DIY Transmission Full Fluid Exchange (Flush)

Yes, I've heard of both failures.

You don't have to connect a jumper wire. Using a jumper wire lets you do it in several seconds, instead of minutes (still, the PCM caps usually discharge in less than a minute anyway).

Always, always, disconnect the negative terminal first and reconnect the negative terminal last. It's for your safety. If you touch the positive terminal with a metal wrench while the negative is still connected, you could slip and hit some metal part of the car. If you do, that battery could supply over 1000 amps of current through that wrench. If it doesn't burn you, then it could at least damage the negative cable to the battery, and/or the battery itself. Apparently, you've been getting away with it, so you don't have any damage to worry about. Just disconnect the negative terminal instead from here on out.
 
Yes, I've heard of both failures.

You don't have to connect a jumper wire. Using a jumper wire lets you do it in several seconds, instead of minutes (still, the PCM caps usually discharge in less than a minute anyway).

Always, always, disconnect the negative terminal first and reconnect the negative terminal last. It's for your safety. If you touch the positive terminal with a metal wrench while the negative is still connected, you could slip and hit some metal part of the car. If you do, that battery could supply over 1000 amps of current through that wrench. If it doesn't burn you, then it could at least damage the negative cable to the battery, and/or the battery itself. Apparently, you've been getting away with it, so you don't have any damage to worry about. Just disconnect the negative terminal instead from here on out.



what are symptoms of valve body failing or transmission servo bore?
 
If your servo bore is worn and not sealing, you will have a harsh 1-2 shift, or no shift at all. 5th OD will not hold either: http://www.fordservoboretransmissionfixsolution.com/symptoms--solution.html

Valve body issues were fixed in late production 03s, there was a quality control issue on the supplier's side for some early builds. There is a tiny spring inside the valve body that controls some aspect of shifting, but I can't recall what exactly. There is info in the 5R55S rebuild thread.
 
drove the car for about 60 kms shifts in drive have gotten better gear 1 is still kind harsh gear 2 3 4 5 perfect shifting

P to D smooth shift 50% of the time the other 50% kinda harsh and transmission still slams into reverse just like before 99% of the time

I've double checked the fluid level and both times there was 5 litres of fluid in drain pan which is plenty

i don't have a good enough reason to replace the PCM which is a damn expensive part i doubt the valve body is failing or transmission servo bore otherwise i would have other more serious symptoms i've never had hesitation, lost gears, or any problems down shifting etc

I've dropped the pan total of 3 times and I've never seen any debris just some black stuff on the magnet

good news is there was a slight vibration in the steering wheel in drive at red lights which is completely gone

as for the harsh shifts i have no idea what's causing it keep in mind i've put in a brand new solenoid pack brand new fluid and filter
 
most likely the valve body or PCM...anyone know how much these parts will cost? and where can i buy?

does the valve body on this car have electronics on top of it that can fail? or is it only a metal block?

never mind i believe this is the valve body here Build012.jpg

2004 LS does not have the failing spring in the valve body does it??

if there is no failing spring or electronics then i don't see how this metal block can fail...this narrows down the problem to the PCM

Build012.jpg
 
BIG NEWS!

i think iv'e FINALLY fixed my transmission shifting so heres what happened

the first time i changed the solenoid i didn't properly check the fluid level and the fluid level was too low Second time i changed the solenoid the fluid level was too high

i went to a mechanic shop the other day checked the fluid level PROPERLY this time on a hoist (not in my garage on jack stands) a bit more then 1 litre drained out right away after leaving the shop the car was shifting better no more slamming into gear i guess higher fluid level can cause slamming into gear just as well as lower fluid level

I will update in a few weeks
 
its been about 700kms since proper fluid level check and transmission is shifting smoothly in all gears

incorrect fluid level was the problem the whole time after changing the solenoid pack the first time
 
Yes, I've heard of both failures.

You don't have to connect a jumper wire. Using a jumper wire lets you do it in several seconds, instead of minutes (still, the PCM caps usually discharge in less than a minute anyway).

Always, always, disconnect the negative terminal first and reconnect the negative terminal last. It's for your safety. If you touch the positive terminal with a metal wrench while the negative is still connected, you could slip and hit some metal part of the car. If you do, that battery could supply over 1000 amps of current through that wrench. If it doesn't burn you, then it could at least damage the negative cable to the battery, and/or the battery itself. Apparently, you've been getting away with it, so you don't have any damage to worry about. Just disconnect the negative terminal instead from here on out.

Looking at that pic I was just thinking it wouldn't hurt too use thicker jumper wires too. Im sure the amount of time it's got current flowing through it is fine but always better safe then sorry I would say. I've seen what happens with those thin wires burning up haha
 
Looking at that pic I was just thinking it wouldn't hurt too use thicker jumper wires too. Im sure the amount of time it's got current flowing through it is fine but always better safe then sorry I would say. I've seen what happens with those thin wires burning up haha

You mean to short the positive to the negative after the battery is disconnected? That wire is plenty big enough for that. There's very little current involved in this. It's just draining some small caps.
 
You mean to short the positive to the negative after the battery is disconnected? That wire is plenty big enough for that. There's very little current involved in this. It's just draining some small caps.

Ya you're probably right, just tryin to throw in my safety two cents, I'm pretty nervous around electrical.
 
its been about 700kms since proper fluid level check and transmission is shifting smoothly in all gears

incorrect fluid level was the problem the whole time after changing the solenoid pack the first time

Excellent, glad to hear. Must be a huge relief..
 
good thread. I had my transmission drained and filled (no flush) at 75k and again at 150k as maintenance. $140 or so each time if I recall. PLan to sell the LS in 12 months so that method worked for me, although im fairly confident the transmission would last another 12 months even if I never had the fluid touched.
 

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