KOHL4321

I have a 2004 Tl with 82,000 miles. It has a shudder between 20 and 40 mph. I know alot of people have complained about this but i have done everything suggested to fix it and its still doing it. I've changed the 3rd and 4th gear pressure switches did a full tranny flush and i took it to aamco and had it diagnosed and they said i need a new tranny. 2,000 dollars. but it shifts fine. Doesnt slip and rarely does the shudder occur. any tips would be greatly appreciated. Should i just wait till the tranny to go? or???? I just dont know what to do.

handsom-hustla

iTrader: (3)

yes this has been covered many times with many different situations and solutions. In my case the shutter was comming from a crack/tear in the flex part of my stock jpipe. at first I too was going crazy bc I could not solve this problem. I didnt even think it was my stock jpipe but after I swapped them I never heard the shudder again. Hope this giving you something else to look for. GL

egorss78

Had the same issue in my 04, thought it was the pressure sensors as well. My issue was studder right before 3-4 gear shift. I was lucky and had the acuracare extended warranty, they said it was the torque convertor. Price for repair on the paperwork said 2200(I only had to pay 100).

Same as you, it would always shift, just studdered over slow accleration.

nostra

I had a similar problem last year and it happened to be the Engine Mounts!

I hate cars

For the convertor to cause shudder, it has to be the torque convertor clutch (TCC). The TCC just like other clutches is greatly effected by the fluid's friction coefficient. While swapping switches will have no effect, changing to a different fluid type will. To the OP, try the Type F fluid. It will either make it much worse or cure it completely. At this point you have nothing to lose besides a few $$.

rock3try

I have been having a problem with my 04 tl and i figured you guys would be the only one who could help.
My transmission has the infamous shudder anywhere from 30-40 mph under low acceleration. I have tried doing a 3x3 (2x3 with d4 and then a 1x3 with racing) and the pressure switches to see if this would fix the problem but neither have. It has gotten better but it is still there for sure.

Any other ideas for me to try?

Thanks,

Ryan

Project_CLean

iTrader: (2)

2 year thread revive.

There's too many of these threads already.

Search in the 3G garage.

rock3try

I know it is a very old thread. I have been looking around a TON... trust me. I just dont know how many of the fixes apply to me. I was thinking about trying egr valve, clutch screen( the one next to the 4th gear pressure sensor) and maybe the solenoid screens but i dont know if any of those are even related to my issue.

What do you think?

Thanks

I hate cars

Try accelerating normally but with your foot on the brake just enough to make the brake lights come on. Let us know if the shudder is still there.

rock3try

Ok. Ill try that in an hour when I am off of work. I am pretty experienced with cars and this has me confused. My last guess would be that it isn't the transmission shuddering at all but rather a faulty motor mount. But I have no way to test motor mounts other than just replacing them

I hate cars

Dragging the brakes will eliminate the converter as an issue.

rock3try

So if I still have shudder when dragging the brakes then it is most likely the TC?

I hate cars

If you still have the shudder while dragging the brakes, it's probably not the converter since it won't lock when the brakes are applied. Just make sure to only hit them hard enough to make the lights come on.

rock3try

Still shudders with the brakes lightly applied. In fact, I would say it shudders harder than normal

I hate cars

Are you able to confirm the brake lights are coming on so we know the brakes are on enough to trigger the brake switch? You can try setting cruise control (it shouldn't work)while you have the brakes on to make sure the brake switch is being tripped.

It sounds like you've eliminated the converter.

I would make sure there's no sudder if you powerbrake it with the car sitting still. Obviously if you feel the shudder with the engine under load and the car sitting still it's probably going to be an ignition problem.

See if it gets the shudder at the speeds you mentioned but manually hold it in each gear to see if it will shudder when it's not shifting gears.

Last, does it start to go away as you get into the throttle harder and harder? Any chance you installed the wrong switch in the wrong hole? As you get deep into the throttle, the swtiches aren't used as much.

rock3try

I will have to try it again with the cruise to make sure it is engaged. I will do it later tonight when I can see my brake lights.
What do you mean by powerbrake with it sitting still? Like give it some revs?
Should I try holding the gear along with the brakes and see if that makes it shudder?
I will also have to check if it goes away on harder throttle. I want to say yes but usually I just back off the gas until it goes away. I am 99% sure I installed the switches in the right holes, since they were color coated it was easy to tell. I dont think it was that because it started to shudder less with the new switches installed, which I dont think would happen if they were put in backwards.

Thanks for your help IHC... This issue has been bugging me forever

abirvalg

have you changed the ATF filter?
if not, do it and look at the white epoxy around the paper element
if you have changed it, try to recall what the epoxy looked like

if any of the epoxy seals looked cracked or were(are) missing chunks
the missing pieces most likely plugged the banjo bolt and restricted the ATF flow

the filter is mounted in the cooler return line
if the flow was restricted the clutches may have suffered permanent damage from overheating

that's what had happened to me anyway

once the ATF flow was re-established there was no further deterioration to the clutches, but the damage was already done and i ended up replacing the AT

another good indicator of overheating is dark fluid

if you've never seen your fluid go as dark or darker than ripe cherry, then my suggestion probably does not apply

rock3try

I have not changed the ATF filter. This was my first tranny fluid change since I owned the car. The fluid came out EXTREMELY dark when I did it, almost looked like used motor oil. I havent looked at how my new fluid is holding up. If there are chunks of the epoxy in the banjo bolt, is that something that can be cleaned?

rock3try

IHC,

I was unable to get the car to shudder while held in gear. I will try again after work on some of the roads that always make it shudder.

I also tried doing a small power brake. I only got the RPM's to around 2000 cuz I didn't want to break anything. Should I be doing it harder?

rock3try

I also tried holding the brakes lightly while it was held in 4th and it still wouldn't shudder.

abirvalg

if i were you, i'd stop torturing your trany with the brakes and get on the ATF filter ASAP

my fluid turned black from fresh in a week when the line was plugged
the longer you keep the old filter the more damage it can do

the shudder will not go away when you clean up the line, the damage to the clutches is already done

but at least it won't get any worse, giving you time to make your your mind on how you want to repair it

i'm sure it could be rebuilt, but i chose to replace as my dealer gave me 50% good will

the first thing i did when i got her home with the new AT was ditch the stock filter add an aftermarket cooler and install a magnefine inline before the new cooler

abirvalg

this could still fall into the pattern i'm suggesting
my AT didn't shudder with agrassive driving
it only did it when gears were shifted at a relaxed pace

by applying the brakes you put more load on the AT so it engages the gears with more pressure

the shudder i'm talking about comes from worn friction coating in the clutches

AT clutches are designed to slip a little when engaging
if they don't slip at all you get jerky shifts, if they slip too much you get shudder or lag

the friction coating wears off (possibly just faster than normal) when AT overheats, so you get more slipping

pressure switches could have a similar effect, by not letting the gears engage fully, that's why they are the first thing that needs to be checked

a racing fluid that allows for less slipping won't fix the already done damage, although it could augment it somewhat

i hope it dosn't cost you an arm and a leg to get this taken care of!
good luck!

rock3try

OK. Thanks for your help. I will get on the AT filter as soon as I can and let you know the results. I did a 2x3 with d4 and a 1x3 with racing already. Should I do another 1x3 with racing and see if that helps more?

Also, can someone confirm the colors (brown and grey) of which one is the 3rd and 4th gear switch just so I make sure I was not really stupid when I installed them

rock3try

Anybody???

abirvalg

i would have told you, but i had dealer do mine
something tells me if you google for pic and videos you may find the answer
of just stop by a dealership and check with their parts dep

rock3try

OK. I checked on it and my sensors are correct.
I was more wondering if I should do another 1x3 of racing. I dont want to go over the 65% mixture tho.

Ill tell you what I have done thus far.

When I got the car, it had 100% Z1 in it.
I did a 2x3 with redline d4 first.
Then my last 1x3 was with racing.
I dont know what that puts my racing mixture at but I am guessing it is low.

I hate cars

Applying the brakes does not cause the transmisison to engage gears with more pressure. Only throttle position affects this.
Threre's no friction coating in the clutces.
They're not designed for slip, you can burn an AT clutch from only a second of slip.
There's no coating to wear off. The only thing that happens when the sump temp is excessive is the fluid oxidizes and needs to be changed more often. A high temp for oil in the sump is 250F. The clutch packs will regularly see 300F+ on a good shift. On a slow, sloppy shift they will see 500F+. The clutches are bathed in ATF so this directly affects fluid life. This is where a synthetic is helpful. It's not needed to handle the normal sump temperatures, it's needed to handle the internal clutch pack temps.

Basically a transmission cooler extends the life of the fluid. A synthetic fluid also extends the drain interval and provides the high temperature protection in the clutch packs.
They don't affect whether or not a gear engages fully, there's no actual shifting happening in an auto anyway. Switches control shift timing and I have good reason to believe throttle timing on the shifts.
All the racing fluid does is reduce or eliminate the friction modifier level, making the fluid less slippery, raising the friction coefficient of the clutches. If the clutches are good, the quicker shifts and resulting less slippage results in less wear over the life of the transmission. If the friction surface is damaged as in burned and the friction coefficient has been lowered, the racing fluid can bring the friction coefficient back up to where it's suppose to be or at least higher than it was with regular fluid. "Racing" is a misused term designed by the marketing guys. I wish they would just state Type F or the FM level of each fluid instead of labeling it as "racing" which is not what that fluid was originally designed for.

A little more detail:

AT clutches are not designed to slip. If you were to slip an AT clutch pack as you do a MT clutch when taking off from a stop you would fry them. Slippage in an automatic should be measured in miliseconds.

Shudder is slip. It's when the clutches are barely on the verge of slipping, they slip-grab-slip-grap, over and over, causing the shudder you feel. When there is shudder, there's excessive wear.

The friction materials in an auto do not contain a friction coating. You have a clutch that is steel and a friction wear material on it's face, similar to a MT clutch. You don't wear away any kind of coating when there's excessive slip or shudder but you can damage the friction surface. Once the surface is burned, it's friction coefficient goes way down and it's more prone to slip after that. Just like brake pads that get glazed. You have a metal backing plate with a friction material bonded to it. You overheat the friction material, it can glaze and lower the friction coefficient between the pad and rotor, however, brake pads' friction material is much more tolerant of abuse.

Jerky shifts in our case is usually from too slow of a shift, a bump shift. Shift timing is everything in an auto. Get it right and you can have lightning quick shifts that can't be felt by the driver. Get it wrong and you have bind (one clutch pack has not released but the other clutch pack is engaging) or slip (one clutch pack releases before the othe engages causing a flare or bump shift). A bump shift is where the shift is not linear in the time domain. The shift begins and line pressure to the apply piston is ramped up but the clutches don't want to grab so they slip. As the pressure ramps up the clutches engage suddenly all at once at the end of the shift. This causes the jerky feeling and it causes extra wear. The pressure switches have some input on shift timing.

Our cars close the throttle during a shift. It's the same as letting off the throttle when you shift a manual except the ECU does it much quicker than any of us could let off and reapply the throttle ourselves. It's usually not noticeable unless you have exhaust or intake and can hear the momentary closing of the throttle. This greatly reduces wear on the transmission because you have almost zero power going thorugh the transmission when it shifts. This also makes shifts less noticeable, with the throttle being closed it's pretty hard to have a jerk shift. I have a lot of reason to believe the pressure switches are linked to the timing of the throttle closure and the shift timing. Now that my switches are 3+ years old I'm starting to notice they need replacing again and one thing that sticks out now that I'm paying more attention than I did back in '08 is the throttle is reapplied before the shift is complete. So to sum up, the pressure switches can cause bad shift timing and bad throttle timing on shifts.

As I said before, the switches are not used at full throttle and their input has less weight on it as you dip deeper into the throttle. This is the most likely reason why shudder usually shows up at low throttle and goes away at heavy throttle.

Slip causes extreme temperatures in the clutches and the fluid in the clutchesk. On a normal shift that's quick and crisp you will still have a momentary temperature spike up to 300F in the clutch pack. A slow sloppy shift can cause spikes past 500F. The bulk fluid temp in the sump is kind of important but not nearly as important as retaining quick shifts to keep those temp spikes to a minimum. Sump temps range between 160F and 230F so you can see clutch pack temps are what will kill a fluid the quickest. The only saving factor here is it's a very small volume of fluid that's super heated at a time.

Power braking does not hurt a thing. Our ECU limits throttle to somewhere around 1/4 throttle when powerbraking so it never sees much power. Even if it did, it hurts nothing. If powerbraking hurt anything so would flooring the car from a roll. Powerbraking will produce a lot of heat but if you're doing it for less than 20 second intervals with a few minutes of cooldown in between you won't overheat it.

What I was asking the OP to do is apply the brakes only hard enough to trip the brake switch but the goal was not to actually apply the brakes if possible. The power braking was to identify a misfire.

rock3try

So do we think it is a transmission issue for sure? I figured maybe the engine/transmission mounts were going since they have never been changed and my car is an '04.

I could try a 1x3 with racing to bring my amount of FM down even more if you think it is worth it.

I dont know how to tell if my engine mounts are bad, short of having a friend look for excessive movement while power braking.

abirvalg

IHC, thanks for all the details!
i'm sketchy on them as i haven't seen my AT open (they won't give it back to me!)
but this is a quote from a web site explaining how ATs work
"Clutch disks are usually made of thin, durable steel. They are covered with a special coating that permits them to “bite” into steel plates, while not being so aggressive as to destroy them. - See more at: http://etereman.com/blog/automatic-transmission-2/everything-you-wanted-to-know-about-automatic-transmission-clutch-disks-and-more/#sthash.Q1AWc1Bx.dpuf"
albeit, they are not talking about a Honda AT

my Acura tech told me that with bad damage there could be little chunks of almost fabric-like looking stuff in the ATF, that's why i assumed it was coating

in any case, i'm not trying to prove or disprove anything
the main thing is the end result, whether it comes from missing coating or glazing, and it's the slipping, which means the AT needs repair or replacement

then mine went down i did a 3x3 with pure type F and didn't help a bit, i guess i was past the point of return

rock3try, engine mounts should show themselves at other times than shifts, possibly even without any special testing
so, if your car only shakes with shifts there is a good chance it's not the mounts

when an independent AT shopped tested my failing AT, the guy just drove it slowly allowing it to extend the shifts and felt for any vibration, which was only present 3rd-4th and then less so 4th-5th

I hate cars

Thank you for the help as well. I was just bored the other day and felt like writing lol.

Your Acura tech is right. The clutches are metal and they have a fiber mateial bonded to them. When they start wearing it looks like fiber/fabric in stuck in the filter.

The Type F also won't always fix the problem as you found out. Since one of the big problems is the 4-2 downshift where 3rd gear energizes momentarily and 3rd and 2nd gear are applied at the same time. You end up with a bind that 2nd gear wins every time and excessive wear on the 3rd gear clutches. It's a design defect and one of the only times the Type F fluid can cause more wear. With the defect causing 2nd and 3rd to fight each other, a more "slippery" fluid could lessen wear while they're slipping.

I'll have to read that article but got to go to lunch real quick.

JGrex1

I'm going to re-bump this thread, as I have had a similar problem.

2004 TL, AT, 107,000 miles. Car shudders changing gears around 30 miles per hour. I did the brake test as described above by IHC, and felt the shudder get worse like Rock3try.

That should eliminate the torque converter as a possible cause, which is no doubt a relief, but it still leaves us without an answer.

One question for you guys... if experiencing the shudder while power braking eliminates the torque converter, why the debate about transmission flushes and the like?

I get a sneaking suspicion this is not a transmission-related problem. When the car shudders, I can also hear a subtle gurgling/popping noise from the front right of the car. Also, this problem fluctuates depending on weather conditions. Usually wet or damp air makes it worse.

Here's what it could be:

1. Motor mounts (but the mechanic said they're fine)
2. Transmission mounts
3. Vacuum line? (hence the sucking/gurgling noise)
4. CV boot?

Has anyone made progress with this issue? This has been happening for 60,000 miles now... and it's not getting any better (but also not getting any worse thankfully). Please help!!!

rock3try

I figured it was the Motor or Transmission mounts but I didn't want to drop the cash on something that I wasn't sure on.

But I agree with you that it doesn't seem like the transmission that is at fault. I do not hear the gurgle noise that you do tho, but I doubt we have separate issues. My idle has been getting more rough lately so maybe a vacuum leak is possible. I have also heard of EGR valves failing on our TL's before, so that could be something else I could into. But I dont want to replace that blindly either.

sho423

My car has been doing this lately, I just changed my 3rd and 4th pressure gears too and it still shudder sometimes.

Off2kw17

I have a 04 TL, and my car does the shudder thing as well. I have replaced one motor mount that needed done, and the shudder went away. That was about a year and a half ago. Now, I have the same shudder back, and upon inspection, need to replace mount again. So might be good place to start.