Jeep 6-spd shifting issue

[SHoppe715]

I thought it was a symptom of the old stock trans mount going bad, but it's still there with the new mount.

When cold, it feels perfect. Smooth, clean, firm click in and out of all gears. When good and warm, like after 15+ hwy miles, it feels like stirring cookie dough. More so in 5-6, a little less in 3-4, and not really at all in 1-2.

My first guess would be water. The fluid these transmissions use is some special light synthetic oil about the viscosity of ATF. If there is water in there, I'm thinking it froths up on the hwy but settles out of the synthetic oil as the driveline cools.

I don't really want to drain and refill if there may be another answer. With the priceyness of the fluid it'd be like throwing parts at an engine until you find the proiblem.

Other details I've learned online about the trans:
Mercedes sourced - NSG370
Triple cone synchros on 1-2
Double cone 3-4
Single cone 5-6
Close relative to 6-spd used in Chrysler Crossfires but with heavier parts.

Marek, you said yours feels that way too. Did you replace that trans mount yet?

[SHoppe715]

Yup. Chocolate milkshake. You wouldn't believe how scarce 14mm and 17mm allen wrenches are around town to get the drain/fill plugs out. Ended up welding nuts to a piece of flat bar to make my very own special wrench.

http://www.arcticoffroad.com/forum/gallery/files/3/9/5/image065.jpg

[TJVigilante]

I just used a bolt with the proper sized head and two nuts so I could turn it. this for the t-case, not the tranny.

[SHoppe715]

That worked for the fill plug, but check out how close the drain plug is to the belly pan. The front edge of the plate is right across the plug and there's barely enough room for fingers. I had to unbolt the isolators and jack up the transmission just to fit that nut and flat bar in between. Either that or I'd have to drop the pan. I figured while I was at it with the 17mm nut, I might as well put both sizes on.

http://www.arcticoffroad.com/forum/gallery/files/3/9/5/imgp2251.jpg