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Checked Rear Drive...found this

3K views 23 replies 12 participants last post by  jackd 
#1 ·
After ride today I decided to check tires and rearend etc. Found this leak at boot.
Any opinons or next step to take?
Thanks
Mick
 

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#2 ·
MickS said:
After ride today I decided to check tires and rearend etc. Found this leak at boot.
Any opinons or next step to take?
Thanks
Mick
I would clean it up and try to clean under the rubber boot with a dry rag. You need to try to understand how bad it is and it's source. There are a few seals for the driveshaft inside the swing arm. One at the top and another at the bottom. If I remember correctly the bottom one you can almost see good enough to rule it out once you clean up the area and run for a week or so..

I had a similar find just before traveling to CCR in 2005. I found that it still is leaking but pretty much at a constant rate that is more an irritant than a problem that needs immediate attention. I could not tell from level drop where it was coming from. When I did the weep hole drill this fall I found that the source is from the transmission driveshaft area.. I cleaned it real good and I'm still monitoring... 30K later... YMMV...

I am told that if I use synthetic in the tranny, which I do, I could switch to the SAE 90 weight and then it will most likely stop.. Key here I believe is if it getting worse. If you can't find any oil tracks up the swing arm (I couldn't) and the rear end is NOT down fluid I would clean and monitor... don't overfill anything especially the rearend.
 
#4 ·
Same Boat

One of my riding buddies had the same leak only not as severe as yours. He took it to dealer in Iowa City (Ginas) and they replaced the final drive seal for a MEASELY $600.That dealer has had a history of overcharging for repairs but that is ridiculous. If you cannot do the repair yourself. I would suggest investigating the reputation of the service dept. from known previous customers that you plan to use. I believe there are many reputable dealers out there, hopefully one near you.---------Rethy
 
#6 ·
Rethy
....Thats what I'm wanting to avoid.

The closest dealers to me are Millers in Tallahassee Fl and Bogarts in Birmingham Al. Both 3 to 4 hrs away.

Guess I'll clean and monitor for a bit.
Mick
 
#7 ·
That leak is either from the transmission output shaft seal or the final drive input shaft seal. I think you can pull the boot back and see the final drive seal and check to see if that is leaking. You can check the transmission output shaft seal by removing the right fairing in front of the saddle bag and pulling the boot back off transmission. Just be careful not to pull the boot too much. There is a circlip on the inside of the swing arm that holds the boot on. If you knock that out of place it will be a pain to get it back in there.

I don't think it would take more than an hour to replace the seal on the drive or two hours to replace the seal on the transmission. I'm sure someone here has done both and can comment better than I can.

Kevin
 
#8 ·
MickS said:
Rethy
....Thats what I'm wanting to avoid.

The closest dealers to me are Millers in Tallahassee Fl and Bogarts in Birmingham Al. Both 3 to 4 hrs away.

Guess I'll clean and monitor for a bit.
Mick
Mick.. clean.. verify fluid levels... when you have the boot loose try to wiggle the driveshaft for a wearing bearing... if bearings are wearing it will leak and will need fixing.. cheaper to fix it before it leaves you on the roadside.

I suggest you ask around here for a "tech session" if you have any serious concerns..
 
#9 ·
#10 ·
if you have the 30 mm special socket, might as well tear it apart, change out the seal, and drill a weep hole for your slave cylinder if you haven't done it yet.
 
#11 ·
kevincook said:
I don't think it would take more than an hour to replace the seal on the drive or two hours to replace the seal on the transmission. I'm sure someone here has done both and can comment better than I can.

Kevin
Kevin, are you saying it is possible to replace the output saft seal without removing the swing arm? TIA
 
#12 ·
zippy_gg said:
Kevin, are you saying it is possible to replace the output saft seal without removing the swing arm? TIA

I'm not sure about that. I know it wouldn't be any fun trying to do it though.

I'd remove the swing arm to get easy access to the seal. The last couple of slave cylinders I helped with were done in 2 hours or less. I think replacing the seal would require about the same amount of time. This of course is assuming that you have all the tools ready to go. If you have to go searching for them it would take much longer.

Kevin
 
#13 ·
My wrench told me that if the rear is over filled, that can cause some grease to leak out. From his explanation, leaking does not necessarily mean the seal is bad. Mine started leaking....after I did the rear service. I will be taking some grease out and cleaning the boot as the first attempt to stop the leak.

Benton
 
#15 ·
kevincook said:
I'm not sure about that. I know it wouldn't be any fun trying to do it though.

I'd remove the swing arm to get easy access to the seal. The last couple of slave cylinders I helped with were done in 2 hours or less. I think replacing the seal would require about the same amount of time. This of course is assuming that you have all the tools ready to go. If you have to go searching for them it would take much longer.

Kevin
It isn't possible. The FD, swing arm and drive shaft must be removed. The process is identical to gaining access to the slave cylinder. (See attached photo)

On the left is the slave and on the right is the trans output shaft.

I took this shot last month at cccpastorjack's NC Tech Session. Yes, that's my leaking trans output seal... BTW, the slave was leaking too! It was a very productive day! :D

To remove the old seal, you need to puncture it...very carefully...and get a hook into it and pull it out. The new seal can be pressed in with the 30mm socket used on the swing arm.
 

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#16 ·
My findings....

Thanks for talking me thru this so far.
Here is what I found:

1.Reardrive oil level looks good. At bottom of lower threads. (I may have overfilled 3 weeks ago when I changed oil in rear drive)

2. Trans oil level full

3. A trail leading forward when I removed boot. (photo lower arrow)

4. A drop with possible trail to rear of bike. ( photo higher arrow)

At first I thought it must be trans trail but now think it might be coming from rear to drop point and then dropping to trail back to rear.

Can any of you tell anything from photo and findings so far?
thanks
Mick
 

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#17 ·
JATownsend said:
It isn't possible. The FD, swing arm and drive shaft must be removed. The process is identical to gaining access to the slave cylinder. (See attached photo)

On the left is the slave and on the right is the trans output shaft.

I took this shot last month at cccpastorjack's NC Tech Session. Yes, that's my leaking trans output seal... BTW, the slave was leaking too! It was a very productive day! :D

To remove the old seal, you need to puncture it...very carefully...and get a hook into it and pull it out. The new seal can be pressed in with the 30mm socket used on the swing arm.
Averill, how many miles on the bike when you went to the tech session? My machine only has about 39K miles.
 
#18 ·
kevincook said:
I'm not sure about that. I know it wouldn't be any fun trying to do it though.

I'd remove the swing arm to get easy access to the seal. The last couple of slave cylinders I helped with were done in 2 hours or less. I think replacing the seal would require about the same amount of time. This of course is assuming that you have all the tools ready to go. If you have to go searching for them it would take much longer.

Kevin
Thanks Kev, I just needed confirmation. 2 hours sound very good... if all goes well!!!
 
#19 ·
MickS said:
...Can any of you tell anything from photo and findings so far?
thanks, Mick
No. I think you need to take the next step. Remove the FD unit, and look, with a flashlight, up into the swing arm under the drive shaft, if the trans seal is leaking, you WILL see an oil trail!

When we discovered my leak, we couldn't be sure either. Both the FD and Trans showed FULL. It was only by careful study, by multiple eyes, that determined it was indeed the trans seal.

The removal of the FD is not such a big deal. Nothing, compared to removal and re-install of the swingarm, shaft, etc.

BTW, for Gilles, my LT had 48K going into the session. BUT, the trans seal failure was probably exacerbated by my rear shock failing this last summer (in a spectacular way!) in SD. Shock load to the trans output shaft is suspected. I believe David Shealey when he says that MOST Slave clyinders will not go past 60K...and to change them out starting at 45K! Mine was leaking at 48K. :eek: Thanks David!
 
#20 ·
Benton, I'll support what your mechanic said. I overfilled mine on the last fluids change and had all the extra in the boot. :eek: Once I dumped all that was in the boot and cleaned it up I haven't had anymore issues. I'll be extremely careful on the next fluids change.
 
#22 ·
I stand corrected, it is oil and not grease.
My wrench told me that most of his rear seal repairs are in fact from "over servicing". I then questioned if this was a nice way to say "over filled, stupid". He confirmed that. That appears to be my reason for leaking, too.

Benton
 
#24 ·
MickS said:
Here is my latest after cleaning around boot.
Road 140 miles today and checked for leaks.
None showing up so far.
I would suspect that if you really have an issue and you cleaned it will you won't see anything for a few thousand miles.. That has been my experience.
 
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