Clunk elimination has begun, with pics

[Zedyone_kenobi]

The Z had one last peaceful night in her garage before it was time to start the investigation into her rear end clunk.

With tools put away, and the garage cleaned up, she was ready for a peaceful nights sleep.

Then while waiting on Hurricane Gustav this weekend I had time to do a little work. I started cleaning my replacement diff in case I decided to use it, and started the task of getting the car safely in the air and well supported. I had to put the garage stereo on easy listening so to lull her to sleep for surgery.

THen the tires came off, followed quickly by the drivers side half shaft, which put up next to no fight at all.

Here is the picture of the half shaft, and replacement diff before cleaning. AFter shots pending. I cant find my brass and wire brush at the moment. May have to pick up new ones to clean off the diff and get it ready for prime and paint.

The good news is that the rubber boot on the half shaft is soft and supple, with no cracks I can see or feel. The U-joints no matter how hard I try have no slop and and are completely smooth in all directions. I have ordered new U-joints for both half shafts, but I cannot see replacing parts that are probably OEM and are probably in great shape. Opinions? Here is a better look at the U-Joint.

So far the project is going well. I have new drive shaft U-joints coming as well, and a Urethane Mustache bar kit. You can see the new diff mount in the picture. I am going to be very interested to see the condition of the mustache bar bushings. More pics to come.

[Sailor Bob]

Gotto say that car is very easy on the eyes. Good luck with the clunk - I have two Z cars and two clunks. I'll be following your thread.

[7277]

if the u joints are TIGHT...leave 'em alone IMO

[WW2Winger]

Good pictures Stephen, I am closing in on the completion of replacing differential, transmission, brakes, bushings, steering rack, radiator, and more, so I understand exactly where you are with your project. Mine is also a '71. Best of luck and be sure to give us the "after" pictures.

[xray]

Nice garage! What's your floor coating?

Good luck finding the clunk! When you repaint....I used both POR-15 and Eastwood products to do parts of the undercarriage/suspension. Whichever you choose, be sure not to mix and match, as they will cause wrinkling/lifting if one topcoat is placed on the other's anti-rust product. The finish and degree of gloss is similar between both "Chassis Black" products.

I had to use the Eastwood product for some components since it came as an aerosol (and I didn't have HVLP or compressor equipment) and POR15 only comes in a can.

Good luck! And remember: once you clean some parts, the rest looks more and more like it needs to be done, too. "While I'm there, I may as well...."

[Six_Shooter]

I'll be interested in the result as well. My '73 has that rear end clunk. I'm debating on swapping the solid axle in earlier than planned, just to eliminate it.

[Zedyone_kenobi]

Nice garage! What's your floor coating?

Good luck finding the clunk! When you repaint....I used both POR-15 and Eastwood products to do parts of the undercarriage/suspension. Whichever you choose, be sure not to mix and match, as they will cause wrinkling/lifting if one topcoat is placed on the other's anti-rust product. The finish and degree of gloss is similar between both "Chassis Black" products.

I had to use the Eastwood product for some components since it came as an aerosol (and I didn't have HVLP or compressor equipment) and POR15 only comes in a can.

Good luck! And remember: once you clean some parts, the rest looks more and more like it needs to be done, too. "While I'm there, I may as well...."

I used UCOATIT light grey, followed by their tinted gloss coat. I elected not to use the flakes, as based on past experience, trying to find a nut or a small screw on a flaked floor is impossible. I cannot tell you how happy I am with the results. The floor is almost rubbery smooth, and sweeping and mopping it are effortless. NOTHING sticks to it, and its hard as nails. I highly recommend it.

[jagster]

Somewhere before 1972, there were some strange things going on with the rear-ends on these cars, and the transmission had the 'monkey-motion' linkage. Also, there was a large, rubber strap going over the front nose of the differential, just in case the nose wanted to rear it's head on hard acceleration. Of course, the differential mount on all the cars had rubber in it to quiet down the noise transmitted through the car, and the rubber gets rotten and comes apart. Also, the early cars had the differential mounted more forward than the later cars. This causes the half shafts to move in strange directions, all at the same time. Most gearheads choose to get the later differential move it back with the necessary pieces and line up the halfshafts just like the factory did. And a later 4 or 5 speed transmission for their cars, along with the needed, longer drive shaf. This sounds like a lot, but actually, it is all bolt-in from a donor car. good luck and keep us posted.

[rdefabri]

Good luck - I have a replacement diff too that's in similar shape, so I am keenly interested in your progress. The "replacement" is actually the standard 1972 diff, I currently have 4.11 R180, but I want to get mine back as close to stock as possible.

BTW, your garage is CLEEEEEANN. IIRC, you just had your first child? Mine was like that once...ONCE - then the kids got at it and the clutter overwhelmed me and the garage

[Zedyone_kenobi]

Thanks, yeah, my little boy is 6 months old.. and he is why this project will take several weeks instead of one weekend.

I spend 15 minutes a week sweeping it and mopping it. It actually pretty cluttered. The wooden shelves are destined for my shed thats going in the back yard in a few weeks. So then I will have more room for the compressor air lines, I plan on installing next year. Right now my compressor is next to my tool box. Its out of the way, but having several air bosses would be nice.

But first the clunk. I have added replacing my tranny mount to the list. As I am sure it along with the engine mounts are original too.

Keep in mind my car only has 69234 miles on her. So most of these parts should be in great shape.

[Zedyone_kenobi]

My car has a 7/71 build date, so does that put me in the scooted forward rear diff catagory? Also, is there any way to identify the pedigree of the diff I have on my bench? My current diff has numbers stamped into the bottom of it, and I would wager that they are meaningful to some degree. This new diff is smooth all over, no numbers anywhere. So I am left scratching my head. Its more of a curiosity than anything else. I would actually like to keep the stock diff in my car if I can, but I think I have bearing issues. It makes a noticeable noise when you coast in gear off the gas

Edited September 2, 2008 by Zedyone_kenobi

[jmortensen]

My car has a 7/71 build date, so does that put me in the scooted forward rear diff catagory?

Look at the link between the rear control arms, right where the fill plug is. If the link is straight, then it is in the forward position. If the link is curved back then it is in the rearward position. I think there was a recall so even if your car was in the forward position it may already have been switched.

Did you have a chance to check that backlash? Just curious...