IMS Bearing Retrofit Service
The IMS retrofit is the definitive solution for the most consequential known issue in modern Porsche ownership. Here's what the service involves, what you should request alongside it, and what to receive as documentation when it's complete.
What the Retrofit Involves
The IMS retrofit replaces the factory sealed IMS bearing with an aftermarket unit that connects to the engine's pressurized oil supply, providing continuous lubrication. The most established retrofit kit is manufactured by LN Engineering, who developed the solution specifically for this Porsche failure mode. The LN Engineering IMS Retrofit Pro kit includes the replacement bearing carrier, an oil feed fitting that taps into the existing oil passage near the rear of the engine, and associated hardware.
Access to the IMS bearing requires removing the transmission. This is a significant disassembly — on a 911, the engine and transmission are mid-rear mounted and transmission removal is a 4–6 hour job in itself. Because the transmission is out for IMS bearing access, this is the natural opportunity to address every other item that's accessible with the transmission removed. Doing these simultaneously avoids paying for the same access twice.
What to Combine with IMS Retrofit
With the transmission out, the following items are accessible and should be considered for simultaneous service: Rear Main Seal (RMS) replacement — the RMS is on the rear of the engine where it mates to the transmission, and it leaks on virtually every M96/M97 engine past 60,000–80,000 miles. If the RMS is seeping or leaking, replacement adds a small amount of parts cost to a job where the access labor is already paid. Clutch inspection and replacement — if the clutch is at or approaching end of life (typically 60,000–80,000 miles depending on driving style), replacing it now avoids another transmission removal. Flywheel inspection — check for hot spots, cracks, and glazing while the clutch is out. Pilot bearing replacement — a wear item accessible with the transmission removed.
A car with documented simultaneous IMS retrofit + RMS replacement + clutch replacement is significantly more valuable than one with only the IMS work. It represents a comprehensive transmission-out service event that will not need to be repeated for many miles.
Documentation to Receive
When IMS retrofit is complete, you should receive: an itemized invoice specifying the LN Engineering IMS Retrofit Pro (or equivalent kit name and part number), the mileage at service, the name of the technician/shop, and what other items were addressed simultaneously. This documentation is what separates a car with "claimed" IMS work from one with verified, documented service history. In the used market, the invoice adds real value to the transaction — sellers with documentation command a premium, and rightfully so.
Service Cost
| Service | Typical Cost Range |
|---|---|
| IMS Retrofit only (transmission out + back in) | $2,500–$3,500 |
| Add RMS seal replacement | $150–$300 additional parts/labor |
| Add clutch replacement (parts + labor) | $800–$1,500 additional |
| Full transmission-out service (IMS + RMS + clutch) | $3,500–$5,500 |
The combined service at $3,500–$5,500 is a significant maintenance investment, but represents the comprehensive solution for the most important known risk on an M96/M97 Porsche — and a car with this work documented is worth more on resale than one without it.