe and don't trust a 20.00 universal strap to protect you and your investment from serious injury or even death.

I got lucky this time-are you feeling lucky?

When I was in high school a guy we knew was street racing and his driveshaft failed about a foot from the front joint. The portion remaining in the trans beat the crap out of his floorboards and the back half stuck in the pavement and vaulted the car up in the air. He put two loops in the next day. Put them close to the joints and tight around the shaft (ha) as the shaft will do less damage spinning vs. flailing around wildly.

Glad your car wasn't too beat up Jeff.

Great advice glad it wasn't even worse. Heck I broke three rear joints with bone stock 351 I know they are weak. This was when brand new now after 40 years no telling.

Now when you get the driveshaft beefed up the clutch will go, then the transmission, then the axles they the rear. Something has to be the weakest link.

David

Good call ESPECIALLY for manual trans cars!

I broke countless U-Joints and even a pinion shaft banging gears

with a 302 Mustang. Embarrassing moments at Baylands Raceway Park

back in the day!

Paul

That's one thing I don't have to do on mine, has a huge stiffening plate across the underside that will prevent driveshaft or ujoint failure to cause any other problems

I am glad to hear it was not as bad as it could've been.

Would the safety loop that attaches to the subframe connectors interfere with the exahust?

1971 M-code Mach 1

is there a commercially available rugged strap ?

I have the Tinman connectors and they sell a safety loop that attaches to the connectors. I want to install them but i am wondering if they end up in the way of the exhaust.

1971 M-code Mach 1

I have the Tinman connectors and they sell a safety loop that attaches to the connectors. I want to install them but i am wondering if they end up in the way of the exhaust.

1971 M-code Mach 1

Click to expand...

It did in my car, but I have a 3" exhaust and the bar was also a little short. I would measure between the subframe connectors and check with them on the length.

The loop is a nice size and would fit the tunnel well.

As to commercially available ones-yes there are many better ones available

I'm having one made by a friend that has a mandrel bender at work that is similar to this one, but it will be a little different.

http://www.summitracing.com/parts/cee-3029/overview/

One of the problems I see with the universal loops isn't so much the strength of the materials, but the numerous mounting bolts and assembly bolts all are points of weakness. Additionally mounting to the floorpans ends up under the seats where the floor and the riser both are.

I suppose if you were to fabricate a mount with a tube that slipped up through the floor and supported the bolt under the riser it would be better, but still not optimum.