Torque converter ? rpm bumps @ high speed

[pilotguy]

I have a 94 Legend that's started a new issue lately. In the higher highway speeds, (70-90mph) If I'm steady on the gas and the rpm is stable, and I VERY LIGHTLY accelerate, the rpm "bumps" down about 300 rpm. If I let off the tiny movement of the accelerator, it returns back to "normal". Feels like a Torque converter lockup clutch action, but the rpm action is opposite to what I would expect. I would think the rpm would increase with the accel, and as the lockup unlocked, and then the rpm would go back down. I've driven the car the last 50k, and this is a new thing....any thoughts?

[Swift]

how does the fluid look?

[pilotguy]

all the basic stuff is pretty well checked I think. I drain the fluid about every 30k, and I understand there isn't a filter to be changed, just a magnet.. Haven't ever pulled the pan off though. The fluid looks fair, and doesn't smell bad/burned..

[OEM Bob]

Hmmmm...If I am not mistaken, I believe you not only have to drain the tranny, but the torque converter as well.

I would also look for a vacumn leak.

Please let us know what you find out.
Good luck
OEM Bob

[pilotguy]

Well, I did a drain and fill, total of 5 quarts changed, and it has improved my problem to almost fixed. I suspect that the friction quality additives have broken down, despite no significant discoloration. I had this problem in a Mits Sigma years ago, when I used after market fluid rather than dealer fluid. I've only ever used Acura fluid in this, but I'm going to do one more drain and fill, to try to get some more that was in the T.C. swapped out too. I think it actually was the lockup clutches in the Torque Converter bumping...

[arock]

pilotguy:

I have the EXACT same issue except with my 1994 Integra LS automatic. I've had the tranny fluid replaced, but it didn't help a whole lot. However, as far as I know, I did not have the torque converter drained when my repair shop did the work. I'm not a mechanic by any means, but what is the difference between draining the tranny vs. draining the torque converter?

If you've already drained the t.c. let me know how you're Legend is doing.

[shawnhu]

Sounds to me like your ECU is not responding well to the extra air in the mixture, and is running a little lean, causing the RPM's to drop a little. But you're right, Acura/Honda ATF works wonders in their tranny's.

The difference between training the tranny and the T.C, is.... well there is no difference. You can't drain the T.C. unless you remove it. However, you can "flush" the T.C using several methods. The preferred method for an entire tranny flush(including the T.C) is to use the engine's power along with the tranny cooler lines. In the Vigor, you'll need about 10 quarts, probably more in a Legend.

[sam o nela]

Here's a good procedure that many have had success with:

Originally Posted by Ben Hedrington

Total stuff needed:
(1) Bottle of smart blend ( Black Bottle)
(I used Lube Guard from NAPA for $11.00)

(4) quarts of "F" type Trans fluid
(7) quarts of Dextron fluid
(4) quarts of Genuine Honda fluid

Time to play with your car.......

1. Drain the fluid and add 3.5 quarts of "F" type fluid. F-fluid (ATF) is what is used in Ford transmissions. It has a very high detergent base to it that is designed to clean the internal parts and to break down varnish build up.

2. Drive the car around for several miles and then drain it again . I do not recommend that you leave the F-type fluid in the car for an
extended time.

3. Now having drained the fluid refill the unit with 3.5 qt's of
Dextron II or III and again drive the car around for a few miles
working the Dextron in. While you are doing this what you are
actually doing is diluting the F-type fluid and flushing the dirty fluid
out of the converter at the same time.

4. Return to the driveway and dump the fluid again and

5. repeat the process again. (Steps 3-4)

6. Now , having returned once again , you have drained one last
time. At this point what little F-type fluid that was left has been
drastically diluted and the majority of what you have left is Dextron.

7. Now fill the tranny up with Genuine Honda ATF . Honda fluid has
a high silicone base to it and that is what will keep your tranny
shifting smooth. You now have 3.5 quarts of Honda fluid mixed in
with about 5qts of Dextron mixed with .5 qts of F type fluid (Mix) .
Not enough to hurt a thing. Now to even things out and bring us all
back to Basic Honda fluid , get a bottle of a product called "Smart
Blend" It's made by a company called "Life Products" Be sure to
get the Black bottle as it is specially designed to convert Dextron
over to Honda fluid, this is a product that we endorse, and use it in
all our transmissions through out the building process. If you can't
find it then try Lube Guard , and again use the Black bottle. Both
products have red bottles and I thin also a Blue one too?

8. Pour one full bottle of Smart Blend into the tranny and you're set. Smart blend reduces operating temps as well as is a friction modifier that will reduce clutch pack chatter as well as help with converter lock up. Now the reason you start with the F type fluid is to clean . Then you use Dextron to dilute the F-type (Ford) and besides to dump that much Honda fluid just to flush would be a
sin, not to mention costly as all get up.


4x Tranny Flush by Gil - The Acura Legend & Acura RL Forum

[pilotguy]

Well, I've driven the car another 10- 15,000 miles or so since the post, mainly high speed highway from Fresno to Oakland and back, and for the past 3 months, its only acted up once. (very briefly) I think I'll drain and fill again.
As mentioned above, there isn't a way to "drain" the torque converter. unless you go throught the trans cooler lines, which, in my estimation (as a former 12 year dealer tech (on Dodge) is asking for a can of worms.
An even larger can is the post above in my own opinion. Mixing fluids, and "trying" additives is a risky chance I'm not willing to take, unless the thing is just so bad you can't drive. Its like going from Valvoline to Penzoil. You're gonna get a smoker every time....
OEM fluid is still hard to beat for what ever car you own, and this comes from a tightwad-mechanic..
End result, is that I'm happy with the outcome, and it's not driving me nuts anymore. (upon looking at the Smart Blend mentioned above, it might be something I try, just as an addition to my next drain and fill..)

[sam o nela]

Yeah I know the post I put "sounds" iffy and experimental, but it was posted years ago (back in 02!) by a the VP of a Honda/Acura Transmission rebuilding company...so hes definitely got a good knowledge base...

And thusly, since 2002, there have been numerous G2 Legend owners that have successfully done this procedure and experienced absolutely no ill effects...in fact the norm is a HUGE improvement in shifting