The automatic transmission in my '98 Civic DX is slowly degrading. It's been slipping, making noise and shifting late/early and hard for the past four and a half years. Lately, it's been getting worse so I'm just wanting to think about it now to prepare for the inevitable (it no longer shifting).

-The car has about 188,000 miles on it.

-Runs very smoothly and gets good MPG (around 35MPG in the city during the summer)

-Only rust is on the body around the rear wheel wells (where all Hondas rust)

-What's been replaced over the past 4.5 years: front/rear brakes, exhaust manifold, resonator and head pipe, plugs, wires, distributor cap and rotor, oxygen sensor, engine mounts, all belts (including timing belt), rear wheel bushings and upper and lower tie rods on both sides.

-Only other known issues: coolant level seems to slowly go down and either the rear main seal or oil pan gasket are leaking slightly

Would it be worth it to replace the transmission if it goes?

 

Define "worth it". That is a relative term.

IMO, not worth messing with auto. Just swap to Manual

You could sell the car as is (needing a new trans) for about $1k tops... depending on your area of course.

If you do the work yourself, you are looking at parts cost only, I would guess around $400 or so if you locate a trans cheap enough and a nice long weekends worth of work if you have never done something like this.

If you take it tot a shop, expect to pay at least $500 for labor.

 

By "worth it" I mean financially would I be better off fixing this one or buying another car altogether? Doing the work myself is out of the question because I wouldn't have a clue how to do it. I've talked to my mechanic and he said they charge around $500 to swap out transmissions. Is this reasonable? Also, I'd be weary of a used transmission from a junk yard, but I also priced out rebuilt transmissions a couple of years ago and they were selling for around $1,700. The last time I checked (a couple of weeks ago) this Civic blue-booked for around $2500.