AOD Tranny Issue

[aggiemachfive]

I've got 108,000 miles on my daily driver '01 GT Vert and my transmission intermittently shifts late in second gear. Is this a tranny service fluid fix or more pressing?

 

[Mike97gt]

How late of a shift are we talking about? You can try to flush the tranny fluid out and see if that helps, but many times issues like this are due to trans overheating or worn clutches/bands. Another cause could be a line pressure problem such as a intermittently stuck EPC solenoid

 

[Shiroelex]

What about the 1-2 shift acccumulator springs being shattered, like in the AODEs? I've done about a billion of them, and they've made that shift a thousand times better.

 

[Ram5773]

Would high line pressure cause late shifts??

 

[GodAmGT00]

I would think High line pressure would quicken the shifts, since you're actuating faster..



JT

 

[Mike97gt]

Would high line pressure cause late shifts??

a low line presure can cause late shifts, high line presure would cause a hard fast shift. but that would happen in every gear not just 1-2 so I doubt my EPC suggestion is it either.

What about the 1-2 shift acccumulator springs being shattered, like in the AODEs? I've done about a billion of them, and they've made that shift a thousand times better.

or how about a accumulator piston cup cracked or leaking. since it don't always do it maybe the cup is not sealing right under certian conditions.. hell there are many things that can cause a concern like this.

 

[Shiroelex]

I had one that had a cracked spring, that scored the cylinder wall down low, so when the piston would reach that spot in the bore, it would stick, or jam sideways completely, and cause random 1-2 issues. I just ran some emery cloth around the bore, and got replacement springs, and that nice revised Ford piston for it, and it shifted like butter afterwards. You can also remove the upper spring, to firm up thte 1-2 shift too.

 

[CobraRed_96_GT]

im having the problem of it shifting late at WOT w/ 110k miles. So let me know how it worx out. BTW i did a flush and it didn't change, just a tad bit smoother.

 

[Dark Knight GT]

At 108,000 miles, it could be a number of things. Have you recieved a flashing o/d light on the dash panel ?

Quick Note: Please do NOT adjust line pressure unless if you're sure you know what you're doing (most people don't). If you adjust the line pressure, and you don't know what you're doing, you will cause more problems than the ones you currently have.

As for changing the transmission fluid, the regular maintenance for the transmission should be a fluid change every 30k miles under normal conditions, or 15-20k under harsh driving conditions. You should always use at least Mercon V or superiror fluid, as that is what is meant to be used in the 4r70w transmission (the kind of transmission the 98-04 automatic GT's come equipped with).

If you're unsure whether the transmission fluid should be changed or not, then check the transmission fluid coloring on the end of the transmission fluid dip-stick. If it's not a pinkish/red color, and if it's turned darker (like brownish maroon), then it needs changed.

As for the accumulator pistons, the accumulator pistons in the 4r70w automatic transmissions is pretty stout. They are rubber bonded, and are meant to take abuse. I wouldn't bother with them until you're sure it's an internal transmission problem, and not something else like bad fluid or valve body clogging.

 

[03ghoststang]

At 108,000 miles, it could be a number of things. Have you recieved a flashing o/d light on the dash panel ?

Quick Note: Please do NOT adjust line pressure unless if you're sure you know what you're doing (most people don't). If you adjust the line pressure, and you don't know what you're doing, you will cause more problems than the ones you currently have.

As for changing the transmission fluid, the regular maintenance for the transmission should be a fluid change every 30k miles under normal conditions, or 15-20k under harsh driving conditions. You should always use at least Mercon V or superiror fluid, as that is what is meant to be used in the 4r70w transmission (the kind of transmission the 98-04 automatic GT's come equipped with).

If you're unsure whether the transmission fluid should be changed or not, then check the transmission fluid coloring on the end of the transmission fluid dip-stick. If it's not a pinkish/red color, and if it's turned darker (like brownish maroon), then it needs changed.

As for the accumulator pistons, the accumulator pistons in the 4r70w automatic transmissions is pretty stout. They are rubber bonded, and are meant to take abuse. I wouldn't bother with them until you're sure it's an internal transmission problem, and not something else like bad fluid or valve body clogging.

good points ^, i would do a tranny flush first with a filter change an then we will go form there.