'98 Intrepid transmission???

Fist the basics:

-Is the fluid level correct?

-Are you using the correct fluid? (ONLY Mopar ATF+3 or preferably ATF+4, NOTHING else under any circumstances)

-When was the last fluid/filter change? ATF+3 needed to be changed about every 50k miles. Its short life was the main reason that ATF+4 was developed).

Try a fluid/filter change before anything else. Also, if someone else has been driving the car lately or if you've changed your driving habits, the transmission controller may have just adapted to a firmer shift. The transmission controller in these cars gradually "learns" your driving style and adjusts shift rates and shift points. More aggressive driving will eventually result in firmer shifts.

If all you're feeling is slightly firmer shifts, I seriously doubt there's anything wrong at all, except maybe old worn-out fluid.

ATF+3 seems to exhibit "morning sickness" more as time goes on, but

50K is "short life??" I always change fluid at 24K or two years anyway. Neglected fluid is the #1 cause of auto trans failure...always has been since the HydraMatic/Powerflite/Fordomatic days.

Nonsense. What happens is that its friction modifiers break down, and it also tends to oxidize. The #1 symptom is torque convertor clutch shudder.

Yes. Pitifully.

Neglecting the fluid by letting it get too low- yes. But if the fluid is kept topped off, automatic trans fluid should easily last 100k miles if not much more. Unlike engine oil it doesn't suffer from dilution with fuel and combustion by-products such as water, carbon, acids, etc. The ONLY limits to ATF life are 1) oxidation, 2) degradation of friction modifiers, and 3) loading with clutch material from normal wear. Changing the fluid at 50k is not unreasonable, especially in hard service. 24k miles is a big waste of fluid, and ATF+4 is $30 a gallon so it adds up. The beef I have with ATF+3 is that changing it at 50k isn't a *choice*, its a necessity. And SAE papers on its oxidation rates and friction modifier lifetime tell the whole story- its a short-life fluid even compared to Dexron-III, Mercon V, and Type F. Its *horrible* compared to ATF+4, which is probably the best fluid currently on the market.

All good points...things have improved considerably since the Type A days, for certain. Back then, fluid oxidation if left in service too long killed a lot of FMXs, C4s and Hydra-Matics back in my day, although I do remember 727s would soldier on regardless. The brown, crusty residue left behind by an overheat or a unit that had never been serviced always told the tale.

ATF+4 is a superior fluid, but there's info that it will be deleterious to seals in older units, like the A-904. Any experience on this? My 904 is working perfectly (except for the usual "no flow in Park" factory design you pointed out) and I really don't want to risk blowing out seals at this stage. The ATF+3 in the unit now has

24K miles on it and is still cherry red and smells "unburned," which used to be the way you'd tell if fluid was old and oxidized. If it's a 50K mile fluid, I'm just going to skip this year's service, since it's obvious the bands don't need adjustment.

Hydraulic fluid has come a long way from my '62 GMC with cast iron Hydra-Matic. That one used MIL spec (low ash, such as Delo) 20W-20 motor oil as its preferred fluid, and would use Type A "for light duty oro emergencies only." GMC was the last make, aside from AMC's Rambler that year, to use the old cast iron Hydra-Matics and the line was discontinued early that year. GMC was then forced to go with the Powerslide from Chevrolet Division in '63 (and a lot of other Chevy parts to cheapen the GMC light truck line) and AMC went with the old three band Borg-Warner for about 15 years. Checker also used the B-W with great success until going to the THM-400 at the same time AMC went running to Chrysler for 727 and 904s. Reason? B-W was closing their Chicago plant, being content with royalty revenues from Toyota and VW and figuring that supplying AMC and Checker wasn't a big money maker.

I still have a case of Valvoline Type A I found out in the garage. Rather than recycle it, maybe I should find a pigeon on eBay.

"Info?" What info? Everything I've ever read says that ATF+3 and +4 is

100% backward compatible to all the Dexrons and Type A. And no one I know who has used it in an older transmission has had any sealing problems.

However, using +3 in an old 904 or 727 (or hydramatic, or any other transmission that uses the Type A / Dexron family of fluids) is a bit silly, because current dual-spec Dexron III/MerconV fluids have better oxidation and additive life properties. ATF+4 is better on all counts, but SHEESH, its not worth the cost right now. Except in modern Chrysler transmissions that need the friction modifier package.

allpar.com has a trans fluid compatibility chart provided by a trans shop owner/wrench. He reported some seal problems with older Torqueflites using ATF+4 that were formerly on +3. That, however, is the only reference I've seen to that complaint. Everything else points to it being backward compatable. But it's a moot point...can't justify the cost if the unit doesn't need the visocity improver/modifier package in +4. I realize the new DC products MUST have it to function properly.