top of page

Whiteline Transmission Mount Insert Review

So a few months ago I installed the Whiteline transmission mount insert (part number KDT956) into my forester and I think its time I gave it a review.

Initially I purchased this insert after speaking to Matt from Subieliftoz, when a conversation was stuck on reducing the wear on the CV boots.

Now the common issues leading to CV boot failure (in regards to lifted Subaru's) is: not using OEM parts, (aftermarket CV boots don't seem to be as thick, tear easier and don't last long.) The vehicle is lifted to high without using subframe spacers and the CV's are on extreme angles, and the last one being the torque twist in the transmission on acceleration, leading to excessive wear on the boots.

I had previously run aftermarket CV boots on my forester and learnt my lesson to stay away from them, as they continuously failed, so now the only other way to reduce wear to the boots was to stiffen up the transmission mounts and reduce the torque twist.

Matt recommended a few different inserts from RalliTEK or Whiteline, and being a previous Whiteline customer my choice was made.

Priced at $70.50 from Whiteline direct, (if you do some browsing, you can find them cheaper from other retailers), the mount was soon on its way.

Now come the installation of the mount, it was pretty easy to do and only required basic tools, but the concept is that you remove the old mount, add the insert and then refit.

I found the insert was a little tricky to install into the transmission mount and took some time for me to align it and fit it right. I used a rubber mallet and gave the insert a few good hits to get it properly into place.

Another tip to make the process easier is to clean up the old mount and remove any excess rubber left from the factory mould. I'll leave the link to the video of how I installed it here:

Now for my review, two months on!

I have taken the forester on multiple trips after installing the insert, including one of the hardest trips I have done so far in the Victoria High Country. The CV's endured wheel lifts, spins and downright nasty rocks and I haven't had a singe CV issue so far!

I have heard from others that the insert has added vibrations to the car, which some find excessive, but to my findings the only time I notice this is when the car is sitting at idle, but once under acceleration the vibrations are gone. I find this can be a little irritating when sitting at traffic lights but for majority of driving I do not notice this, and knowing that I don't have to get my hands greasy from changing CV boots as frequently is a huge bonus for me!

One thing to remember is that this insert is designed for manual transmissions only, so keep that in mind if your chasing a mount for an auto transmission.

Part: Whiteline Transmission Mount Insert

Part Number: KDT956 (Manual Only)

Aplicable models: Refer to Whiteline website

Price: $70.50AUD

Installation: Can be done with basic tools and will take 1-2hrs

Product Quality: Direct fit, super durable, does what its suppose to

Recommendations: Highly recommend but be aware that this may add vibrations

521 views4 comments

Recent Posts

See All


Instead of getting the insert just buy the Group N transmission mount or if you can find a sti mount they are both the same, they are one solid unit instead of having the holes in them. They would also be stiffer than the insert. That will solve the cabin noise. I had one in my 98 forester and it didnt make any noise or vibration at all.

Bill Williams
Bill Williams
Jul 25, 2021
Replying to

Aug 20, 2019

Honestly I had one of these on my Forester when I first got it and couldn't wait to get it off the car. The in cab buzzing it created was intolerable.


Nick forester
Nick forester
Aug 16, 2019

Bloody awesome review mate

I’ll have to order this with my monster lift 😉👍🏼

Cheers mate

bottom of page