R150f issues

[Johamilt]

Just rebuilt my r150f with new bearings only. Syncros and gears were okay. The counter shaft was done, it was all pitted on the surface for the rear bearing. Picked up a used one from eBay. Got everything back together, but had a bad whine in 5th gear and a lot of dark grey sludge when I tried to do a fluid change. I opened everything back up to see what I did wrong but besides the grey sludge, everything seems fine.

Questions:
1) how much play should be in the countershaft? When I have the tranny apart (just center plate remaining) the counter shaft can move in and out maybe 2 or 3 mm.
2) what is the greg sludge? Why would I have so much of it?
3) what would cause a whine in 5th gear?

Thanks!

[97HiluxAus]

Gears may be whining from too much backlash causing them to have improper contact,

Are you using the right oil?
Did you get the correct backlash before installing?

Backlash can be found free in a R151F 150F manual kicking around, here:

Countershaft 5th thrust clearance should be:
- (0.10mm - 0.35mm) or (.0039-.0138 inches)
- Absolute maxiumum is 0.40mm(0.0157 inches)