Whiteline Rear Differential Mount Inserts Subaru WRX 08-26 / STI 08-21 / Forester XT 09-18 | KDT903

I paired these Whiteline Inserts (KDT903) with a new OEM rear differential plate mount and replaced the almost decade old Perrin rear inserts to freshen up and further "lock down" the rear drivetrain on my 2007 Subaru Legacy GT Limited.

Performance: The worn factory mounts allow the differential to twist, causing an annoying clunk during hard shifts. Putting these inserts into a fresh, new OEM mount reduces that movement, providing crisp gear changes and improved throttle response. When paired with a transmission mount insert, gear changes and throttle response are increased even further.

Comfort & NVH: Since you are using a new rubber OEM mount with slip-in inserts rather than solid bushings, noise and vibration remain exceptionally low, even when paired with a transmission mount insert.

Installation: A clean and straightforward DIY job. Because the new factory mount is fresh and clean, the Whiteline inserts slide into the open bushing voids effortlessly with the provided grease. Given that I had Perrin rear inserts installed years prior and the limited space, the rear mounting inserts sild in pretty easily too.

I highly recommend this "factory-plus" upgrade from Whiteline for the 4th-Gen Legacy GT. It noticeably reduces drivetrain slop and increases output response without adding cabin harshness.

Great small upgrade , worth the money

If your car is brand new, these won't feel like anything has changed but also will not make the car feel sloppy down the line.

If your car feels off, these will make it feel like fresh from the dealer.

This is a no brainer. Just do it. You can feel a direct connection from the throttle to the power at the wheels. No more lag in getting the car moving. Drastically more responsive.

For information purposes. 26k miles on my car. I installed on ramps and supported the rear diff with a small jack just in case. Still had to poke with a razor blade to get the rear diff inserts to go in partially, then torqued down the rest of the way in. For the brace inserts I was able to wiggle the brace back in, then smacked it with the palm of my hand most of the way, but had to use my other jack to get the inserts side the final couple cms. All in all about an hour between going to my desk to work then back outside to work on it.

This is one of a couple upgrades I did to my 16 WRX and let me tell you. The differential is more stable and you can feel more the car when you are accelerating. I totally recommend this parts

Did this before other mounts, there’s a noticeable difference when shifting and especially when starting from a stop. The carrier inserts are a bit of a pain. Keep in mind they only go in on one side. You’ll probably need to use a jack to press it back in, take your time. I didn’t have to drop my exhaust but it would’ve made things easier.

Easy install

Not too challenging, can do it with two jacks and or one and a jack stand. Just need to be able to jack the differential up a little to get the forward brace off. Not sure if I can tell a difference with the other drive train stuff I’ve put on but can’t go wrong with white line

definitely makes a difference. Car feels tighter, more responsive. little added nvh, mostly heard on decel. worth the tradeoff.

These mounts are super easy to install and give you the piece of mind when your driving a subaru how it should be driven; fast! I had great customer service from Dane, and got my package earlier than expected.