Hi,

my 300D just crossed 194k... was doing great. started like a charm when 12F outside, goes along nicely... until last night. It had sat in slightly above freezing weather for the past few days, then it got cold (say 28 or so), and I decided to take the car out. Both ways on my trip (10 mi each way, never faster then 55), I noticed an odd vibration, more like a thump thump thump, felt through the steering wheel, transmission lever, and the floor of the car.
Last time I drove it it wasn't like that.
I looked at all the tires, no sign of a nail. Cant imagine a broken balance weight without me noticing it last time I drove it. Broken belt in a tire? Ive had that before with similar result, but cant imagine it would break a belt from sitting.
I had a look at my rear diff (actually the cv boots at either end, had one fail and when it did, the car drove smoothly at 75, but had a loud clicking noise). The passenger side halfshaft, cv join, etc was all replaced about 15k ago by the dealer. the drivers side ones looked fine, no sign of cv joint lube splattered (as it was when the other side's boot failed), etc. What I did see was that the diff semed to be sweating a bit at the location where the driveshaft goes into the diff.
ANy suggestions what to start looking at first? How much 'sweating' is normal on that area of the diff? Could general diff oil thickening cause a phenomena like this vibration? What about low oil levels? I had the engine mounts done 15k ago as well, and the other mouts seemed ok to me.
Any info would be most appreciated. Thanks

JMH

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Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (113k)
1991 350SD (206k)
1991 300D (228k)
1993 300SD (291k)
1993 300D 2.5T (338k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (265k)

Past Diesels:
1983 300D (228K)
1985 300D (233K)