Thorp VS MIP by the numbers...

[Gen_Atrain]

This post is meant to be for information and is not intended to say one differential is better than another. The facts are easy since Thorp is long out of business and their products are hard to find and when you do find them....very expensive.

	THORP 4550 BALL DIFF	MIP SUPER BALL DIFF
THRUST WASHERS	24.90mm (0.980") O.D.                                             X                                                                                               14.46mm (0.569") I.D.                                                              X                                                                                                 0.8mm (0.031") TK	27.11mm (1.067") O.D.                                             X                                                                                               18.35mm (0.722") I.D.                                                              X                                                                                                 0.91mm (0.036") TK
DIFF GEAR	38.55mm (1.517") O.D.                                             X                                                                                               9.68mm (0.381") I.D.                                                              X                                                                                                 7.53mm (0.296") TK	39.66mm (1.561") O.D.                                             X                                                                                               8.00mm (0.315") I.D.                                                              X                                                                                                 7.51mm (0.295") TK
No. OF TEETH	47	48
PEAK TO PEAK	2.73mm (0.107")	2.82mm (0.111")
DIFF BALLS	3.16mm (0.125") diameter	2.49mm (0.098") diameter
No. OF DIFF BALLS	12	14
THRUST BALL LOAD	BELLEVILLE WASHERS X 4	COIL SPRING
THRUST BALLS	1.58mm (0.062") diameter	2.00mm (0.078") diameter
No. OF THRUST BALLS	8	5

[iluvmud]

Certainly interesting numbers especially diff and thrust ball sizes...

[Frog Jumper]

When we were discussing the MIP Diff during development, I made some notes during one of my Frog Jumper tranny rebuilds...

Sorry to hi-jack your thread.  Just thought I could add to the Knowledge Base...

Terry

 

Blackfoot Counter: 52T outer, 17T inner

Blackfoot Diff: 48T

Frog Counter 01: 49T outer, 18T inner

Frog Counter 02: 50T

Frog Counter 03: 52T

Frog Diff: 47T

Thorp Counter: 52T outer, 18T inner

Thorp Diff: 47T

The Blackfoot Counter, the Frog Counter 03, and the Thorp Counter are all 52T and are the same diameter. The Frog 50T is slightly smaller, with the 49T being smaller still... The 18T Frog and the Thorp Counter inner gears are the same diameter. The 17T BF inner is slightly smaller...

The 47T Frog and the Thorp Diff are the same diameter, and the 48T BF is slightly larger.

The Frog and BF gears are the same thickness, and the Thorp are slightly thicker.

 

[Champ85]

Yeah, the Thorp diff was designed for the Frog / Hotshot (and others that share the same diff) while the new MIP diff was designed only for the BF and MB. 

It is possible to use the BF counter in the Frog with the MIP diff, understanding that the gear ratio will be different from stock (will be slower).

If MIP releases a 47T diff then it would be a drop-in replacement for the stock gear diff for the Frog.   Not sure if MIP has plans to do so.