On the way to work this morning, 60 mph, I start hearing a knocking noise from the back of the car. I quickly pull over and as I come to a stop, I hear a clunk and one or both of the rear wheels lock up. I didn't think to see if it was one or both of them at the time. Put the shifter in Reverse and it backs up fine. When I go forward, I get the thumping noise which varies in pitch and volume, and sometimes locks the driveline, just as if it were suddenly jammed into park.
I limped the car home, about 5 miles, and have looked at the driveshaft and rear wheel assemblies. Same thing when turning the driveshaft by hand or by the motor. When it is turned to move the car forward, it "catches" sometimes. Nothing appears to be out of the ordinary other than my driveshaft center bearing mount rubber is shot. But I can't find anything that is obviously locking up the driveline.
What are the chances of part of a tooth broken off of the ring or pinion gear and getting stuck in between occaisionally?

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'83 300D Turrrbo 295K miles

first off drain the fluid and look for metal, if there is non then it probably isn't the diff.

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http://i148.photobucket.com/albums/s...titled-1-3.jpg
1981 300d

check your calipers... if a bolt has backed out, the caliper will rotate and grab a wheel...
also possible is the swaybar links can break and jam in there...

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
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My drivers:
1987 190D 2.5Turbo
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1987 300TD
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1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

1984 300d Tubo 146k
Check The 1/2 Drive Left And Right And Front And Rear Flex Drive Shaft Joint

Thanks for all the suggestions, but it's nothing that obvious. I have looked over the entire driveline from the trans output to the wheels, and don't see what it could be.
I was planning to open up the differential next unless anyone has a different suggestion.

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'83 300D Turrrbo 295K miles

It could be half shafts. You have to park it so there is no stress on them and see if they will wiggle.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

second that.

I fail to see how a half shaft problem can lock up a wheel...
however, the E-Brake is hidden inside the rear rotor, and a defect with a shoe could cause knocking and lockup... have you pulled the rotor?

Maybe not but it can make a hellofa racket.....and he drove it away so it wasn't actually very locked up.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

I've lost a pinion bearing in a rear diff before- I did make it almost all the way to my destination- about 6 more miles- then the whole works let loose and the pinion gear got drawn into the ring gear and locked up the rear diff. I could still get towed backwards, but no go forward.

that was fun making a U turn on a narrow gravel road while being towed backwards in my stepvan by an old Allis-Chamlers.

hold on tite- ditch to ditch. but I made it the last 1/2 mile backwards!!

FWIW- the rear end did have a wicked howl before it all let loose.

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1984 123.193 372,xxx miles, room for Seven.

1999 Dodge Durango Cummins 4BTAA 47RE 5k lb 4x4 getting 25+mpgs, room for Seven.

Thanks for the replies.
I don't think it is the CV shafts causing it to lock up. The boots are very cracked but not leaking yet, and there is no play in the joints.
I pulled the rotors as well and the E-brake assembly looks to be in order. This all happened very suddenly with the noise and at first I had thought a driveshaft disk was coming apart. The the intermittent driveline lockups are a bit puzzling, only in forward and they release when I reverse. I can just picture part of a pinion gear tooth swimming around in there and getting stuck occasionally.
I plan to open up the diff tonight or in the morning.

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'83 300D Turrrbo 295K miles

At least I think that's the correct term. See attached photo.
The pin that secures one of the small gears on the casting that the ring gear is bolted to shattered. I haven't completely disassembled it so I don't know if any damage was done to the casting, but I'm not sure I even want to mess with it. I think I may be further ahead to put in a used diff. Any comments?
Thanks.

Attached Thumbnails

 

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'83 300D Turrrbo 295K miles

Go to the junkyard and get a new diff, dont waste your time taking it apart.

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Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?

As long as they would add one additional commandment for you to keep thy religion to thyself.
George Carlin (Wonder where he is now..)

1981 240d (engine donor 1983 240d) recently rebuilt engine hurray! - No more.. fought a tree and the tree won.

pearl black 1983 240d 4speed (Converted!@$$%) atleast the tranny was rebuilt.

Interesting....only the 2nd diff I've seen fail on one of these cars. Mine is quiet and has Mobil 1 in it, and no play, so hopefully it will be fine.

The '83 SD has a lot of slop in the diff and clunks/whirrs....but its been going strong for 45k so far since we got it....and it has Mobil 1 as well, it reduced probably 70% of the whirring.

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-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

Wow, Not a common occurrence for sure. You might think about swapping half shafts, (side to side) as long as your in there, might get a few more miles outa them.

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"