I have tried a bunch of trans fluid trying to get the trans shifting smooth on my 2016 Harley Davidson ultra. The AMSOIL severe gear is by far the best thing I have used, shifts are smooth and easy! Plus it looks clean. Good looking stuff going in. I use AMSOIL in the trans, primary and engine , absolutely love AMSOIL!
75w85 severe gear is a yes for me! Decided to switch from oem toyota oils for differentials based on others suggestions. Bought 7 just incase and used 5.8 for both, even with a little shot to flush each oil after drain, so you 6 needed for those wondering. As a very picky person who CDO (OCD, alphabetically the way it should be) I can say for sure the fluid made a notable improvement, especially with the light humming sound when I was in 4x4 that is now gone with the new fluid. The fill bags are a great benefit as well. Cut one fill cap and moved it to the next bag, draining the last of each used bag into the next as I filled. Only wish Amsoil would come out with a 75w gl4 for the transfer case oil to help avoid the #120 a liter oem oil.
New to Amsoil and a can now be considered a new and growing fan boy. Thanks to the engineering team at Amsoil for their incredible product.
Bottom Line
Yes, I would recommend this to a friend.
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5 star rating
The best of the best
By 
JIM, 
a 
Verified Buyer 
from 
Lake Co. Ohio 
on 
September 28, 2025
My Diesel Ram and my motorcycles run on AMSOIL I have us this products for years they manufacture the best lubricants.
The High Quality of the 80W90 convinced me that I should use ALL of the Amsoil products made for my Duramax truck. I see now why once someone uses this brand of gear and engine oil- they never use anything else
Bottom Line
Yes, I would recommend this to a friend.
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5 star rating
Great product
By 
MILES, 
a 
Verified Buyer 
from 
East texas 
on 
September 24, 2025
Replaced the fluid in my Mustang gt. I did it preventative and didn’t notice any changes however I think it’s better quality than Motorcraft.
Bottom Line
Yes, I would recommend this to a friend.
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5 star rating
The best .
By 
GREG, 
a 
Verified Buyer 
from 
Sylvan Lake Alberta  
on 
September 24, 2025
Hi I am very happy with this product it is a high quality product that I can completely count on at every level .
Worth the extra few bucks to have a high quality lubricant in the differential, thank you amsoil for bringing a great product to my door quickly and priced fairly, working awesomely!
got this for 2nd gen tacoma differentials. the bag is awesome, beats using a pump. oh ya, get rid of those 10mm hex plugs that strip in the front dif!! replace them with some that take a regular socket - fill plug is m18 drain is m24 threads
I am about to embark on a cross country journey with my wife to camp, hike and 4Wheel the U.S. and I knew there was only one brand I wanted to trust from past experience so I came to Amsoil and luckily I found this which has a better viscosity and I know I will be good--- with a few more changes during my few hundred k travels.
Bottom Line
Yes, I would recommend this to a friend.
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5 star rating
Best gear oil
By 
BENJAMIN, 
a 
Verified Buyer 
on 
September 08, 2025
Great product and the differentials is one place where the extra money for Amsoil lubricants is 100% worth it
Bottom Line
Yes, I would recommend this to a friend.
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5 star rating
F350 Super Duty
By 
ROBERT, 
a 
Verified Buyer 
from 
St. Augustine Florida  
on 
September 07, 2025
The easy fill packs make refilling much easier. It's more economical than the Motorcraft Fluid. I am also a fan of having it delivered to the house. I installed a new Banks Differential Cover. It's the fluid recommended by Gale Banks himself. So I am confident it exceeds the OEM fluid from Ford with is nearly 7 dollars a quart more.
Bottom Line
Yes, I would recommend this to a friend.
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5 star rating
Harley Transmission Fluid Severe gear 75W-140
By 
ROBERT D, 
a 
Verified Buyer 
from 
Laguna Hills, CA 
on 
September 05, 2025
I have been using the severe gear 75W-140 in my Harley Davidson 6 speed transmission for a few years now. There are clunky transmissions but it seems to quite the tranny a little. Bit I feel more secure with it in their knowing all the issues HD.s have with 3rd gear on these transmissions.
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