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Matt's Off Road Recovery.

Steve300xcw said:
Wonder if a guy could plumb in a system like what some of the log trucks are running around here.

Flip the switch an it drops the air to whatever psi its set for.

Flip it back an the bitch airs back up.
Click to expand...
The axletech 4ks are supposed to be CTI if I am reading it correctly.
 
CarterKraft said:
More dumb ass math says 250 hp into a 63 rpm shaft = 20841 lb ft of torque...
Every doubling of shaft speed reduces the torque output by half.

Am I way off base? This is the first time I have gone this far into drive shaft speeds, gear ratios etc.
Click to expand...

The math is right, but where does your 250 HP figure come from?

I always use torque for this stuff, since HP is derived from torque x rpm anyway. The torque ratio:

2.48 (trans first gear) x 1.96 (NP-205) x 2.72 (ORD) = a torque multiplier of 13.2213.

If the engine originally spit out 600 foot pounds of torque to it's output shaft and you put that into a perfect driveline with no losses and those ratios, you would be getting around 7932.8 foot pounds of torque (600 x 13.2213 = 7932.8256) going to the output shafts of the NP-205 (but there are two outputs loaded in 4x4). Then there is the driveline losses through the slushbox and the cases which will further reduce it... On the flip side, the slush-o-matic torque converter can boost the torque output momentarily, maybe by up to 2x or so. This is a built transmission, and I don't remember what the details are.

There are two beefier output shafts that I know of for a 205:


The Titan you have to machine the 205 and loose the speedo output. The JB is drop in, it is just machined away less than stock (smaller/shorter oiling grooves).

The ORD rebuilt NP-205's let the customer specify what size output shaft you want when you order them. So probably, a 32 spline stock Ford output shaft was used.
 
In one of the latest videos, I watched him clear snow off a customers newer Toyota with a metal fucking shovel...how stupid do you have to be to do that?:flipoff2:
 
Pablo said:
The math is right, but where does your 250 HP figure come from?

I always use torque for this stuff, since HP is derived from torque x rpm anyway. The torque ratio:

2.48 (trans first gear) x 1.96 (NP-205) x 2.72 (ORD) = a torque multiplier of 13.2213.

If the engine originally spit out 600 foot pounds of torque to it's output shaft and you put that into a perfect driveline with no losses and those ratios, you would be getting around 7932.8 foot pounds of torque (600 x 13.2213 = 7932.8256) going to the output shafts of the NP-205 (but there are two outputs loaded in 4x4). Then there is the driveline losses through the slushbox and the cases which will further reduce it... On the flip side, the slush-o-matic torque converter can boost the torque output momentarily, maybe by up to 2x or so. This is a built transmission, and I don't remember what the details are.

There are two beefier output shafts that I know of for a 205:


The Titan you have to machine the 205 and loose the speedo output. The JB is drop in, it is just machined away less than stock (smaller/shorter oiling grooves).

The ORD rebuilt NP-205's let the customer specify what size output shaft you want when you order them. So probably, a 32 spline stock Ford output shaft was used.
Click to expand...
I am over my skis on these maths... I just found a online calculator that allowed for HP/speed = torque output.
My practical knowledge is from farm equipment, 540 rpm shafts vs 1000 rpm. You can put much more HP/torque through a shaft spinning twice as fast.
 
dave_dj1 said:
Matt did mention he needs to have it run down the road at 60-70 mph, what gear would work for that and still have a respectable crawl ration?
Click to expand...

I honestly don't think that speed is realistic. Maybe 60?

With that big of tire, even 10:1 axle gear was like 2800 rpm at 60 mph. So maybe something in the 8-9.xx like Carter is saying would be the best comprise.

5.xx are for 40s :laughing:
 
CarterKraft said:
It wasn't lost on me when I started watching him I was thinking "damn that's not what I would do" but then POP he had them pulled out and on there way while I'm sill looking for rigging gear...:homer:
Click to expand...
Those types of recoveries are pretty common around here unless someone sunk their rig in a mud hole. Soft sand or slightly too deep ruts don't take much to get in or out of.
 
Steve300xcw said:
Wonder if a guy could plumb in a system like what some of the log trucks are running around here.

Flip the switch an it drops the air to whatever psi its set for.

Flip it back an the bitch airs back up.
Click to expand...
Fairly sure his axles are set up for central tire inflation.
 
GM Guy said:
From the site: $4,784.87
Click to expand...
So call it $4k+1k.

Either way, the SCS doesn't even list a price so I assume that it's well north of an Atlas.

GM Guy said:
"$3000 core charge, 6 month warranty from the day of install. Thanks so much!"
Click to expand...
Did it actuallt list a core charge? I didn't see one.

Bebop said:
That's a straight through case.

They need a drop case.
Click to expand...
SCS makes a whole product line of drop cases with pretty much all the same features.
 
arse_sidewards said:
So call it $4k+1k.

Either way, the SCS doesn't even list a price so I assume that it's well north of an Atlas.


Did it actuallt list a core charge? I didn't see one.


SCS makes a whole product line of drop cases with pretty much all the same features.
Click to expand...
They make all sorts of transmissions too.
www.scsgearbox.com

Transmissions - SCS Gearbox Inc

Transmissions 20 Series With Reverse 1 9/16-24 Output Neutral and Reverse Switch Included Input Length per Customer, 1 3/8-10 Spline in Stock Pilot ID Per Customer 30 Series (Click to View PDF, Exploded Views, and Parts Break Down) Bellhousing or independent mounting Uses heavy-duty 10 Series...
www.scsgearbox.com www.scsgearbox.com
 
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arse_sidewards said:
So call it $4k+1k.

Either way, the SCS doesn't even list a price so I assume that it's well north of an Atlas.


Did it actuallt list a core charge? I didn't see one.


SCS makes a whole product line of drop cases with pretty much all the same features.
Click to expand...
You have to look at the SCS vendors.
Heres a 12.66" 4x4 direct mount box Not too bad pricing with all the options.

1677592030995.png



Here's a 10.66 with th400 mount, 1550 yokes, it looks like if they try they willm have a equal product to Atlas, hero, etc.
1677592456488.png
 
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3.7 ratio competitive price

IT still doesn't get the drive shaft speed up but it might help.
1677593460846.png
 
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CarterKraft said:
I am over my skis on these maths... I just found a online calculator that allowed for HP/speed = torque output.
My practical knowledge is from farm equipment, 540 rpm shafts vs 1000 rpm. You can put much more HP/torque through a shaft spinning twice as fast.
Click to expand...

That is correct as far as I know, it is just that the engine's input HP to the gear box isn't at all the same as the HP that comes out of the gear reduction box, so you cannot apply the same HP number to the shaft speed or you get crazy torque figures.

The shaft only cares about the torque as long as the RPM is below what it is balanced at. If you exceed its max torque handling ability it breaks regardless of shaft RPM. If you have a tractor that is 50HP and you put that into a gearbox PTO with an output of 540 rpm-- you have much more torque on the shaft than if you put the same 50 HP into a gearbox PTO with an output of 1000 rpm. Either way, after going through the reduction gearing the HP being produced by the shaft is no where near the original 50 engine HP.

I wouldn't try to fix the output shaft issues by increasing the output shaft rpm as it defeats the purpose of the gear reduction. Even with steeper axle gears those outputs are still going to see the max torque output if the skinny pedal is pressed while crawling in double underdrive, so he would still break stuff if this is the problem-- just maybe less often.

However, It is probable the shafts are binding. The case and shafts are flexing towards each other somehow. I bet those heavy ass axles are moving back and forth front to back or the case is moving towards them or to the side when skinny pedal applied-- too much slop somewhere. He always breaks when flexed and climbing and getting on the throttle. Maybe disconnect the shafts and measure the distances sitting level, then flex it and remeasure distances? Stick a go pro thing on it close up and flex and hammer and see what is moving...
 
Pablo said:
That is correct as far as I know, it is just that the engine's input HP to the gear box isn't at all the same as the HP that comes out of the gear reduction box, so you cannot apply the same HP number to the shaft speed or you get crazy torque figures.

The shaft only cares about the torque as long as the RPM is below what it is balanced at. If you exceed its max torque handling ability it breaks regardless of shaft RPM. If you have a tractor that is 50HP and you put that into a gearbox PTO with an output of 540 rpm-- you have much more torque on the shaft than if you put the same 50 HP into a gearbox PTO with an output of 1000 rpm. Either way, after going through the reduction gearing the HP being produced by the shaft is no where near the original 50 engine HP.

I wouldn't try to fix the output shaft issues by increasing the output shaft rpm as it defeats the purpose of the gear reduction. Even with steeper axle gears those outputs are still going to see the max torque output if the skinny pedal is pressed while crawling in double underdrive, so he would still break stuff if this is the problem-- just maybe less often.

However, It is probable the shafts are binding. The case and shafts are flexing towards each other somehow. I bet those heavy ass axles are moving back and forth front to back or the case is moving towards them or to the side when skinny pedal applied-- too much slop somewhere. He always breaks when flexed and climbing and getting on the throttle. Maybe disconnect the shafts and measure the distances sitting level, then flex it and remeasure distances? Stick a go pro thing on it close up and flex and hammer and see what is moving...
Click to expand...
Just saying—if 50hp goes into a gear reduction box, what comes out of it is 50hp minus friction losses. So, 45hp or something. The rpm (and therefore torque) may go through massive changes, but the horsepower is the horsepower.
 
OHV Wildcat said:
Just saying—if 50hp goes into a gear reduction box, what comes out of it is 50hp minus friction losses. So, 45hp or something. The rpm (and therefore torque) may go through massive changes, but the horsepower is the horsepower.
Click to expand...
Yeah, that checks out mathwise... ignore me... ignore.
 
The NWF titan 205 shafts for F/R are $1500 and 12 weeks out
Pablo said:
That is correct as far as I know, it is just that the engine's input HP to the gear box isn't at all the same as the HP that comes out of the gear reduction box, so you cannot apply the same HP number to the shaft speed or you get crazy torque figures.

The shaft only cares about the torque as long as the RPM is below what it is balanced at. If you exceed its max torque handling ability it breaks regardless of shaft RPM. If you have a tractor that is 50HP and you put that into a gearbox PTO with an output of 540 rpm-- you have much more torque on the shaft than if you put the same 50 HP into a gearbox PTO with an output of 1000 rpm. Either way, after going through the reduction gearing the HP being produced by the shaft is no where near the original 50 engine HP.

I wouldn't try to fix the output shaft issues by increasing the output shaft rpm as it defeats the purpose of the gear reduction. Even with steeper axle gears those outputs are still going to see the max torque output if the skinny pedal is pressed while crawling in double underdrive, so he would still break stuff if this is the problem-- just maybe less often.

However, It is probable the shafts are binding. The case and shafts are flexing towards each other somehow. I bet those heavy ass axles are moving back and forth front to back or the case is moving towards them or to the side when skinny pedal applied-- too much slop somewhere. He always breaks when flexed and climbing and getting on the throttle. Maybe disconnect the shafts and measure the distances sitting level, then flex it and remeasure distances? Stick a go pro thing on it close up and flex and hammer and see what is moving...
Click to expand...
So lets go further with this. He is breaking front mid-drive shaft and rear output shaft in that video.

If all the reduction is between the axle and the engine then those parts have to be able to handle the multiplication of torque.

How would more reduction in the middle of the power when stalled?
I don't think I am smart enough at the moment to understand this theory. It sort of undermines all I know about heavy machinery drivetrains.
The whole magic of planetary axles is moving that torque out to the wheels not using 1' diameter drive shafts between deep reduction gear boxes and 1:1 axles.
 
CarterKraft said:
The NWF titan 205 shafts for F/R are $1500 and 12 weeks out

So lets go further with this. He is breaking front mid-drive shaft and rear output shaft in that video.

If all the reduction is between the axle and the engine then those parts have to be able to handle the multiplication of torque.

How would more reduction in the middle of the power when stalled?
I don't think I am smart enough at the moment to understand this theory. It sort of undermines all I know about heavy machinery drivetrains.
The whole magic of planetary axles is moving that torque out to the wheels not using 1' diameter drive shafts between deep reduction gear boxes and 1:1 axles.
Click to expand...
Your idea is right, the HP figure you are using is just off. You can safely ignore the HP loss part. I am wrong about that. See the response to post above. HP in is HP out minus losses.

It is just that 250 HP number and the 68ish RPM shaft speed that are not right.

To have a 68 rpm shaft speed from the double under gear reduction ratio of 13.2213 with 250 horse ponies on it isn't happening. It means you have to be at idle, 900 RPM and making 250 HP. That comes from just multiplying the shaft rpm by the doubler reduction factor to get engine RPM: 68 x 13.2213 = 899.0484 RPM. To produce 250 HP at 900 RPM requires around 1461 foot pounds of input torque from the engine at that speed. That ain't happening at that close to idle and that is why your previous torque figure is so much higher than it should be when you plug it into the formula. It seems reasonable, it just ain't at that engine rpm.
 
Pablo said:
Your idea is right, the HP figure you are using is just off. You can safely ignore the HP loss part. I am wrong about that. See the response to post above. HP in is HP out minus losses.

It is just that 250 HP number and the 68ish RPM shaft speed that are not right.

To have a 68 rpm shaft speed from the double under gear reduction ratio of 13.2213 with 250 horse ponies on it isn't happening. It means you have to be at idle, 900 RPM and making 250 HP. That comes from just multiplying the shaft rpm by the doubler reduction factor to get engine RPM: 68 x 13.2213 = 899.0484 RPM. To produce 250 HP at 900 RPM requires around 1461 foot pounds of input torque from the engine at that speed. That ain't happening at that close to idle and that is why your previous torque figure is so much higher than it should be when you plug it into the formula. It seems reasonable, it just ain't at that engine rpm.
Click to expand...
I was throwing the 250hp number out as a guess, the math is the same though in regards to speed/capacity doubling.
I'd be curious to know what the stall speed of that rig is when power braked.


Here's my comparison. Terex TA300 haul truck has 9 liter 370 hp engine that makes 1400 lb ft @ 1400 RPM
The auto trans ratios are unknown but it's max rated speed in 6th gear is 50 mph. 1st gear max speed is 3.5 mph
The drop box is built in to the transmission with unknown ratios.
The tires are 57" tall and has differential ratios of 3.875:1 and 5.71:1 for a final drive axle ratio of 22.12:1

I am not smart enough to know what it would take to get that same setup to 70 mph but just halfing the axle final drive ratio to 11:1 would seem to double the speed at 100 MPH. Does this make sense?
The whole point of planetary axles is to put the large torque numbers at the end of the chain.

1677700766409.png
 
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