I have been a long time user of Mobil 1 V Twin and Amsoil 20W50 in all 3 holes on my last 3 Harleys. I decided this time around I would try a 75/140 full synthetic in the trans. I finished this am and took my 2011 Heritage for a ride. Results were a definate improvement in shifting and easier to find neutral. I had about 3100 miles since last service with Mobil 1 20w50 in all 3 holes. All 3 drain plugs had little to no metal on the magnets. The Mobile 1 appears to be doing well in the wear dept. Drained primary fluid had no silver/copper color in it. I am impressed with the syn gear lube in the trans. I will update, in the future. with the long term results.

 

I've been using shockproof heavy in my trans since I found out about it on this forum.
And I will never go backwards using motor oil in my tranny ever again.
Shifts more smoothly,easier to find neutral,less hard clunk into gear.
Thicker is better

 

I agree, appears to be the case.

 

This subject gets about as much interest than any other posting. I run the Amsoil 20/50 in engine and primary and 6 speed syn lub in tranny. I tried the shockproof in my tranny and my bike did not like that stuff at all. I could not get it out of there quick enough. Was hard shifting, clanked in and out of neutral and whined like crazy. I drained it out, flushed it, put the 6 speed syn tranny lube back in it and it was back to how it was before the shockproof. It's odd how bikes, the same models, can be different from each other when it comes to things like fluids.

 

All good info. Just an FYI post if someone is on the fence.

 

I have run the Amsoil 20/50 in engine and primary and Amsoil severe gear oil in the tranny in both my Ultras and am pushing close to 100k between the two with no problems.

 

I had been using Spectro Platinum 6 speed in my tranny for about 15K & decided to try Mobil-1 75w-140 syn gear oil mainly for comparison purposes. No difference that I could tell, 5th gear whine about the same, easy shifting with both, no problem finding neutral with either. I should mention both quieted the whine down a lot compared to the factory fill Formula+.

 

I use the Mobil 1 syn gear lube 75w-140 and have been for a good 10k now and love it shifts better, no 5th gear noise but then again never heard it anyway as no shield or helmet, so the wind noise and exaust is louder than the little gear whine...

 

+1.. same thing I experienced with the BEL-RAY Hipoid 85-140.. She shifted really hard till she had about 10-15 miles to warm up. Took it out ASAP.

I'll stick with Mobile 1 75-90 for our climate here in IND..




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Run Amsoil 20W 50 in crankcase, Amsoil 10W 40 in primary and Amsoil 75W 90 sevier gear oil in the tranny. Thicker in tranny, shifts smoother, with less clunk.