Old automatic tranny maintenance

[Bill S]

My 92 XLT is showing 150,000 miles on the odometer. I just picked up the vehicle last week so I don’t know the complete maintenance history on it. So the tranny might have been rebuilt in the past. The ATF is dark but doesn’t smell too bad. So I dropped the pan on the tranny and changed out the tranny filter last night. The pan had a little sludge on the bottom nothing to bad. I didn’t see any black chunks or brass. After buttoning it up on the test drive the shifting was a lot smoother. So the question I’ve got is do I do a complete transfusion at this point or just let it go at a 5 quart change? I was talking to my local mechanic who told me I run the risk of neutralizing the tranny if I did the transfusion. Because the clutches need the grit in the old fluid to grab, and could just slip with all new stuff in there. But with the relatively clean pan its got me wondering if the risk is worth the benefits.

 

[CHH777]

Never heard of "neutralizing" a tranny. Mine got "vaporized" though.

I put a $2 drain plug in the pan so I can just replace ~5 courts of ATF each oil change. It's my "eventual" full flush method.

 

[Bill S]

Good solution

 

[Chris Jella']

If it shifts better after the fluid change, sounds like you're on the right track. If the fluid was pretty dirty I'd go ahead and flush the rest out. There are quite a few posts on flushing it yourself. If you have an aux trans cooler on yours, on the front of your radiator like mine, it's a cinch to do. The lines run from the cooler and radiator and attach to the hard lines that run to the tranny. Mines a 93 and the line on the drivers side is the line that feed the fluid from the tranny to the radiator. Pull that line and attach a section of rubber hose to the hard line and run the other end to something to collect the fluid. I use an old 5 gal red gas can. Fire up the engine and monitor the flow, when its shows signs of slowing, turn it off. Put 3 or 4 qts back in and repeat the process. The tranny holds around 12 qts, so I usually use 14 or so just to get it all. It's also not a bad idea to flush the cooler with compressed air.

Hope it helps

 

[TDG]

I like Chris Jellas idea, and if I had been thinking about it that much I probably would have done that every oil/filter change, however I have always done the pan off 5qt change every 10,000 miles. (Nice round number) My trans lasted till 190k when I had it updated/rebuilt just for peace of mind. I've have always had a light foot and tried to take care of the trans by moderating my driving style. On the other hand half of the A4LD battle is pure luck, sometimes you get a winner that lasts forever and others just can't seem to stay working no matter how easy you drive them.

 

[Bill S]

Dropping that pan sure is a mess though. I'm going to do that drain plug idea next time I have it off.

 

[Bill S]

Can you do a direct swap of a 5R55E for the A4LD from what I'm reading it's the same tranny just computer controlled with a 5th gear? When they say computer controlled is there a dedicated processor for the tranny or is it the same one that controls the other vehicle functions?

 

[TDG]

From what I have heard and read there are too many differences electrically to make it worth while. If you were going to go that far why not swap in a SOHC engine? It might make the job easier cause it should have all of the electronics you need. Not sure about the controls if dedicated or controlled by the existing. A long time ago I heard about a guy who was trying to put a 700R4 in an explorer not sure what became of the conversion