M8 in the Dyna’s
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Road Master
Joined: Oct 2009
Posts: 861
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From: Wisconsin
M8 in the Dyna’s
A buddy of mine is looking at newer street Bob’s. Are the M8 owners of the softails having the same types of problems as the M8 touring owners are ? Sumping and tranny fluid migration into the primary come to mind. Any input would be apreciated.
Jonnierock
Jonnierock
Outstanding HDF Member
Joined: Oct 2016
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From: Wayne County, PA
Is there an actual physical difference between the m8 used in the softail and the m8 used in the touring? If not then yes its just as susceptible to sumping. I dont get why one would and not the other.
Seasoned HDF Member
Joined: Oct 2013
Posts: 9,238
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From: On the Big Blue marble
Lets put it this way
My 17 RGU has 16k on the clock and havent had a single issue
My 18 FB114 hasnt had a single issue
My 17 RGU has 16k on the clock and havent had a single issue
My 18 FB114 hasnt had a single issue
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Grand HDF Member
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From: Texas
The Softail version is oil-cooled only, the Touring ones come in oil-cooled or twin-cooled. That means different oil pumps at least, and who knows what other issues may arise because of those differences.
Perhaps not the smallest difference is that the engine is hauling around a 650lb bike, instead of a 950lb touring bike, so it doesn't have to work nearly as hard in the Softail, which may explain some resistance to sumping even if everything else was equal.
Last edited by FatBob2018; Feb 26, 2019 at 04:19 PM.
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From: Cleveland Zoo
I just switched from a touring bike to new Softail and very happy.
Road Master
Joined: Aug 2018
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From: NoVa
The word on the sumping issue is that it was primarily with the 114 motors and especially the motors that had all the other performance upgrades (Stage III and Stage IV) and were typically run hard at high rpm for lots of the time. Even there, it was a somewhat rare occurrence.
In mid 2017 production, HD upgraded the oil pump in all the M8 engines and this has pretty much cured the issue, period. This would cover just about all the Softail lineup which launched in 2018 with early production starting in late 2017. Some people are even doing 124" kits from S&S and not reporting issues with the new oil pump.
I'm still having trouble figuring out how the hydraulic clutch could have anything to do with it. IIRC, the Touring engines have an overflow passage to the trans so that if the sumping occurred, it transferred some of that fluid into the transmission - a reasonable place to catch it rather than dump it into the air intake since the same oil is good in both the engine and transmission and the amount of fluid transferred by sumping was observed to be small in the engine test program. That might explain why some might think the hydraulic clutch could have something to do with it. Will look for the service bulletin and update this post if I find out different than the above.
UPDATE: The TSB is M1450. I couldn't find a PDF of this, but someone photographed it and posted it in number 7 of this thread
https://www.hdforums.com/forum/milwa...tin-m1450.html
I also entered my VIN for my 2019 Low Rider in the HD website and it came back with no Service Bulletins at this time.
In mid 2017 production, HD upgraded the oil pump in all the M8 engines and this has pretty much cured the issue, period. This would cover just about all the Softail lineup which launched in 2018 with early production starting in late 2017. Some people are even doing 124" kits from S&S and not reporting issues with the new oil pump.
I'm still having trouble figuring out how the hydraulic clutch could have anything to do with it. IIRC, the Touring engines have an overflow passage to the trans so that if the sumping occurred, it transferred some of that fluid into the transmission - a reasonable place to catch it rather than dump it into the air intake since the same oil is good in both the engine and transmission and the amount of fluid transferred by sumping was observed to be small in the engine test program. That might explain why some might think the hydraulic clutch could have something to do with it. Will look for the service bulletin and update this post if I find out different than the above.
UPDATE: The TSB is M1450. I couldn't find a PDF of this, but someone photographed it and posted it in number 7 of this thread
https://www.hdforums.com/forum/milwa...tin-m1450.html
I also entered my VIN for my 2019 Low Rider in the HD website and it came back with no Service Bulletins at this time.
Last edited by AJ88V; Feb 26, 2019 at 09:13 PM.