Hermle 851 UWF Spindle Getting Warmer Than Usual

Hi all,
Yesterday when machining I noticed the tool holder was much warmer than I'm used to. Checked the oil flow through the spindle and flow looks good. Appears the bearing(s) may be going in the spindle. Looking for any information on spindle rebuilding services around Colorado, whether or not anyone has been into this spindle(is it a good candidate to repair in-house?), and any spindle repair houses that are recommended.

I have a service call into Hermle. Waiting to hear back. I'll update the post with their recommendations.

UPDATE: Heard back from Hermle. They are sending over a parts list, quote for new bearings, drawings and instructions for repairing. Looks like the only other option, through Hermle, is to pack the spindle up and send to Germany which I don't think I'll be doing. I've had nothing but great service from Hermle in Wisconsin. Always surprises me that they even pick up the phone for me and my 29 year old machine.

Being that Hermle USA is in Wisconsin it is no surprise that you had good service.
I worked for an dealer that sold Hermle for a while, and I can tell you that they are crazy complicated.
A good spindle house may have a hard time with that spindle, if they have no experience with German engineering.

I'd get a hold of Setco. They say they do Hermle spindles, but who knows, mileage may vary. They have always treated me well in the past.

My favorite local university physics department had to pack up their spindle of their late 90's Hermle and send it out. I'm not sure if it was Germany or Wisconsin but it was a big production. They have two Hermles, the first one from like 1989 or something, still trucking.

Yea, I received drawings and the bearings numbers from Hermle. I believe my issue is contamination of the tapered roller bearing near the spindle taper. Heat is localized there. Kicking myself for not installing a small guard to provide a more tortuous path for coolant. There is a labrynth already but I'm gonna add a bit more protection when I do the bearing replacement.

The tapered roller bearing uses the quill as the outer race. I'm hoping the quill isn't too buggered up but not holding my breath. Surprisingly the cost for a replacement quill is "only" $1800.