When considering an IMS bearing replacement, one should ask two questions:
- Which replacement bearing design will last the longest
- Who is best person to do the work
When considering which bearing design will last the longest, there are two sub-questions to also consider:
- Should the replacement bearing be sealed or unsealed
- Which bearing design has the highest load carrying capacity
The general consensus seems to be that unsealed bearing designs are better than sealed ones because they avoid the failure mode where bearing grease and oil mix together and degrade lubrication. There have been heated debates whether splash oil lubrication is adequate for lubricating unsealed bearings. The LN retrofit data suggests the answer is yes. Direct oil feed advocates would argue the splash oil isn't up to the task, but none have been willing to state how much longer their designs will extend bearing life beyond splash oil lubrication alone.
The IMS Solution, which only fits the early single row IMSB engines has the highest load carrying capacity. Dual row ceramic bearings - like the IMS Retrofit and Gen 2 Single Row Pro Retrofit - as well as the roller bearing designs come next. Single row designs have lower load carrying capacities.
Finally, whether you are a professional, a seasoned shade tree mechanic or a newbie, the best installers share several key characteristics. They fully understand what the best procedure is for carrying out the replacement, they have and use the proper tools, and most importantly they don't cut corners.
The answers to the questions above aren't black and white. If you search the forums, you'll see lots of opinions. Your challenges will be to separate fact from marketing hype. I did my homework and I was 1) lucky enough to afford the IMS Solution, which in my opinion will likely last the longest and 2) smart enough to know I'd didn't have the skills to replace the bearing myself.