1998 Accord Transmission Problem

Guys,

I would like to know if I can put a TL or other Acura transmission in to my 1998 Accord without modifications...

those not a bit more reliable then your transmission.

you can put 6sp manual transmission from CL-S or you can put Dr. Evil (http://www.dreviltransmissions.com/home.html) transmission.
for more information on those transmission check V6P (www.v6performance.net), use keywords like v6p transmission and 6sp swap in search function.

What did they told you when they rebuilt the transsmission? The problem is fixed or it probably will brake again? I'm asking becuse mine died 2 days ago, and I'm wondering if it is worth repairing it.

i had different problems on mine, worn clutches and bad torque converter.

i can't really if it worth to fix or not. its up to your financial situation and your future plan for this car.
but i can tell you this, there was a lot cases when people went to Honda and asked them to assist them in solving transmission problem and Honda gave them new (remanufactured) transmission for free, but they had to pay for installation, its about $500-$600.