Porsche IMS bearings explained

Whether you're shopping for a used Porsche 996 or you already own one, there's one problem you probably hear of quite often, and that is IMS (Intermediate Shaft) bearing failure. There is one reason for this, and that is because if left unattended, IMS bearing failure can, and will, result in catastrophic engine damage. 

Porsche IMS Bearing Kit Replacement Symptoms

There are 4 main Porsche IMS bearing failure methods. Typically, a single failure method isn't the cause of the problem, and it's a combination of more than one. 

• Over time, engine oil works its way past the bearing seal. When this happens, the specific lubrication inside the bearing is contaminated with engine oil, and it will fail prematurely. 
• Spalling is another source of failure. This occurs over the life of the IMS bearing and indicates that it's reached the end of its life. 
• Oil leaking through the IMS bearing cover causes improper lubrication of the IMS bearing itself, leading to premature failure. 
• The IMS center bolt breaks, causing the shaft to "float." This will cause the engine to skip timing and grenade itself. 

There are 5 symptoms you should watch out for when buying a used Porsche or during your ownership that hint that the IMS bearing has failed. These are:

• Metal particles in your engine oil
  • When doing your regular oil changes, you should be checking the oil for metal shavings and fragments. These are indicators that the IMS bearing is wearing and that it should be replaced. 
• Unusual noises
  • Knocking, rattling, or metallic noises coming from the rear of the engine are all signs that the IMS bearing could be failing. If you are hearing any of these, you should have this inspected before driving it further and causing catastrophic damage. 
• Loose center shaft and/or bearing
  • This should be inspected any time the clutch is replaced. If either of these are loose, it should be addressed immediately.
• Check engine light
  • When IMS bearing failure is significant enough, it can cause engine timing to be so far off that it triggers a check engine light. Again, this is severe enough that you should discontinue driving the vehicle until the situation is addressed. 
• Catastrophic engine failure
  • This is the absolute worst-case scenario. As stated above, if left unattended, IMS bearing failure can, and will, cause the engine to fail completely, requiring a complete teardown and rebuild. This is usually due to the engine losing timing and the valves contacting the pistons. 

If you have a stock IMS bearing, you should be replacing it every 30,000 to 50,000 miles. If you don't know if your car has an upgraded bearing, you should still replace it at this interval to be safe. If you have an upgraded bearing like the LN Engineering IMS bearing, the service interval on this is every 75,000 miles. 

This is admittedly not an easy job. If you were to bring your car to a shop to have this done, it could easily cost you north of $2500. Depending on your vehicle, this could require a complete engine-out procedure. On a scale of one to five, with five being the most difficult, this rates a five. You can expect this job to take a minimum of five hours and can easily require multiple times that. 

Porsche Models Applicable

Depending on the kits listed below, these IMS bearings can fit multiple models of Porsches. These are:

• 1995-2008 Porsche 911
• 1997-2008 Porsche Boxster
• 2006-2008 Porsche Cayman

Before replacing your IMS bearing, you'll want to verify which one your engine actually has installed. There were three variations used over the course of the engine's production.

• The double-row bearing is typically used in early cars (1999-2001).
• Single-row bearing (2002-2005).
• Oversized non-replaceable bearing (2006-2008).

Throughout the production run of the M96 engine, Porsche replaced a lot of IMS bearings or complete engines. Because of this, there can be engines where the bearings are mixed and matched to the engines they're installed in⁠—meaning the parts catalog reference may not be entirely accurate. To identify which bearing is in your engine, begin by removing the transmission and locating the IMS bearing cover. If your engine has a deep dish IMS bearing cover, it's a single row bearing (19.27mm deep). If it has a shallow dish bearing cover, it's a double row bearing (13.34mm deep).

This is one part where you can't completely rely on the "My Garage" tool in the upper left-hand corner of our homepage and should confirm your fitment by measuring the bearing you remove from your car. 

• Porsche Intermediate Shaft Bearing Update Kit - LN Engineering 106-08.2.2
• Porsche Intermediate Shaft Bearing Update Kit - LN Engineering 106-08.30
• Porsche Intermediate Shaft Bearing Update Kit - LN Engineering 106-08.4

Additional Parts Required with Porsche IMS Bearing Kit

• There aren't any additional parts required when replacing your Porsche IMS bearing. 

Special Tools Required with Porsche IMS Bearing Kit

IMS bearing replacement is one of the jobs that requires a few special tools. There are four you will need.

• Intermediate Shaft Bearing Tool Set
• Intermediate Shaft Bearing Faultless Tool Set
• Intermediate Shaft Bearing Supplemental Tool Set
• Torque Wrench

Additional Parts Recommended with Porsche IMS Bearing Kit

Since the transmission and clutch have to be removed to replace or inspect the IMS bearing, we recommend replacing the clutch and flywheel while you have it off. 

• Porsche 996 Clutch Kit
• Porsche 996 Flywheel Kit

Aftermarket Upgrades or Genuine Option for Porsche IMS Bearing Kit

These IMS bearing kits are already the aftermarket upgrades. We really don't recommend using a genuine Porsche IMS bearing. 

All of these Porsche IMS bearing kits come with our Lifetime Replacement Guarantee like everything else we sell. These IMS bearings will fail again in the future, maybe not in 30,000 miles, but instead in 75,000 miles. When it does, purchase yourself a new one and return your old one back to us using our extremely simple return process, and have that part refunded. 

In the video below, Eric Hirschberg, our Porsche Catalog Manager, gets up close with these Porsche Intermediate Shaft Bearing kits. If you're unsure if this kit will work on your car, you can verify the fitment by going to our homepage and use the vehicle selection tool in the upper left corner. As usual, if you like this Really Quick Product Review, subscribe and check back here for regular releases in the future.