98 mitsubishi eclipse manual shift jumps out of fifth gear

Foot on the brake before you shift
Lift up lightly on the shifter and wiggle
If nothing pull the center console and check the shifter to see what is in the way

If you have the five speed manual, almost certainly the fifth gear is an overdrive gear. Overdrive means that the gear ratio is less than 1:1, and in most 5 speeds, the fourth gear is 1:1, the fifth gear being less, such as 0.85:1 for instance. So yes, you probably have overdrive, it's just not called that in a standard transmission.

Auto gearbox faulty! Could be synchro mesh or gear selector?

5speed manual transmission.
jumps to neutral? moving fast, slow, hills ,turns, down hill, where>?
my guess. is:
1: bad engine/tranny mounts
2: bad shift linkage.
3: bad trans.

think so big time ,like a drive shaft

I expect you are having internal issues within the tranny. There are valves within in that, from time to time, may fail. Soory to say but from this vantage point I suspect you'll need to drp the tranny and rebuild or replace with another used/rebuild.

I hope this may have asisted you,
Tom

Yeah you might need a new tranny. Not even replacing the fluids or changing the filter will help bc it would make it even worse by flushing away metal parts in your gears which would eventually cause slippage then failure.

Make cure ALL Plugs are Pluged in Good

http://www.onlinefreeebooks.net/go.php?url=http://tearstone.com/eclipsefsm/23A.PDF

just copy and paste this in the address bar. This is the manual for the automatic transmission.

http://www.onlinefreeebooks.net/go.php?url=http://tearstone.com/eclipsefsm/16.PDF

do the same with this one. This link is for the engine electrical.

It sounds as if your husband knows what he is doing. The information in these two manuals is extensive right down to the last bolt if there is other info that you need just let me know.
I hope this helps

transmission is gone