A855 - 5 Speed

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Jarlaxle said:
Troll on, dude.
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Got. You don’t know why it’s right or wrong. You don’t have an answer.

I’ll say it again so anyone who comes along can learn for themselves. Rating a transmission on torque is a idiotic as buying a cylinder head based on flow numbers.

Simple as that.
 
Rat Bastid said:
Got. You don’t know why it’s right or wrong. You don’t have an answer.

I’ll say it again so anyone who comes along can learn for themselves. Rating a transmission on torque is a idiotic as buying a cylinder head based on flow numbers.

Simple as that.
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I do know...but you don't care...so I'm not going to bother.

But by all means: put a transmission rated for 300 lb-ft behind a 440. Torque capacity doesn't matter, so you should be fine, right? :rolleyes:
 
Rat Bastid said:
Got. You don’t know why it’s right or wrong. You don’t have an answer.

I’ll say it again so anyone who comes along can learn for themselves. Rating a transmission on torque is a idiotic as buying a cylinder head based on flow numbers.

Simple as that.
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That's how all of the T5 transmissions are rated, by torque. I'm listenin if you care to splain.
 
RustyRatRod said:
That's how all of the T5 transmissions are rated, by torque. I'm listenin if you care to splain.
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I already did somewhere, but I’ll explain it again. It’s simple really.

You can take any transmission and apply this to it, but because 300 foot pounds is the number in this thread, we can use that.

It doesn’t take much to make 300 ft/lbs does it? Let’s take a 273 2V engine. I don’t know what it made for torque, but I could look it up. If it’s 300 that’s all it is. That’s only 1.099 foot pounds per cubic inch. Pretty anemic.

So let’s drop in that 300 ft/lb gear box and let’s leave the 7 inch, rock hard pizza cutter tires on it. There is no way you’d ever break that gear box with that combination. Long before the gear box broke, youd smoke the tires.

Along that same line, we drop a 408 in there and it’s now making 500 TQ. That’s what? A 66.6% increase in torque. It’s the same thing. Long before the gear box breaks, the tires smoke like a chimney. So how does a torque rating make any sense?

Throw some bite on the 300 TQ combination and unless you can turn the tires it will break the gear box. Now add in a parts breaking clutch and you just made it worse by an order of magnitude.

Along the same lines, we can follow it up with a different example.

I have no clue what an A833 is torque rated for because I’ve never seen a number published. For the sake of the argument I’m sure it’s at least as strong a TKO60 which is rated at 600 TQ.

Let’s take a 340, making an honest 450 torque in a 2800 pound car. The A833 should be more than strong enough. So should the TKO60 box.

That same 405 TQ, 2800 pound car has a set of 14-32’s on it and let’s say a Ram 3 puck clutch. It’s highly unlikely that will spin those big steam rollers, especially in 3rd gear down the track. 3rd gear is the weakest gear in the transmission.

You bang 3rd and crap 3rd gear so fast you can’t get the clutch back in. Was the gear box rated too high, or did a big tire and a parts breaking clutch kill it?

I’ve seen guys miss on their clutch tune up and break Top Loaders and about every brand you can think of. I’ve seen one Liberty get hurt, but that was low gear. I’ve seen a couple of GForce G101’s get killed by engines that were nowhere near the torque rating.

My point is that torque is a piss poor way to rate a gear box. It’s basis is in marketing not in fact. It’s a simple way for the manufacturers to establish some arbitrary number to scale so the average guy can think he has a way to compare transmissions.

It’s like comparing cylinder heads by CFM and totally ignoring port size and shape.

Transmission torque ratings mean very little. Buying a transmission based on a torque rating is like buying a cam based solely on seat to seat timing. It ignores the big picture.

Simple as that. Make the tires spin and you can run a very low rated gear box. Put some bite to it, add a lock up clutch in front of it and then drop the hammer on it and you can’t buy a good enough transmission.
 
Jarlaxle said:
I do know...but you don't care...so I'm not going to bother.

But by all means: put a transmission rated for 300 lb-ft behind a 440. Torque capacity doesn't matter, so you should be fine, right? :rolleyes:
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I explain it in post 430. Read it. It’s real world examples. Torque capacity ratings are for marketing.
 
I forgot to mention the Jerico box. It’s based on the Top Loader. They used to come with a warning that said the clutch will break his transmission.

You can break any transmission with way less torque than they are rated for with a parts breaking clutch and bite.
 
Here you go. Read page 3 very close. https://www.jericoperformance.com/break_in.pdf

There is another set of instructions I can’t find for clutch assisted gear boxes. Simple reasoning says if you can’t lock up a clutchless box that goes into the next gear before it comes out of the lower gear, you damn sure can’t lock up a clutch on the shifts and not kill the box.

In a clutchless gear box, the slider goes into second before it disengages from first. Same as you go up in the gear changes.
 
think it can be summed up in
torque handling or torque capacity and shock load handling or capacity are two very different things.
A shock load Tends...Notice i say tends...... towards infinite for an infinietesimal moment in time. and any mechanical system can only recover from that a set number of times you can't measure it easily so you cant supply a rateing.

if the wheels don't move and you unleash the full torque of the motor on the unsuspecting drive train once twice thrice ..... you will break the box or diff eventually. evety shock load alters the bonding and grain boundaries in the structure of the shocked componets. work hardening brittleness, loss of elacticty and the number stress risers change in form and value.
hence you could in theory ruin a hemi spec A 833 with a slant 6.

In the same way you can break a toughend glass screen with enough tap tap tapping from a pointed steel mallet. punching it, kicking it doesn't work, leaning agints it doesn't work... but the tiny plastic mallet with the steel point does.

torque rateing is "leaning againts it" shock loading is your little "plastic n steel" mallet.

Dave
 
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Rat Bastid said:
I already did somewhere, but I’ll explain it again. It’s simple really.

You can take any transmission and apply this to it, but because 300 foot pounds is the number in this thread, we can use that.

It doesn’t take much to make 300 ft/lbs does it? Let’s take a 273 2V engine. I don’t know what it made for torque, but I could look it up. If it’s 300 that’s all it is. That’s only 1.099 foot pounds per cubic inch. Pretty anemic.

So let’s drop in that 300 ft/lb gear box and let’s leave the 7 inch, rock hard pizza cutter tires on it. There is no way you’d ever break that gear box with that combination. Long before the gear box broke, youd smoke the tires.

Along that same line, we drop a 408 in there and it’s now making 500 TQ. That’s what? A 66.6% increase in torque. It’s the same thing. Long before the gear box breaks, the tires smoke like a chimney. So how does a torque rating make any sense?

Throw some bite on the 300 TQ combination and unless you can turn the tires it will break the gear box. Now add in a parts breaking clutch and you just made it worse by an order of magnitude.

Along the same lines, we can follow it up with a different example.

I have no clue what an A833 is torque rated for because I’ve never seen a number published. For the sake of the argument I’m sure it’s at least as strong a TKO60 which is rated at 600 TQ.

Let’s take a 340, making an honest 450 torque in a 2800 pound car. The A833 should be more than strong enough. So should the TKO60 box.

That same 405 TQ, 2800 pound car has a set of 14-32’s on it and let’s say a Ram 3 puck clutch. It’s highly unlikely that will spin those big steam rollers, especially in 3rd gear down the track. 3rd gear is the weakest gear in the transmission.

You bang 3rd and crap 3rd gear so fast you can’t get the clutch back in. Was the gear box rated too high, or did a big tire and a parts breaking clutch kill it?

I’ve seen guys miss on their clutch tune up and break Top Loaders and about every brand you can think of. I’ve seen one Liberty get hurt, but that was low gear. I’ve seen a couple of GForce G101’s get killed by engines that were nowhere near the torque rating.

My point is that torque is a piss poor way to rate a gear box. It’s basis is in marketing not in fact. It’s a simple way for the manufacturers to establish some arbitrary number to scale so the average guy can think he has a way to compare transmissions.

It’s like comparing cylinder heads by CFM and totally ignoring port size and shape.

Transmission torque ratings mean very little. Buying a transmission based on a torque rating is like buying a cam based solely on seat to seat timing. It ignores the big picture.

Simple as that. Make the tires spin and you can run a very low rated gear box. Put some bite to it, add a lock up clutch in front of it and then drop the hammer on it and you can’t buy a good enough transmission.
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Thanks. I understand your explanation.....and agree with it. If the torque "has nowhere to go" it will make a path.......through broken parts. But to say that 300 LB FT is "anemic" is a blanket statement, no? 300 LB FT is "pretty good" for instance, for a slant 6.
 
RustyRatRod said:
Thanks. I understand your explanation.....and agree with it. If the torque "has nowhere to go" it will make a path.......through broken parts. But to say that 300 LB FT is "anemic" is a blanket statement, no? 300 LB FT is "pretty good" for instance, for a slant 6.
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So you mean 300 itself is anemic? It depends. For some engines it may be a very good number. For a 500 inch engine even in a mild state of tune, 300 would be an anemic number.

I was using that number because that’s what was thrown out there and for 99% of what gets lit around here, 300 would be a pretty low torque number.
 
I ag
Rat Bastid said:
So you mean 300 itself is anemic? It depends. For some engines it may be a very good number. For a 500 inch engine even in a mild state of tune, 300 would be an anemic number.

I was using that number because that’s what was thrown out there and for 99% of what gets lit around here, 300 would be a pretty low torque number.
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I agree normally it would, but I ain't normal.
 
Engine torque is something most car guys think they understand, so giving them transmission torque ratings to compare preemptively answers the question at the top of most lists. Turns out whether a transmission lives or dies is more complicated than just engine torque, but the transmission manufacturer has little control over those other variables. Hard to fault the them for throwing a number out there anyway, as they are just trying to satisfy the masses.

Grant
 
weedburner said:
Engine torque is something most car guys think they understand, so giving them transmission torque ratings to compare preemptively answers the question at the top of most lists. Turns out whether a transmission lives or dies is more complicated than just engine torque, but the transmission manufacturer has little control over those other variables. Hard to fault the them for throwing a number out there anyway, as they are just trying to satisfy the masses.

Grant
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Exactly.
 
I sure wish my wife's grandfather was still alive. He worked in the dyno room at New Process Gear all the during development and at least the first decade of production of the A-833. I'm pretty sure he could set us straight in industry standard terms. He passed away relatively young, forty years ago, two years before I met my wife. His daughter, my mother in law, always said we'd have gotten along very well.
 
S'cuder said:
I sure wish my wife's grandfather was still alive. He worked in the dyno room at New Process Gear all the during development and at least the first decade of production of the A-833. I'm pretty sure he could set us straight in industry standard terms. He passed away relatively young, forty years ago, two years before I met my wife. His daughter, my mother in law, always said we'd have gotten along very well.
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Have you ever seen a torque rating for the 833? I’ve looked and I have never seen one. It would be interesting to know how Chrysler rated the 833.

I do know years ago I read an article on the 833 and how at least part of it was developed. It said they would build the transmission and then flog it until it failed. They would fix that failure and then flog it again until it failed and fixed that.

I’d love to find where I read that, but that was some time ago and I have no clue where it came from.
 
Somewhere I read that a major determinant of transmission torque capacity is the distance between the countershaft and mainshaft. So boxes with higher (lower numerically) first gears tend to be stronger. Can't find the source though.
 
DrCharles said:
Somewhere I read that a major determinant of transmission torque capacity is the distance between the countershaft and mainshaft. So boxes with higher (lower numerically) first gears tend to be stronger. Can't find the source though.
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Physics. It's a matter of leverage. But that's also an 'all things equal' kind of comparison. It's similar to why larger ring gears are stronger. It's possible, to a point, to be 'stronger' with a closer spacing, but at some point the engineer runs out of super-alloys on their available materials list and has to resort to increasing the lever-arms to reduce the point loads.

Think of it this way: if you're transmitting 100 ft-lbs of torque from the pinion to the ring gear, and the ring gear is 1ft in diameter, the force applied at the ring gear interface is 200 lbs (200 lbs * 1/2 ft = 100 ft-lbs), if the ring gear is 1/2 ft in diameter (6"), then the force applied at the interface is 400 lbs (400 lbs * 1/4 ft = 100 ft-lbs). Note that the force is multiplied the lever-arm distance, or 1/2 the diameter which is also the radius. Obviously the numbers are all made up, but it gives you an idea of the maths.

@Rat Bastid is also right about the torque 'rating' of a box. The method used to establish that rating is too important to ignore it. So is the rating for a static load? For a dynamic load? Is it a CYA number so that they can 'exempt' themselves from any warranty on anything more than a stock motor?

Driveline weight, and not to mention car weight, would have a significant impact on how much load can even be placed on a gearbox. A dyno may be able to get a motor to generate 500 ft-lbs, but that same torque is going to accelerate a car quicker than the reaction force can be generated or sustained.
Engine masters even did some tests about how RPM rate (300/s vs 600/s) can affect engine output. All things equal, you can make a mundane engine look like a hero by slowing the rev-rate.
But in either case, most cars are going to rev far faster than even 600rpm/s - think about it: if you did only rev at 600rpm/s it would take 10 seconds to go from idle to 7k! Most higher powered cars are going from 4k to 7k 3-4 times (or more) in that same 10 seconds - or about 900rpm/s at least! Lots of motors are going to see a major dip in their rated output at that kind of rev rate, and the corresponding load on the gearbox.

All that to say: a 300ft-lb box MAY survive behind a 500ft-lbs motor in a 2k pound car, but put it into a 4k boat with 305 ft-lbs and it might shatter. Fix the clutch and it can survive behind both, but that's a different matter..
 
Rat Bastid said:
Here you go. Read page 3 very close. https://www.jericoperformance.com/break_in.pdf

There is another set of instructions I can’t find for clutch assisted gear boxes. Simple reasoning says if you can’t lock up a clutchless box that goes into the next gear before it comes out of the lower gear, you damn sure can’t lock up a clutch on the shifts and not kill the box.

In a clutchless gear box, the slider goes into second before it disengages from first. Same as you go up in the gear changes.
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I remember watching road kill garage (season6 episode3) when Dulcich put a paddle clutch in the cougar and thinking here we go!, split the toploader case in half with a sub 500hp 363 small block and street tires.
 
Rat Bastid said:
Have you ever seen a torque rating for the 833? I’ve looked and I have never seen one. It would be interesting to know how Chrysler rated the 833.

I do know years ago I read an article on the 833 and how at least part of it was developed. It said they would build the transmission and then flog it until it failed. They would fix that failure and then flog it again until it failed and fixed that.

I’d love to find where I read that, but that was some time ago and I have no clue where it came from.
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That jives with what my wife told me. She said her Grandpa told her that his job was "to break stuff."
 
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One important thing I don't see in any of the posts about torque relative to a transmission is the effect of the pressure plate and flywheel.
There was an excellent post by weedburner aka Grant, the man who makes and sells the Clutch Tamer and HitMaster "launch control" products for manual transmissions.
There is WAY more torque imparted on a transmission than the max torque rating of the engine. The numbers are staggering.
Read and learn:
ClutchTamer.com
 
A855 came up again on FBBO.

Firmly believe the A855 should be discontinued.

As I just noted on FBBO regarding Passon:
If he had integrity he would remove his name from it, break any association with it, and stop marketing it as his own.

If he had any decency he would get on these Mopar forums and address concerns, and spread the word that it has a know issue.

His complete silence on Mopar forums regarding an exclusive Mopar aftermarket 5 speed bolt in trans speaks volumes.

Passon Performance
 
People should just no longer buy them, it's that easy.

The Tremec T56 Magnum swap has been done enough times now -> just forget about ever returning the car to stock (you're not going to anyway), do the ToddRon crossmember and the T56 Magnum, proven stuff, liberty can face plate it, whatever you think you need. It's even the Chevy LS transmission so these will be around forever. Once you get the crossmember in and the floor figured out, the rest is frankly very easy.
 
A Modern 4, 5 or 6 speed manual has synchro sliders that have splines cut differently in 4 places around the sliders
3 splines at every 90* have a taper into the middle which is really quite pronounced in the center spline of the 3 tapered splines in each position

these coincide with the synchro hub keys and the aim is to draw the slider/hub into as central sensible running position as possible when under load and that actively keeps the transmission in gear.

common in transmissions made in Europe and Japan from the 70s onwards

now common in anything that grew out of Borg Warners "World Class" program on the T5 i.e Everything tremec did since 1986
but it is not a feature of 50s/60s US designs

I do wonder if this is what is missing on this transmission.



I think this fella, who runs 5 speeds .com, Paul Cangialosi, would have the issue sussed out in no time, can rebuild an A833 standing on his head seems to be most comfortable man-handling any manual trans around his bench
check him out of you tube to get a feel for the guy... i'd have him fix my trans.
i once purchased some shims and a support plate off him...that's all

5Speeds Transmission Home Page

maybe owners should club together and get him to investigate
he is a business like kinda guy, seems happy to go on record and say this is crap or this is good, A confidence that obviously comes from years and years of experience.

Has no link to any manufacturer, is not beholden to any corporation, his reputation is his to make or break, so i guess he would supply an unbiased view and potentially quote to fix the issue.

Dave
 
goldduster318 said:
People should just no longer buy them, it's that easy.

The Tremec T56 Magnum swap has been done enough times now -> just forget about ever returning the car to stock (you're not going to anyway), do the ToddRon crossmember and the T56 Magnum, proven stuff, liberty can face plate it, whatever you think you need. It's even the Chevy LS transmission so these will be around forever. Once you get the crossmember in and the floor figured out, the rest is frankly very easy.
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Some people are just not comfortable hacking structural parts.
 
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