Rear End?

[68chargerboy]

i have what i believe to be a 8 3/4 rearend in my car.  the problem is only one tire spins when i floor it/ peel out, but when i jack up the car and try to turn one wheel i cant turn it with out turning the other.  what do you think could be wrong?  thanks in advance



                          Zach

[RallyeMike]

Which way does other wheel turn? If it's the opposite direction, that's normal for one legger axle.

[68chargerboy]

it turns opposite.

[myk]

Then you're running an open differential.  Also, you'll know if it's an 8-3/4 rear if there is no cover on the back of the differential...

[kamkuda]

This is an 8 3/4 (minus the coil overs)

[68chargerboy]

thanks.  i know how the 8 3/4 has the welded on backplate but i have a 68 coronet that has a welded on back plate but it is definatley smaller then a 8 3/4.   thanks


                     Zach

[68chargerboy]

also were did you get that coil over setup, and do you think its good?

[kamkuda]

Its a ladder bar set-up designed to give me better launches for the 1/4 mile.  It should be my only advantage over Firefighters Charger

It is not necessarily the best street suspension for handling.

Its a Dana now

[myk]

Speaking of rear-ends, I've never been satisfied with the open differential in the car.  I'm on the verge of having a limited slip unit installed, but I'd like to know what the added benefits of having a limited slip differential are, asides from the obvious ability to lay down two patches when the hammer drops?  Will a limited slip differential improve the road-capabilities of the car?  If yes, then how so?

[Brian in GA]

I'm anxious to hear the response on this one.  I recently bought a 68 r/t and have found a guy with two rearends he wants to get rid of--one a limited slip (unknown ratio) for $425 and one an open with 3:23 ratio for $175.  Is the limited slip worth the difference?  I am not using the car to race, but for street only.  Thanks for the advice.

[OttawaCharger]

With an ordinary open differential, torque is sent to the wheel with the least traction so a lot of power can be wasted during wheel spin under acceleration.  So as long as both tires have good traction and your engine doesn't have enough power to overcome the traction of either one of the tires, an open diff is fine.  Now lets up the power of your engine or lower the traction available to your tires.  And you'll quickly see where the Limited slip shines.  Instead of burning up the one tire and wasting time spinning,  it splits the torque between the two tires and gets you moving. 

[myk]

Well, torque is something we have in abundance, so I should probably get it done...

[firefighter3931]

A bone stock 440 will boil the tire with a one legger.....you definately want a suregrip. 


Ron

[68chargerboy]

does anyone know where i can get a 8 3/4 sure grip.  also will a 4.10 gear be to much gear (go through first gear to quick) in a 3700-3800 lbs. car.  thanks alot




          Zach

[OttawaCharger]

will a 4.10 gear be to much gear (go through first gear to quick) in a 3700-3800 lbs. car. 

Depends what you want to do with it and which tranny you're hooking to it as well.  What are your plans for the car and which tranny are you using?

[68chargerboy]

will a 4.10 gear be to much gear (go through first gear to quick) in a 3700-3800 lbs. car. 

Depends what you want to do with it and which tranny you're hooking to it as well. What are your plans for the car and which tranny are you using?

i am using the car as a driver, but will see track action atleast once a week.  the trans will probably be a street/strip trans with a reverse manual valve body through ati (if you know a better place please tell me).  my plans are to have a 500 ci engine with close to 600 hp or higher.  the stall speed will be around 2800.  thanks



             Zach

[myk]

A bone stock 440 will boil the tire with a one legger.....you definately want a suregrip. 


Ron

Yeah, really.  So what was the logic in not making limited slip differentials standard in 440 equipped cars? 

[Ghoste]

Cost.  A lot of things weren't standard back then.   You could get dangerously small brakes on GM musclecars.
You get 340 Dusters or later Road Runners with 3 speed manual trans.  All sorts of wierd combinations in the name of advertising a low price.

[OttawaCharger]

will a 4.10 gear be to much gear (go through first gear to quick) in a 3700-3800 lbs. car. 

Depends what you want to do with it and which tranny you're hooking to it as well. What are your plans for the car and which tranny are you using?

i am using the car as a driver, but will see track action atleast once a week.  the trans will probably be a street/strip trans with a reverse manual valve body through ati (if you know a better place please tell me).  my plans are to have a 500 ci engine with close to 600 hp or higher.  the stall speed will be around 2800.  thanks



             Zach

I am sure the other guys will be able to help out here but until then; personally, I think 4.10 is going to be too high.  Especially if you do any expressway driving as your mileage is going to be very poor and I imagine that you'll get tired or the engine running that high in the revs for extended periods.
I'd go with the 3.23 or 3:55 sure grip myself.   something to bear in mind also is that if you put taller tires on the car, the gear ratio will be reduced.  Every inch taller a tire is over factory specs reduces the gear ratio by about .10.

[firefighter3931]

will see track action atleast once a week.   my plans are to have a 500 ci engine with close to 600 hp or higher.  the stall speed will be around 2800.  thanks

Zach

With a stroker and slicks, you should be looking at buying a Dana 60. I like 4.10's and with a tall tire.....highway driving is manageable. I have a 4.10 Dana going in mine ; with a 29.5 in tire the ratio drops to 3.63 


Ron

[68chargerboy]

sounds like im going with the 4.10 and am now shopping around for the dana 60.  good thing i dont do any highway driving 

[OttawaCharger]

Sounds like you're going to have a lot of fun! 

[myk]

Cost.  A lot of things weren't standard back then.   You could get dangerously small brakes on GM musclecars.
You get 340 Dusters or later Road Runners with 3 speed manual trans.  All sorts of wierd combinations in the name of advertising a low price.

Silly me.  I keep thinking along modern car lines and I'm used to cars and their equipment making sense.  Could you imagine the new GTO with an open differential?  Lol...

[Ghoste]

True.  Hell, seatbelts weren't even standard equipment until 67 for most cars.  Same with dual master cylinders.  Bare bones was bare bones back then.