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Rear end repair.

11K views 19 replies 6 participants last post by  Hal 
#1 ·
I was told I could change the pinion seal on my '63 Impala with the car on the ground. I have the rear end on jack stands with both wheels off the ground. I have already removed the two U bolts which help secure the universal joint at the rear of the drive shaft to the differential. Can anyone please tell me what the next step is I must do in order to drop the drive shaft away from the differential? Thanks!
 
#2 ·
Welcome Les! I believe all you need to do is slide it foward out of the yolk. If you still don't have the room you can slide it out towards the back. Those driveshafts are a 2 piece design and one slips into the other at the X part of the frame. I am a post 64' year guy so I'm a little rusty on them. :).
 
#3 ·
Loosen the bolts that hold the center carrier bearing in the middle of the X frame. Then the drive shaft will move forward and backward (slip yoke at the transmission taking up the slack).

As I recall the next step is to remove a bolt behind the U-joint so you can remove the pinion yoke and then get at the seal. I did not do my own differerntial rebuild, so I only recall seeing the guys at the differential shop do that.



 
#5 ·
Thank you, gentlemen. I just recalled that there is a steel plate welded in place along a section of the X frame's bottom. I assume this is simply a part of the entire X frame. As a result of this design the X frame provides a "tunnel" which the drive shaft runs through. Since I never noticed before, are the bolts for the center carrier bearing still accessible in spite of this? Thanks!
 
#6 ·
Center carrier

There should be a small indentation near the center of the X frame and you will see 2 bolts that hold the center carrier brg. This might be a good time to check the center carrier as the brg is mounted in rubber and over time(and maybe a few hard takeoffs) the mounting rubber or bearing can be damaged.:D
 
#7 ·
Thanks, Robin. I looked up the center carrier bearing on RockAuto.com and they show a picture of it with a mounting bracket that has two bolts. It sounds like these correspond to what you described. If so, then it looks like the heads of the two mounting bolts are the only things that appear on the outer surface of the bottom of the X frame where the indentation is, keeping the bearing itself hidden up in the "tunnel." I wonder, though, where is the middle universal joint, connecting the two drive shaft sections, in relation to the center carrier bearing, fore or aft of it? Thanks!
 
#8 ·
If you look carefully, at the bottom center of the picture, you can see the two somewhat silver bolts that hold the center carrier bearing. This is looking from the transmission to the rear (wow, my car looks a lot better under there now a days).




Here is what it looks like inside the "tunnel". This is looking from the rear to the front. You can see the raised area with the two bolt holes. This is not the normal color, I had just painted it with rust encapsulator.





This is what the drive shaft looks like. Transmission end is on the left. Silver thing with the two bolts on it is the center carrier bearing followed by the second u-joint. Mine has a slip joint after that, which is not standard, I had it added when I serviced the driveshaft. Just outside the picture on the right is the u-joint at the differential.




 
#9 ·
Thanks, David! These photos are a tremendous help. Though I now have to jack my '63 up higher in the center and squeeze my old, fat arse further underneath, at least your pictures make it clear why the middle universal joint is out of sight when one looks at only the bottom of the chassis. So, as you instructed in your earlier post, I only have to loosen those two bolts and the entire drive shaft assembly will slide forward, allowing the rear end section to drop away from the pinion snout, right? Are you certain I don't have to fully remove the bolts? Because I'm curious to know how the shaft can slide in either direction if the two bolts are still in their holes as well as the bearing bracket? Thanks again.
 
#10 ·
You should be able to just loosen them and get enough play to disengage the rear u-joint (with the u-joint straps removed, of course). The bolt holes are oval shaped for variation in the placement of the bearing.

BTW, do you know the proper places to put the jack stands ? This is from the shop manual. In my mind, it seems like it would be tippy with the jacks seeming to be too much to the center, but it is quite stable.




 
#11 ·
Thanks again, David. The Lifting Points illustration is appreciated. As it turns out I placed my two jackstands correctly for the rear end, each one just inside the rear wheels and under the axle. For further up front I'll place one of them as shown in the diagram and the other one under the rear axle again but on same side of the car. I must lift the car off the floor on the driver's side only because I'm stuck with doing this repair at the storage facility where I have it garaged and she's parked extra close to the right side wall in order to provide more room on the driver's side. The garage is only 10 by 20 ft. in size. BTW, if I wanted to change the center bearing as well, it looks like I'd have to disengage the front universal joint also and pull the whole shaft assembly out of the tunnel, either forward or rearward. Is that about right? Thanks!
 
#12 ·
If you want to remove the drive shaft, just remove the center bearing bolts all the way, push the drive shaft forward a tiny bit to free it from the unbolted differential pinion yoke in the rear, then pull the drive shaft to the rear and the front u-joint yoke will slip out of the transmission. Put a pan under the end of the transmission as it will dump a quart or so of fluid when you do this (always fun when you are right underneath ;) ). It is easier to service that u-joint out of the car, since a press is needed to get it out.

I was able to wangle my drive shaft out with the wheels off the ground. This makes the rear axle is lower and rather in the way. I suspect is may be easier if the rear axle is kept higher (jacks on the axle or ramps under the wheels).



 
#13 ·
Thanks for the latest tip, Dave. However, if a press is needed to remove old universal joints from their yokes, I'll put that off for another time as this old retiree don't have access to such equipment. I was under the impression, if I had to change them, I could simply remove the retaining snap rings and pound the crapola out of them with a hammer and punch till they broke free. Oh, well. ;-) On the bright side, the factory originals on my '63 have only a little over 79,000 original miles under their belts, just like the rest of the car! Hardly ever driven and always garaged.
 
#15 ·
Yes, I don't think the tool needed is difficult to come by, you might even be able to 'rent' one for free from auto parts stores like AutoZone. Also, if you do change the u-joint in the middle of the drive shaft, mark the shaft so you can put it together the same way. It was balanced as a unit, and if you re-assemble it 180 degrees out, it will probably give you vibration issues.



 
#16 ·
Good point, Dave. And thanks to you too, Mike. But Mike: when you refer to this "socket" method with a vise, I'm trying to visualize it; do you mean to use a socket attached to a drive extension then pound it out with a hammer while the yoke is secured in the vise? Thanks!
 
#18 ·
I mean place one end of the u joint on the open end of a socket so it can be pushed into it. The socket must be large enough for the cap to be pushed into it but small enough to be placed on the yoke. Then put the other end of the U joint into the vice with a smaller socket that pushed on the U joint. Tighten the vice and the U joint should be pushed through so you can remove the caps and remove the U joint from the yoke.
 
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