I finally hit the 1000 mile mark and changed the oil in my bevel box.
I pulled the drain plug only to find nothing coming out, yes nothing!
I removed the fill plug and poured new gear oil in to see if it would run through and drain out. After a few pumps of new oil it made its way through and out the drain hole, although mixed with a murky nasty gooey gray colored fluid.
I had the whole machine elevated so I put the transmission in neutral and turned the drive shaft by hand. The dirty goo continued to drain.
I decided to try to get as much of the old goo out before filling with new oil.
I left the drain open then put the trans in 2nd gear. I started the engine and allowed it to run, spinning the drive train as I slowly pumped new fluid into the bevel box. I did this until the oil coming out was relatively clean knowing it would not be perfect.
I left it overnight to allow as much oil to drain as possible. The next morning I reinstalled the drain plug and filled the BB with new fluid. I used Royal Purple 85-140 synthetic gear lube mixed 60/40 with Lucas Heavy Duty Oil Stabilizer.
Royal Purple is a high quality lube and the Lucas product has additives for high heat/high load applications. It also causes the lube to cling to the gears and not be thrown off as easily.
After cleaning up and putting it all back together the wife and I took the M3W for a long drive to our favorite breakfast place at the end of 25 mile windy canyon road.
The bevel box noise was almost gone altogether, sounding more like tire whine on the open road than gear box noise.
My BB was not overly noisy to begin with but now it is almost not noticeable.
I did take time to properly break in my Bevel Box gears during the first 1000 miles so I think that helped a lot to make it quiet. I drove it easy and at varying speeds and always downshifting especially going downhill to allow the gears to wear in together both under load and deceleration.
I plan to perform the same service process after another 1000 miles then follow the standard service interval.
While I was at it I also changed the engine oil and filter. I used Mobil 1 synthetic oil along with the Lucas product. 5 qts Mobil and 1qt Lucas.
Maybe is was just my imagination but the engine felt smoother after our drive. It also seemed to start easier with less clatter during turnover.
The Lucas Product is recommended as a 25% replacement in Harley engines due to its heat stabilization, keeping the oil from breaking down. It claims to reduce wear under cold start conditions as it supposedly clings to the internal parts better thus providing lubrication before the oil pressure reaches the operating range.
I am usually skeptical of products that make grand claims, but so far I am impressed with this one.
Not sure if others would have the same results and in no way advertising for Lucas, but these were just my observations, thought I'd share.
And yes I know a running engine, spinning drives shaft, belt and rear tire are a dangerous way to exchange fluid in the BB. I did it with the utmost safety and I still have all my fingers!
