Transmission shot or easy fix?

[mrathell]

2000 x5 4.4i with auto tran.

When I put my x5 in reverse, it initially kicks in for a second the disengages.

If I hit the gas immediately after putting it in reverse it will push the x5 back enough to get out of my garage. The initial push only last for a second, the rest of the distance rolling in reverse is from pure inertia.

I get a bigger push if I put in in drive first and then go to reverse, opposed to putting in in reverse straight from park or neutral.

All forward gears work perfect.

After the x5 warms up, the reverse is completely useless.

Occasionally, maybe twice in the past few months, the reverse worked for a brief moment. Meaning I was able to put it in reverse and drive backwards under the full control of the reverse gear for an extended distance.

Is the this sign of the reverse gear being shot or a solenoid or something else?