jim1967

I put a 3.40 posi in 7 years ago and have had no problems until recently. When I turn, left or right, I get popping, clicking and clunking noises from the right and/or left wheel. The wheel will drag as well. I have just sucked out some gear oil and added 2 4oz Ford additive and drove around and did tight circles and figure 8's but I am still getting the same noises. Can anyone offer any ideas as to what the problem is?

67mustang302

How many miles on it? Clutch type posi units wear out over time, just like any clutch assembly.

jim1967

About 7000.

67mustang302

Is it just noisy, like chirping or engagement sounds, or can does it feel like something is banging around?

jim1967

It feels like something is catching. it clunks and feels like the tire stops turning and i hear the tire skidding a little.

67mustang302

And you're using a proper mix of oil and additive?

racer_dave

Is there still good backlash? Jack up the LR till the tire is off the ground, but leave the right touching. Rotate the LR forward and backward. How much play is there? It sounds like the diff isn't releasing the way it should. Normally as they wear the opposite happens, they don't lock up as much, so that's why I wonder about the backlash. If it tightened up, the diff might not feel the release correctly.

Al Newman

Other than the above posts, the only thing that comes to mind is that your pinion pin has shifted in the carrier due to really hard abuse, and the differential gears bind a bit on turns until they can force shift the pinion pin back where they want it. When you drained some oil from the gear case, you should have seen some metal particulate in the oil if you are experiencing an internal problem. If you do have a pinion pin problem, you will need to locate a new carrier and pinion pin as a minimum. Better sooner than later, as you are in danger of destroying everything if you keep driving it.
Best,
Al

jim1967

I just checked the left rear wheel. It will move forward about 2" but will not turn the rear. I checked some fluid that dripped out when I check to be sure the rear end was full of fluid and I can see very small pieces of metal?? I do not drive it very hard but will hold the brakes to light the rear tires up on occasion. other than that, I drive fairly conservative.

racer_dave

Yeah, that's kinda hard on it...

If the wheel has 2" play then you've got plenty of backlash. At this point I think I'd drain it, pull the pig and find out what's going on. I know that's not what you want to hear, but it's the only way to tell for sure.