Quote:
Originally Posted by Froggo
The original bearing is a $10 bearing , the "Solution " is in excess of $2000 .The critical point to note is that it should be replaced as early as possible in the life cycle of the engine . It seems to me to be a situation of a very expensive sledge hammer to crack a very small nut.
JFP, When you talk of IMS run out I guess you are meaning that the shaft ( tube ) is either bent or not round or both to a max of .010"?
|
The cost benefit calculation for the IMS Solution is multi faceted. First, and perhaps most importantly, it is a permanent fix that never needs replacement. So if you plan on keeping the car for a longer period, you need to consider the cost of multiple IMS retrofits vs. the one time cost of around $1700 for the Solution. Secondly, the IMS Solution is tolerant of conditions that no other retrofit would tolerate, such as high run out shafts. As I keep my cars for a long time (my daily driver, purchased new, will turn 20 next year), when I retrofitted both my and my better half's M96 cars (both purchased new), I did not even consider another choice, they both got IMS Solutions (one dual row, one single row), and I could not be happier with the outcome. And as we do PPI's for customers, I can also tell you that buyer's are aware of the value of the IMS Solution as well. People tend to forget that even a quality IMS retrofit that has 60K miles on it looses some of its value at resale, as the buyer has to factor in doing it again in the foreseeable future. The IMS Solution does not.
When I refer to run out, I am looking at how true the surface that hold the IMS bearing stays as the shaft rotates. Exactly where the movement comes from is a more complex issue than just bending. Because the bearing mount surface is machined into the shaft, its center line may not be on the shaft's center line, which could give you a straight shaft that turns true, but that is not what the bearing sees. Some shafts may also not be true themselves (perhaps from the process of pressing the chain gears on), causing the same issue even if both centerlines coincide. And while I have obviously not personally seen the numbers of these units that Jakes has, he has shown photos of shafts where the run out was well beyond 0.010 " and mentioned how he has had to develop screening procedure's to test shafts going into the engines he builds. Just another one of the joys of the M96 engine.