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Discussion Starter #1
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
 

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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
 

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Flap1 said:
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
 

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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!
 

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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?
 

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InsuredDisaster said:
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.
 

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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.
 

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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?
 

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Discussion Starter #11
It is the drain plug

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
 

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Flap1 said:
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:
 

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Discussion Starter #13
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
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Flap1 said:
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
 

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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
 

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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
 

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Discussion Starter #18
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.
 

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

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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
 
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