Hey,

I have a 740 N/A manual (m47)... I just got new springs on (lowering ones) and have found that on takeoff between 200-2700 in first gear only, i can feel a "rumble", and it really feels like i am forcing it to drive, it is worse when i floor it. While testing the car today, i jacked up the axle, putting jack stands under either side, so i could run the car in gear, to see if there was any vibration.....

However, i noticed that the diff was quite warm (been on a 45 min. drive and car had sat for 1 hour), it wasn't really quite warm, more "hot"...i could touch it, but it was quite hot. While the rear wheels were up in the air, i spun 1 rear wheel with my hands, and the car out of gear. When spinning, the diff has a constant "click click click". I think it was the diff, either that, or the wheel bearings? Once i started the car, i put it into 5th gear, and let the clutch out slowly, so the car idled in 5th gear.....what i heard was terrible. It sounds like a constant (but "unconsistant") rumble, with something rattling at the same time. Is this normal? I have never heard a sound like this before, while driving or anything, but, since i have bought the car i have noticed that there is more of a "clunk" in what i believe to be universal joints, when i go from stop, into reverse, or, if i let the clutch out quick. Please help me with this!

One other thing i noticed, was it looks like the "front" (tailshaft) seal on the diff has gone before (what looks to be lots of old oil/dirt around the area, and around the underneath of the car in that area. Is it possible that the previous owner has ruined the diff by running without oil, or something similar?

Please someone help me, as this sounds expensive!!

p.s. while i was under the car, it sounded like the sound was comming from the rear of the car....

Thanks in advance,

Az