TT Oversteer

I’ve seen LN’s published data on the radial vs axial load ratings of the dual row ceramic ball bearing as well as the RND roller bearing. It’s clear that thrust control is the issue with roller bearings. My question is: does anyone have any data on what axial loads the IMS typically experiences during normal operation? Has this ever been measured, calculated or discussed?

Charles Navarro

Short answer, no. There is no data.

However, we know that Porsche originally chose a ball bearing rather than a roller bearing, so there must have been a thrust component to the load, especially since there is no thrust control on the other end. Also when Porsche developed their own "retrofit kit", they still chose to use a ball bearing (a sealed ceramic hybrid ball bearing in fact).

Normally in applications where there is a thrust load, roller bearings are typically paired up with a ball bearing, like in a gearbox.

I can tell you from the numerous other used roller bearing kits we've seen, there is indeed thrust load present with visible wear to the roller bearing itself and associated flange or "thrust" surfaces. That's one reason why SSF Imported Auto Parts came to us and asked for a roller bearing option since shops were asking for something better than what was already out there. SSF had the exclusive on these for a while but they are now available through Worldpac and other wholesalers.

It just turned out that when we were developing the IMS Retrofit, we considered using a roller bearing and already had a cylindrical roller bearing ims bearing replacement option available (which became the RND RS Roller kit):

https://lnengineering.com/products/t...ofit-kits.html

For those curious as to the load ratings for various IMS bearings, we have them listed here:

https://imsretrofit.com/roller-bearings/

These figures can be found from any bearing supplier as from brand to brand these ratings remain universal for each specific bearing type/model.

I'll add that with these hard numbers it is easy to see that claims made by some suppliers as to bearing strength are seriously inflated. Unfortunately magazine publishers have no interest in policing the claims made by these sellers, who when pressed on this forum about this years ago, left and never came back.