How often should you change (and clean the transmission fluid filter)?

I have read many places about pulling the bottom AT plan and draining fluid and cleaning the filter at least every year, but to me AT is kindof black magic and so i'm a little gun-shy messing with this too much.

Service manual recommends 24,000 miles or 24 months whichever comes first for normal use ('68 service manual, TH400). You replace, don't clean, the filter.

It's a messy job at best. Most important thing to remember is do not overtorque the pan bolts, if you bend the flange it will leak.

If yours is leaking like mine, no need to change, just fill up....LOL

j.k.

Vikiis advice is correct!

Sounds like a free transmission flush to me!

How does the fluid in the transmission look regarding color and smell? Old nasty fluid will not be a bright red. Typical to be brown or brownish red. Not to say that new transmission fluid smell GOOD, but it shouldn't smell burnt. The main point here is that when you do the pan drop and filter change, you will still have old dirty fluid in the torque converter. If it isn't practical to have the fluid flushed, you should probably do the pan drop and plan to do it again in the not too distant future.

Sorry for the late return to this thread - i was on vacation.

Any tips for re-filling the AT fluid after dropping the pan? I have heard horror stories about ruined transmissions from over or underfilling.

Thanks for the relies.

There may be a refrence, but it seems as it would be safe to put 4 quarts in after the pan drop and check/add 'till its right.

I did this few weeks back and it took me about 4 1/2 quarts to get it back to the right level. That was the car sitting pretty level on jack stands. I think that makes a bit of a difference.

thanks