Got a '95 LX auto coupe I bought new. In the last 50k miles or so (it's got 140k on it now), every once in a while, when accelerating enuff to increase speed a little, the tranny will sometimes backshift like from 4th gear to 3rd gear (or maybe it's just the TC decoupling, not sure)......

....when it UPshifts again, the tranny will start to shudder/vibrate....and all I have to do to stop it, is to momentarily let up on the accelerator and reapply it again.

The tranny does not and has not ever shifted hard, or slips between shifts....and this shuddering thing only happens on infrequent occasions.

What could this possibly be doing this? A faulty vacuum modulator (do Hondas even use these things?), Torque converter going bad? It has never gotten worse over the years.

Dealer insisted the tranny is going bad and needs replacing.....and this was nearly 7yrs ago when this started and it's still running strong and smooth otherwise. Any ideas?

MagikDraggin:

When was the last time you changed the ATF? How often do you change it? Have you had your dealer check the ECU to see if it indicates an error code?

Depending upon operational mode (say for example, as you ascend a hill), the "Grade Logic" system will unlock the TC and/or downshift the transmission to a lower gear. The system is extremely sophisticated, receiving and processing multiple inputs simultaneously.

Sorry, but just way too many possibilities for me to speculate upon. Faulty torque converter, faulty clutch pack(s), faulty hydraulic/electrical servos, faulty ECU, etcetera.

Before you sink a ton of $$$$ into a tranny replacement, I suggest you have basic tests performed by a qualified mechanic...preferably at a Honda dealership.

Also have your axles inspected. A faulty CV joint, especially on the inboard side, could also produce the shudder/vibration you describe.

MagikDraggin:

When was the last time you changed the ATF? How often do you change it? Have you had your dealer check the ECU to see if it indicates an error code?

Depending upon operational mode (say for example, as you ascend a hill), the "Grade Logic" system will unlock the TC and/or downshift the transmission to a lower gear. The system is extremely sophisticated, receiving and processing multiple inputs simultaneously.

Sorry, but just way too many possibilities for me to speculate upon. Faulty torque converter, faulty clutch pack(s), faulty hydraulic/electrical servos, faulty ECU, etcetera.

Before you sink a ton of $$$$ into a tranny replacement, I suggest you have basic tests performed by a qualified mechanic...preferably at a Honda dealership.

Also have your axles inspected. A faulty CV joint, especially on the inboard side, could also produce the shudder/vibration you describe.

I can certainly understand the lack of information for you to make an informed decision as to what could be the problem. It is NOT the CV joints, btw....remember, it only happens ONCE in while...not constantly or every time it shifts.

However, I do take exception to your suggesting that I take it to my dealer for an evaluation. To put it rather bluntly, THIS particular dealer is nothing short of a crook in my honest opinion.

A few examples:

One day the wife took it in to the dealer for one of their so-called 27 point service checks and was told the back brakes needed replacing.....this after I had JUST replaced all 4 corners not three weeks prior to the inspection.....the service manager apologized for the "error".

On another occasion, while at the same dealer for a routine A/C service, I was informed that the "Quad Ring" was leaking and should be replaced. Was told by the service adviser that this operation would cost 260 bucks to remedy. After inquiring just what exactly IS a "quad ring", a mechanic came out and pointed it out to me on the vehicle. Low and behold, the "quad ring" was nothing more than the O-ring that seals the t-stat housing to the head/block.....easily accessible with a short extension and ratchet.....the part cost all of 2 bucks and was done there on the spot by me in all of 5 minutes.

And on yet another occasion, while I was out of town, the car refused to start on a particularly cold morning. The wife had it towed to the dealer, where they informed her it would take, this electrical module, this sending unit, this other gadget and about 450 bucks. I got back in town, when down there and asked the mechanic if he checked the spark plugs...and he said yes, they were "a little worn". He also said the car started right up for them in the warm shop. I told them to button it up and I drove it back home, pulled the plugs, found the gap to be in excess of .080, replaced the 4 plugs and the car has started flawlessly ever since in even COLDER weather.

And the icing on the cake with this dealer was when I took the car in to have the front suspension checked due to a "hitch" in the steering......was told the lower A-frame/ball joint needed replacing. Fine, had it replaced.....picked the car up that evening, got as far and the dealership driveway and began to make a left turn onto the roadway when all of sudden there was a loud "snap" and the L/F wheel literally collapsed under the car. It seems the mechanic had not adusted the tie rod end correctly and it caused the brand NEW ball joint to snap off, allowing the entire spindle to flop over and drop to the pavement.

And you want me to take it in to the dealer to have them check out what might be wrong with it and why it sometimes shimmies when attempting to shift into an upper gear?

Not a chance!

But I WILL change the tranny oil and have the TC flushed as well, as a just in case and see what that does for it. Personally, I believe the valve body is becoming a little glazed over the years and "sticks" on occasion...but that's just MY unprofessional opinion.

MagikDraggin:

Needless to say, there are good dealers and bad dealers. Based upon what you state, you, most regrettably, have a bad dealer. I would not hesitate to file a complaint against said bad dealer with HMC. If nothing else, you will FEEL better.

Find someone whom you consider COMPETENT, whom you TRUST, to inspect/work on your car.

The shudder/shimmy/vibration you describe is most likely NOT caused by a malfunctioning valve body. It is something rotating inside and/or outside of the transmission. Might I also suggest you have all the motor and transmission mounts inspected?

MagikDraggin:

Needless to say, there are good dealers and bad dealers. Based upon what you state, you, most regrettably, have a bad dealer. I would not hesitate to file a complaint against said bad dealer with HMC. If nothing else, you will FEEL better.

Find someone whom you consider COMPETENT, whom you TRUST, to inspect/work on your car.

The shudder/shimmy/vibration you describe is most likely NOT caused by a malfunctioning valve body. It is something rotating inside and/or outside of the transmission. Might I also suggest you have all the motor and transmission mounts inspected?

Thanks for your reasoned response, in light of my frustration with the local dealer. It is particularly troublesome to trouble-shoot this problem due to its sporatic nature.

It's not like something that's worn out or necessarily "broken"...as it only acts up once in a while...almost always at low speeds and only when upshifting normally (ie not under hard acceleration).

And when it does occur, simply letting up on the accelerator and reapplying it lightly again, stops the shudder.

Honestly it "almost" feels like when it shifts, a spark-plug wire falls off just at that instant, it's that same sort of "shudder"....but it's not the spark plugs or plug wires.

Motor/tranny mounts are fine. This has been going on for years now, with no discernable change in frequency or intensity of the shudder. I have had the computer checked for "codes" and found none.

The only thing that has happened to the car in the past few years is the ABS began acting up, causing a "pulsing" in the electrical system, as it attempted to "reset" itself after having been activated. I could never get that particular problem resolved either and do not believe they are necessarily even related, but pulling the fuse at least stopped it from pulsing.

The only thing I haven't done is changed the tranny fluid since the car was new. Prolly not a wise decision, huh? I'll get that done and see what happens after that.

Thanks again

You should get the trans service done somewhere where they use HONDA FLUID and nothing else.

NO FLUSH MACHINES!!!

Just drain and refill's 2-3 times with driving in between to clean the system.

You should get the trans service done somewhere where they use HONDA FLUID and nothing else.

NO FLUSH MACHINES!!!

Just drain and refill's 2-3 times with driving in between to clean the system.


Well, I can certainly do that.....just go and purchase some Honda fluid. But what exactly are you saying?......to drain the existing fluid, refill with new fluid, drive it for a while and drain that fluid and refill with more NEW fluid? and do that a few times?

That's a lot of fluid to be trashing isn't it? I am guessing that's what you meant to do, right? And I NEVER have an automatic physically "power flushed".

Lemme know if I got all that right, and I'll get right on it.

Thanks

Well, I can certainly do that.....just go and purchase some Honda fluid. But what exactly are you saying?......to drain the existing fluid, refill with new fluid, drive it for a while and drain that fluid and refill with more NEW fluid? and do that a few times?

That's a lot of fluid to be trashing isn't it? I am guessing that's what you meant to do, right? And I NEVER have an automatic physically "power flushed".

Lemme know if I got all that right, and I'll get right on it.

Thanks

Doing the drain/fill method with Honda Z-1 is as easy as an oil change. About 3 quarts should come out then slowly refill with 3 new quarts thru the atf dipstick hole. Instead of driving it for a few miles then doing another d/f I would space the d/f's a week a part assuming the car is driven daily. Probably 3 d/f's would be ideal. This may very well solve the initial problem that you described. If not its great over due preventative maintenance.

What color is your atf now? It should be pink to med. red.

Doing the drain/fill method with Honda Z-1 is as easy as an oil change. About 3 quarts should come out then slowly refill with 3 new quarts thru the atf dipstick hole. Instead of driving it for a few miles then doing another d/f I would space the d/f's a week a part assuming the car is driven daily. Probably 3 d/f's would be ideal. This may very well solve the initial problem that you described. If not its great over due preventative maintenance.

What color is your atf now? It should be pink to med. red.

While I pride myself for trying to be being reasonably attentive to the car's needs, changing the tranny fluid has not been one of them. (The spark plugs as mentioned previously, were well under the 100k lifetime of the plug, but apparently were inferior aftermarket types.)

After 145k miles, the fluid is a "burnt sienna" (no pun intended) sort of brownish red. No foaming or nasty burned odor is present.

I will do the change as suggested and get back to y'all with the results.

Not to hijack this thread, but why would the multiple drain fill routine be superior to the flush? We were planning on having the Ridgeline fluid flushed at 30K, and it's at 29K. :)

Magikdraggin and All:

Changing tranny fluid at specified intervals is not only essential, it's "cheap insurance." I can NOT imagine driving any vehicle 145,000 miles without changing the tranny fluid, be it automatic or manual.

The "B7XA" (auto) tranny in my '02 is notoriously prone to fail at any mileage, and regardless of (hours of) operational service. This is WHY I shall soon install a (CompTech 560-025) tranny cooler this Spring/Summer. And I will change the fluid once per year, regardless of mileage driven. FredSVT and I have had a LONG discussion about (particularly) automatic transmission servicing in previous threads. I strongly urge you to pay close attention to Sir Fred's brilliant words of advice.

While I pride myself for trying to be being reasonably attentive to the car's needs, changing the tranny fluid has not been one of them. (The spark plugs as mentioned previously, were well under the 100k lifetime of the plug, but apparently were inferior aftermarket types.)

After 145k miles, the fluid is a "burnt sienna" (no pun intended) sort of brownish red. No foaming or nasty burned odor is present.

I will do the change as suggested and get back to y'all with the results.

My ATF is that same color. Brownish red. I bought the car at 121k and I'm at 134k now. Transmission is shifting a bit rough sometimes I feel a strong jolt or jump forward. A couple of times I have even heard the tires chirp between 2 and 3.

But I also have that problem with the car downshifting then upshifting with a loud, strong jolt. It sucks. I really don't want to get a new tranny or rebuild.

Hopefully draining the ATF and filling a few times will help.

To All:

Unlike the "conventional," automatic trannies most of you are familiar with (e.g., GM Turbo-Hydramatic (M25, M35, M40, 700-R4, et al), Ford "Cruise-O-Matic" (C4 & C6), and Chrysler "Torque-Flite" (A-727 & A-904), Honda's auto trannies are (radically) different.

The old-style, conventional automatic trannies typically incorporate a "Planetary" gear, a "Sun" gear, and an "Annulus" gear, working in conjunction with a "viscous-drive" torque converter. (In essence, a "fluid-driven" clutch.)

To this very day, Borg-Warner Corporation STILL holds most of the patents for automatic transmission technology, dating back to the 1940s (if not earlier!). I (vaguely) recall the FIRST "modern" automatic tranny introduced in the 1949 Mercury, as their "Merc-O-Matic." GM quickly followed suit, making their (two-speed, cast-iron) "Power Glide" tranny available (circa) 1950. Anyone old enough to remember the famous "Dyna-Flow" trannies used by Chrysler Corporation?

(Nevemind. Us "Old Farts" are terribly prone to aimlessly wander around in the (almost forgotten) past!)

Conversely, a Honda "automatic" is essentially a hydraulically-shifted MANUAL transmission!

They essentially took a "man trans" unit, replaced all the (brass) synchros with wet clutch packs, then added a (viscous-driven) torque converter, all controlled by an ECU.

Regardless of what your driving "habits" may be, frequent fluid changes are an EXCELLENT idea!

My owner's manual expresses a 30K tranny fluid change interval, on my '02. Trusting my experience and my instincts above HMC, I am changing the tranny fluid once per year, regardless of mileage driven and/or hours of operation. And with HEAT being the eternal enemy of any transmission, I'm adding a (CompTech 560-025) tranny cooler within the next two (2) months. Kick in an inline tranny filter, used on the '03-'09 Honda Element.

In MY book, "an ounce of prevention" is always worth MORE than "a pound of cure!"

While I pride myself for trying to be being reasonably attentive to the car's needs, changing the tranny fluid has not been one of them. (The spark plugs as mentioned previously, were well under the 100k lifetime of the plug, but apparently were inferior aftermarket types.)


Honda doesn't make their own spark plugs so you have to go aftermarket. NGK or Densos are what Honda recommends. Don't use Bosche(sp?) since they can cause driveability probs.

Any updates on the trans. operation?

...
(Nevemind. Us "Old Farts" are terribly prone to aimlessly wander around in the (almost forgotten) past!)...

In MY book, "an ounce of prevention" is always worth MORE than "a pound of cure!"

"old farts" provide wisdom for our new world (i'm 36!) and we should take advice from them... :thmsup:

BTW, I like the last statement. I do the same thing on all my Hondas :dude:

Honda doesn't make their own spark plugs so you have to go aftermarket. NGK or Densos are what Honda recommends. Don't use Bosche(sp?) since they can cause driveability probs.

Any updates on the trans. operation?


Yes there is, as a matter of fact. I just finished the 3rd set of drains and refills, while driving a few hundred miles between each.

The result is that you people were absolutely on the mark with that suggestion/recommendation. The tranny fluid that came out had something in the bottom of the pan that looked suspiciously like some kind of graphite paste....almost like lubriplate grease.

Not really sure what that stuff was or what it was from, and the fluid itself was a black as good ol' used motor oil.

Now the tranny shifts smoother, and withOUT that annoying shimmy after it would shift at lower speeds under lite throttle pressure.

Thanks again for all your help...a valuable lesson was learned here for me. I have just purchased a brand new 09 Accord coupe AT, and I can guarantee you that tranny will get serviced when it needs to be serviced.

BTW, I still have the 95 coupe...that one's a definite "keeper". See my new post in regards to something else I learned on my son's 97 Civic.