IMS question.

[schoir]

Originally Posted by cnavarro

No problem, glad you found it informative.

We just got an IMS in that was literally minutes away from failure - the 2.5 engine it came out of actually suffered a rod bolt failure before the IMS and that's why it came apart.

I'll get some video of the IMS bearing out of this one so everyone can see one right prior to failing - it's amazing!

Charles:

Did the connecting rod bolt actually break apart or did it just start to unscrew itself?

How much mileage on the engine?

Any indications of overrevs or was it another cause?

I know of another M96 engine with a similar failure and am trying to compare notes.

Regards, Maurice.

[cnavarro]

Maurice,

I just answered this same question on the ppbb forums - the bolt indeed broke.

Mileage was 115,000 mi. I'll have to ask what the computer had for over-revs.

I actually updated our IMS page again to include a more sure-fire way of identifying which IMS your engine has. I've had so many discrepancies in what an engine had versus what I thought it should have had, I can't guess which ones are single row bearing IMSs, hence the need to visually identify each one.

I also took some video of the failing IMS bearing as well as some photos of another dual row that was just sent in with 70,000 mi that completely came apart in the engine. It's posted on Youtube:

http://www.youtube.com/watch?v=xvLRMGs-Ti8

As you'll see in the video, it's physically possible to check for how much play there is in the bearing and gauge it's condition.

[jmatta]

Charles -Jake, thanks for the great video; it really gives us an insite to how all these parts interplay. I've looked at the PET diagram, but it doesn't show the bearing housing as a separate part...should I assume this part fits into the intermediate shaft?

When you recommend removing the seal for greater lubrication, again, I assume you mean the outer one that you removed in the video?

I won't be tearing my engine down soon, but as an active club DE instructor/some times racer, I am very interested in this topic.

[cnavarro]

Yes, that's the seal I refer to removing, just like in the video.

The bearing in pressed into the intermediate shaft itself. On the dual row, there's a wire loc that you can see on the outside diameter of the bearing that expands into a matching groove in the bore of the IMS. On the single row, it has a physical circlip that can be removed externally, then the bearing can be pulled out of the IMS. Does that help?

[schoir]

Originally Posted by cnavarro

Maurice,

I just answered this same question on the ppbb forums - the bolt indeed broke.

Mileage was 115,000 mi. I'll have to ask what the computer had for over-revs.

I actually updated our IMS page again to include a more sure-fire way of identifying which IMS your engine has. I've had so many discrepancies in what an engine had versus what I thought it should have had, I can't guess which ones are single row bearing IMSs, hence the need to visually identify each one.

I also took some video of the failing IMS bearing as well as some photos of another dual row that was just sent in with 70,000 mi that completely came apart in the engine. It's posted on Youtube:

http://www.youtube.com/watch?v=xvLRMGs-Ti8

As you'll see in the video, it's physically possible to check for how much play there is in the bearing and gauge it's condition.

Charles: Thanks for taking the time to give me a detailed answer. It is much appreciated.

The video is worth a million words, especially because it is so well done that it takes a lot of the mystery out of this particular weak point in the M96 engines. It is an excellent supplement to the article on your website.

Keep up the good work!

Regards, Maurice.