Anyone messed around with, or seen one of these?
www.powertrainsavers.com

Wow....if it's not like the Tornado Fuel Saver device, that's got possibilities.... I am a little concerned that they describe installation as necessarily being on the "yolk" end of the d/s.

:laughing: :shaking:

While cool in principle. I'll bet it's heavy as hell and expensive, not to mention big. Might be worth it on a high-powered Diesel towtruck though.

But to answer your question, this is the first I have heard of it.

looks like a rock grabber to me!

torque fuse? fancy name for a shear pin.


looks interesting, but isn't that what U-joints do for you? :eek:

torque fuse? fancy name for a shear pin.


looks interesting, but isn't that what U-joints do for you? :eek:

Principle behind it is to allow the "fuses" (sheer pins) to bust first, before a UJ, R&P, Axle, etc.... Also, instead of falling to the ground and potentially spinning wildly, it free spools on itself. You simply replace the fuses.

By being mounted on the t-case side of the shaft, I don't think it would be that vulnerable to damage (course, shit happens).

If the thing actually worked, it would be a lot easier to replace the fuse than replacing axles, uj's, or R&P's.....I bet Keith and Norman could have used it.

I like the theory behind it, but I'd like to see one up close. Not sure about prices, either.

Principle behind it is to allow the "fuses" (sheer pins) to bust first, before a UJ, R&P, Axle, etc.... Also, instead of falling to the ground and potentially spinning wildly, it free spools on itself. You simply replace the fuses.

By being mounted on the t-case side of the shaft, I don't think it would be that vulnerable to damage (course, shit happens).

If the thing actually worked, it would be a lot easier to replace the fuse than replacing axles, uj's, or R&P's.....I bet Keith and Norman could have used it.

I like the theory behind it, but I'd like to see one up close. Not sure about prices, either.

They did a write up on this in one of the last 4-wheeler or whatever magazine. They put it on the new XXX Titan. Fuses start at 2000LB and they are basically shear pins. The are $100 a pop to replace and the unit is way expensive. I can't remember the number but I do remember being shocked. One advantage I see to this is that it stops the d-shaft from dropping if it severs, but that really doesn't do much for the crawling crowd.

To me, this seems stupid. I just don't believe in fuses. Build as strong as you can and hope for the best.

oops, I guess this one- :eek: doesn't mean sarcasm,

is this more like it :flipoff2: ?

I understand the design, I was questioning it's value vs. price/complexity/weight added. It doesn't look cheap to buy or install


I deal with shear pins at work on a regular basis, and they are a PITA..., but probably better than repacing broken equipment.

Their was previously a rover hub flange that had clutches in it. Tom Walsh used them for a trip or two. They sucked. So often you need just a kunts hair more torque than you setup can handle constantly but does fine in short burst. Basically in 4 wheeling, your drive train has two limits. These are constant and momentary. Your momentary strength far exceeds the constant limit. So, a fuse or something of the sort that is designed to break or slip well before anything critical breaks, will be set at the constant limit of the drive train. It will then break or slip at critical moments that you are trying to use the momentary strength of your drive train. This can litteraly stop you from doing simple trails, due to premature breakage or slippage. Case in point, In moab, before burning up his rear diff, Tom Walsh could not climb Dump Bump. It is a fairly simple obstical, that should have either been climbed easily by his truck or he should have flipped over backwards. He could do neither due to the flanges slipping

I think I already have fuses in my driveline anyway. CV joints....

I think I already have fuses in my driveline anyway. CV joints....

Their was previously a rover hub flange that had clutches in it. Tom Walsh used them for a trip or two. They sucked. So often you need just a kunts hair more torque than you setup can handle constantly but does fine in short burst. Basically in 4 wheeling, your drive train has two limits. These are constant and momentary. Your momentary strength far exceeds the constant limit. So, a fuse or something of the sort that is designed to break or slip well before anything critical breaks, will be set at the constant limit of the drive train. It will then break or slip at critical moments that you are trying to use the momentary strength of your drive train. This can litteraly stop you from doing simple trails, due to premature breakage or slippage. Case in point, In moab, before burning up his rear diff, Tom Walsh could not climb Dump Bump. It is a fairly simple obstical, that should have either been climbed easily by his truck or he should have flipped over backwards. He could do neither due to the flanges slipping

I think that was well put. I have always thought along those lines about the GkN Rover hub torque limiters but couldn't think how to explain it.
Bill.

I wouldnt say well put, but thank you.

maybe some destructive testing is in order, if the momentary torqe for breaking something comes out to 5000ftlbs (guess), then maybe 4800ftlb "fuses" are in order?

The light truck shear pins are available at 2000-8500ftlbs, that's a pretty broad range to pick from. I don't know where to get real break-strength values from, (doubt LRNA would be much help) but it would be a good start point. The supplier ought to be able to help with a good ballpark starting point, knowing your application.

If you're popping shear pins on stuff you shouldn't, put in a higher rated set. If you break a ujoint or diff, go lower rated.

If they cost $100 a pop that would be some expensive testing to go through several sets,

K.C. Making Friends!?!?!?

Sorry just kidding I couldn't have described the GKN stuff any better..

Freinds No, I hate all of you. Its sorta my thing lately. Ive gotta take my rage out on someone.

And by the way, toyota longfields have been tested at over 10K lbs from what I remember. Rovers are much less though. I will say this, the drive shaft is minorly protected from the diff gears. But Im not sure what the division of torque is. I guess it could be the max torque at the wheel, divided by the ratio of the diff gear set. But please correct me if I am wrong.

Assuming 10k at the wheel you would have 2400 or so at the drive shaft with 4.11 gears. Is that right. So lets say a rover cv is good for 7000ft/lbs, you would have 1703 ft/lbs at the drive shaft with 4.11 gears. I guess that explains why you dont see many rovers popping good ujoints.

We've used them in the boat (twin 1000hp Cats) but have never broken anything. I'm not sure I'd want to try and figure out this "momentary tourqe " thing and depend on shear pins to save the drive train. We just use them (and they are designed to break well before anything else) so if something does break the shaft doesn't go flying through the hull, or snap the shaft outside the hull and send a $2500 wheel to the bottom.

Freinds No, I hate all of you. Its sorta my thing lately. Ive gotta take my rage out on someone.


Yeah, yeah, yeah. Just like Pendy. Get either of you on the phone and you're both pussy cats!

PT

So often you need just a kunts hair more torque than you setup can handle constantly but does fine in short burst.

Haha...you said 'hair'. :laughing:

Thats just pendy and myselfs charm.

"So lets say a rover cv is good for 7000ft/lbs"

That's mighty generous..

You, Pendy, charm? again:

That's mighty generous..

But then Rage.... That's a good thing...

Bills Fully modded front axle held up fairly well in his TDI with 130 some odd to 1 crawl ratio, and put well over 15K of torque on the setup being carefull How much the CV's ever actually saw, is anybodies guess.

We've used them in the boat (twin 1000hp Cats) but have never broken anything. I'm not sure I'd want to try and figure out this "momentary tourqe " thing and depend on shear pins to save the drive train. We just use them (and they are designed to break well before anything else) so if something does break the shaft doesn't go flying through the hull, or snap the shaft outside the hull and send a $2500 wheel to the bottom.

What would be wrong with , on the driveshaft,using spring loaded slipping overload clutches, similar to what is used on tractor pto driven slashers . If the slasher blade hits a rock or piece of derelict machinary buried in the bushes, the clutch slips, absorbing the impact. I have never seen one but I assume the GKN hub uses the same principal at the wheel ends.
Bill.

Again, the "fuse" or "clutch" would have to be set so low to prevent breakage, you could not use the truck in serious situations. The momentary load that a cv or shaft can handle could be thousands of lbs higher than the constant.

On a stock shaft, I don't think the U-joint is the weak spot. It's the flange. This is the second flange I've broken.

The U-joint was a Spicer 5-x4, or what ever the number is to that effect.
http://www.virginia4x4.org/gallery/albums/userpics/10001/Jeremy%20Cupp%20%28Custom%20Harley%20Davidson%29%2 0426.jpg


Although it's not clear as to what actuall broke first, I feel it was the flange because of the way it's peeled open.

Id say you are running the wrong gear ratio for your tire size(relative terms), or you have alot of power (relative terms). Because the half shafts even if upgraded tend to fail before the drive shaft. Running 3.54 gears on a 35" tire will likely lead to more broken drive shafts, where a 4.11 or better gear set will lead to more broken half shafts. Make since?

Sure, makes sense. I've got 33" tires, 3.54 gears, and a 4.6 making about 250hp. First time this happened was on the trail. Second time was due to stupid games....

Those are interesting numbers. Not sure where those would put you. Would be interesting to know what 4.11's would do to you. I should think your driveline "fuse ie ujoint's" would move down into the cv's and the rear halfshafts. But I would think you would be pretty close either way you went

On a stock shaft, I don't think the U-joint is the weak spot. It's the flange. This is the second flange I've broken.

The U-joint was a Spicer 5-x4, or what ever the number is to that effect.
http://www.virginia4x4.org/gallery/albums/userpics/10001/Jeremy%20Cupp%20%28Custom%20Harley%20Davidson%29%2 0426.jpg


Although it's not clear as to what actuall broke first, I feel it was the flange because of the way it's peeled open.

I have replaced a number of front driveshafts of that type recently on customers trucks due to seizure of the plastic coated slip joints. Any chance that a similar seizure contributed to flange or UJ failure?
Bill.

I have replaced a number of front driveshafts of that type recently on customers trucks due to seizure of the plastic coated slip joints. Any chance that a similar seizure contributed to flange or UJ failure?
Bill.

I bent a 12-ton hydraulic press trying to separate a seized sliding joint on a front driveshaft. Once you get that shit out of there, you'd be surprised just how long and how well a front driveshaft without that plastic shit will last.

Wonder why they seize and how they seize so tightly.

PT

I have replaced a number of front driveshafts of that type recently on customers trucks due to seizure of the plastic coated slip joints. Any chance that a similar seizure contributed to flange or UJ failure?
Bill.

This was a rear shaft. Don't think it was plastic coated, but it came apart easy.....

I have very recently become a believer in devices that absorb shock loads, but not necessarily shear pin designs.

The circumstantial evidence I'm leaning against is my Suzuki trialer, that after two years of no breakage has consumed five CV's and three front halfshafts in three comps. In the latest one, I broke the right shaft clean off and pulverized the cage in the left CV in the very first stage.

The only thing I have changed is that I have beefed up my steering with new balljoints, cromo bars and reinforced the sloppy frame bracket for the servo. Previosly, the steering would flex when a front tire suddenly gripped. It has cost me many penalty point when the truck (can something the size of a large ATV be called a truck?) suddenly changed direction, but I also believe it has saved me from breakage.

Now, going back to diffuse steering is obviously not an option, but flexy drive flanges, if availabe, might be.

On a stock shaft, I don't think the U-joint is the weak spot. It's the flange. This is the second flange I've broken.

The U-joint was a Spicer 5-x4, or what ever the number is to that effect.
http://www.virginia4x4.org/gallery/albums/userpics/10001/Jeremy%20Cupp%20%28Custom%20Harley%20Davidson%29%2 0426.jpg


Although it's not clear as to what actuall broke first, I feel it was the flange because of the way it's peeled open.I see the broken yoke, but can't make out the break on the flange.

Wow....if it's not like the Tornado Fuel Saver device, that's got possibilities.... I am a little concerned that they describe installation as necessarily being on the "yolk" end of the d/s.

:laughing: :shaking:Don't they have egg on their faces!

Now, going back to diffuse steering is obviously not an option, but flexy drive flanges, if availabe, might be.

Like these you mean:-


http://www.outerlimits4x4.com/PHP_Modules/phpBB2/viewtopic.php?t=56246

Yes, couldn't remember where I saw them. Only problem, I need them primarily for a Zuk...

I bent a 12-ton hydraulic press trying to separate a seized sliding joint on a front driveshaft. Once you get that shit out of there, you'd be surprised just how long and how well a front driveshaft without that plastic shit will last.



PT

If you remove all the plastic lining I would have thought the slip joint would be too loose and sloppy ?
Bill.