IMS - Going with SKF hybrid

[Gelbster]

Originally Posted by Silber

This is where i got my temperature data:

Temperature limits

If it turns out the skf bearing is a no-go thats OK. If my analysis of the root cause is good, the pelican bearing shouldbe just fine with a freeze plug behind it to stop grease washout.

Silber

The freeze plug & grease washout.I don't understand.
The fundamental problem is that conventional IMSB wisdom suggests the bearing seals deteriorate because of heat.(BTW, the same problem affects a similar bearing in the 6 speed gearbox.) Then the grease washes out because the bearing is partially(1/3) immersed in engine oil.
How will a freeze plug solve the heat deterioration problem for the bearing seals ?
If you fit a Freeze plug and remove one or both seals, that is different.
If you remove both seals ,the logic of a freeze plug is obvious.You avoid partial filling the IMS tube with oil
If you remove just the outer seal, the freeze plug seems unnecessary.
So what does the freeze plug achieve exactly and with which seals remaining/removed?
Assuming it is a good interference fit & doesn't distort the tube during install.

[Silber]

Originally Posted by Gelbster

The freeze plug & grease washout.I don't understand.
The fundamental problem is that conventional IMSB wisdom suggests the bearing seals deteriorate because of heat.

I am not sure this is entirely right, I think the main problem is the heat cycles of the air in the IMS tube sucking oil past the seals. I am trying to solve that issue.

So, I am correcting the problem I think to be the root cause of the issue. I can see heat deteriorating the seals to some degree, perhaps a bearing with Viton seals would be ideal. If heat deterioration was the only issue, why would the oil run into the IMS tube, but not come back out?

I am leaning toward the pelican bearing with the freeze plug rather than a fancy ceramic bearing, not sure if I really believe ceramic is needed at this point especially if I change them every time I change the clutch. Standard 6204's are around US $6-10 each. Porsche thought they were a lifetime solution and if I can fix the oil ingress issue, I can probably make 75k miles or so.

Silber

P.S. - Here was where I explain my theory IMS - Going with SKF hybrid