Is it normal to get a small drip from the rear final drive? There is a rectangular opening in the bottom of the drive housing, and that is where my drip is coming from and landing on the rear tire. I just had it at the local shop for tires and to look at the leak. They said the leak was from a loose drain plug and they tightened it, but it still leaks the same. I'm not sure if I believe them!

Flap1
'93 VN750 - Stock

I'm not sure if it's normal, maybe someone else has more experience with it. However, my bike developed the same leak after I pulled the rear wheel off (to lube/inspect the drive shaft). I was thinking I might have pinched/rolled the inner seal when I reinstalled the wheel. This weekend I was planning on removing the rear wheel again to chek it out. Sorry if this doesn't help

Is it normal to get a small drip from the rear final drive? There is a rectangular opening in the bottom of the drive housing, and that is where my drip is coming from and landing on the rear tire. I just had it at the local shop for tires....

Maybe your leak is what I had on my '03 a while back. It wasn't rearend grease out of the final drive gearbox, but excess grease from the splines on the rear wheel hub coupling assembly. Water from wet roads or washing the bike would flush a little of the grease out of the hub, and it looked like oil slinging out or dripping out on the rear wheel. Since you just had tire work done, the existing grease on the hub spline was disturbed and/or more added, making a new batch of grease that can get flushed out through the square notch in the bottom side of the Final Drive case. Look at the photos of mine to see what I'm talking about. http://www.cdthayer.com/cruisermaint_3.htm#Propeller

Ol Poop...I really appreciate you posting your work progress with pics on your site. It helped guide me in doing the work on both the wifes and my 750.

Thanks again!

You're quite welcome.

CD in Frederick, OK

Quick question, while we are on the subject of final drive oil. How often do you check the level, and it apears that you just set the bike on the center stand, unscrew a very big "bolt" like plug, and make sure the oil level comes up to the hole. Is it pretty easy to just unscrew the plug?

Quick question, while we are on the subject of final drive oil. How often do you check the level, and it apears that you just set the bike on the center stand, unscrew a very big "bolt" like plug, and make sure the oil level comes up to the hole. Is it pretty easy to just unscrew the plug?

You got it.

Use the center stand on level ground and then remove the small bolt lower than the big one and drain the old fluid out. Then remove the big plug and let the airflow help the remainder of fluid drain. After draining put the small bottom bolt in and tightend it down (gently) and then add the final drive fluid until it is at the edge of the threads where the plug goes in. Once it's filled put the plug back in and go for a ride. You can check it up returning to make sure the level is up.

It looks like you need a wrench of some sort. Or a socket set, if you have big enough socket. is that correct? For the oil level/ oil filler cap I mean.

It looks like you need a wrench of some sort. Or a socket set, if you have big enough socket. is that correct? For the oil level/ oil filler cap I mean.

Yes a 1 1/16 SAE or 27 MM socket will work.

Also if you need a manual you can download it below.

http://www.tocmanufacturing.com/Files%20for%20Download/VN750%20Manual%20and%20Parts.pdf

Hey thanks for the link! I really appreciate it. You guys are really helpful. I don't know if anyone else noticed this, but it seems the parts list is only 107 pages long, and it repeats itself over and over again. So the manual and parts list should only go from pp 1-439. Does anyone else agree?

I took a good look at my leak, and it is the drain plug. The rear drive oil runs from the drain plug along the bottom of the main housing, and drips off right at the rectangular opening at the bottom of the housing onto the side of my rear tire. If tightening the plug does not stop the leak, is teflon tape acceptable to use on the plug to stop leaking? Or could it contaminate the lubricant in some way?

'93 VN750 Stock

I took a good look at my leak, and it is the drain plug. The rear drive oil runs from the drain plug along the bottom of the main housing, and drips off right at the rectangular opening at the bottom of the housing onto the side of my rear tire. If tightening the plug does not stop the leak, is teflon tape acceptable to use on the plug to stop leaking? Or could it contaminate the lubricant in some way?

'93 VN750 Stock
There's an O ring, part 92055B, that should seal it. I don't think teflon tape would hurt anything, but I'd try and find an o ring that fit it. It's not over filled is it? The gear oil should only come up to the bottom of the filler hole when the bike's sitting on the center stand. It's possible to overfill by turning the wheel while putting oil in. The oil sticks to the ring gear which allows one to put more oil in than necessary. I know, because I did it. Had a bit of a mess to clean up after the oil drained off the gear and dribbled out the filler hole. :doh:

I just realized that my rear drive drain plug is stripped. Anybody know of a simple fix for this short of draining, drilling, installing a sealed thread insert, and re-filling? I don't dare ride it like this for fear of the plug falling out.

'93 VNB750
Dk. Blue/Teal
Stock

Epoxy the bolt in?

I just realized that my rear drive drain plug is stripped....

Which is stripped? The threads on the plug, the threads in the housing, or both? If it's the housing threads that are stripped, you might try using a plug or bolt that's the same size but with a different thread. The different thread may be enough to get a new bite in the damaged housing threads. If you use a bolt, put an O-ring on it. If that doesn't work, you'll still be able to go the long route that you referred to...

CD in Frederick, OK

Hello Flap1,
My 98 Vulcan, I am happy to report, does not leak at all. Makes me wonder if removing the rear wheel and lubricating the driveshaft might not result in a similar problem, especially after reading Hydrorobert's response. Maybe we can hook up and ride sometime this summer.
Bye,
Sam612
Stock '98 VN750

Hi Again Flap1,
By the way, thanks for the tip regarding the use of the silicon sealant on the swing arm caps. I lost one and bought two. Your tip was used and it really secures the caps but they are still easily removable.
Thanks,
Sam612

I'm not sure which is stripped. I assume it's the housing since it is cast aluminum, and the plug is steel. Haven't had the time to check yet. A machinist friend of mine said it should take a good shop only about 30 min. to fix it if they have to helicoil the hole. Maybe I'll ask how much the local shop wants to do the job, since I don't have metric drills, helicoil taps, or helicoils.

You're welcome Sam. I believe it was somewhere on this forum that I saw that tip last year.

Hi Flap1,
How about a slightly larger self tapping plug (bolt or screw) of some sort?
Good Luck,
Sam612

Is it normal to get a small drip from the rear final drive? There is a rectangular opening in the bottom of the drive housing, and that is where my drip is coming from and landing on the rear tire. I just had it at the local shop for tires and to look at the leak. They said the leak was from a loose drain plug and they tightened it, but it still leaks the same. I'm not sure if I believe them!

Flap1
'93 VN750 - Stock



I have the exact same problem. Checked the drainplug ofcourse, no luck. Had the final drive out last weekend for the shaft lube and the spacer inside the FDU was wet with gear oil. Looks like the oil seal where the gear meets up with the case (inside the drive gear, where the spacer for the FDU goes, on the outboard side) is leaking. Not a lot, just a few drops, but leaking. Anybody have the FDU apart? Special tools needed? Where can I find torque specs? And finally... parts.

2002 with 2300 miles. You'd think that seal would last a little longer...

D

So this week my 94 started leaking a little. It was definately gear oil, you can tell by the smell. So this morning I disassembled to check the oil seal...sure enough you can see the oil on the face where it has leaked past the seal. For those who havn't seen the inside of their rear wheel before.

The large silver case in the middle of your final drive, where it mates up to the rear wheel. The gear in the middle mates to the female gear on the rear wheel hub (this is where you need your moly lube). The black circle around the gear is the oil seal in question.

Will order new seal today...I have pics of the whole thing so look for writeup on this fix in the future.

http://folks.harbornet.com/blackdragon/pics/finaldrive.jpg

Edit: In case you were wondering, disassembly to check this only took 30 minutes. It's not difficult wrenching up to this point.

alrighty then...factory service manual says to change the oil seal.

Remove final drive assembly.
Remove ring gear asembly from final drive
Soak ring gear in oil and heat to 280-300 degrees Fahrenheight
Pry out ring gear oil seal (careful not to score mating surfaces)
Press in new oil seal using special tool.

Ok, now, I understand what the manual wants, but how the heck am I supposed to heat the ring gear up to 300 degrees, put it in the oven?

That's what it seems like. But I wouldn't use the house oven !!!
Maybe check out garage sales or flea markets for a toaster oven for a few bucks. They should get up to that temp.

I've heard of a kitchen oven being used, believe it or not. Just don't let any females catch ya, and run the cleaning cycle when through. Mmm, nothing better than the flavor of motor oil in a Granny Smith apple pie!

Alternately, you can send it down to Fergy or Hizzo and they can lay it out in the sun for 30 minutes.

My concern with hot oil and exposed heating elements is that there would be a fire. <bevis> Fire! </bevis> Primarily the fumes from the hot oil coming in contact with the red hot element might set it off. I don't want to end up on stupidest home videos. (aside: I still remember the video of little johnny and his brother heating gasoline on and open pit fire...it didn't have a happy ending)

Anyway, I'm wondering if there is a translation problem...maybe soak should be "submerge?" I can see heating a bucket of oil to 300 degrees with the gear in the oil.

Obviously the heat part is to expand the metal...is it just to make changing the seal easier or is it so that there will be a proper seal formed when the metal cools?

Maybe I should just take it to the Kawi shop...guess it can't hurt to ask 'em how much they would charge just to swap the seal.

I'm not really sure why you would heat the seal, unless it's the middle part that needs to be bigger. Guess I'd have to look more closely at the parts to understand. And why would it have to be in oil? All the stories of heating engine blocks never required being in oil.

But as to 300 degrees causing a flash over, then seems like it would for any oil. In that case, it's probably best not to cook anything in the oven. And what about turkey fryers? As long as they are done right...

Actually, if you're worried about the heating element, then turn the oven up higher than 300, then when it reaches temp, turn it off, and stick in the seal submerged in oil, and wait for it to heat up. As long as the temp stays below flash over point, all will be ok.

Yea, I guess your right about the flash over thing. I'm probably being a little over cautious.

Your questions are valid... I'm wondering the same things. I mean, the manual says, soak the seal in oil and heat it...then it has "Caution: Do not heat ring gear and seal with a torch as this will warp the case." So naturally I'm wondering how else would you heat it and that leads me to WHY.

But what do I know, I'm not a trained Kawi technician. I'm going to try calling the Kawi shop today.

If you had a seal, your questions would probably be answered. I don't know why you would have to be a Kawasaki technician. Just go down to the zoo and pick one up. The meat can't be bad without oil, 'cause a thousand polar bears wouldn't have eaten it! Umm... are we talking about the same thing???

Well, I changed out the seal tonight. I'll be putting together a writeup with pics in the next couple days.

The seal is not hard to get out or put in, it takes a littel finese and patience but I don't see why you would need to heat it up.

Interestingly, a roll of aluminum duct tape works great as a seal press. The new seal slid part way in, I put the roll of tape (which was EXACTLY the right size) on top and press down gently, the seal slides in and pops into place. No need to guess if it was installed right, I could feel it seat properly.

And I got to lube my splines, so to speak. :)

This is not a difficult job for an experienced wrench and is within the ability of most people, if they have any mechanical aptitude at all.

Oh, I don't think I said, the Kawi shop wanted $70/hr to swap out the seal, minimum 1hr labor. I bet it took me 5 minutes to swap out the seal. Dealerships are such a rip-off.

The seal is not hard to get out or put in, it takes a littel finese and patience but I don't see why you would need to heat it up. .
For the same reason ya don't need 75% of the 'special tools' they say ya need.

And that 1hr minimum is a bunch of bull !! That's why alot of people refer to them as Stealers (not the football kind) rather than Dealers.

Glad ya got things straightened out yourself.

Great! I know there are others here recently that had questions about it. Glad to know what it DOESN'T require.