72Duster440
Well-Known Member
Curious as well, what is considered a 'junk' clutch?
75-76 Aluminum 833 4 speed Overdrive trans questions ?
- Thread starter Brooks James
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Curious as well, what is considered a 'junk' clutch?
Rat Bastid
Dunamis Metron
All those dual friction, ceramic and whatever gimmick they use to make the clutch not slip.
There are two cutch discs to use. An organic disc (both sides) with 2400-2800 pounds of plate pressure at the most.
Or you use the sintered iron disc and keep the plate load between 800-1500 pounds, maybe a bit less if the car is light.
The rest of that **** is just that. ****.
A clutch is NOT a toggle switch. But that’s what they are when you use the gimmicks. And that breaks parts.
I took a video of a guys car at a race last year. He is screwed up on virtually everything for a stick car. What he has wrong applies to street/strip cars just like it does a drag car.
He has WAAAAAAAAAAAAAAAAAAAAAAAAAAAAY too much flywheel weight. By a BUNCH.
He has his traction bars running up hill. That’s a no no, no matter what the internet experts say.
His clutch is either on or off. A toggle switch.
He has a pretty low first gear (overall) which isn’t a bad thing but since he can’t control his clutch he’s screwed.
He has WAAAAAAAAAAAAAAAAAAAAAAAAAAAY too much torque for the RPM range he’s trying to run. If he would kill 100 foot pounds of torque below peak he’d be far better off. But he won’t do that because the experts all think torque is god. It’s not.
He probably has some other issues that I’m forgetting now, but it doesn’t matter. I’m not going to publicly post his video because I never told him I was taking it, nor did I have the chance to show it to him and talk to him about WTF he is doing.
The amount of shear violence this guy applies to the tires is staggering.
Between his garbage clutch and his heavy flywheel and all that torque he will never get it right.
Then his buddies who don’t know **** from shinola will convince him to put a leaky, slow assed automatic in it. Then it will go faster than his junked up bullshit he now has because it’s garbage and they will all proclaim the automatic the KING of the world.
If you can run a pop up toaster, you can run an automatic. That about sums that up.
If I had shown the guy the video and told him my thoughts I would have no issues making it public now. Since he didn’t get that opportunity I won’t post it. Yet.
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Possibly, if so it would be a package deal, the complete set up one, and the spare one
72Duster440
Well-Known Member
OK good, my basic McLeod dual faced organic diaphragm one doesn't fall into the 'junk' category so I should be good! Still working on swapping from an auto, so I haven't driven it yet
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Dear @Rat Bastid , if your scathing comment was directed at me, then here is a refresher for you; If not to me then it's still a refresher; no foul/no harm.
Yes I agree that my Clutch killed that weakazz A833 overdrive gear. so then;
I took out that dual-friction, very early in the program, and put it on the wall of shame. I replaced it with a factory 340 disc that I had in stock since the IDK 70s or 80s.
When the hub tore out of that, I reduced the clamp load, and installed another brand-new 340 disc.
When the friction material on that one shredded, I learned to reduce power on the GearVendor during split shifts.
After that, she's been a lot easier on discs, going sometimes three summers on a disc.
See; I can learn.
The static clamp load is so low now, that, with a starter gear of 10.97, I can about dump the clutch at just off idle, and the factory 340 flywheel will motor the car away, with just the right amount of slip.
The unit slips a lil below ~2800, on power application, but by 3000/3200 she is on the flyweights, and the tires are on fire.
I'll tell ya, not one of those od gears ever got full power, and my lo-po winter-318 snapped one too. So IDK, call me crazy but I'm sticking with those A833od gears being weakazz. I mean look at them; they don't have even 3 full teeth engaged at any time. That's 3 teeth for a what? say a 200 ftlb, stock, smoggerteen on the TQ primaries?
I learned to toe the clutch on the manually shifted GV; and To baby it into double overdrive. And I geared the car up, so that the A833od was rarely used. With 3.55s, 65=2240 in GVod/1590 in double over. The 230* cam didn't like double anyway at 65mph. At cruise power, the clutch does not slip. I set it up for that.
After the Third weakazz A833od gear broke, I stopped using that combo. I still have at least one spare, maybe two. It's been 18 years so not sure. I do remember that one of them has a slick-shifted second, and possibly direct also, cuz I ran it with 4.30s to 5.38s, to get a crawler gear.
BTW-1
for those that might want to know:
With 3.55s the roadgears were;
10.97-8.56-5.93-4.62-3.55-2.77-1.97 with splits of
.78-.69-.78-.77-.78-.71 GV ratios in red.
Shifting at 5600, the rpm drop with a .78split is to 4370 =1230rpm..... so she is riding the very top of the powercurve.... almost like a CVT. It was a lotta lotta fun; until the camlobes began to fall off.
Btw-2
I took the broken od gear out of one of the busted ones, that still had a usable core section, cleaned it all out, reassembled it, and drove it as 3 speed with the GVod bringing up the rear, still splitting gears,as the occasion presented itself, but gone was the Double-od, which I never missed. I left the non-functional od gear in there to support the brass ring and make sure the struts stayed where they belonged, so I could still have a synchronized shift into Direct gear.
Btw-3
With 3.55s, 5600 is 127mph in Direct gear. I almost never go there, but if I did, I would next hit the splitter, for 127=~4400 in Direct/GVod. I would then slow to 75 or so, and at 75=2600, now would be the time to engage the weakazz A833od gear, which would take 2600 down to ~1850
Ok so by this time, the engine has been steadily winding down, and the throttle plates are and have been, nearly closed, for a good long time.
If that weakazz A833od gear can't take a shift at 2600 with the throttles nearly closed....... what can be said?
However:
What I did do often with that combo, was shift 1-1od-2-2od for 5600=97 mph in 2od. Now remember, the main stick is still in Second. From there I should go to 3od which would be 3340 rpm and the carb should be closed, cuz you know, I gotta get back to sub65mph before I get a ticket.
But one time, I mean one time, I slammed it straight into 4od and the engine had to go from 5600 to 2370 in the blink of an eye, and the od gear just said; "are you effing kidding me?, not-a-stinking-chance."
Ok I get that one. My bad.
Now; I want to point out that, in the same situation, it is my belief and opinion, that no other similarly-rated aftermarket 5-speed/od, would have suffered such a catastrophe.
Ok there's your update; feel free to scathe me some more.
Yes I agree that my Clutch killed that weakazz A833 overdrive gear. so then;
I took out that dual-friction, very early in the program, and put it on the wall of shame. I replaced it with a factory 340 disc that I had in stock since the IDK 70s or 80s.
When the hub tore out of that, I reduced the clamp load, and installed another brand-new 340 disc.
When the friction material on that one shredded, I learned to reduce power on the GearVendor during split shifts.
After that, she's been a lot easier on discs, going sometimes three summers on a disc.
See; I can learn.
The static clamp load is so low now, that, with a starter gear of 10.97, I can about dump the clutch at just off idle, and the factory 340 flywheel will motor the car away, with just the right amount of slip.
The unit slips a lil below ~2800, on power application, but by 3000/3200 she is on the flyweights, and the tires are on fire.
I'll tell ya, not one of those od gears ever got full power, and my lo-po winter-318 snapped one too. So IDK, call me crazy but I'm sticking with those A833od gears being weakazz. I mean look at them; they don't have even 3 full teeth engaged at any time. That's 3 teeth for a what? say a 200 ftlb, stock, smoggerteen on the TQ primaries?
I learned to toe the clutch on the manually shifted GV; and To baby it into double overdrive. And I geared the car up, so that the A833od was rarely used. With 3.55s, 65=2240 in GVod/1590 in double over. The 230* cam didn't like double anyway at 65mph. At cruise power, the clutch does not slip. I set it up for that.
After the Third weakazz A833od gear broke, I stopped using that combo. I still have at least one spare, maybe two. It's been 18 years so not sure. I do remember that one of them has a slick-shifted second, and possibly direct also, cuz I ran it with 4.30s to 5.38s, to get a crawler gear.
BTW-1
for those that might want to know:
With 3.55s the roadgears were;
10.97-8.56-5.93-4.62-3.55-2.77-1.97 with splits of
.78-.69-.78-.77-.78-.71 GV ratios in red.
Shifting at 5600, the rpm drop with a .78split is to 4370 =1230rpm..... so she is riding the very top of the powercurve.... almost like a CVT. It was a lotta lotta fun; until the camlobes began to fall off.
Btw-2
I took the broken od gear out of one of the busted ones, that still had a usable core section, cleaned it all out, reassembled it, and drove it as 3 speed with the GVod bringing up the rear, still splitting gears,as the occasion presented itself, but gone was the Double-od, which I never missed. I left the non-functional od gear in there to support the brass ring and make sure the struts stayed where they belonged, so I could still have a synchronized shift into Direct gear.
Btw-3
With 3.55s, 5600 is 127mph in Direct gear. I almost never go there, but if I did, I would next hit the splitter, for 127=~4400 in Direct/GVod. I would then slow to 75 or so, and at 75=2600, now would be the time to engage the weakazz A833od gear, which would take 2600 down to ~1850
Ok so by this time, the engine has been steadily winding down, and the throttle plates are and have been, nearly closed, for a good long time.
If that weakazz A833od gear can't take a shift at 2600 with the throttles nearly closed....... what can be said?
However:
What I did do often with that combo, was shift 1-1od-2-2od for 5600=97 mph in 2od. Now remember, the main stick is still in Second. From there I should go to 3od which would be 3340 rpm and the carb should be closed, cuz you know, I gotta get back to sub65mph before I get a ticket.
But one time, I mean one time, I slammed it straight into 4od and the engine had to go from 5600 to 2370 in the blink of an eye, and the od gear just said; "are you effing kidding me?, not-a-stinking-chance."
Ok I get that one. My bad.
Now; I want to point out that, in the same situation, it is my belief and opinion, that no other similarly-rated aftermarket 5-speed/od, would have suffered such a catastrophe.
Ok there's your update; feel free to scathe me some more.
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Rat Bastid
Dunamis Metron
That’s a great clutch for a good street car or even street/strip IF you don’t mind getting 70-80 hard runs out of it and changing the disc.
Keep your plate load at 2400 pounds or so (unless your car is pig heavy with really tall gears…like 3800 pounds heavy and 3.08’s or something) and that clutch won’t kill your stuff.
Rat Bastid
Dunamis Metron
TL
RIt wasn’t directed at you.
I pointed out what YOU failed to say.
The OD is NOT inherently any weaker than a non OD box. Your clutch killed it.
Thats all.
This is big boy stuff. If that upsets you, that’s on you.
Junk is junk at any price and junk clutches outnumber good clutches by a big number.
72Duster440
Well-Known Member
Rat Bastid
Dunamis Metron
NICE!
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Ok thanks;TL
It wasn’t directed at you.
I pointed out what YOU failed to say.
The OD is NOT inherently any weaker than a non OD box. Your clutch killed it.
Thats all.
This is big boy stuff. If that upsets you, that’s on you.
Junk is junk at any price and junk clutches outnumber good clutches by a big number.
No foul. It's all good.
But I must say;
it seems that just in general, you're a little crankier than usual. Are you in pain? Cuz pain is what makes me cranky.
Late last summer my teeth began to crumble, which made me cranky. First I asked for a miraculous healing; but when that didn't seem forthcoming, I asked to be free of pain and infection. Well that took right away, and all my grumpiness went away. I just hadda ask the right question.
I'll guess there are about a dozen useless nubs in there now.
Rat Bastid
Dunamis Metron
Not cranky at all. But 44 years of junk clutches killing gearboxes and evidently very few even trying to learn why these things fail is irritating.
The clutch will kill more parts faster that anything else. And the junk **** clutch manufacturers spend ALL their money on advertising rather than building a clutch that works.
Lets hope at least a few people start learning clutches and clutch tuning.
Stick shift drag racing is making a big comeback. Finally guys are getting sick of running pop up toaster transmissions.
I want to keep it moving forward and junk clutches and the lying liars who produce that **** need to be exposed.
weedburner
Well-Known Member
I don't have a problem with the different friction materials, or even the dual friction disc, they just need to be matched with a pressure plate that provides an appropriate amount of clamp pressure for that friction material and application.
The problem is the typical aftermarket manufacturer doesn't give you many choices when it comes to clamp pressure, they instead generally adjust torque capacity by varying the friction material. Since there are only a few common friction materials available, the step from one to another can be pretty big.
The typical aftermarket 10.5" diaphragm pressure plate has around 2800lbs of clamp.
......with an organic disc that's ballpark for around 500ftlbs.
......with a typical dual friction, now it's ballpark for around 650ftlbs.
......with cerametallic or iron disc, it becomes ballpark for around 820ftlbs.
So what do you choose if you have a street/strip car making say 550ftlbs, more than what the organic disc can reliably take? The next step up is dual friction, which has about 30% more clamp pressure than what is ideal for 550ftlbs. If you go for the cerametallic or iron disc it's even worse, about 64% more clamp than what's ideal for 550ftlbs.
Excess clamp pressure is what makes clutches act like on/off switches. The more excess you have, the worse it gets. The more excess you have, the more bog/spin you get, also the harder it beats on your drivetrain. Excess clamp pressure means higher than necessary pedal effort as well.
To me it would make more sense if we could choose the friction material for the application first, and then choose the clamp pressure to suit the application. Street applications would most always get organic single disc up to about 500ftlbs to keep pedal effort acceptable, organic dual or triple disc above that. Street/strip could step up to more aggressive friction materials that would be less street friendly but last longer under extreme conditions.
Diaphragm clutches are easier to operate for a given clamp pressure, and the clamp pressure stays in a tighter range over the life of the disc. Wouldn't it be nice if someone made diaphragms available in 200lb increments from 1200-2800? Not likely to happen.
They do make adjustable clamp Diaphragm, Long, and B&B pressure plates, so that's an option if you can find one with a suitable range.
What do I do? I'm a guy that likes to get more than expected out of common affordable parts. For my street/strip applications I take the common 2800lb PP, and then use my clutch hit control products to make that 2800lb pressure plate initially hit like a much softer 1800-2000lb unit, then transition to hold like a 2800lb unit. Softer hit on the drivetrain without giving up any of the holding power.
Grant
The problem is the typical aftermarket manufacturer doesn't give you many choices when it comes to clamp pressure, they instead generally adjust torque capacity by varying the friction material. Since there are only a few common friction materials available, the step from one to another can be pretty big.
The typical aftermarket 10.5" diaphragm pressure plate has around 2800lbs of clamp.
......with an organic disc that's ballpark for around 500ftlbs.
......with a typical dual friction, now it's ballpark for around 650ftlbs.
......with cerametallic or iron disc, it becomes ballpark for around 820ftlbs.
So what do you choose if you have a street/strip car making say 550ftlbs, more than what the organic disc can reliably take? The next step up is dual friction, which has about 30% more clamp pressure than what is ideal for 550ftlbs. If you go for the cerametallic or iron disc it's even worse, about 64% more clamp than what's ideal for 550ftlbs.
Excess clamp pressure is what makes clutches act like on/off switches. The more excess you have, the worse it gets. The more excess you have, the more bog/spin you get, also the harder it beats on your drivetrain. Excess clamp pressure means higher than necessary pedal effort as well.
To me it would make more sense if we could choose the friction material for the application first, and then choose the clamp pressure to suit the application. Street applications would most always get organic single disc up to about 500ftlbs to keep pedal effort acceptable, organic dual or triple disc above that. Street/strip could step up to more aggressive friction materials that would be less street friendly but last longer under extreme conditions.
Diaphragm clutches are easier to operate for a given clamp pressure, and the clamp pressure stays in a tighter range over the life of the disc. Wouldn't it be nice if someone made diaphragms available in 200lb increments from 1200-2800? Not likely to happen.
They do make adjustable clamp Diaphragm, Long, and B&B pressure plates, so that's an option if you can find one with a suitable range.
What do I do? I'm a guy that likes to get more than expected out of common affordable parts. For my street/strip applications I take the common 2800lb PP, and then use my clutch hit control products to make that 2800lb pressure plate initially hit like a much softer 1800-2000lb unit, then transition to hold like a 2800lb unit. Softer hit on the drivetrain without giving up any of the holding power.
Grant
Rat Bastid
Dunamis Metron
I agree. The issue I’ve had is most of those metallic discs (not the sintered iron) don’t do well when the clutch is being slipped.
The stuff balls up and gets gooey.
I‘m hoping that guys learn and understand that you have to have some way to control the application of the clutch. The cars will always be quicker and faster plus they don’t break parts when you get a handle on it.
I can’t count how many guys have told me over the years they quit running sticks because they broke everything. You find out what they had for clutches and you’re like all hell yeah it broke stuff.
I‘m old enough to remember (and to have used) one of the Direct Connection “green” cover pressure plate. Bought one in 1981. Actually two of those junkers. One for myself and the other for a buddy. I bought them the Friday before the Super Bowl and we changed out both as we listened to the Raiders beat the Eagles.
That thing SUCKED. Way too much plate load even for a rag disc. My friend bolted on some cheater slicks and promptly **** the driveline right out.
Of course, we were both proud as hell because we thought man, now she’s hooking and making power. It was a slow pig but a little bite and that clutch broke the driveline first and then we got that all beefed up it **** the 8 3/4.
And that was the start of parts destroying clutches over the years until I figured out you can’t just make the clutch a toggle switch.
So something needs to control the application of the clutch.
EDIT: I forgot to ask what disc you are using for your car.
weedburner
Well-Known Member
Back in 1975, i bought a new Hapco clutch for my '65 Chevelle from my local hero's, at the time the F/MP national record holder...
Les sold me a 3300lb B&B with an organic disc for my tunnel rammed 301 with a Muncie and 4.88's. Bog city with an aluminum flywheel, but I was still a happy high school kid thinking it needed more gear. Wish I had known then what I know now...
I've got a bin with most everything from organic to full face iron, at the moment my street/strip car has a dual friction. I put some miles on it last fall, the dual friction drives nice and takes more abuse than I thought it would, but i've only sprayed it with one kit on a delay. My 900 series iron puck is down to .310", while the full face iron's narrow hub is almost worn out from all the street miles but the friction is still .340".
Grant
Les sold me a 3300lb B&B with an organic disc for my tunnel rammed 301 with a Muncie and 4.88's. Bog city with an aluminum flywheel, but I was still a happy high school kid thinking it needed more gear. Wish I had known then what I know now...
I've got a bin with most everything from organic to full face iron, at the moment my street/strip car has a dual friction. I put some miles on it last fall, the dual friction drives nice and takes more abuse than I thought it would, but i've only sprayed it with one kit on a delay. My 900 series iron puck is down to .310", while the full face iron's narrow hub is almost worn out from all the street miles but the friction is still .340".
Grant
Time to mention again that I have one behind a 1969 440 in a truck.
The factory rated the non-HP 1969 440 at 350 gross HP and a previous owner installed a mild upgrade cam and truck headers.
My guess is it's close to or slightly more than the 375 HP of the factory HP engines.
I have no idea if the shafts are bushed and I have no idea how they got the bell housing to work, but the bell is iron.
I also have no idea what gear is in the axle, but the axle is an 8 1/4 one wheeler.
It was an original 225 truck and I've "been told" it could have had anything from 2.76 to 3.55.
I haven't driven it in a while but when I was driving it about once a month, they were usually "spirited" drives.
I don't power shift in to OD, though.
The factory rated the non-HP 1969 440 at 350 gross HP and a previous owner installed a mild upgrade cam and truck headers.
My guess is it's close to or slightly more than the 375 HP of the factory HP engines.
I have no idea if the shafts are bushed and I have no idea how they got the bell housing to work, but the bell is iron.
I also have no idea what gear is in the axle, but the axle is an 8 1/4 one wheeler.
It was an original 225 truck and I've "been told" it could have had anything from 2.76 to 3.55.
I haven't driven it in a while but when I was driving it about once a month, they were usually "spirited" drives.
I don't power shift in to OD, though.
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Rat Bastid
Dunamis Metron
I have two OD833 transmissions behind mildly upgraded 340 engines and have not had any problems with either of them. They are not bushed but came out of slant six 1980s pickup trucks. I am just running street tires so not a great deal of stress is applied and I have never powershifted into OD so no problems there. I do first and second gear burnouts all the time but not powershifting. My form is not as good as it used to be so I let off the gas when I shift these days. I am wondering why bushing the countershaft helps with strength. Is it just a larger surface area pushing against the aluminum because of the bushing. The shaft doesn't turn in the case so there's not rotational wear. Just wondering.
It is the larger surface area.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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From the factory, the hole is slightly loose. The pin thus, rides in oil. which allows it to bang around and eventually the hole goes oval. This allows the cluster, under load, to move away from the input gear, decreasing the gear-tooth engagement.This is said to reduce the torque-load rating, which makes sense. I cannot speak to that.
The sloppy fit is said to reduce gear-rattle.
I thought to myself that this was not a good idea, so on one of mine, I loctited the pin in. But you guessed it, at tear-down the loc-tite was gone..... so I bit the bullet and bushed it. It didn't cost that much.
The sloppy fit is said to reduce gear-rattle.
I thought to myself that this was not a good idea, so on one of mine, I loctited the pin in. But you guessed it, at tear-down the loc-tite was gone..... so I bit the bullet and bushed it. It didn't cost that much.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Slanty ods come with the small mainshaft and the A904-sized yoke.
A high pressure 367 like mine (up to 195psi at one time) makes short work of 7260 U-joints. My driveshaft now carries 1350 yokes on both ends, which are finally surviving.
How much pressure is your mildly upgraded 340 making?
My guess is, that with a modest cam, in an early hi-compression 340, then perhaps as much as 160psi. But if the later Low-compression model, then, perhaps as little as 115 psi.
Pressure is torque, the more pressure your engine makes, the more torque it will make.
Torque breaks parts.
If your 340 is still on 7260 U-joints and she is not breaking them, then, my guess is that the pressure is down, or like you say, the street tires are not stressed, and/or, the clutch is comparatively gentle, or you yourself are fairly gentle; I get that. Do not equate low pressure with low power. I am not insulting your engine.
You can install a 292 cam in an 8/1 340 and it will make gobs of power at high rpm. But it may barely spin the tires at a lo-rpm take off. That's the pressure difference.
And yes, the higher pressure will make more power at peak, all things being equal, but at 5500rpm, the difference is not as pronounced as at 2000.
I am running a 292 duration cam in one of the 340s. The other has a Comp Cams .468 270 duration solid. Both are high compression early 340s. I took one of the transmissions out myself so I know it came from behind a slant six but both have large spline output shafts. I think just running street tires is the key to them living behind 340s maybe.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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maybe so but I broke three of them with street tires., one of them with a dead-stock 1973 318 with nothing more than a 4bbl and headers.
Maybe after a few more thousand miles, I might find out the hard way. As long as they don't tear anything else up when they go, I'll keep putting them to the test.
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