Any non electric 4 speed autos for a 360 mag out there?

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If it came out with those gears on it then;IDK what caused that. Those spider gear teeth look almost new.
I've seen a lotta rearend carnage since 1972 but I haven't ever seen that combination.Put a SureGrip in it and that will never happen again
What's a JY?
The smallest rearend that will live behind a 408 is a Mopar 8.75, and it should be a clutch-type 4-spider Trac-Loc . Unless..... of course......... you got skinny tires. But I don't see the point of 408 plus skinny tires. That's just a recipe for disaster. And a big old embarrassment when a big-tired 360 throws dirt on your hood. If you peg-leg your rear, it won't be long before the crosspin retaining pin gives up the ghost and the pin launches somewhere; hopefully not into the gas tank, cuz it might be super hot. Remember when peg-legging, the spinning axle is doing double what the speedO says! And the oil temp is rapidly rising, cuz there just ain't a lot of it in there.And if you happen to be going around a corner some of it may not even be in the sump.
Sideways is the whole point of a 408 isn't it? Just remember skinny tires don't brake when going sideways. They just slide and slide and slide 'til you hit something.

I thought this was rather odd as well. JY is Junk Yard. It is a 8-3/4, but I can't imagine for one, how this kind of wear occurred, but secondly, how this pin held up under that much torque.

I was afraid that having the tall, 2:72's in it did this because motor was trying so hard to move the car, I guess that's out huh? That's good, because I will probably, eventually go with a better gear combo for the 408's torque.

I appreciate your explaining that the axle is doing twice the speedometer indication. Wow!

If both tires spin on a straight away, and only one on a curve, what type of rearend is that? Trac-Loc?

Bob
 
I thought this was rather odd as well. JY is Junk Yard. It is a 8-3/4, but I can't imagine for one, how this kind of wear occurred, but secondly, how this pin held up under that much torque.

Bob

Low speed with high torque, like rock climbing with big tires.
 
comments in the quote

I thought this was rather odd as well. JY is Junk Yard.DoH!
It is a 8-3/4, but I can't imagine for one, how this kind of wear occurred, but secondly, how this pin held up under that much torque. Me either.
I was afraid that having the tall, 2:72's in it did this because motor was trying so hard to move the car, I guess that's out huh? Yeah, no, that will never happen in your combo.
That's good, because I will probably, eventually go with a better gear combo for the 408's torque. Yeah that's your call.
I appreciate your explaining that the axle is doing twice the speedometer indication. Wow! That is because the spider/side-gear ratio is 2:1
If both tires spin on a straight away, and only one on a curve, what type of rearend is that? IDK, never seen one do that,lol. Oh wait I can imagine a situation,lol. I suppose either Mopar SG could be set-up to do that, but I wouldn't recommend it.
Trac-Loc? The trak-loc has 4 spiders to transmit the torque, instead of 2. And the cross-pins cannot come out ,no how. And the more torque you put into them the harder they jam up. But if you set them up right, they will almost act like an open diff under light throttle, as in around easy turns. The thing is that if you start pushing power into it during the turn she could lock up, spin both tires, and you could find yourself going backwards pretty quick. So I don't set mine up that loose, cuz I've had enough of that!
Bob
 
I know one thing.........would love to do this in my car.........if I live to see that day. The broken ribs have pretty much set the tone for THIS winter..................


I even bought a scrap crossmember "cut out" from another member........to make a pattern for the mods needed to mine

For the near future I can't lift a damn thing
 
I know one thing.........would love to do this in my car.........if I live to see that day. The broken ribs have pretty much set the tone for THIS winter..................


I even bought a scrap crossmember "cut out" from another member........to make a pattern for the mods needed to mine

For the near future I can't lift a damn thing

Oh man, that sucks.
 
comments in the quote

I had the diff rebuilt by a Mopar mechanic that worked at a dealership for new Mopars. He did diffs on the side for money. I am rather sure that both tires will have power because I have left two wheel burnouts going straight, and only one tire spins around a turn. Hmm. It is an 8-3/4, but I wonder why it is doing this if it isn't the norm. Would the traction bars make it do that, well ladder bars?

Yeah I freaked out when I saw that pin, I was like, WTH? Chrysler really made stuff extra, super strong in the day. That rear end came out of a Duster, not a 4x4 so it is really weird that the pin took that much wear.

I need to absorb my extravagant spending on the engine, tranny and power steering gear box before I can get the gears in the rear end. It only comes in so slow, but can go out in seconds flat, lol...

Have had broken ribs before, they hurt to breathe, kill you when you cough or sneeze, so do your best not to get a cold!!! Good Luck...
 
I am rather sure that both tires will have power because I have left two-wheel burnouts going straight, and only one tire spins around a turn. Hmm. It is an 8-3/4, but I wonder why it is doing this if it isn't the norm. Would the traction bars make it do that, well ladder bars?

When in a turn, the power has do divide between the inner wheel and the outer. If it didn't, you wouldn't be able to turn at all unless one of them spins. Around a turn, depending on the speed, some of the weight on the rear of the car transfers to the outer wheel. This makes it easier for the inside wheel to spin.
If your diff is a cone-type SG, then it may be set up a little on the tight side. The clutchpack may not be slipping, which is the whole point of having a Limited-Slip-Differential. It is kindof acting like a spool.
To rebuild those, I have made a stub axle that I clamp in a vice. Then I drop the diff-case on that. Then I have a second stub with a big ol' nut welded on the end,that I drop into the top side-gear. Then I can put a torque wrench on it and measure the breakaway torque, and the turning torque. Of course the clutches have to be lubricated prior,with the same LSD-oil that is gonna be in the car.
Using this method I can tailor the diff to the application.
In my car with no traction aider, and with 295/50-15s,and a cone-type LSD; I have found by repeated testing and adjustments, that for turning torque ;
100 is not nearly enough. And
110 was good with 245/60-14s, and a 318.
120ftlbs is a good number for my HO 367, and 295s. And at
140 it acts like a spool. Until install the 325/50-15 BFG Comp T/A Dragradials. But it's still a little tight, slipping the inside rear tire on less than perfect surfaces.

So I target 115 to 125. Adjustment is by shimming the side-gears, and the oil concoction. For me, 120 has been just right.

You could test yours on the car, but to be accurate you would have to make a tool to mount onto the axle flange, so you could use the torque wrench.
If you just want to make sure it ain't worn out, that's easy. Just jack up one side of the car, and chock the opposite side wheels. Then put it in neutral. And attempt to rotate the jacked up tire.
Can't do it, is too tight
Spins easy, is worn out
In-between, is a judgement call, based on amount of effort required and degree of misbehavior encountered during usage.
If you drive the car off the jack during testing, you forgot to chock the opposite side tires! Don't do that.
EDIT for clarity;
that is to say; if whilst attempting to turn the tire with your arms, you accidentally push the car off the jack you will get seriously hurt. So make sure the car cannot move forward or backwards; chock the wheels on the opposite side.
You could start the engine and put in in gear,rev it up a little and see if the jacked up tire spins. If it doesn't and you put more power into it, you could drive it off the jack and damage the car. But you would have no idea of what the actual turning torque might be...... so don't do that.
 
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When in a turn, the power has do divide between the inner wheel and the outer. If it didn't, you wouldn't be able to turn at all unless one of them spins. Around a turn, depending on the speed, some of the weight on the rear of the car transfers to the outer wheel. This makes it easier for the inside wheel to spin.
If your diff is a cone-type SG, then it may be set up a little on the tight side. The clutchpack may not be slipping, which is the whole point of having a Limited-Slip-Differential. It is kindof acting like a spool.
To rebuild those, I have made a stub axle that I clamp in a vice. Then I drop the diff-case on that. Then I have a second stub with a big ol' nut welded on the end,that I drop into the top side-gear. Then I can put a torque wrench on it and measure the breakaway torque, and the turning torque. Of course the clutches have to be lubricated prior,with the same LSD-oil that is gonna be in the car.
Using this method I can tailor the diff to the application.
In my car with no traction aider, and with 295/50-15s,and a cone-type LSD; I have found by repeated testing and adjustments, that for turning torque ;
100 is not nearly enough. And
110 was good with 245/60-14s, and a 318.
120ftlbs is a good number for my HO 367, and 295s. And at
140 it acts like a spool. Until install the 325/50-15 BFG Comp T/A Dragradials. But it's still a little tight, slipping the inside rear tire on less than perfect surfaces.

So I target 115 to 125. Adjustment is by shimming the side-gears, and the oil concoction. For me, 120 has been just right.

You could test yours on the car, but to be accurate you would have to make a tool to mount onto the axle flange, so you could use the torque wrench.
If you just want to make sure it ain't worn out, that's easy. Just jack up one side of the car, and chock the opposite side wheels. Then put it in neutral. And attempt to rotate the jacked up tire.
Can't do it, is too tight
Spins easy, is worn out
In-between, is a judgement call, based on amount of effort required and degree of misbehavior encountered during usage.
If you drive the car off the jack during testing, you forgot to chock the opposite side tires! Don't do that.

I don't understand what is to move the jacked up wheel. Me or the engine... If it is me, then how could I drive the car off the jack during the test, and if it is the engine, how could I tell how hard it is to turn it, as well as how can I turn the wheel with the engine in neutral?

I think you mean to try to turn the wheel by hand right?

Thanks
 
You turn the wheel by hand or try to. You need the trans in neutral. Here's the deal. With an "open" or "single" or "singletrack" axle, the axle can turn through the spider gears and turn the pinion/ drive shaft (if in neutral). That is why an "open" axle spins one wheel with a burnout

With a suregrip/ "posi" / limited slip, the axles are basically "clutched" together. On a good one, your arms cannot generate enough torque to turn the axle/ driveshaft by slipping the sure grip/ limited slip clutches
 
I think you mean to try to turn the wheel by hand right?
Yes you got it right
EDIT
that is to say; if whilst attempting to turn the tire with your arms, you accidentally push the car off the jack you will get seriously hurt. So make sure the car cannot move forward or backwards; chock the wheels on the opposite side.
You could start the engine and put in in gear,rev it up a little and see if the jacked up tire spins. If it doesn't and you put more power into it, you could drive it off the jack and damage the car. But you would have no idea of what the actual turning torque might be...... so don't do that.
 
Yes you got it right
EDIT
that is to say; if whilst attempting to turn the tire with your arms, you accidentally push the car off the jack you will get seriously hurt. So make sure the car cannot move forward or backwards; chock the wheels on the opposite side.
You could start the engine and put in in gear,rev it up a little and see if the jacked up tire spins. If it doesn't and you put more power into it, you could drive it off the jack and damage the car. But you would have no idea of what the actual turning torque might be...... so don't do that.

Gotcha,

That makes sense. I will give it a whirl. I have to take the wheels off to polish the rims here soon anyway, so I will do it when I do that... Extra cool!
 
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