Sled pulling....anyone done it with a 17+

qzillanut · Jun 6, 2018

Has anyone pulled a new 17+ on a sled yet? I’m considering it this weekend, but concerned about the aluminum rear drive shaft.

ZCherry27 · Jun 6, 2018

Not me personally, but the farmer next to me pulled his brand new 17 at the county fair last year.

Stock class, did decent, and hasn't had any issues yet, and it would probably be easier to count the number of times I haven't seen it hooked to a trailer. So it still gets worked pretty good.

qzillanut · Jun 7, 2018

Thanks. I want to grudge match my brother’s dodge. He should destroy me as he has twin pumps, big manifold, huge turbo, and too much other crap I can’t remember. But it’s just plain stupid to ride in. 4th gear dry pavement burnouts are nearly effortless.

SoGrand · Jun 7, 2018

qzillanut said:
Thanks. I want to grudge match my brother’s dodge. He should destroy me as he has twin pumps, big manifold, huge turbo, and too much other crap I can’t remember. But it’s just plain stupid to ride in. 4th gear dry pavement burnouts are nearly effortless.

Then why do it and take the chance of hurting something on the truck if he has all that done? :shrug: Not even a fair comparison if you ask me and stupid cause it means nothing unless you do all the same stuff to your truck and then yes yours would be stupid to ride in also and then make it a fair comparison.

BK39 · Jun 7, 2018

Exactly what I was thinking. Knife to a gun fight kinda deal.

Not to mention, you are already complaining about the way your truck shifts. Put a big tune in it, hooked to a sled.............bye bye tranny.

qzillanut · Jun 8, 2018

Omg you guys sound like my wife. Truck pulling was born here. It’s what we do on weekends. And who actually takes theirs to the dealer for repair. A breakdown is just a reason to upgrade.

qzillanut · Jun 8, 2018

The only reason I broke subject was fear of that beer can repurposed, and aimed at my rear axle

BK39 · Jun 8, 2018

qzillanut said:
Omg you guys sound like my wife. Truck pulling was born here. It’s what we do on weekends. And who actually takes theirs to the dealer for repair. A breakdown is just a reason to upgrade.

I hear you. As long as you are cool with it breaking and not mad after it does. Best of luck this weekend, shoot some video of it.

BOSS450 · Jun 8, 2018

Doesn’t care about breaking a transmission but worried about a drive shaft.

qzillanut · Jun 9, 2018

BOSS450 said:
Doesn’t care about breaking a transmission but worried about a drive shaft.

my trans doesn’t mess up in 1-3. The only shift concerning is 3-4 and that’s not gonna happen pulling a sled. So yeah my trans will be fine.

BOSS450 · Jun 9, 2018

qzillanut said:
my trans doesn’t mess up in 1-3. The only shift concerning is 3-4 and that’s not gonna happen pulling a sled. So yeah my trans will be fine.

So you’re reasoning why your transmission will be fine is bc it doesn’t mess up in those gears yet. With that reasoning that means your driveshaft won’t fail bc it’s fine now too. You see the flaw in that?

qzillanut · Jun 10, 2018

BOSS450 said:
So you’re reasoning why your transmission will be fine is bc it doesn’t mess up in those gears yet. With that reasoning that means your driveshaft won’t fail bc it’s fine now too. You see the flaw in that?

My reasoning that my trans will be fine is that I have seen dozens of d’leeted and tuned 6.7’s pull with no issue. I truly have no idea when Ford went with an aluminum rear drive shaft, but I know all 6.7’s have 6r140’s. I pulled my old 7.3 truck many times over the year’s with no issue. I can’t imagine a 6r140 is gonna is gonna take a dump pulling it one time a year at the county fair in hometown class. I’ve not yet ever seen that happen. I’ve seen plenty of trucks chuck driveshafts though.

qzillanut · Jun 10, 2018

Another reason is that when sled pulling you run low range. The lower axle and transfer case ratio’s help to reduce the torque output on the rear output shaft of the trans. It’s really not facing anymore torque when pulling a sled in third gear than it is in high range pulling a trailer.

I have built pulling trucks for years. We have successfully used bone stock old school 3 speed manual transmissions behind 1000+ hp pro stock head gas engines running down the track at 9000+ rpm. With profab transfer cases and 6.20:1 axle ratios you pull them in 3rd which is direct. The trans only has to deal with the peak torque of the engine in direct. We no longer use the 3 speeds as the 1 1/16 input shaft will eventually fail. But we are talking about 1000+ hp trucks pulling many times a weekend chasing a points series.

qzillanut · Jun 10, 2018

Some simple math you might grasp. If you pull a 6.7 truck in high range 1st gear you will pull at 14.1:1 final drive ratio. It’s 3.974X3.55 if you have 3.55 geared truck. Which is a decent final ratio for a diesel. If you pull in low side of the transfer and 3 gear of the trans it’s about a 14.6:1 final drive ratio. To break that down it’s 1.516X2.71X3.55. I’m not 100% on the transfer case ratio. I’ve found a few discrepancies on it in my brief search to prove a point. It’s irrelevant to the point. So the engine produces roughly 1500 ft lbs of torque at the crank when tuned. We will use that as a constant for the math of my point. And we won’t consider losses for the sake of a point because they will be fairly linear. So pulling in high range the rear output of the transmission has to deal with roughly 5,961 ft lbs of torque at full hook, full power, no parasitic losses. Pulling in low range the rear output of the transmission has to deal with roughly 2,274 ft lbs of torque at full torque, 100% hook, and no parasitic losses. However the axels deal with roughly 21,150 ft lbs of torque for high range and 21,750 ft lbs for low range 3 gear transmission. Of course no losses. I simply stated all of this to illustrate how torque is distributed differently amonst the drive train under load.

qzillanut · Jun 10, 2018

So back to what I was saying about pulling a trailer. Let’s consider pulling a steep mountain grade. You are full throttle in 3rd gear (*** that mountain). It’s the same torque on the transmission output as pulling the sled in low range, however it’s significantly less on the drive shafts and the axles. It’s only 8072 on the axles. It’s the same 2,274 ft lbs of torque on the transmission rear output as pulling in low range on the sled. So there it is....mathematically explained why I care more about my drive shaft sled pulling than my transmission. And also the fact that in the 30+ years I’ve been sled pulling I’ve seen maybe a couple dozen transmission failures. I’ve seen hundreds if not thousands of broken axles and driveshafts.

Jomax · Jun 10, 2018

The drive shafts aren’t aluminum. At least mine wasn’t.

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Spatel23 · Jun 10, 2018

With all this “experience” wtf are you even asking ?!

go hill billy your **** already or sit in the crowd doing more “mathematical” simulations on your abacus