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Author Topic: 700s rear drive seal replacement  (Read 266 times)

Offline Kevdog3019

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700s rear drive seal replacement
« on: May 09, 2017, 11:12:56 AM »
New to the board. Just bought an '85 Nighthawk 700s in pristine shape (13k mikes). I have a weeping rear drive seal it now appears (at the wheel).  Can I take the wheel off, undo the 6 or so bolts of the drive, and pull the seal and replace without removing the unit from the bike?  If anyone has done this job, please explain how you did it. I'd rather not deal with the shaft removal as it seems it comes out with the rear drive unit. Is this correct?  Getting it back attached with the output shaft easy? 
Thanks much for your help.
Kevin

Offline mollusc

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Re: 700s rear drive seal replacement
« Reply #1 on: May 09, 2017, 01:34:02 PM »
Get yourself a copy of the Honda Service Manual or the Clymer manual.  Most important tool in your toolbox when it comes to these bikes.
The rear end is pretty straightforward.  If you're taking it off for the first time I'd recommend pulling the drive unit and shaft out though, as there's a damper on the driveshaft that you should change the oil in.
made of meat

Offline Kevdog3019

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Re: 700s rear drive seal replacement
« Reply #2 on: May 09, 2017, 07:36:54 PM »
Thanks Mollusc,
     I do have the manual and see what you suggest. I will pull the wheel and see what's up and decide to do a simple fix of the seal or pull the drive and grease the splines and oil the damper. I've got low miles but it's also 32 yrs. old.
I am assuming I can undo the 8 bolts and remove the plate with the seal while still in place on the bike??  The manual doesn't mention that.

Offline Rakillia

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Re: 700s rear drive seal replacement
« Reply #3 on: May 09, 2017, 07:49:44 PM »
It's not much extra work to check the splines. The bottom shock bolt has given me problems. If the entire bolt starts coming out of the case stop. Only the nut is supposed to come off. Some kind of impact driver helps. But after that the whole thing just slides out.  I haven't been in there in a few years but iirc yes just unbolt those 8 bolts and the plate comes off. I think there are different sizes so keep track which bolt goes where. 13k means nothing to the seals. It's the years. You will be replacing some rubber.

Offline Kevdog3019

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Re: 700s rear drive seal replacement
« Reply #4 on: May 10, 2017, 03:51:12 AM »
The bottom shock bolt?  I thought you just twist things to get the canister to come apart?  Which bolt and nut are you talking about?

Offline mollusc

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Re: 700s rear drive seal replacement
« Reply #5 on: May 10, 2017, 05:31:49 AM »
The bottom of the left shock bolts onto the final drive case.  I haven't had any problems with it rotating.
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Offline Kevdog3019

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Re: 700s rear drive seal replacement
« Reply #6 on: May 10, 2017, 11:50:25 AM »
My bad, I thought you were referring to a bolt/nut near the driveshaft internals. I didn't see one in the manual. It looks as if the damper portion just wiggles off for re-oiling. 

Offline Kevdog3019

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Re: 700s rear drive seal replacement
« Reply #7 on: May 13, 2017, 08:30:52 AM »
It seems the seal has sealed itself. One of three things:
1. It may have been a little over-filled by po.

2. It may have been the cold temps I was riding in at the time... last ride the temps allowed it to swell.

3. I used dino oil and the po may have had synth in it.

Will continue to watch.

 

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