Help!!! Did I wreck my diff??

[Fm3 a66]

Ok thanks for the info 1 wild R/T I pulled out the axles and center section today and It actually all looked pretty good!?!? I was kinda hoping something would fall apart so I could see a problem to fix! There is a fair bit of backlash in the gears but I think that's normal. I did however put a screwdriver between the bearing caps and the ring gear and noticed a bit of play? Not sure if that's the carrier bearings? Also  drivers side axle has some weird wear at the end of the splines? I will attach a pic. But in the meantime while I try to get this back on the road ASAP  I remembered I have a 70 challenger that's got a 8 3/4. Rear in it so I went over and dropped the axles and center out of that to use and the casting on that unit is 2881489 (pic attached) and it has 3.23 gears with a sure grip setup in it! I got that installed except the pass side axle has a weird looking bearing on that end? Don't know if that's for preload or what??? (Also pic attached) put oil in the diff went to install driveshaft only to realize the u joint doesn't fit??? I think I need some type of combination one? I gave up went in to watch the hockey game!

[Chryco Psycho]

The threaded adjuster is on the right side & takes up the end play so the axle brgs are seated properly

[Bullitt-]

& you will need this to hold the adjuster in place



http://www.ebay.com/itm/Mopar-8-3-4-Rear-Axle-Adjusting-Nut-Locking-Pawl-Dodge-Plymouth-/151499867198?hash=item234618843e

[don340-4]

  I believe those OEM bearings need to be packed with wheel bearing grease, maybe someone can confirm that.

   

[Bullitt-]

  I believe those OEM bearings need to be packed with wheel bearing grease, maybe someone can confirm that.

   

Yep....good how to by ShelbyDogg http://www.cuda-challenger.com/cc/index.php?topic=35471.msg355781#msg355781

[Bullitt-]

maybe the universal joint you need
http://www.doctordiff.com/1350-to-7290-conversion-u-joint.html

[Fm3 a66]

Great! Good info guys and thanks for the links Bullitt. So I will pull the axles back out today and grease the bearings and re-adjust the pass side bearing for end play and start hunting local for that u-joint. Now since the ujount is a pinch smaller I'm guessing I need smaller u-joint straps? I will have to do a google search on that?

[RzeroB]

I was kinda hoping something would fall apart so I could see a problem to fix!

I hear you there!

I remembered I have a 70 challenger that's got a 8 3/4. Rear in it so I went over and dropped the axles and center out of that to use and the casting on that unit is 2881489 (pic attached) and it has 3.23 gears with a sure grip setup in it!

Hmmmm? At the beginning of this thread I thought you said that you "were not a Mopar guy..."? Now you have a Challenger? Interesting. Let me guess ... with a forum name of "Fm3 a66" would your Challenger happen to be a FM3 Panther Pink A66 hardtop?    Do tell ...

[TelisSE440]

 

[Fm3 a66]

Ahahahahhahah yes RzeroB! I am not a mopar guy I am a first gen camaro guy!  Being a car guy I do appreciate all muscle cars and I have been restoring cars since I was a kid! (Mostly Chevy) after  redoing my dads cuda a few years back I developed a liking for the dodge/plymouths. When I  had the chance to pic up a 70 challenger to add to my collection I jumped on it and yes It is a fm3 a66 hardtop car. I actually signed up to this forum to learn more about the a66 cars! The challenger is rough and in need of restoration but it does have the original rear that I grabbed to put into the cuda this weekend.  Which actually seems to have been a waste of time!?!? I managed to get it all together and even got the conversion u-joint! Backed the cuda down my driveway put it in gear and it wouldn't move stuck right there! I push on the pedal abit and the motors definatly working but I'm not moving! Back into reverse it breaks free and then I popped her back into drive and got it into the garage! Now I'm thinking trans and I don't have any spares of them! (Unless my pops does?) lol. So once again I'm stuck! Does this sound like a trans problem???

[Bullitt-]

For sure there are other casting #s , I have come across them before & never found any info inthe internet on other #s
 Looking again both 7s seem to have a miscast on them so they could both either be 3 or 7 so it likely is a 741 . If the diff still turns easily I would look further up the driveline , could be in the trans

Maybe I am wrong but that looks like 2070341 , could be from the late 50s or early 60s .
could it be the sprag in the trans that has the problem if the diff turns freely with the driveshaft out ?

[Fm3 a66]

The trans turns freely one way but is very hard to turn back the other way with the driveshaft out. This car has always had a problem of shifting very fast into drive! What I mean by that is when I put it into drive and go it automatically shifts through all gears before I get to 30mph! Not sure if that's got anything to do with it or not? Could the sprag cause the trans to lock up momentarily???

[jhaag]

Yes a failed sprag will cause your symptoms. Also your throttle to trans linkage is out of adjustment causing the shifting symptom you described. This linkage controls line pressure and shift points.

[Chryco Psycho]

 

[Fm3 a66]

Hmmm so your thinking the sprag could do this? So I guess I will start doing my reading on sprag issues now before I tear the trans out! That sucks! I did a quick google of sprag issues and of course it looks like it's the last piece in the trans to get at so complete tear down / rebuild will be required I'm guessing.