Dana 300 issues help please
About a year ago my D300 momentarily popped out of gear while in low range going down a steep descent. Then never again. Just last Saturday however it happened several times on the Peavine run. Going forward under power up hill or level, it is fine, but descending a steep hill, etc using engine braking causes the T case to go BAM! and momentarily jump or slip a gear, then it holds in gear. It doesn't pop out into neutral, rather a sickening BAM sound and the drive train takes a very hard hit like it's not fully engaged, but it does stay in gear. I tried this in all 4 fwd gears on the T175 and no change.
The t-case lever is tight and feels like its properly engaged. It does not hit any sheet metal. I tried it w/ front hubs unlocked and it still did it. Went into 4 high and it did not happen-- back to 4 low range and then it happede-- tested and it repeated that several times. So the T case works fine in 4 high or 2 high but gets fussy in 4 low.
I know it is the T-case, since i experimented with different combinations of crawler box with T-case in and out. Not the tranny or R/P gears.
Preliminary research shows it can be: bent shift fork, bad or reversed clutch sleeve, bad selector ring or bad shift rail detent springs.
Before it gets all torn out of the rig, which is a PITA, any way to further isolate or verify the problem?
It only happens in 4 low descending a steep incline under engine brake.
Ideas anyone? The case is not clocked and is a single stick.