drive shaft [Archive] - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums

: drive shaft


justin
12-21-2004, 09:05 AM
During a long stator replacement job I encountered an unlubed, dried, extremely worn propellor drive shaft joint which I replaced for $ 90.00 or so. I didn't tear into the rear differential yet to see the looks of it, but I can guess it ain't good. Does the factory rebuild those or do I have to fork out a thousand bucks for a new one? By the way, I bought this bike because everyone writes about the low maintenance and reliability of it.....I've yet to understand just what it is they mean. It's a great ride and I actually like the looks...but I've had the motor rebuilt twice in the first few months of it's life (under warranty) and nothing but a bunch of stupid problems and then the stator replacement and now the drive shaft. What's up with the engineers at Kawasaki that can't get it right after 20 years?
Justin
2003 VN750
23000 miles
Electrex charging system
fused stator
M880 tires
W & M saddlebags
Volt/Temp/Clock meter
Meir Windshield

jdegreif
12-21-2004, 02:16 PM
I haven't understood the statements of low maintenance either. Years ago I had a Yamaha and put thousands of miles on it and never had to do anything to it except change oil, and it was shaft drive. There are definitely too many problems with the VN750 that should have been addressed and fixed a long time ago by the factory. As for the final drive, as long as ther is gear oil in the differential then it won't need any kind of maintenance, unless a bearing or seal goes bad. But where the drive shaft connetcs to the pinion is a different story. The splines there have to be lubed every 7,000 miles or so but as long as the splines on the pinion and drive shaft coupling are good then you shouldn't have to do anything to it except for grease.

justin
12-21-2004, 03:10 PM
It's the splines I'm worried about, I figure they are probably worn just like the coupler was. Is there a company the fixes these or is it a part I can get and replace myself?

Justin

nitrofish420
12-21-2004, 04:42 PM
You can hit up Ebay for a rearend or driveshaft relatively cheap.

Dianna
12-22-2004, 11:16 AM
There is a final drive on eBay right now, 8 hours left
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=4512772321&rd=1&sspagename=STRK%3AMEWA%3AIT

as for the actual driveshaft, I happen to have a couple in stock. Chance are if the drive shaft gears are worn the final drive has suffered the same damage. Good news is it's not hard to fix if you can pick up the part at a reasonable price. Requires pulling the rear wheel of course and be sure and use a good moly to grease the splines. Honda moly seems to be the preferred one.

Ol Poop
12-23-2004, 07:43 AM
Justin,
I've been through the same thing with one of mine.

When you say "I didn't tear into the rear differential yet to see the looks of it, but I can guess it ain't good.", if you mean inside of the Final Drive Case itself, there shouldn't be anything wrong in there just because the Propeller Shaft Joint was dry. If there were any damage to the splines on the Final Drive pinion shaft, you would have been able to see that clearly when you removed the Final Drive to replace the Joint. Normally, due to the way the Joint is held together with the clip inside of the Joint on the Drive Shaft, most wear or destruction of the splines will occur on the Pinion Shaft instead of the Drive Shaft. If the splines were good on the pinion shaft, that Final Drive Unit should be good to go. It's filled with SAE80 or SAE90 gear oil.

I haven't found anyone yet that rebuilds the Final Drive. It takes specialized tools and machines, and is not something that is easily done in a residential garage setting. The machined gears have to be replaced in pairs, and everything assembled to very close tolerances. The cost of rebuilding may be prohibitive due to the number of year models that will interchange with it and the availability of used replacements at a relatively low cost.

I have photos of my Final Drive Joint replacement at:
http://www.cdthayer.com/cruisermaint_2.htm#Final%20Drive

CD in Anadarko, OK
1995 VN750
2003 VN750

justin
12-23-2004, 01:43 PM
I replaced the drive shaft sleeve by removing the shaft thru the front by the bevel gear, so looking down the shaft to see what the pinion gear looked like was impossible. I didn't mean literally tearing into my rear diff., I just meant removing the final drive and looking at the pinion that fits into the collar. I suppose it is probably worn like the collar was...but maybe not. It sucks that they design it in such a way that it wears at all. The collar should be the weak link that is replaceable (for $90) not the final drive that cost $1,000. This is Kawasaki genius engineers planning on making more money on repairs of their bike instead of the purchase cost.

Justin

PS: When it's all together..what do you think it would sell for?
2003 VN 750
23000 miles
W & M saddlebags
Meir Windscreen
Clock/Volt/Temp meter
Electrex charging system
Fused stator
ME 880 tires

Dianna
12-24-2004, 10:42 AM
These two areas from CD Thayer's page
( http://www.cdthayer.com/cruisermain...m#Final%20Drive ) are the most important. If the teeth are fine here I would say you are good to go. Both are visible with removal of the rear wheel without tearing into anything
This is what my pinion shaft spline looks like after I failed to lubricate it at the regular mileage interval.
http://www.cdthayer.com/imagesbike/FD_MVC-302S_small.JPG


Here's a look inside of the Propeller Shaft Joint, showing the clip ring that holds it in place on the Propeller Shaft. I ground a small set of clip ring pliers down on the bench grinder so they would fit inside of the joint.
After removing the clip ring, spacer and Propeller Shaft Joint, I inspected the splines on the drive shaft. They were not damaged, so my problems were confined to the pinion shaft.
http://www.cdthayer.com/imagesbike/FD_MVC-303S_small.JPG

The design is fine as long as it is maintained. Unfortunately your bike seems to fall into a period (2002, 2003 models) that seems to have not been initially molyed or improperly molyed by either the factory at initial assembly or checked by the dealer at the setup or 500 mile check-up. Some dealers don't even KNOW about splines and think you are talking final gear instead. A discussion over on the yahoo group earlier this year had several checking theirs and we found a few dry splines. In most cases they were caught in time. We even did a spline lube clinic at Kentucky Lake Gathering so many could see the process. Hey if this wrench wench can do it then you guys should be able to!
General rule is.. If you have the back tire off, check the splines while you are at it. Once the reccommended moly is applied you are usually good to go for many many miles.
CD's (aka Old Poop *G*) site has been an excellent source for the spline maintenance, along with a few others in the group.

Ol Poop
12-26-2004, 07:29 AM
Justin,

OK, I understand what you're saying now. Makes sense. You came in from the front.

Compared to the stator replacement, dropping the Final Drive out for a peek at the pinion spline should be a piece of cake for you. I just hope yours doesn't look as bad as mine did.

CD in Anadarko, OK
1995 VN750
2003 VN750

justin
12-27-2004, 08:08 AM
CD,

I saw your web page w/good pics of your repair on the rear end. Did you have to just go ahead and buy a new differential to repair it or just replace the pinion gear in it?

Justin

justin
12-27-2004, 12:33 PM
Never mind my last post...read you bought a used rear end for it...just how much do they sell for?

Ol Poop
12-31-2004, 05:35 AM
Best price that I found (two places) at on-line salvage yards was $350.

I ended up finding a vandalized bike locally and bought it for a parts bike, so I didn't go with a salvage yard final drive.

You can pick them up on Ebay fairly regular for less.

CD in Anadarko, OK
2003 VN750
1995 VN750

rock
12-31-2004, 04:08 PM
Howdy, I'm new here and would like to say thanks for the site.
I have an 05 vulcan 750. I did not know about greasing the splines.
I did change the rear end oil at 500 miles.
I only have 1800 miles on it. I will be ordering a shop manual pretty soon. Should I go ahead and grease the splines now? I seen the pics and it looks like maybe I should. thanks.

Dianna
01-01-2005, 10:08 AM
If nothing else Rock, you can check them when that back wheel is pulled. Then just to nake sure they are greased with the proper stuff, clean and repack with Honda Moly.
One note on this, some have noticed thin streaks on their rear wheel. this is usually excess grease seeping through and spinning out onto the wheel. It usually goes away after a few hundred miles if it is just excess. If it is persistent it could be a bad or slightly misplaced seal ring. Good news is.. it means the splines have been greased and you won't see the dreaded red dust.
When this problem did surface a lot of us did the precautionary check. The older bikes came through pretty good. It was the newer bikes that seemed to have the dry splines. Not enough of the 2005's yet to tell if this is a continuing problem or if Kawasaki and the Dealers have addressed yet now.
Dealers seem ignorant of just where the splines are and the required maintenace. Pointing it out to them from the manual helps educate them *L*
Also a good thing to add to your check list anytime you have the rear tire off (like for tire changes later on.) Once they have been properly greased it does last.

jm1515
01-01-2005, 10:09 AM
Howdy, I'm new here and would like to say thanks for the site.
I have an 05 vulcan 750. I did not know about greasing the splines.
I did change the rear end oil at 500 miles.
I only have 1800 miles on it. I will be ordering a shop manual pretty soon. Should I go ahead and grease the splines now? I seen the pics and it looks like maybe I should. thanks.
Rock...welcome to the group!
The spline discussion has been a long standing issue. There have been recent issues w/ new(er) low mileage bikes like yours that have been discovered to have been greased improperly or 'not greased at all' at the factory (QC failure by Kaw), or higher mileage bikes that have had the splines fail or look like Justin's (and mine!), which is ultimately our and/or the dealer's fault.
Kawasaki says to check & grease the splines at 6000mi and then again at 18000mi. Says so right in the back of the OM, but it seems likes dealers are oblivious to this service. Mine was...even tho I had in at 3, 6, & 12k for 'full service' and new tires. My splines & coupler blew up at 20000mi and took the driveshaft and FinalDrive with it.
Bottom line....after you get your shop manual, I would definitely not wait till 6000mi, but pull off the rear wheel and final drive and check the splines, front and rear, ASAP. It is not a hard procedure, and you'll get all the help here you will need. I've done mine twice now, and helped out on a third. I plan to check mine every 10000mi or whenever I change the rear tire.
As with any shaftie, it is a very necessary maintenence...just ask any old time BMW rider.

rock
01-02-2005, 11:13 AM
thanks for the info. I will check and grease them soon.

Bruce
01-03-2005, 08:31 PM
Justin,

The VN750 is, IMO, very reliable if:

1. the driveshaft splines are lubed with a good Moly Paste (I use the Honda Stuff) with each change of a back tire
2. the battery's water level is checked weekly and topped off as needed (or simply replaced with a WestCo maint free battery)

Diana,
I think grease on the back wheel is most likely from to much lube on the wheel's splines. The driveshaft spline lube is held in by a collar which is itself sealed in the axle tube.

justin
01-03-2005, 11:46 PM
Bruce,

That may be true with most of the VN750's but mine is not like most apparently. Within the first 300 miles mine had a big oil leak between the heads, which was covered under warranty..but they had to replace the gaskets on the head and remove the engine to do it all. The next problem I believe was the hi beams didn't work, the throttle cable retaining screw fell out and the stitching on the seat was coming apart. This too was covered under warranty. The next problem came around 9000 miles, when the coolant started leaking out of the seams of the heads and also covered under warranty but again they had to remove the engine and the plastic heat sheild on the head started to peel and was replaced. Remember all this repairing at the shops cost me in down time and I use the bike for my main transport. The next problem was right after warranty ran out, I lost my running lights due to a bad wire connection under the tank...fortunately they covered it. Than of course the Stator burns out and I did that repair myself at a cost around $400 but an extra $100 for the shaft repairs amd still counting. If this sounds like a dependable bike than I guess my definitions are all off....but I'm sure you'll agree I got a lemon.
Justin

Red Baron
01-04-2005, 09:41 PM
It seems like you did get a lemon. How is it running how, hopefully you got a ride bell on it and got all the gremlins worked out. ;-)

RB

justin
01-05-2005, 12:22 AM
Riding much better so far, but I'm not riding it as much until I get my tax returns back and buy a maintenance free batt. Then I'll feel much better.

Justin

Bruce
01-10-2005, 06:14 PM
justin,

Yep, I 'll agree with ya - sounds like a lemon. Hopefully all is straightened out now and you can enjoy many trouble free miles.