HarleyTechTalk

Technical Forums => Evo Sportster => Topic started by: andyxlh on July 20, 2020, 02:02:48 AM

Title: Oil out of trans vent tube 1997 motor
Post by: andyxlh on July 20, 2020, 02:02:48 AM
Hello!
1997 motor in 1989 frame, v low miles on engine. Has started blowing trans fluid out of vent tube under the seat. Not overfilled, only leaks after long runs on the highway at 60-75mph
Pickup sensor plated, enough mess to produce a few drops on the floor as well as a mess over chain guard and swingarm
Any ideas???
Title: Re: Oil out of trans vent tube 1997 motor
Post by: PC_Hater on July 20, 2020, 01:52:44 PM
My best guess is the crankshaft oil seal is failing so pressure from the crankcase is finding its way into the transmission.
With a bit of luck the engine breathers are blocked and clearing them will fix it.
If not, you get to remove the primary drive and fit a new oil seal.
Title: Re: Oil out of trans vent tube 1997 motor
Post by: andyxlh on July 21, 2020, 02:54:29 AM
Yes that was my thoughts too. Thanks. I'll have a look
Title: Re: Oil out of trans vent tube 1997 motor
Post by: andyxlh on July 22, 2020, 02:57:23 AM
Thinking my aftermarket air cleaner breather bolts might not be free flowing enough, the holes are way smaller than the OEM SE setup, so I'll increase the breathing and see if that fixes it. I'm kinda confident...