Is this pinion right for a 489 case?

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LXguy

LXguy

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Hey All:

I've got a 489 carrier and am experiencing some weirdness. I bought a used A body 8.75 from a pretty well known Mopar vendor. The third member was supposedly a "known good" unit. Needless to say I got the car together and the thing is making all kinds of noise. Whining on acceleration and decel, vibrating, etc. The carrier is actually a 489.

I pulled it apart, and some of the bearing are pretty grotty, and it dumped a load of small (1mm) fingernail clipping shaped filings when I pulled the pinion.

Currently the pinion bearing is still pressed on the pinion. I measured it right by the bearing and my reasonably decent calipers come back with 1.480. I thought the 489 was supposed to be 1-7/8? Am I measuring it at the right place?

Here's a pic:

pinion.jpg


Any help is greatly appreciated.

Steve
 
That looks like a straight pinion. 489's have a large tapered pinion. 742 is 1 3/4. 741 is 1 3/8. 489 is 1 7/8. Someone probably used a smaller pinion with a bearing with smaller dia. as to fit it in the carrier.
 
Demon416 said:
That looks like a straight pinion. 498's have a large tapered pinion. 742 is 1 3/4. 741 is 1 3/8. 489 is 1 7/8. Someone probably used a smaller pinion with a bearing with smaller dia. as to fit it in the carrier.
Click to expand...
Thats not a 489 pinion ~
 
That's what I said. But it was installed in the 489 carrier.
 
That's a 741 pinion, I guess with a bastard inner end bearing it would work I just have not seen anyone try it. The outer pinion bearing on the 741 and 489 are the same but the inner bearing between the two are totally different in size and part#.

Terry
 
I've seen it done back in the day. All you needed were the right bearings to make it fit. Looks like that's what was done here. If I was LXguy, I'd ***** to the guy I bought it from. That's just not right!
 
If he,s a Mopar vendor??He knew exactly what he was scamming..oops! selling you?I would be royaly pissed!
 
Thanks for the responses and the pic:

I'll be calling the guy first thing Monday. At this point, I won't say he knew he was selling this to me as a half-assed deal. He sells used parts and it could have been assembled when he got it. Why the hell would anyone do this and put a 4.10 in the thing? who would want a 4.10 if they weren't going to beat on it?

This vendor has treated me well so far. Wish me luck.

Steve
 
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