8 3/4 Endplay Problem

[Powerflite]

I purchased a 3.23 open gearset in a 489 case from a swapmeet that looked to be in good condition etc. After installing it, I have about 3/16" to 1/4" of play in the axles on each side. A lot more than I had with the 3.55 open gears in a 489 case that I pulled. What would cause this much endplay? I don't think that the adjuster can take out this much play, but what would cause it? I know that clutch type sure grip units in 742 cases need an insert to take up the play, but I have never encountered this kind of a problem with an open differential.

Any ideas?

 

[Meep-Meep]

Is the open rear end possibly missing the floating thrust piece? It's been a while, but I'm pretty sure there is a cylindrical part with a slot that the spider gear pin passes through. I hope I'm not confusing this with something else, but I just don't see how you can have this problem otherwise.

 

[Powerflite]

Yeah, I thought about that too, but wouldn't the spider gears come out if that was missing? How easy is it for that pin to come out?

 

[Cranky]

The spider gears cross shaft is what the slot is for in the thrust pin. This one is out of a cone type Sure Grip but the one in the open carrier is similar.

The shiny part is what the end of the axle mates up to. The only way this can come out is if someone took it out or something very wrong happened.

 

[Powerflite]

So, I pulled it back apart today. Sure enough, that thrust pin is completely missing. I guess the previous owner had axle problems with green bearings so he just removed it. But how do I get a new one, does someone sell these things? I don't want to have to convert to green bearings just to use these gears.

Also, how does the spider gear pin come out? It has a slot on the top of it, but it doesn't want to turn.

 

[Kernel Sanders]

To remove the spider gear cross pin you must remove the ring gear to access the roll pin holding it in. Once the roll pin is removed the cross pin will just slide out so that you can replace the thrust button.

- - - Updated - - -

Oh! If you cant find one I can mail you one

 

[Powerflite]

Thanks alot for the offer. I found one locally, but it looks exactly like the one Cranky showed. Are the sure grip and open versions different or the same? I know that 1964 and older open versions were shorter than the later ones. Mine is 1.5" long, but I don't have anything to reference to.

I am going to attempt to replace this myself, but I have never torn apart a differential before. I assume that in order to remove the ring gear that I would need to remove the carrier first. If I mark the adjusters before taking the carrier out, can I just put them back to where they were before and not have any trouble with it? Anything I should know first?

Thanks again.

 

[RustyRatRod]

The clutch type sure grip takes a three piece pin like this.

http://www.ebay.com/itm/NOS-MOPAR-S...Parts_Accessories&hash=item337da72b31&vxp=mtr

 

[1948 santa]

Don't bother marking the adjusters,mark carrier caps so they go back on same side,remove case then mark ring gear to case position,roll pin will only drive out in one direction toward ring gear side,then drive out pin.Be carful when reinstalling axle and spider gears to align thrust washers exactly before driving in pin.Reinstall ring gear(left hand thread)then case in carrier and set backlash and preload with adjusters.Not too much preload because you have used bearings then.006 to .008 backlash.

 

[Powerflite]

Thanks a lot for the very helpful tips! I didn't know about the left hand thread and that could have been bad if I didn't notice the "L" on the bolts. I put the thrust block in yesterday and it worked out great with no noise or any problems! Nice to have my car back on the road .

The only difficulty I had was installing and removing the ring gear. That thing must be a press fit. It took forever to nudge off the gear from the carrier going opposite side to side. I heated the gear to put it back on, and that really helped, but I couldn't get it aligned properly before it cooled down a lot.

Is there a trick to dealing with that ring gear?

 

[RustyRatRod]

I always just knock um off with a brass drift and use the bolts to pull um up with rotating in a star pattern until they are tight.