I have a 90 crx with a b16 swap and a j1 transmmision when i put it in 5th after 30 seconds it comes out of gear. what could that be

 

A few things:

Incorrect shift linkage - ie it's not the right length
Worn motor mounts jerking the engine back and forth
Clutch cable incorrectly adjusted - should only be a few millimetres of play on the clutch arm, not completely tight
Or, your synchros/sleeves are worn out inside the tranny. If so, contact GearSpeed for a rebuild kit. I had my synchros done and they work perfectly. But I didn't replace the sleeves.

 

check the oil level. when i bought my car the tranny had NO oil in it...barely a drop. and it popped out of 5th all the time. drove it from ohio to new york like that and found the problem later. added oil and it hasn't popped out since

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zrickety &raquo;</TD></TR><TR><TD CLASS="quote">check the oil level. when i bought my car the tranny had NO oil in it...barely a drop. and it popped out of 5th all the time. drove it from ohio to new york like that and found the problem later. added oil and it hasn't popped out since </TD></TR></TABLE>

x2
this happened to me recently also..same j1 tranny only 5th gear went and topped off the tranny fluid and works like new so that would be what i would check first

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zrickety &raquo;</TD></TR><TR><TD CLASS="quote">check the oil level. when i bought my car the tranny had NO oil in it...barely a drop. and it popped out of 5th all the time. drove it from ohio to new york like that and found the problem later. added oil and it hasn't popped out since </TD></TR></TABLE>

Good call, I just assumed that his fluid level was fine