Hard Shift

Bnewton530

Bnewton530

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inhave a 2004 LS which I only recently bought. It has 260k on it and after ironing out a few issues, it runs and drives great. The only problem left now is the hard shifts. It shifts hard 2-3 and 3-4. It only does it once I have gone 20 miles. It will even intermittently shift fine. What I want to know is how I should go about this. I am too busy in school right now to fix it. Also I drive mostly highway. Can anyone give me some info on this common problem?
 
It's usually the solenoid assembly in the transmission, or sometimes it's the valve body or the PCM. There are other possibilities too. There are steps (with the right equipment) to diagnose it instead of guessing at it.
 
The pcm was professionally tested at Ford. I'm wondering how long I can let this go before I can fix it. I was planning on swapping the solenoids next
 
It difficult to say if it is causing damage to the transmission or not. Being uncertain about that, I would do it sooner rather than later. If you are doing this yourself, you might as well rebuild the valve body while you have the solenoids out. A "shift kit" is not too expensive for this transmission.
Did they verify the solenoid drive current from the PCM?
 
I don't know. My dad is a veteran Ford mechanic. He has been working on LS's since they were new. The pcm was his first target. We actually took it in after hours and reinstalled the software after he tested it. I don't have hard reverse shifts or anything. I'm assuming it is just sticky solenoids. I just wonder if there is something to add to the trans fluid that will stop them from sticking.
 
Not that I know of. I wouldn't worry about that. Realistically, how many more miles do you expect to get out of it? The new solenoid assembly (if that is the problem) should go at least 100K miles.
 
Well that may just be what I do then. Do you think it could make it until mid march? That's spring break for me
 
Bnewton530 said:
... We actually took it in after hours and ...
Click to expand...

If your going to gently keep driving it like that and you have the ability to get it in and up on a hoist for free, at the very least for now have the fluid level checked. Just for piece of mind sakes. Not saying this is the issue just that your able to get it up on a hoist quickly, I'd want to know if it was me.
 
It's going back on the rack tonight. I'll check the fluid level. Although the reason it's going back up is that I ran over a nail with my brand new tires
 
Bnewton530 said:
Well that may just be what I do then. Do you think it could make it until mid march?
Click to expand...

That depends on your driving habits. My original solenoid pack started giving me major symptoms at around 110k miles. Tne symptom was a hard "bang" downshift to first gear when coming to a stop, (after driving 65 miles on the highway).

I finally got to the solenoid pack change... at around 135K miles... and all was good until a very hot summer a year or so later. I noticed that when leaving a certain gas station, (with a major slope), that the trans was slipping.

I'd shut the LS off and wait 30 seconds... and all was fine. I determined the fluid was low... and solenoid pack was getting hot, (due to lack of fluid cooling).

So I added roughly a quart or more... (putting me close to 10+ quarts on a tranny fluid change on the LS. Then again... since most LS torque converters aren't drainable... I'd start the engine and let the tranny fluid spray out the bottom for a few seconds.

Done this for years, (i'm sure Joe's hair is standing on end at this point)... but the idea was to get all old fluid out without burning up the pump or torque converter. It worked for decades,,, when we had a dipstick. Usually good for an extra quart or 2.

Worst case scenario... if you overfill the 5r55s tranny on the LS,,, fluid expansion will cause the fluid to flow through the "breather tube" on the passenger side of the tranny,,, making an appearant leak on the passenger side of the trans... or causing the overflow of excess tranny fluid to dump into the bellhousing area.
 
Hello,
I also have an 06 LS with a similar problem. I tried snooping around with someone with my problem but I feel like mines a little unique. I live very close to the city so there is a lot of stop and go traffic. I can tell when my LS is about to shift into the next gear (usually second) and I'm conditioned to let go of the gas if I feel I don't need to move any faster. However if my foot is off the gas and I happen to press on the gas again while the car is in the transition to shifting into the next gear it makes a really hard thump. Any suggestions of what that might be? The solenoid assembly? Thanks

I really love my LS a lot but my mechanic is hinting me to can it as parts are no longer made for this car.
 
That may be normal. Trans shifting is based on how hard you are pressing on the gas pedal. Best case... you might be unintentionally playing "mind games" with the computer.

The LS has an "adaptive" shift strategy... based on engine throttle opening, (throttle position sensor).

At times... I have noticed what seems to be a hard shift,,, when I let off the gas just as ther tranny shifts.

Try changing your gas pedal pressure during "stop and go" traffic... and see if the trans shifts "more friendly".

FYI... your mechanic is full of Bull Dung!!! His response to you tells me that he has no clue how to work on an LS!!!
 
04_Sport_LS said:
That may be normal. Trans shifting is based on how hard you are pressing on the gas pedal. Best case... you might be unintentionally playing "mind games" with the computer.

The LS has an "adaptive" shift strategy... based on engine throttle opening, (throttle position sensor).

At times... I have noticed what seems to be a hard shift,,, when I let off the gas just as ther tranny shifts.

Try changing your gas pedal pressure during "stop and go" traffic... and see if the trans shifts "more friendly".

FYI... your mechanic is full of Bull Dung!!! His response to you tells me that he has no clue how to work on an LS!!!
Click to expand...
Really appreciate your reply! I heard about the LS shift strategy. So changing the gas pedal pressure can be achieved by tightening the bolts attached to the pedal? If so I will give this a try when I get my car back from the shop later on.
 
No... You letting off the gas pedal at about the exact time the trans wants to upshift... is what is most likely what is causing your clunk. IMHO... when in "stop and go" traffic,,, you just need to learn how to feather the gas pedal a little better.
 
04_Sport_LS said:
No... You letting off the gas pedal at about the exact time the trans wants to upshift... is what is most likely what is causing your clunk. IMHO... when in "stop and go" traffic,,, you just need to learn how to feather the gas pedal a little better.
Click to expand...
Thanks again for replying and taking the time to talk with me about this problem.
Hmm.. I feel that I don't apply much pressure on the gas *about 1/4 of the way down). If I have to further "feather" the gas pedal in the city of Boston i'll just get a bunch of angry drivers honking at me then speeding up to cut me off for driving to slow lol... I don't even drive that fast about 20-25mph in the city compared to the crazy Uber/Taxi drives doing 30-35+.
Me letting letting go of the gas pedal is what I do to prevent the clunk from happening. On occasion the car will clunk anyway if I accelerate at moderate or at a low level, only time I never notice a clunk is if I floor it.
 
yeah... trans is trying to grab the next gear at low engine throttle. I've noticed this on rare occasion with my LS. If you have SST mode... you could manual shift. Otherwise,,, you may have to live with it.
 
Yeah, that's worth a try. Last question, do you think this will have any negative effects to the transmission or the car itself after so many clunks/thumps overtime? Sometimes I can't avoid them. I also asked my mechanic and he told me not really. It just sounds like it would do some serious damage overtime lol
 
Probably, I just hit a little over 88k miles not to long ago. I brought it 3 years ago on Feb 11 2014 with 72k miles and notice this problem maybe months after owning the car. Thinking about it now I never really looked thoroughly at its service records because I fell in love with it so much after seeing a neighbor with one. Btw this is my first car lol
 
You might want to take it to a reputible shop for a fluid and filter change if you didn't do that when you bought it. Make sure the shop installs Motorcraft Mercron 5.

Others with better knowledge will pipe in with with possible other suggestions. Trans solenoid pack could be an issue. Might even be ignition coil issues causing problems. I can't suggest that diagnostic problem. Wait a day and see who responds.
 
Alright i'll give my local AAMCO a visit they seem reputable enough. Thank you for your input its been really insightful for me and i'll definitely check here again when I get up in the morning. 3am over here time for bed lol
 
AAmoco is decent... dependin on location. Wait and see what others have to say. Give it a day,,, and see who else responds. I actuallu didn't know AAmoco was still around. They disappeared around here years ago.
 
Strangely enough for the last few days my LS no longer shifts hard. So strange. And I've gone like 400 miles now without a hard shift.
 
04_Sport_LS said:
No... You letting off the gas pedal at about the exact time the trans wants to upshift...
Click to expand...

Yep, my wife used to do that, and it caused the same odd shift behavior. When I realized she was doing that, I pointed it out to her. A week or so after she stopped doing it, the transmission relearned and shifted much better.
 
Meanwhile somewhere in a neglected LS the servo bore continues to wear out.

~ just saying o_O
 
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