GT 380 Oil Leak

[Ohisashiburi]

Hi, can anyone help? Just suddenly my 1975 Gt 380 started to drip engine/gear box oil quite rapidly from the base and toward rear of the engine, it seems to be in line with the gear shifter (on left side in USA), leaking stops when engine is cool again, is there a case seal between gear box and engine, if so would a Bar's type sealer work to repair the old seal? What other suggestions? Thanks. GH

[jabcb]

Had the same problem on my T350.
Seems fairly common for a leak to develop at the gear shift lever shaft as that oil seal is below the oil level.

That seal can be replaced without removing the motor or splitting the cases.
Just need to drain the transmission oil, and remove the gear shift lever + cover.
Had my seal replaced a few years ago & haven't had any problem since.

[yeadon_m]

Most likely, it is the O-ring under the gear position indicator switch. Its a $2 part and you may find that simply gently tightening up the two screws that hold the switch to the case will stop the leak. You'll need to whip off the gear change lever, left footrest and then the outer and inner sprocket covers to get to it. No other dismantling required. Even if its not that, the only other seals there are clutch pushrod and final drive sprocket. Clean the area up and see what leaks.

Good luck!
Mike

[Ohisashiburi]

Thanks to both you guys, I will try what you both suggest, walking steadily through it. I bought the bike almost junked...now it looks great and has been running just fine until this sudden leak...thanks again, I will follow up later.

[Ohisashiburi]

I did as you guys suggested, it seems the only leak I could observe was slowly coming from the clutch push rod seal, I ordered a new one and will try to fit it when I get it. it seems it just slides into place on the push rod? Thanks for your help and I will let you know how it goes...one other problem, quite suddenly after filling up with fuel, the bike started to backfire on low revs, when I open it up it seems fine...before the fuel refill it ran just fine, thanks

[rocc99]

Just had a similar leak start on my T350. Taking the cover off this week to try and determine the source. You guys made my life much easier pointing out all the possible culprit seals...and to think that all of them are still available from Suzuki, must be my lucky day!!!

[rocc99]

Just checked mine...also the clutch push rod seal. As op asked, any tips for removal of old seal and installation of new one?

[rocc99]

Just checking back in to see if anyone has any recommendations on the best way to replace this seal...

There is a constant amount of seepage which makes me think the tranny oil needs to be drained before replacing. But, this seal seems like it should be above the oil level. Could I just have the bike tilted to the right during replacement?

Also, any tips on removal? Carefully with a fine tip flathead, remove clutchrod first and then pull from the center? As for replacement, just use the old seal to tap the new one into place?

Thanks again.

[Ohisashiburi]

Hey I did not do mine yet BUT be careful not to pull on the push rod as I think there is something attached to it inside the transmission case, also my rubber seal has a centre that is threaded, I am thinking to use a spike (like metal toothpick) to gently unscrew it while holding the push rod in place, hopefully it should work..I will let you know...good luck...PS does the oil still seep when the engine is cold? It should be easy to drain the oil, I did so when checking BUT on most bikes you shouldn't need to do so I think.

[rocc99]

Hm, that is interesting. I took a look at the parts diagram for both of our bikes and it is the same seal. My push rod was definitely not attached to anything and I don't believe there are any threads. I didn't pull on it, but I can feel that it would easily come out with no effort...

I haven't run the bike in a few days and it still seems like it is seeping...not much, just barely. I imagine it would stop entirely pretty soon.

Thanks for the input...please let me know how you make out...

[Ohisashiburi]

Yea I will let you know. Yea my push rod slides outward easily BUT I let it come out only a very little as I read that it could easily detach from another part inside. I won't drain my oil BUT I will stand a tray underneath just in case....

[rocc99]

FYI - planning on doing the swap this coming Wed, 10/8/14. Let me know if you happen to beat me to it...and thanks for the insight.

[Ohisashiburi]

rocc, I fixed it on Saturday, I am pleased to say at this time 'NO drips'.....it went quite well, the old seal was hard and a little difficult to remove, it is set back inside the casing a bit, it seems to be rubber-coated over metal (the actual seal,) finally I managed to cut the rubber with a surgical knife blade just enough to push a small screwdriver enough under the seal surface to pry it out, then I got my fingers around it and eased it along and off of the push rod. Just in case I recommend that while you pull the old seal off hold the push rod in place. Be sure that the new seal is flat side out (facing you) and that it seats flat and completely into the space, maybe you can use a large socket just to give even pressure pushing the seal into place, the socket will allow the thin push rod to pass through it (socket)...you will see, have any problems let me know, I am also on Skype (ochisuki).....Oh, also I had to remove the front sprocket but without removing the chain because the seal would not easily clear the sprocket, but it is only 3 small nuts and a locking plate that you simply twist to get off. All in all not a bad job at all, good luck. PS no oil draining was required.

[rocc99]

Ohisashiburi - thanks very much, great advice. I'll let you know if I have any troubles.

[Ohisashiburi]

rocc99, welcome my friend, let me know how it goes