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Thread: Trans oil really, really hot! Reply to Thread
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  Topic Review (Newest First)
09-12-2014 04:44 PM
rlaf75 Not to start another oil thread but I just switched from the HD syn3 20w50 in the trans to Lucas 80w90 gear oil. I know it's fairly close to the viscosity of the 20w50 bit it quieted my 5th gear whining quite a bit and I get it for free. Like mentioned before the trans is all gears meshing together creating friction. Add that and being pretty much right above the cross under pipe and being next to the motor oil it will get very hot.
09-12-2014 02:55 PM
Tanny oil temp

Originally Posted by Big_gary View Post
Good move changing up from the thin moco oil in there. I use Red Line shock proof gear oil in the trans. I wouldn't worry about the cross over pipe. Just use a good synthetic oil.
Love the redline shock proof!

Never hurts to get a 2/1 pipe with a/c and tune, cut some weight and get rid of thet extra heat in the motor and coming up under the tranny from the x-over pipe.
09-08-2014 01:07 AM
ironmark It is called friction!! The trans is just a gear box and when the gears are meshed and in motion there will be friction even with the best lubricant.
09-07-2014 07:32 PM
moose1 Changing the oil out to the heavier oil will or should fix you right up. 20/50 in a tranny is just way to thin IMO
09-07-2014 07:18 PM
tmd The transmission oil pan and engine oil pan are in the same housing is why it gets so hot. It is what it is but wont hurt anything.
09-07-2014 07:15 PM
Big_gary Good move changing up from the thin moco oil in there. I use Red Line shock proof gear oil in the trans. I wouldn't worry about the cross over pipe. Just use a good synthetic oil.
09-07-2014 07:01 PM
Trans oil really, really hot!

Pardon me if this is the wrong forum for these questions.

I changed the transmission oil on my new 2013 RGU this morning after a short ride. This is the first time that I've opened any of the sumps on this, particular bike. This is my first Fl with the new frame, but my fourth HD FLT.

I was very surprised at how hot the trans oil was coming out of the drain. It was like water in viscosity. I believe the bike was serviced with HD synthetic, but don't know for sure. Let's assume that some kind of "correct" lubricant was in the trans.

In thinking about what might have made the transmission oil so hot, it occurred to me that the exhaust cross-over pipe is hung directly to the transmission sump.

So, my questions are as follows. Do the new frames with cross-over pipes that run under the bike transfer more heat to the trans than did the old frame?

Doe this increased heat present any issues to the durability of the transmission?

Can the transmission hanger be shimmed or connected in any way that keeps this heat off the sump?

Putting BelRey 80-140 in the the trans, which was my whole reason for emptying the sump in the first place.

Thanks for any knowledge, experience, or advice you can offer!

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