Changing tranny fluid

[gadget73]

The small one comes with the filter, but you have to make sure you put it on. Its easy to forget, and the trans will not shift correctly without it.

Also, AOD's have a torque converter drain plug. If you want to do the job more completely, pull that and drain the converter. You may have to rotate the engine by hand (breaker bar) to get the plug at the bottom. The lower part of the dust shield on the trans bellhouse comes out to access it.

[porschpow]

yeah, i wanted to drain the converter too, but since these AOD's are finiscky, i do not want to put my engine in shock by changing all the oil (since I do not know when the last time this oil was changed

[porschpow]

and I keep getting asked how many bolts is the pan.....14 bolt. is that what these guys have??

[86VickyLX]

Word of advice, don't change it. If I recall, that has a bunch of miles on it...

[kodiak]

OK, someone PLEASE give a link to WHY changing all the fluid is a bad idea. No hearsay, I want facts. It sounds like BS to me.

Sent from my '85 Lincolin Town Car

[LithiumCobalt]

OK, someone PLEASE give a link to WHY changing all the fluid is a bad idea. No hearsay, I want facts. It sounds like BS to me.

Sent from my '85 Lincolin Town Car

Lots of wives tales circulate about this. Usually it is from people that already have marginal transmissions. New fluid is always better than old is what I have been told by many transmission engineers. Not doing a complete drain is also dumb because all you are doing is mixing new fluid with old shitty fluid.

[kishy]

Lots of wives tales circulate about this. Usually it is from people that already have marginal transmissions. New fluid is always better than old is what I have been told by many transmission engineers. Not doing a complete drain is also dumb because all you are doing is mixing new fluid with old shitty fluid.

I don't have the experience to back it up one way or another, but according to the theory of it, absolutely correct.
If a trans fails following a fluid change, it was already dead, you just didn't know it yet.
Therefore, if in doubt, expect that it WILL fail and be prepared to replace/rebuild. Or drive it into the ground with the fluid it has and after rebuilding at that point, follow a regular maintenance schedule. Auto trans are wear parts, they won't last forever.

Transmission fluid is a type of hydraulic oil. It's used to transfer force (e.g. operate valves, provide fluid coupling in torque converter) and provide lubrication. It isn't some secret magic mystery fluid. If you replace that fluid and something breaks...well, use logic here. It's either coincidence, or the method used to change it was harmful.

[Piece-it pete]

It's an old argument that has no solution.

Pete

[porschpow]

Im going to check my fluid again, but I need to chamge the gasket anyways, it leaks.

Word of advice, don't change it. If I recall, that has a bunch of miles on it...

True, I don't know when the last time it was changed. This is why I will just change the fluid and filter itn he pan.

The color if I can remember is like a reddish brown

[Louis]

OK, someone PLEASE give a link to WHY changing all the fluid is a bad idea. No hearsay, I want facts. It sounds like BS to me.

Sent from my '85 Lincolin Town Car

If the fluid and trans is very old with a ton of miles, the grit and grime that are in the fluid actually provide a level of friction to worn out clutch plates. In some cases, brand new fluid will then cause slippage in a well-worn trans which was probably on its last legs anyway.

I never do a complete fluid exchange (flush), just a pan drop, filter change and 4-5 qts. new Mercon....this freshens it up with enhanced lubricating properties and really smooths out the shifts. Some guys get a U-Haul pan with the drain and change out the fluid every so often rather than a full blown flush. And some just add some Lucas additive without changing the fluid at all.

[gadget73]

I've always thought that was a load of bollocks. If it dies after a fluid change, it was dead anyway and just hadn't realized it yet. I've changed pitch black fluid before and it still works. The Mark VII had 75k mile old fluid in it that was the same color as the paint. Trans still works 15k later. It does have a slightly wonky 4-3 downshift, but I think thats from an over-tightened trans filter. I did the full shebang on it too, torque converter and pan, something like 11 quarts of fluid. I did the Towncar too, but only got about 5k on it before I caught the car on fire and burned the transmission up from it. It was working fine up to that point though, something like 130k on the original fluid.

[porschpow]

Wow, Min eisn't that color its more of a reddish brown,

Why did it catch on fire?!?!?!?!

How many quarts should I add in if....IF i drain the pan and converter?? 11? 12?

And the 89 town car take Mercon V right?

[kodiak]

Yep V is good to go.

Sent from my '85 Lincolin Town Car

[LithiumCobalt]

I guess I don't understand what the point to changing the fluid would be if you only change 4-5 quarts out of a total capacity of 11-12 quarts. That's nearly akin to taking a shower and then putting dirty underwear back on. But, to each his own.

[miamibob]

I guess I don't understand what the point to changing the fluid would be if you only change 4-5 quarts out of a total capacity of 11-12 quarts. That's nearly akin to taking a shower and then putting dirty underwear back on. But, to each his own.

Agreed but probably a little better than doing nothing as it adds some new "lube" to the mixture. Especially with the filter change.