If you own a Subaru, you should know.

M.H. · 16 January 2025

(function() { P.when('cr-A', 'ready').execute(function(A) { if(typeof A.toggleExpanderAriaLabel === 'function') { A.toggleExpanderAriaLabel('review_text_read_more', 'Read more of this review', 'Read less of this review'); } }); })(); .review-text-read-more-expander:focus-visible { outline: 2px solid #2162a1; outline-offset: 2px; border-radius: 5px; } Was having minor issues with Subaru after a scheduled transmission flush. Mechanics said it needed a new transmission. Took car to a transmission shop that turned us away, referred us to another small repair/inspection shop that sold me a bottle of this. They assured me that the original shop should have known and was yanking my chain. Well, 3 years and 12,000 miles later, they were right! This should be added after any transmission fluid change on a Subaru.

Absolutely liquid silk

L.H. · 27 August 2023

This additive made such a difference in my truck “shuddering” when turning at slow speeds…great for my LS differential on my Toyota Tacoma

Great Product

J. · 26 February 2024

First off, I never leave reviews. This is a fantastic product. I have a background in automotive repair. Master technician status for 20 years at General Motors and 18 years at BMW. A few years ago, I changed the rear diff fluid in my 2006 Toyota Tacoma 4X4. I used the recommended GL5 fluid. I should have stopped there. I decided to add the limited slip additive that we use in the BMW X5, what a mistake. From no rear diff chatter to some good chatter on tight slow turns. So, the chatter finely got bad enough that I decided to do another rear diff service. This time I used Valvoline full synthetic, that fluid made it worse. Drained that fluid and used Ultra 1 Plus GL5 with no additive, slightly less chatter after that service. Based on the positive reviews, I added the Sta-Lube Equa-Torque Diff Friction Modifier SL2411-4 fl oz. Took the truck out for a drive and within a few blocks the chatter was completely gone. I highly recommend this product.

Works on LSD Tacoma

A.I. · 2 February 2025

It is the only thing that worked for my Toyota Tacoma LSD Limited Slip Differential.

Came as described

G.P. · 25 May 2025

Only giving this 4 stars as the verdict is still out concerning quality. This is a supplement and therefore it's effect is not completely verifiable. I added this due to chattering in the drive train which I assume was caused by the servicer not adding the friction modifier when they changed the fluid. After adding this, the chatter may have improved but it was not night and day. Hopefully more driving will help the issue. Probably will go with a different brand next time unless the noise eventually goes away completely.