73 rear end noise
Intermediate
Joined: Nov 2005
Posts: 34
Likes: 0
I had a similar noise and ended up being the rear axle u-joints. Changed fluid and added additive just as a precautionary measure. I really couldn't mimic the problem or tell it was the u-joints until I pulled the axles off. Replaced them and problem was solved. I could definately see the wear and tear. Just my two cents. Best of luck.
Thread Starter
Racer
Joined: Oct 2006
Posts: 473
Likes: 6
From: New Port Richey FL
While I was tearing down my rear and yanking out the halfshafts I found one seriously bad u-joint. I'm surprised that I didn't see it while I had it on one of the two lifts before. Anyway, I've got my halfshafts and flanges cleaned and painted now. I'll be pressing the u-joints on tomorrow and bolting it all back together. With anyluck all will be well. I'm going to change out my front differencial cushion while I'm down there, it looked pretty bad. I will be updating everyone soon. Thanks!!!
Thread Starter
Racer
Joined: Oct 2006
Posts: 473
Likes: 6
From: New Port Richey FL
I now have a new front carrier cushions (upper and lower) and 4 new u-joints in my car. The rear is now completely solid. No noise, no cluck, no weird things that happen only when you do this or that. My lower carrier cushion looked ok, but the upper one was unrecognizable. I'm certain that the clunk I noticed was from the bad u-joint, but I could tell this wasn't helping any. For those other people out there wondering if they need carrier cushions, my suggestion is to crawl under the car and inspect the lower cushion. The only way to inspect the upper one would be to remove it. Its not as big of a deal as one would think. The lower cushion is the bear to put back in. The upper is a piece of cake. Just remove the nut, then the bolt and the upper cushion. If all looks well its easy enough to put back in. To install the lower cushion I needed a helper (make sure you trust your helper, otherwise you will have smashed fingers). One person used a pry bar to lower the front diff mount and I slid the cushion in. It took a couple tries but it went in without too much fuss. Beware of the rear brake line that is in the vicinity. It looks important and care should be made not to crush it. If you do crush it, well, your rear brake pads will last a lot longer.
Intermediate
Joined: Nov 2006
Posts: 32
Likes: 0
From: wilmington de
More Diff Draining Tips
Originally Posted by Green73
Still haven't changed out the fluid yet, but did get my car up on the lifts at my friends place. After on the regular lift and not finding anything crazy, we put it on the drive on lift. On there and moving the driveshaft back and forth we found play in the carrier bearings. All the U-joints looked fine. There was some movement in the front carrier mount bushing also. I'll be removing the diff and sending it to the local diff repair shop. Then begins the long (read expensive) process of basically rebuilding the hole rear end. Many of my bushings are original and definitly showing thier age. Judging sizable oil spot on the bottom of the right storage compartment, its something that needs to be address sooner or later. In this case, its going to be sooner. Just wish it would have popped up later... this is convertible weather in Florida. I shall keep everyone updated. Thanks!
Good Luck !!!
Burning Brakes
Joined: Jan 2006
Posts: 957
Likes: 6
From: Burlington wisconsin
Originally Posted by gkayea
If you are not planning on drilling & tapping a drain hole, buy a drill pump at Pep Boys or Auto Zone & about 4 Ft. of 3/8" clear Poly Tygon Tubing at Lowes or Home Depot, the tubing is flexable enough to get to the bottom of the diff. and the clear tubing makes it easy to see what you are doing while draining and refilling, I reccomend measuring what you drain out, that will let you know if you were low to begin with & how much you couldn't get out, 3.50 pints I think is about right to refill and don't forget the Posi Additive , the level should be about 1/2" below the fill hole when refilled, Make sure the car is level side to side and front to rear if you are doing this on the ground and not on a lift. My 73 had the original gear lube in the rear for 32 years and the rear started making noises like the emergency brake shoes dragging, changed out the lube & It is okay now, Oh I didn't know about the figure 8's
Good Luck !!!
Good Luck !!!
Last edited by cherrybombc3; Nov 26, 2006 at 01:20 AM.
