Rear diff torque rating?

[70spider]

I was wondering what kind of torque can the rear diff take? Would 150 ft./lbs. be to much?

[TX82FIAT]

150 seems high to me. I would think the differential front flange is about 90 ft/lb and the cover is about 40 ft/pd. I may be misunderstanding the question.

[Nut124]

Engine torque?

The rear diff is the weakest part of the 124 drivetrain. I have broken four diffs in my 1800 by launching hard. Used to be I broke the diff every time I got sticky new tires. The diff fails as the pass side diff gear carrier bearing journal snaps off, weak, cast iron. Hard launching does it or stepping on it in reverse.

The russian LSD is stronger, steel, and mine has held up so far. Not sure what the availability is now with the war.

[70spider]

The rear diff is the weakest part of the 124 drivetrain

That's what I thought. There goes the plans of an engine swap unless I can figure out how to put a stronger axle assembly in him.
Thanks for your input.

[Nut124]

What kind of engine swap were you thinking of?

The russian, steel LSD I have looks to be much stronger than the Fiat cast iron unit. It fits in a -70 axle.

[70spider]

I was looking at a few options. The more practical one is the old mustang ii 2.8l v6 with a T-5 trany, seemed liked the best one but the torque rating of the engine is 140 ft.lbs, HP was ok around 110. The other two (honda k20 and mazda renesis) were a little higher around 150-160 ft.lbs. The reason why I was considering it is I moved to an area that the only road between towns is the interstate and my little 1438 with the 4.30 rear end isn't practical at 75-80 mph. I thought about the 3.90 rear end gears from AutoRicambi combined with the 0.63 overdrive in the T-5 would be good, reducing the rpms from 4200 to 2700 @ 75mph.

[70spider]

The russian, steel LSD

Wow just looked it up and there over a grand, ouch. I think it would be cheaper to put a ford 8" rear end in it.

[Wolfman2332]

Where can I look at the Russian Differential?

[Nut124]

Where can I look at the Russian Differential?

They could be hard to get now due to the war. Mine came from Ukraine 3 years ago. Looks like the one below. They come with different lock presets.

https://www.ebay.com/itm/185669063599?h ... R76Fz8DHYQ

[Wolfman2332]

Thanks for the lead Nut124 - that looks like a good idea. Would love to hunt down a (aprox) 3.65:1 read end. Limited slip is going to get ordered for next years project list.