Vmax final drive gearing for Royal Stars and Ventures is available on an exchange basis at www.RMSportMax.com.
(saves BIG money over buying a new VMAX rear, and swapping the gears into a RS housing...) Gives more passing/pulling power for 5th gear, especially in 2 up/loaded with gear/trailer/sidecar/any combo thereof/ situations.
So, what all is involved in making this magic happen ??
The point should be made that you need to be comfortable with wrenching, have a good selection of tools, and get a kick out of half the bike being strewn over the garage floor. Not a problem for me (and everytime I take the beast down, there's less and less leftover parts ...
** Psss ... there's 20 pages in the Yammer Hammer service manual which detail the mojo magic required to rebuild the final gear case. You dont' want an inexperienced dealer trying to do the job for you and you certainly don't want to try it yourself. John knows his stuff on these rigs and has all the shims, tools, gauges, and whatnot to do it properly.
NOTE: You'll hear several terms describing the parts we're talking about. Rear end, rear unit, pumpkin, "punkin", etc. The Yammer Hammers call it a final gear case, so I'll stick with that.
SO WHY DO IT ??
Some V-Max owners love the Royal gears. Changes their final ratio in the opposite direction, so the engine doesn't redline as quickly and can cruise at speed with less rpms. Ours are just the opposite - we need more rpm in 4th and 5th gear. The swap is an easy DIY - not even a project, but I would caution anyone who tries to change the ring and pinion gears themselves. You have to know what you are doing to get it right. Some will question the accuracy of the ODO/Speedo after changing the gears. Not a problem - the sensor counts teeth on the original driveshaft pinion gear and sends that info to the ignition and speedo.
LET'S GET ON WITH IT !!
Click HERE for a schematic from the factory service manual.
To take the final gear case off all you do is take off the rear wheel, unbolt the case from the swing arm (4 nuts) and pull it off (of course unbolt the speedo sensor). Then a real good snatch to pull the driveshaft out, and you can then put it back into the universal joint up in the swing arm. When you get the updated unit back from the shop, you push it back up on the shaft and put the nuts back on, but not tight. Next step is to put the axle back into the swingarm and through the diff housing to line it up properly and then tighten up the 4 nuts. No shimming or anything to do.
TOOLS NEEDED:
12, 14, 15, 17, and 28 mm sockets & wrenches, , 3" extension and universal socket for the acorns, 8mm allen, phillips driver, torque wrench, and the ever popular harley hammer.
PRACTICAL EXPERIENCE:
- Depending on the exhaust, might have to take that off. I got Cobras, and I was able to sneak the axle out between the pipes.
- Helps to remove the rear caliper and mount. Even handier to remember how the hell the da*n thing goes together again ...
- Worth mentioning, the speed sensor's a tight fit. I had to pry mine out, always keeping in mind how expensive a replacement would be ifn I screwed it up. A good snatch only works right if you wiggle it a bit, with a bit of the old in and out ...
- A thin bit of lithium on the driveshaft pinion gear, spline, and the o-ring on the sensor prior to assembly is probably a good idea.
- My driveshaft needed a bit of persuasion to release from the final drive. Figured put the acorns back on the studs, a few taps with the harley hammer, and I'm good to go. Figured wrong. The acorns are very soft in the crown, and flattened right out. Best bet is to mount the shaft in a padded vise, then use a board and hammer on the mounting flange to complete the removal. Need I say, be ready to catch the final drive??
UNBELIEVABLY IMPORTANT TO READ & HEED !!
All, It is very very very important that you make abso-freakin-lutley sure that the drive shaft is engaged into the front yoke BEFORE you bolt the diff back up. This is not automatic, and it is possible to bolt it all back up wrong. You may need to get a flashlight look straight into the drive shaft tube to verfiy the shaft is engaged properly. Gravity works against you here. I was warned about this beforehand and I did it wrong anyway. After you are done, but before you start the bike, put it in gear and check that the rear wheel does NOT rotate. If it does, start again. Having said that though, if I can do it anyone can.
Something I found that worked? Take a piece of romex, strip the paper and ground wire, then form the remaining two wires into a vertical "V". Lift the u-joint with a piece of rod stock, slide the romex into the driveshaft tunnel and under the joint, remove the rod stock, and slide the driveshaft home. Once it engages the u-joint, slide the romex out and seat the driveshaft completely. The shaft should spin freely in neutral, but lock in gear.
SWINGARM ANYONE ??
When doing the changeout, it is a GREAT time to lube and inspect the swing arm pivots, just pull the big sucker bolt/nuts and the arm is free for inspection and lubing of the pivots, AND THEY PROBABLY NEED IT !!
A quality air impact wrench and at least a 5 HP compressor is almost a must here to loosen the pivot bolts. Jumping up and down on a six foot prybar don't make it (don't ask me how I know... ). You'll need a 30mm deep axle socket for these monsters, and they are treated with thread lock. Chances are good you'll need to replace both bearings and seals - you might get away with just the seals, so keep your fingers crossed and maybe save $50. Be real honest about evaluating the original bearing condition, and a new set can have an appreciable impact on ride quality. Mine were both dry, and the left bearing on the driveshaft tunnel was actually rusty. I tried cleaning the bearings, but both vibrated badly when I spun them up with the air hose. While you're in there, now's a good time to clean and lube the shock pivot bearings.
Posted by NIFAIRIOUS at December 21, 2002 08:39 PM