Driveshaft loops: Keep it in the frame or let it out?

Okay... I'm to a point where I need to make a decision on my driveshaft loops. I've long since put them in place, but my original thinking was:

1) Retain the front of the driveshaft to prevent catapulting in the event the front yoke were to give out

2) Allow the driveshaft to drop out the rear, in the event that the rear yoke were to let go.

I'm debating rather or not to keep the driveshaft in the loops by adding a lower removable loop to the rear. From the looks of things, I'm guessing it would want to slide out no matter what I did though. I have zero experience with breaking drive shafts, but my logic tells me that whipping drive shafts break things and break people if they get in the way.

Reality is, it will probably never let go because were not talking a real extreme drive train here (400 hp TOPS!), but just in case, I would like to have my bases covered.

One more thing to add... With the way the sheetmetal is at the rear of the car, if the drive shaft were to drop out the back, it could get hung up anyway.

Your experienced input would be appreciated!

Thanks!

Picture of this part of the ch***is...

 

Make a removable lower for the rear. Trust me, that sheetmetal will only make shrapnel if the rear Ujoint goes!

 

You're halfway there. Just make a removeable bottom half for the hoop you already have.

 

Yeah, making it is the easy part. Just wondering if I would be doing more damage by retaining it. I'm guessing not, but just needed to ask.

Anyone with both full front and rear loops ever have a driveshaft let go? How did it behave? Did it stay in the loops or make it's way to the rear and swing up underneigth??

Should I REALLY retain it and make a removable bottom bar as part of the loop that would extend between the front and rear that would catch it in the event that it would slide back and the front would drop down and bring a catapulting effect anyway?

 

Im only going to run one..up near the front of the DS..my thinking is this..if the rear joint lets go..it will soon be out from under the car, even if it beats up some **** as it goes,or gives you time to react and clutch it, or shift to N, im hopeful that it never happens, but if it does my thinking is that the more critical one is the front hoop to deal with the pole vault issue.

im sure its one of those trade off deals..but the loop up front is not an option

 

A driveshaft won't ever come in to visit you!!!! Oughta work.

 

The frame looks great! You're there so might as well make a lower loop. Beyond that I wouldn't worry about all the crazy "could'ves". The wheel could fly off and roll up the street denting the back of Mr. Chuck Norris' brand new Texas Edition Silverado Pickup, but that doesn't mean you should go around with nunchuks in your belt

 

Oh no. I NEVER do that, right? (shaking my head at myself)

Just thinking how close I'm sitting to that driveshaft gives me the heebeegeebees sometimes. I don't ever want that thing coming inside to whop me up side the head, pelvis, or anything else...

 

Actually you should ALWAYS drive around with nunchuks in your belt.

 

(Note to self: Nunchuks under my belt) GOT IT! Okay!! Thanks!!

BWAHAHAHA!!

Waiting for the Chuck Norris driveshaft jokes now.

 

I can screw up a thread like THAT!

 

BWAHAHAHAHA!!!! That rules!!!

(Note to self: Get a pair of Action Jeans for driving around in my Model A. Just in case a fight with a drive shaft breaks out.) Got it! Thanks for the hint!!

Seriously though... Anyone have any experience with driveshaft behavior before this thread turns into pure comedy?

 

Scooooooooot! you know better!

 

WOW!!! You must have been feeling my brain waves, Steve!!! What got me started on this whole thought process was your picture on FB that I commented on!! Thanks for replying... That is some SERIOUS drive shaft retainment!!!

 

I think that driveshaft will come hit ya while you're in bed at 3am just out of spite.

 

BWAHAHAHAHA!!! You're killin' me today!!! HAHAHAHA!!

 

i'd definitely retain it fairly closely anywhere in the driver's compartment but past that i wouldn't worry too much. that front hoop you've got is probably fine. i don't see a reason to try and keep the whole driveshaft from coming out. just limit its whipping area.

 

I'd close in the back but make it structural to tie those two bent rails together. Yes, i've experience with a driveshaft coming loose. At Dinwiddy (Richmond VA) a customer of mine pulled 4th gear when the 9" center section broke loose from its' bolted flange. The driveshaft collapsed, pulled rearward out of the single tubeular restraint and hit him on the shoulder on its' way to the roof. The universal joints exited thru the roof. When i redid the car i enclosed the universal in a chromemoly tube and shortly after NHRA made it manditory to enclose the universal for promods etc.
I would be afraid of the diveshaft coming up, i am more afraid of one of those universal cups winging up thru the tunnell. Consider welding a curved .060 or .090 (approx) shield formed on the upper third of your forward safety loop to deflect any universal cup activity.

 

Probably not a popular opinion, but in the present build, mine will retain the shaft if the front breaks but lets it go if the rear breaks. Experience tells me to get it out when its under power from the engine. It immediatly starts slowing down when the front breaks and will find a place where it just wants to lay there and turn. When the rear beaks, it will start whipping around in the loop at a lot of RPM. You aren't as quick on the throttle as you think. If it gets a dent, it will instantly make a right angle bend and will tear things all to pieces. Make your loop just big enough to not let the driveline hit in normal driving, whatever that may be to you. The bigger the clearance, the more room to beat around. I've been trying to come up with a idea to make the shaft run in a floating bearing that would stop all beating around when something breaks. Easy to do with solid mount engine and differential , not so when you have to have some movement.
Incidently, I am making the tunnel out of 11 ga.

 

Some great info here! I really like the idea of something to cover the universal joint components up front. Maybe an eyebrow shaped thing.

I think I'm going to ditch the rear loop that I made. Think I'll do something different all together. Something a little more substantial. I've sinced changed the ride height slightly, so I can rethink the travel of the driveshaft and everything ***ociated. I also like what Steve has done above to trap the drive shaft.

Makes complete since about a drive shaft finding a right angle and then trashing everything. That's the type of stuff that scares the hell out of me! The last thing I want is part of my floor panelling turning into flying blades of 18 and 20 gage steel!

Great info! Keep it coming! Some examples are good as well.

 

I would contain it at both ends. A loose shaft under the car can still pole vault if it snags the back of the car.

 

Exactly what I'm thining too, Scotty!

 

Some more of Steve's awesome work. Steve, are these loops formed from two u-bends and but welded together?

 

I'd attach the top of the loop to the floor, and leave the bottom half welded to the frame, then you can pull the body off and still have a loop under it.

I used 3/16" thick flat iron on mine and arched it and attached it to the floor runners. Then my subframe is also under the driveshaft so if it did fail I wouldn't pole-vault!!

 

I have a loop in the tunnel as part of the floor already. Ahead of ya' buddy!

 

Then what are you asking for if you already got a loop?? Maybe you're ahead of your thread too??

 

Naw, it's not substantial enough. If the driveshaft wants to come through, it's comin' through! The floor is already done, so not much I can do except add to the ch***is.

Anyone want to share their driveshaft containment devices? Looking online I mostly see just front and rear full loops. Nothing that really looks substantial enough. Am I seriously over-thinking this? (as usual)

 

If you're driveshaft comes off you're worried about it coming through the floor? How's that if you don't ever get it finished??

 

It doesn't take much to contain one. The sfi kits can be as light as 1.5" x 1/4" strap type loops. Take a look at the universal kit from Mr. Gasket. If you have any amount of tubing between the shaft and tin, you are fine.

 

OOOOO!!!! Cheap shot!!! It's like THAT, huh??! How's your coupe?