74 Charger SE: 440 3 speed auto conversion from 4.10 to 3.23....?

[74ChargerSE440]

For obvious reasons I am orienting on the conversion of my 74 440 3 speed auto charger from a 741 4.10 sure grip back to a 3.23 the car came with from factory. I don't have mutch clues at this point. Any do's and don'ts and tops and flops are very appreciated.

 

[#41]

Are you just swapping the 3rd member out whole, or installing new 3.23 gears in the 4.10 unit? The first is straight forward. The second takes a little skill.

 

[Don Frelier]

A gear vendors overdrive would reduce it to almost the same final ratio.
Just a thought.

 

[74ChargerSE440]

Are you just swapping the 3rd member out whole, or installing new 3.23 gears in the 4.10 unit? The first is straight forward. The second takes a little skill.

Well first I don't have any 'technical' skills. Secondly I want to go back to stock configuration. That's what I want, but don't know what it takes. According to the seller it has the original 8 3/4 rear end. So, I was hoping it's just swapping the pinion and ring gear?

 

[74ChargerSE440]

A gear vendors overdrive would reduce it to almost the same final ratio.
Just a thought.

I seems that this option will cost at least $4k?

 

[WileERobby]

Well first I don't have any 'technical' skills. Secondly I want to go back to stock configuration. That's what I want, but don't know what it takes. According to the seller it has the original 8 3/4 rear end. So, I was hoping it's just swapping the pinion and ring gear?

Easiest thing to do is swap the pumpkin.

 

[Fran Blacker]

Easy if both are the same u-joint. But there are combination u-joints available.

 

[74ChargerSE440]

Easiest thing to do is swap the pumpkin.

You guys are killing me with impressive slang. Swapping the third member, pumpkin... What does it cost, such a pumpkin?

 

[#41]

Swapping the pumpkin is the way to go since you have limited skills. You can price them online new, or buy a good used 3.23 Sure Grip (spins BOTH tires) for around $400-600. You'll want one with the larger yoke to match up to your existing driveshaft, and best to have a pumpkin casing with the casting # ending in "742" or "489". It's a 1-hour job for an experienced mechanic, so you could always have a shop install it at reasonable cost.

It's not that complicated to do yourself if you want to give it a go. Some basic tools, a few gaskets, and some silicon sealer. I'm sure there are a multitude of Youtube videos that walk through the subject.

Edit: I see you are in the Netherlands, so an entire pumpkin may be cost prohibitive. In that case, consider buying some new 3.23 gears that fit your existing pumpkin and have a mechanic do the work. Try these guys for info:

RANDYS Worldwide | One Stop Differential & Drivetrain Shop

 

[YY1]

1st- 1974 is too late for a 741 casting "pumpkin".

Factory stock would have been a 489 casting.

 

[YY1]

Second- Changing a ring and pinion set requires special tools like a dial indicator, and knowledge of how to use one.
This is something that "usually" requires someone "seasoned" IE that has done it many times.

 

[YY1]

3rd- Swapping the chunk or pumpkin is WAY easier if you can find a known good unit and, as mentioned above, it has the correct size yoke for the U joint.

Take off the wheels, take off the brake drums, unbolt the axle retainers, slide out the axle shafts.
Remove the U joint, unbolt the chunk. (don't lose the button).

Reverse, but also set the axle end play on the side that has the adjuster.

...and 600 is probably a little light for a good, possibly guaranteed sure grip chunk.

There may be one or more for sale here, or on FABO.

 

[1 Wild R/T]

In spite of being in the Netherlands swapping the pumpkin is the way to go & chances are someone nearby will want your 4:10 enough that they will do the swap & it won't cost you much if anything...

 

[74ChargerSE440]

Swapping the pumpkin is the way to go since you have limited skills. You can price them online new, or buy a good used 3.23 Sure Grip (spins BOTH tires) for around $400-600. You'll want one with the larger yoke to match up to your existing driveshaft, and best to have a pumpkin casing with the casting # ending in "742" or "489". It's a 1-hour job for an experienced mechanic, so you could always have a shop install it at reasonable cost.

It's not that complicated to do yourself if you want to give it a go. Some basic tools, a few gaskets, and some silicon sealer. I'm sure there are a multitude of Youtube videos that walk through the subject.

Edit: I see you are in the Netherlands, so an entire pumpkin may be cost prohibitive. In that case, consider buying some new 3.23 gears that fit your existing pumpkin and have a mechanic do the work. Try these guys for info:

RANDYS Worldwide | One Stop Differential & Drivetrain Shop

Thanks! Now in search of a 489 pumpkin with a 3.23 in it.

 

[74ChargerSE440]

3rd- Swapping the chunk or pumpkin is WAY easier if you can find a known good unit and, as mentioned above, it has the correct size yoke for the U joint.

Take off the wheels, take off the brake drums, unbolt the axle retainers, slide out the axle shafts.
Remove the U joint, unbolt the chunk. (don't lose the button).

Reverse, but also set the axle end play on the side that has the adjuster.

...and 600 is probably a little light for a good, possibly guaranteed sure grip chunk.

There may be one or more for sale here, or on FABO.

Just like this one from 4 years ago: SOLD - Mopar 489 case 3.23 ratio open

 

[74ChargerSE440]

Are you just swapping the 3rd member out whole, or installing new 3.23 gears in the 4.10 unit? The first is straight forward. The second takes a little skill.

I checked my pumpkin and fortunately the seller was wrong. I have a 489 case and not a 741! So now I only have to new 3.23 gears. Correct?

 

[#41]

Yes you can buy a gears, bearings and seals for that brand new. There are several vendors on line.

 

[74ChargerSE440]

Yes you can buy a gears, bearings and seals for that brand new. There are several vendors on line.

Ok! I see serveral vendors online and huge price differences... What to choose?