Rear Motor Mount Inserts

[HKSpeed]

I was encouraged to write this thread after chatting with a forum member about rear motor mount (RMM) options that are softer than PRL, but harder than stock FL5. I noticed older guys (including me) find the PRL RMM has too much NVH. I have a 2.0 (FL2) and this was my journey to find the Goldilocks RMM street/daily driver setup.

Version 1: I didn't like how the engine rocked between shifts with the stock FL2 mount, so I bought a Whiteline insert in November 2024. The NVH was tolerable until I turned on AC five months later. I couldn't tolerate the NVH with AC on. I later discovered this insert is rated 95A (on a scale of 60-95A).

Version 2: I installed a FL5 RMM. No NVH. Coming from the Whitline insert, the FL5 RMM was too numb. I wanted more stiffness.

Version 3: I replaced the FL5 insert with a yellow PowerFlex FL5 insert, rated at 70A. NVH was still too much with AC on, but less than the Whiteline. NVH was very minor with AC off. The amount of feedback between shifts was perfect, but I couldn't stand the NVH with AC on. I bought it from this eBay seller with free shipping. PowerFlex charges $8 shipping.

Version 4: I discovered this thread and learned about PowerFlex's FK8 insert (choose 80A or 95A). Instead of buying another insert, I modified the Whiteline insert to PowerFlex's design. I installed it with the stock FL5 insert in the FL2 mount. No NVH with AC on. Minor NVH in reverse below 900 RPM. Here it is on eBay with free shipping. I am not affiliated with PowerFlex nor the eBay seller.

In an effort to declutter, I posted my Version 3 for sale. If it doesn't sell (I'm not motivated), I'll reinstall it for winter months (when I don't use AC) during an oil change.

I noticed NVH with AC and in reverse is affected more by the smaller gap of the RMM. The larger gap affects engine rock when shifting. That's probably why the stock FL5 RMM has an insert in the large gap only. Maybe I'll modify the PowerFlex insert by removing one or both small gap inserts.

List of RMM options (in no particular order) for reference. I chose to try different inserts than RMMs to save money.

• 27Won
• PRL
• Wunderladen Racing
• Hasport
• eBay generic (black or silver). The design and description are very similar to PRL for $85 less.

Perrin makes a 70A insert for 10th gens, but should fit 11th gens. The insert for the FK8 has a bump in the top gap filler, so I would use their Si insert in an 11th gen.

Sponsored