Two pigs in a poke

[CoronetDarter]

This weekend I'm swapping the 3.55 SG pig from the Dart to the Coronet. The 'net has a 3.23 which is not working with the Hughes cam and Dynamic high stall converter. And the Dart with the Tremec 5 spd needs steeper gears so I'm having a shop install 4.10 or 4.11's in place of the 3.23. Both diffs are 489's so I assume they'll swap over.

The pig on the right is from the Dart. There's obvious differences from the Coronet's. By looking at the pics can anyone tell if the Coronet pig is a SG? I turned one wheel and they both turned simultaneously, but now looking at it I'm having doubts.



And thanks Devin (747Mopar) for talking me through the disassembly.

 

[66Satellite47]

Can't see for sure, but looks like you have the two different styles of "limited slip". The one on the left looks to be the clutch style & the other the cone style. I always preferred the clutch style, they are easy to rebuild.

 

[CoronetDarter]

Can't see for sure, but looks like you have the two different styles of "limited slip". The one on the left looks to be the clutch style & the other the cone style. I always preferred the clutch style, they are easy to rebuild.

The left one is OEM and probably hasn't been cracked open in 47 years; might as well rebuild before slamming it in the Dart.
As an aside, my plan was to swap the Dart pig into the Coronet this weekend and during this week have steeper gears installed in the 'Net's diff before throwing it in the Dart. Not unexpected, things didn't quite work out that way. The U joints are different on each driveshaft; one yoke is 1/2" wider than the other and the Dart ID's are smaller than the 'Nets. Easy fix, just swap yokes. But the Coronet splines are course and the Dart's are fine. Lastly, the Dart diff doesn't have a diff pin because the PO went with green bearings. Hey, there's always next weekend.

 

[Cranky]

The one on the left is a factory Power Lock (clutch style) and the one on the right is an aftermarket limited slip unit but the brand escapes me right now. Are the axle splines the same between the two units?

 

[john-9]

The left one is OEM and probably hasn't been cracked open in 47 years; might as well rebuild before slamming it in the Dart.
As an aside, my plan was to swap the Dart pig into the Coronet this weekend and during this week have steeper gears installed in the 'Net's diff before throwing it in the Dart. Not unexpected, things didn't quite work out that way. The U joints are different on each driveshaft; one yoke is 1/2" wider than the other and the Dart ID's are smaller than the 'Nets. Easy fix, just swap yokes. But the Coronet splines are course and the Dart's are fine. Lastly, the Dart diff doesn't have a diff pin because the PO went with green bearings. Hey, there's always next weekend.

you do not have to switch yokes and you can't because the splines are different --- just buy a conversion u-joint to fit small to big or big to small yokes and drive shafts -- part numbers are --- Spicer # 5-527X --- Precision (Moog) # 347 -- TRW (Federal-Mogul) # 20226 ,,,, any one of these will solve the yoke problem

 

[CoronetDarter]

The one on the left is a factory Power Lock (clutch style) and the one on the right is an aftermarket limited slip unit but the brand escapes me right now. Are the axle splines the same between the two units?

I have to check.
BTW, does the 89 housing use a crush sleeve or shims on the pinion?

 

[CoronetDarter]

you do not have to switch yokes and you can't because the splines are different --- just buy a conversion u-joint to fit small to big or big to small yokes and drive shafts -- part numbers are --- Spicer # 5-527X --- Precision (Moog) # 347 -- TRW (Federal-Mogul) # 20226 ,,,, any one of these will solve the yoke problem

Thanks for the info John.

 

[Cranky]

I have to check.
BTW, does the 89 housing use a crush sleeve or shims on the pinion?

Shims to set pinion depth and a crush sleeve to set front bearing preload.

 

[CoronetDarter]

Shims to set pinion depth and a crush sleeve to set front bearing preload.

Thanks Cranky. And I made the executive decision to swap out the OEM tapered bearings for the greens; no point in sliding 47 year old bearings back in the tube.

 

[biomedtechguy]

you do not have to switch yokes and you can't because the splines are different --- just buy a conversion u-joint to fit small to big or big to small yokes and drive shafts -- part numbers are --- Spicer # 5-527X --- Precision (Moog) # 347 -- TRW (Federal-Mogul) # 20226 ,,,, any one of these will solve the yoke problem

Good advice. I swapped a B-Body 8 3/4 chunk into an 8 3/4 rear axle assembly from a 73 340 4 speed Dart--that replaced my stock factory 8 1/4 in my 79 R/T F body. The spicer u-joint described worked great back in '82.

 

[CoronetDarter]

I wanted to follow up on the diff swap. The 3.55's from the Dart really woke up the Coronet. Went with the green axle bearings too. Had the driveshaft rebalanced while it was out; needed minor correcting.
The only issue seems to be with the EFI system. I think its still learning the steeper gears because the idle jumped to about 1000 RPM vs. 800 target. I've driven about 100 miles so far; if it doesn't settle down I'll reboot the ECU.
The Dart LOVES the 4.11's. With the Tremec it still only turns about 2100 at 65 mph. I had the SG rebuilt, good thing too because the clutches were worn and a spider gear tooth was broken off - found it at the bottom of the housing.

If anyone needs a diff rebuild in the Sacto area, I recommend Jeff at JAWS. Great guy to deal with and he knows his Mopars.