Author Topic: What kinda 3rd member? (Read 1458 times)

T/A Care · « **on:** March 14, 2005 - 05:52:00 PM »

I picked these up a while back. They work fine. (These pictures were taken before they went in.) I've just seen a lot of discussions over time as to what is better; clutch or cone, 742 vs. 489, small yoke vs. large, pinion shaft diameter, gear wear pattern, etc..

Would you guys tell me what I have here, pros and cons?
Thanks.

360 'CUDA · « **Reply #1 on:** March 14, 2005 - 06:00:55 PM »

What you have there is a MONSTER :thumbs:

The best case with the nasty 4:56 gears... running some RPM on the freeway?

I take it burnouts and black line making are not a problem

Do you sometimes have trouble keeping your car on the ground?

T/A Care · « **Reply #2 on:** March 14, 2005 - 06:04:27 PM »

Yes, keeping it stuck is a problem. I'm going to some cheater slicks!

Any ideas on it's make up? I know it's a clutch type. Is it the large pinion? Wide yoke? Any pros and cons?

OUTLAW · « **Reply #3 on:** March 14, 2005 - 07:16:13 PM »

http://sybertek.us/moparsa2e/viewforum.php?f=18 will tell you everything you need to know on the 8 3/4 diff

Chryco Psycho · « **Reply #4 on:** March 15, 2005 - 02:34:15 AM »

I can`t tell the yolk size but you have the strongest large pinion carrier with the strogest /clutch type sure grip , no cons I can think of

T/A Care · « **Reply #5 on:** March 15, 2005 - 11:57:30 AM »

Thanks for the replies guys!

In trying to understand a little better, why do people ask for 489 cases, in the "Wanteds"? Wouldn't they want a 742?

67Vette427 · « **Reply #6 on:** March 15, 2005 - 05:36:32 PM »

I believe the difference is that the 742 case was last used in 69. The 489 is most common afterwards and is found in the e-bodies. 742 is stronger than the 489 but I never broke a 489.... People prob want a 489 for original purposes....

heminut · « **Reply #7 on:** March 15, 2005 - 10:05:50 PM »

Quote from: T/A Care on March 15, 2005 - 11:57:30 AM

Thanks for the replies guys!

In trying to understand a little better, why do people ask for 489 cases, in the "Wanteds"?� Wouldn't they want a 742?

The 489 case actually used a little bigger pinion, but it also used a crush sleeve to set the pinion bearing preload. The 742 case used shims to set the pinion bearing preload, which is a better setup for hard use. There are kits on the market now that eliminate the crush sleeve in the 489 and convert it to the better shim type setup.

Chryco Psycho · « **Reply #8 on:** March 15, 2005 - 10:07:27 PM »

Ratech makes a spacer to eliminate the crush sleeve which is th eweak link in the 489 case , the part# is 4103 from Ratech

Author Topic: What kinda 3rd member? (Read 1458 times)

T/A Care

What kinda 3rd member?

360 'CUDA

Re: What kinda 3rd member?

T/A Care

Re: What kinda 3rd member?

OUTLAW

Re: What kinda 3rd member?

Chryco Psycho

Re: What kinda 3rd member?

T/A Care

Re: What kinda 3rd member?

67Vette427

Re: What kinda 3rd member?

heminut

Re: What kinda 3rd member?

Chryco Psycho

Re: What kinda 3rd member?