The car is a recently acquired 92 400E. Aside from the typical passenger side leak from the trans, there is a "whirring" noise that comes from the trans in reverse. I can only hear it in reverse when it's cold. After warming up it is quiet. The sound is speed-related, the faster I go in reverse, the "faster" the noise. It sounds like something dragging.

Otherwise trans works perfectly. Shifts smoothly, reverse engages as it should. The fluid is nice and red and doesn't smell bad. Whether the fluid freshness is from the trans being serviced lately or from the fluid being replenished constantly from the leak is something I don't know.

I did a search of the tech forum using 722.3 as search criteria and came up with lots of results (I know where the leak probably is), but nothing I saw was like the problem I seem to be having.

Anyone heard of this?
TIA

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Fourings

84 Audi Coupe GT with Turbo engine, EFI (buh-bye CIS), Jamex seats, Koni's/H&R's, e-code lights. 210k and counting.
1992 Anthracite 400E, 161k, "Grey Ghost".
1986 VW Quantum Syncro, 192k, gone to the crusher in the sky.
1989 300TE 172k. (Was mine, now also Mom's car)
72 280SE 4.5 (Mom's car)

BUMP

I have the same problem and would love to read some replies on this topic.

a

My 300D has a 722.3 and it made a whirring, howling noise in reverse. It was pretty slow engaging into reverse and occationally I experienced the noise in reverse when accelerating some then letting off the accelerator. The noise occurred during the coasting in reverse....
I had poor shifting in forward gears 2-3-4, but no leaks. The tranny failed finally and I installed a reman. unit. The funny part is the thing worked fine when I bought the car, but the car had been sitting a while. After using it a while the problems surfaced... it was all down hill. The replacement is working nicely. I am looking forward to someones technical answer to your issue.....

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GS (tnarg)

'67 200D, 225,000 mi - "FINTAIL", 4 on the floor and loving it!
'83 300D-T, 229,000 mi
'85 300D-T, 234,000 mi
'86 524td BMW, 230,000 mi; In-line 6 cyl. Turbo Diesel !! (BUT I SOLD IT AFTER PUTTING OVER 200k ON)

You say there is no delay into reverse, here is one possibility. The reverse clutches flaked and loose their friction material, no reverse or a delay into reverse is the end result. When the wear is too much the reverse piston rubs against the K1 drum when you’re in reverse, making a metallic noise. Water contamination can also cause flaking.

I suppose I should drop the pan and do a service. After posting this question I was flipping through the "Owners Bible" and saw something about noise being made while driving or coasting in reverse. Says it affected trans numbers 3297013 to 3316017. I haven't looked to see what #'s are on mine. Says the problem is defective thrust bearing of K1 clutch. Repair involves removing the trans. Not the answer I was hoping to hear, but not dissimilar with C32's diagnosis.
The bible says I should drop the pan and look for metal shavings. If the clutches are flaked off will I find chunks of material in the pan, or just sludge?
Now I'm wondering if I should just drive the it until the trans fails and replace with a rebuild, or try to fix this one. Either way I gotta pull the trans. I suppose I should see how much garbage is in the pan first.

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Fourings

84 Audi Coupe GT with Turbo engine, EFI (buh-bye CIS), Jamex seats, Koni's/H&R's, e-code lights. 210k and counting.
1992 Anthracite 400E, 161k, "Grey Ghost".
1986 VW Quantum Syncro, 192k, gone to the crusher in the sky.
1989 300TE 172k. (Was mine, now also Mom's car)
72 280SE 4.5 (Mom's car)