Automatic Transmission Life

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What's the maximum any of you have gone on your original automatic transmission without having to do anything to it, except change fluid and filter periodically?
 
I'm sure it's no record, but my 85 Volvo auto tranny shifts smooth as a new car at 262,000mi.

Fluid drain and refill about every 40,000mi - no flush. Cleaned the screen and replaced the pan gasket while at it.
 
318,000 miles on an A4LD in a 1992 3.0 Aerostar.

When I bought the van about 200,000 miles ago the ATF was black. I changed the filter and cleaned the pan - there was a huge mound of magnetic sludge on the magnet. Then every few days I siphoned out 2 quarts of fluid through the dipstick tube and topped up. I did this until the fluid appeared clean. Took at least 10 goes, as I recall. I also used the then-new Mercon V. After a few thousand miles the fluid had become darkish again. I summised that this was because the new additives were cleaning up the AT components. Repeated the above procedure until the fluid was clean, and it's been clean since. I continued with Mercon V for about 100,000 miles, and then switched to a fully synthetic ATF.

Regular mainteneance is every 20,000 miles - filter change and the 3.5 qts of fluid that's in the pan. I use Fram ATF filters as they are the only ones I've seen that have a filtering medium. The other brands (that I've looked at) merely have screens.

Jan Richter
 
I got 85K miles out of an infamous Ford C-3 automatic. I don't know how much longer the transmission or anything else lasted after the car, a 1976 Pinto station wagon, was stolen (!) in early 1992.

Lesson 1: At least on older cars, periodic pan-drop ATF changes (every 20K miles in my case) probably do extend transmission life.

Lesson 2: NO car is theft-proof.
smile.gif
 
Wow. If they catch you stealing a '76 Pinto, they should send you to jail. After they get out, they should probably send you to a psychiatric in-patient care facility for at least a couple weeks.
My mom had one when I was a baby. I just barely remember it.
 
My 85 Somerset had 186,000 miles when I had to haul it to the junk yard. It still shifted well. I don't think the fluid was ever changed. Those old TH125s would last almost forever with a 4 cylinder.

-T
 
A lot of it is how you drive. If your driving mostly city miles with a lot of shifting, obviously, your not going to get as many miles out of one than if you do a lot of highway miles. Clean fluid is a must for longevity.
 
I have the notorious 4R70W in my 97 T-bird, which had a shudder during 3-4(OD) shift when I bought it at 72k miles. Draining the torque converter and trans and refilling with Merc-V with filter change got rid of it. Since then I've been using only Motorcraft Merc-V, and changing every 20k or so(flush). It's shifting fine now at 108k miles, and I hope it'll stay that way. I'd be changing a lot less frequently if it wasn't for the toubled history.

I also try to minimize the number of back and forth 3-4/4-3 shifts by turning off O/D whenever I know I'm driving at slow speeds in city in traffic, which I think helps longevity of these tranny's...
 
Other than Chrysler's, I've never done anything to any transmission other than the regular maintenance. The chrysler's never had just a fluid change, they got re-built more often than the fluid change interval.....
 
I had two used Ford vans in a row that both had a transmission failure after I changed the (probably never changed before fluid). Kind of made me a believer in that adage about if it hasn't been changed for a really long time....
 
With the typical auto tranny not goosing it a lot will probably do better than anything for longer life, and next is regular fluid changes. Auto trannys on the piesel pickups often defuel to protect themselves, even the much talked about Allison does so in 1st and 5th.
 
"Auto trannys on the diesel pickups often defuel to protect themselves"

The 'computer' will cut fuel to the engine in order to keep the torque below a certain level, it seems most often in 1st gear and OD. Otherwise they'd self destruct in short order.

A consequence is some people observing that with a manual tranny they have been able to tow loads that a newer, 'more powerful' diesel pickup with an auto couldn't even budge. I'd suspect that a truck with an auto and a max load could have problems starting on a steep hill.
 
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