Coyote - Manual Transmission

[rguest3]

OK, guys.

What manual transmission would you put behind a Coyote?

Modular Bell Housing and Hydraulic Clutch.

ZF5, ZF6, M5OD-R2, AX-15 with Adaptor???

 

[Digger556]

Personally, I would go with ZF5 or ZF6. Some dont like the wide ratios. I've driven one for years now and it doesnt bother me DDing, towing or crawling.

Tremec TR4050 is $$, but newer and similar to ZF5.

 

[Broncobowsher]

ZF6 is MASSIVE. Makes a NP435 look like a toy. Physically fitting something that big is the issue.

 

[rguest3]

I like the strength of the ZFs but probably not use the 1st gear because it is so low. It's going to be a street truck, not a crawler.

How about the AX-15? I already have one of these in the shop. Would I have to "baby it" a little or is it up for the task? The AX-15 is rated 300 Pounds of Torque in a 7500 pound vehicle. So, what's the Math? How much torque can it handle in a 4500 pound vehicle like the early Bronco?

I have had an AX-15 behind a very nice 351W before with No issues.

 

[Apogee]

Since you have the AX-15, why not start there and see how it does? Coyote's aren't exactly known for their stump pulling torque numbers, and the AX-15's seem to shift nice and quick, making them a fun match behind a relatively quick revving engine IMO. Worst case is you blow it up and need to upgrade later.

 

[rguest3]

Apogee - I'm with you actually. I have all the parts needed already. I'm not going to drive the hell out of it. (Hopefully) Correct, it's a very nice driving 5-speed in the Bronco. This is why I put it on the list.

OK. So, if I blow up the AX-15 behind the Coyote. Which other transmission would you choose? Has to have the Modular Bell Housing, 4X4 version and D20 or Atlas Behind it.

What is everybody else doing for a Manual 4X4 Transmission behind the Coyote? Seems to be very few out there compared to the 6R80.

 

[jamesroney]

OK, guys.

What manual transmission would you put behind a Coyote?

Modular Bell Housing and Hydraulic Clutch.

ZF5, ZF6, M5OD-R2, AX-15 with Adaptor???

Wow. The most mistake prone application engineering exercise ever tackled by drive train engineering and you managed to state it in 9 words.

"What transmission should we put into this vehicle?"

Answer: The AX-15 is surprisingly strong. So I would run the T56.

It is the only modern transmission that is native to a Coyote, and has the rating to handle the torque. Tranzilla has put together an adapter kit to get you to 6 bolt round transfer case. So you can marry a Ford NP205 with a GM Turbo 400 input shaft...and it should fit between your framerails.

The AX-15 will not survive. Period. Just because you have had great success with your 351W does not mean it is strong. It just means that you drive nice. I really want to see some hard 4x4 burnouts and 2-3 upshifts under full throttle. I want to see you TRY to break your AX-15. I'm not asking you to wear it out. Break it. Some rolling backwards downhill on a muddy washboard, 1st gear, against the rev limiter, dump the clutch kind of fun.

In high school, everyone (including Advance Adapters) told me that the Jeep T90 was a "surprisingly strong" transmission that would hold up just fine behind a small block chevy. So I believed them, and made an adapter to my 273 Chrysler. A 10.5:1, solid lifter, 8K redline little screamer. It launched best at about 5K RPM. With 5.38's and 31's I could almost get the front wheels off the ground. Turns out that the T90 is not so strong. The gears strip, and the case will actually split in half. I blew it up and rebuilt it more than 10 times, and grew to hate it.

So I went to college, but didn't get any smarter. I asked around, and everyone told me (including Advance Adapters) that my problems would go away if I used the A833 Mopar transmission, and the Dana 18 transfer case was "surprisingly strong." I broke the case on the Dana 18 and blew the intermediate gear out the pan. I bought a girdle. I bought new gears. I wasted all kinds of money.

Ran a Dana 44 rear. It was "surprisingly strong." Twisted off two right side axle shafts. Bought a floater kit. Exploded a warn locking hub off one side...it hit a curb and went 20 feet straight up in the air. Glad no one was on the sidewalk.

So I learned one thing. "Surprisingly strong" means "weak."

The 47RH behind my Cummins is "surprisingly strong."
The Dana 30 front axle is "surprisingly strong."
Ford 9 inch 28 spline axles are "surprisingly strong."

The AX-15 is surprisingly strong.

 

[Broncobowsher]

Wow. The most mistake prone application engineering exercise ever tackled by drive train engineering and you managed to state it in 9 words.

"What transmission should we put into this vehicle?"

Answer: The AX-15 is surprisingly strong. So I would run the T56.

It is the only modern transmission that is native to a Coyote, and has the rating to handle the torque. Tranzilla has put together an adapter kit to get you to 6 bolt round transfer case. So you can marry a Ford NP205 with a GM Turbo 400 input shaft...and it should fit between your framerails.

The AX-15 will not survive. Period. Just because you have had great success with your 351W does not mean it is strong. It just means that you drive nice. I really want to see some hard 4x4 burnouts and 2-3 upshifts under full throttle. I want to see you TRY to break your AX-15. I'm not asking you to wear it out. Break it. Some rolling backwards downhill on a muddy washboard, 1st gear, against the rev limiter, dump the clutch kind of fun.

In high school, everyone (including Advance Adapters) told me that the Jeep T90 was a "surprisingly strong" transmission that would hold up just fine behind a small block chevy. So I believed them, and made an adapter to my 273 Chrysler. A 10.5:1, solid lifter, 8K redline little screamer. It launched best at about 5K RPM. With 5.38's and 31's I could almost get the front wheels off the ground. Turns out that the T90 is not so strong. The gears strip, and the case will actually split in half. I blew it up and rebuilt it more than 10 times, and grew to hate it.

So I went to college, but didn't get any smarter. I asked around, and everyone told me (including Advance Adapters) that my problems would go away if I used the A833 Mopar transmission, and the Dana 18 transfer case was "surprisingly strong." I broke the case on the Dana 18 and blew the intermediate gear out the pan. I bought a girdle. I bought new gears. I wasted all kinds of money.

Ran a Dana 44 rear. It was "surprisingly strong." Twisted off two right side axle shafts. Bought a floater kit. Exploded a warn locking hub off one side...it hit a curb and went 20 feet straight up in the air. Glad no one was on the sidewalk.

So I learned one thing. "Surprisingly strong" means "weak."

The 47RH behind my Cummins is "surprisingly strong."
The Dana 30 front axle is "surprisingly strong."
Ford 9 inch 28 spline axles are "surprisingly strong."

The AX-15 is surprisingly strong.

You sound like one of those people who could break an anvil with a rubber mallet.

5000 RPM clutch dumps are "surprisingly destructive" in nearly anything.

 

[jamesroney]

You sound like one of those people who could break an anvil with a rubber mallet.

5000 RPM clutch dumps are "surprisingly destructive" in nearly anything.

Sure, but when you sidestep the clutch at 4500 rpm, it starts to bog a little...

 

[rguest3]

My high school days are long gone. At my age I don't try to break stuff anymore. I just want to build a strong Engine and Transmission combo that will work great and be fun to drive.

I've even thought about a Top Loader 4-speed that would be fun as hell behind the Coyote, but I may want the overdrive for highway use.

 

[jamesroney]

My high school days are long gone. At my age I don't try to break stuff anymore. I just want to build a strong Engine and Transmission combo that will work great and be fun to drive.

I've even thought about a Top Loader 4-speed that would be fun as hell behind the Coyote, but I may want the overdrive for highway use.

Don't forget that the top loader is only strong in the close ratio configuration. If you go low ratio, wide ratio, or overdrive...it becomes much weaker. The Toploader, Toploader OD, SROD, T176 and T177 are all the same case dimensions and center distance. But the close ratio toploader can handle a lot more torque. A T176 behind an anemic Jeep 258 will still die.

I have a close ratio toploader in my 67 Shelby. It is not as much fun to shift as my TKO-600. If those were the only two choices I'd go TKO every time. It will be interesting to see if Tremec puts out a 4x4 option in the new TKX.

If you never actually put stress on the transmission, then why ask for strong? Might as well put in an AX5, or a T5. They are lighter, and shift faster. I just pulled out an NV3550 from my 2000TJ and went with the NSG370 six speed. I do like the NSG370, and it is 23 spline output so you can run your dana 20. Been in use since 2005 in the TJ, JK, and JL. 85mm center distance, and build by Mercedes. It's strong. Unfortunately, nobody makes an NSG to SBF or Coyote adapter. The do make a SBC adapter. I looked at putting the NSG into my Bronco, but would need to build a bell adapter...and I'm too lazy to make one.

 

[DirtDonk]

Not only for highway use, but it seems like using a transmission with gear ratios more inline with the power range of the engine would lead to one of the more modern boxes. Although I could be way off on that. A close-ratio top loader might actually keep the rpm's right where you want.
But adding an overdrive does give you more leeway when choosing the differential gears and that's usually a good thing.

Remember that the "7500lb" rating of the AX15 is the GVWR not the weight of the vehicle. Maybe you knew that and your 4500lb quote is your Bronco's GVWR still? Or is this a heavily modified rig with lots of extra weight adding items? If it's still a stock-ish weight you're still at an advantage with a 3900-ish weight while the 7500 rated vehicle is likely at least 5,000lbs empty, if not more.

I know people (customers) still running around on NV3550's like they're Ricky Racer on the street (though probably no 6,000rpm clutch dumps) and have had zero issues. I've heard the AX is stronger, but don't think I've seen an apples-to-apples comparison.
In the old days every time I saw a trans comparison, the close-ratio boxes almost always had a higher torque rating than the wide-ratio boxes did. But never determined personally if that was due to other design features, or if it was at least in part a function of the ratios.

Paul

 

[DirtDonk]

Don't forget that the top loader is only strong in the close ratio configuration. If you go low ratio, wide ratio, or overdrive...it becomes much weaker.

Well there ya go. I should have asked you this before obviously.
I just mentioned that characteristic in my last post, but can you explain the probably obvious please?

Is it the torque multiplication thing working against things like the case and bearings and such?

thanks

Paul

 

[jamesroney]

Well there ya go. I should have asked you this before obviously.
I just mentioned that characteristic in my last post, but can you explain the probably obvious please?

Is it the torque multiplication thing working against things like the case and bearings and such?

thanks

Paul

Naw, it's more simple than that. The strength of a transmission is based on a bunch of things, but if you put them in order of importance...it goes something like this:

1. center distance
2. case length
3. gear size
4. tooth contact area
5. tooth material
6. case material
7. shaft diameter
8. a bunch of other things...

At the end of the day, the strength comes from the ability to keep the gears in mesh, (bending strength of the shafts) and the amount of load seen by the individual tooth. Physically smaller gears see a LOT more load than big ones. You can argue that the load on the small gear is exactly the same at the root of the tooth...but large gears distribute that load over...a larger area.

So the strongest transmission you can make would be a 1:1 transmission where the input gear is the same diameter as the countershaft gear. As you increase ratio...the input gear gets smaller, and the countershaft gets larger. If you look at at close ratio toploader, the input gear is almost the same diameter as the countershaft gear. If you look at a NP435, the input gear is tiny compared to the countershaft gear. In order to get a lot of gear reduction, the countershaft must turn a lot slower than the main shaft. So in order to get the main shaft back up to speed, you end up with a relatively large 3rd gear on the countershaft cluster, and a tiny little 3rd gear on the mainshaft.

The NP435 (T18, T19, SM465, SM420, NV4500, and Clark is strong because it has such a huge center distance in a very compact case.)

This is also why the Mustang T5 always breaks in 3rd gear. It has like a 3.27 first, so they launch just fine. Second gear is actually OK, because both gears are about the same size. and close to the support bearing. But when you get to third...you have a big gear spinning a small gear, out where the shaft has the least support. As the shafts push each other apart, the load gets distributed to the top of the tooth, and that little bitty third gear can't take it. They literally flex themselves into oblivion. (It's also why the low ratio Turbo Coupe T5 can't hang with a V8)

The TKO has 3.27 inch (83mm) center distance, but is not as durable as the 3.03 toploader. That's because the TKO has a puny 5th gear integrated into the output shaft. It can't handle sustained torque at rpm in 5th gear. So it actually wears out instead of breaking.

The AX-15 is an 85mm center distance, but has high gear reduction like 3.8.

To make the strongest transmission in the same package...you actually benefit by adding overdrive ratios. So you can get a 2.95 first, and a .50 overdrive in the T56 and all of the gears are pretty much normal sized.

The NP203 range box is a short case, 1.96 ratio, big center distance 2 speed transmission. Try to break one of those...

Hope that helps.

 

[DirtDonk]

Simple, eh?%)
It does compute however, even though I had to try to visualize it all. Luckily I've been into a couple of gearboxes over the years, so understand the very basics of how they work.

Appreciate the details. Gonna read it again to make sure I got all the pertinent ones.

Thanks!

Paul

 

[trekgurl]

"It just means that you drive nice. "

guess this means me %) although I have broke some stuff and got a few "what WTF were you thinking" comments.

This is the kind of guy when he says you wanna ride with me? you better have your seat belt tight and extra set of drawers,, ;D Its good that we have good solid product testing and reviews on this site.

 

[rguest3]

Thanks guys. Lots of info there.

In post #4 I mentioned the power rating of the AX-15 in a #7500 vehicle. I would guess my Bronco will be about #4500???

So, how does the Math work here?

300 Torque in a #7500 Vehicle

??? Torque in a #4500 Vehicle

I realize tire size and gearing have an effect as well.

Just curious what the estimated torque rating may be with the lighter vehicle?

 

[Broncobowsher]

You are asking for a definite answer. Some mathematical calculation that is probably an exponential curve with an offset and gain values mixed in. Nobody has that. It isn't even really a line, it is a transition zone. More torque and weight may not break it, but it may just wear out faster. Or it might run too warm if you tow 100 miles at full torque in 3rd gear. Nobody knows the engineering that went into the numbers. Maybe the spec was simply to provide a transmission that could survive that GVW and torque level and anything that exceeded those numbers was deemed acceptable.

 

[rguest3]

I agree, an exact answer is not possible. Not always simple math with too many variables involved.

The best answer may be, "Let's see how long it lasts". I'll keep you posted.

 

[Apogee]

Weight simply means more traction due to the greater normal force on the tires, so if you look at torque as a function of traction, you probably find your failure point a little easier. It doesn't matter if your engine puts out 600 ft-lb of torque if your tires can only put half that to the ground, because you need a reaction force to actually put that torque into the transmission.

Now chain it down to a dyno or drop a tire under an axle-eater on the trail and BOOM!