The bevel box threads are getting low on the front page so I thought I'd share my take on one.
After hearing all the horror stories here, I figured I'd go ahead and change the gear lube in the bevel box on my ride. Prior to the change, I took it out for a spirited "bimble" on a set loop to get everything warm. My bevel box has never roared or growled and never given an indication of a problem...but those stories I read here kept haunting me.
Upon my return, I immediately put it up on jacks in preparation. As a passing thought, I grabbed my infrared thermometer from my powder coating gear to check the bevel box temp. It was 240F degrees! I checked the bottom-end on the engine and it was at 220F degrees. Not a good sign.
I pulled the drain plug and I had a few ounces of "liquid" lube come out immediately...but with time, goop came out. The drain plug magnet only had minimal metal and nothing alarming. With the level plug removed, I started blowing compressed air in to assist and encourage the goop out. At that point, I had a slight amount of blue smoke vapor coming out of the drain. Again, not a good sign. After moving all I could, I put a fan on the BB to cool it down. When just warm, I flushed the BB with brake cleaner and flushed a good bit more of the jet-black goop out.
I refilled the box with RedLine 75w140 synthetic gear lube and drove my set loop again at a spirited pace. Upon my return, I put it up on jacks and checked the bevel box temp...this time it was reading between 180-185F degrees depending on where on the box I took the temp. I still got around 220F degrees on the engine bottom-end as expected but just wanted to confirm my readings. Again, I dumped the lube which was still smut black.
I refilled and repeated my loop at the same pace. Upon my return, the measured box temp was 160-165F degrees. Again, I dumped the lube which was still smut black.
I refilled and repeated the loop. Upon return, the measured temp was 160-165F again and the engine bottom-end was still in the 220F range. I dumped and refilled.
I repeated the loop with an extra dose of spirit but this time with a 200 lb. passenger. Upon my return, the box readings were, again, 160-165F and looked like it had improved all it was going to. I bought plenty of gear lube so I plan to change the bevel box lube every couple of hundred miles until it looks like normal drained gear lube.
The "Morgan" lube must have had some kind of additive in it or it may have been some sort of preservative for shelf life and not actual gear lube. I use molybdenum in my Moto Guzzi final drive and it doesn't look like this mess when drained. Gears need lube to "climb" them during operation and I suspect the goop phase was getting pushed away from the gears rather than climbing. Based on the minimal metal found on the drain plug and lack of metallic particles in suspension in the "lube", I hope I've dodged the bullet but only time will tell. I have good faith in Quaife after dealing with their vintage transmissions for decades and knowing what they are building for motorcycle engine-driven cars (not Morgans). I don't think Quiafe is stupid when it comes to gear intensive items...but there seems to be a disconnect somewhere in the process.
Once you get beneath the beautifully executed aluminum bodywork, these cars are not a mechanical work of art. The worst gear lube on any shelf is better than what was in the bevel box...you couldn't do any worse without trying. Geez.
After the lube change, I did an oil and filter change. I was in the process of dropping the feed and return lines from the crankcase...the bolt of the piss-poor clamp on the return side was broken and half missing. The bolt of the feed clamp was bent and well on its way to breaking. Cheap junk. This on a car that cost the same as a 2014 base model Corvette that has 460 hp and will run 180+ mph and gobs of technology. We M3W owners can't get a break. The concept of the M3W is stellar but in reality, its the most poorly executed mechanical thing I've ever seen come off a production line anywhere at any time. At half the price of MSRP, it would still be grossly over-priced based on technical merit. If I were a Morgan engineer (even though the accounting department may have influenced it), I'd be hanging my head in shame. I'm sure the proto-types had bugs but this is what they went to production with? I can't think of a thing on the car that I consider neat or trick in the way they approached it or anything on it that works great. These cars could have been the bomb...instead of the grenade they've turned out to be.
I'm going to fix this SOB if I have to rebuild it from the ground up and that's probably what it will take. Good thing I have my clear and concise Morgan Three Wheeler Service Manual handy.
Z
