Wankenstein

1998 Civic EX (stock D16Y8), A/T. 148K miles. Purchased 6 months ago.

Have been experiencing hard shifts in all gears since purchase. Shifts better at higher RPM's/speeds compared to lower RPM's/speeds. I did a 3 x 3 drain and fill the first week of ownership.. used Valvoline Max Life full synthetic ATF Dex/Merc and a small bottle of Lubegard red. After drain and fills the transmission did shift smoother but, not as smooth as it should. It does not flare or slip and there isn't any hesitation during launches and passing speeds,.. just hard shifts. I've been reading up on this for the past few days and through various resources online..here's a few related responses from various threads I have copied:

1) I'd guess it could be the linear solenoid (as you first mentioned) FIRST-be sure the connections for the linear solenoid are clean and corrosion free. The solenoid can become sluggish or bind with dirt/contaminants--but that again *may* be fixed by draining and filling the fluid 3x. If not, check resistance between #1 & #2 terminals on the solenoid itself. If it's between 4.0-9.0 ohms, you are within spec. If that checks out I'd check the clicking of the valve by connecting #2 to battery positive and #1 to battery negative to be sure it clicks. If it's sticking/binding/sluggish, either remove and clean the valve and the attachment channels or remove and replace.

2) check their resistance with an ohm-meter. Here are the specs.
Lock-up solenoid: 5-25ohm
Shift solenoid: 5-25ohm
Linear solenoid: approx. 5 ohm

3) The G! Acura Legend auto transmissions have the same issues with the solenoids getting clogged. Try connecting the electrical connector to the battery and grounding the soleniod body to activate the solenoid. Spray brake cleaner in the solenoid while activating the connection. Also, smack the solenoid onto a folded up towel on a hard
surface to dislodge the filings. I've done this many times on my G1 Legend auto trans and the results are incredible.

These threads touch on the possible benefits of TPS adjustment:
a) http://honda-tech.com/tech-misc-15/d...e-tps-2947986/
b) http://www.ozhonda.com/forum/showthr...44#post2732844

Does this sound like a good course of action:
1) Remove and clean linear solenoid, spray connections with electronic cleaner or clean and replace dielectric grease.
2) Inspect VSS (variable speed sensor), spray connections with electronic cleaner or clean and replace dielectric grease. My speedometer is not fluctuating.
3) Test TPS and report results here.
4) After posting results hack off TPS and adjust setting to hopefully improve shifts.

ezone

I hate to say anything about the transmissions.

Hondas fluid alone might give softer shifts. MIGHT.
I know use of incorrect fluid can cause weird things to happen sometimes.

1- I dunno. Your call.

2- It's "Vehicle Speed Sensor". Probably will make zero difference. If no codes and no speedo issues seen, it's assumed to not be a problem.

3- Sure. Output voltage should be exactly 0.49v at closed throttle, and somewhere around 4.5v wide open. Smooth and linear increase and decrease in voltage as you slowly move between fully open and fully closed

It's very tough to tell if the sensor output voltage has shifted or skewed though. Sometimes "replace with known good unit" is the only way to tell.

4- Those should be threaded, use pliers or a small punch and hammer to unscrew them. They are breakaway bolts similar to what the steering column lock uses, only smaller and you can't get them through Honda LOL Replace with normal threaded fasteners.


Finally, drive another identical car and see if it shifts like yours.
The older cars IMO did seem to shift firmer than newer cars.

Wankenstein

6th Gens original ATF is AFT-Z1 which has been replaced by DW-1. I read this: http://www.bobistheoilguy.com/forums...Number=2403116 and several other threads. as well as call Valvoline and spoke with a technician before I did the drain and fills. The technician said it's compatible in every-way to DW-1 and safe for 6th gen and other generation Civics.

Quote:

Originally Posted by ezone

Finally, drive another identical car and see if it shifts like yours. The older cars IMO did seem to shift firmer than newer cars.

I read some post that mentioned that too. Just can't imagine it shifted when new like it does now. Very possible that has been rebuilt but, no records when I purchased it.

emich

Replacing the ATF to Honda brand will make noticeable difference in shifting. I have witness this many times after complete flash.

Wankenstein

I though for 6th gens. Honda recommends drain and fills only and not to do complete flushing?

I'll buy 3 qts of DW-1 and do a single drain and fill. If that doesn't do it, others have said Castrol IMV (Import Multi Vehicle) has helped smooth out shifts due to it's thicker viscosity. Appaerently, hardshifting is not a bad thing and can actually help prolong service life (according to info I read on the net). However, it's annoying.

ezone

Complete flushing is fine if you do it correctly.
It's flushing machines and chemicals that are strongly discouraged.



Hondas version of a flush is multiple drain-and-fills with the correct fluid.

This applies to all Honda built automatic transmissions.

Link to (Acura, but Hondas version is the same) PDF here:
http://www.heeltoeauto.com/files/pit...ssionflush.pdf

NOTE: The article was released in 2008. Z-1 fluid is now obsolete and was replaced by DW-1 since the article was written.

Another service info is titled: Transmission Flush Systems: Just Say “No”

Wankenstein

Thanks for the clarification Ezone. I have a few upcoming services for this car that I plan to knock out all at once when it's on jack-stands.

1) OEM accessory belts
2) oil pan gasket
3) ATF drain and fill with DW-1

Hopefully it will shift smoother afterwards and I'll post results.
I have an unrelated question if you care to answer: I live in Florida and obviously it gets hot and humid in the summer days. The mornings and nights are usually cooler and my car seems to run much better during these hours compared to midday hours. I've heard a few older Civic owners say the same thing..is this real or imagined?

ezone

Somewhere in here you (or was it you?) mentioned something about reading firm shifts help extend trans life, I agree to an extent... Soft shifts can shorten clutch life, as the softness comes from a greater amount of clutch slippage. Firm shifts tend to have clutches applied quicker.

Fluid formulation can have a lot to do with shift quality too. Back in the olden days you could dramatically soften or firm up your trans shifting just by changing from Dexron to type F or vise-versa depending on what your goals were. That's an old racer trick for firmer shifts.


If the engine needs a set of belts, does it also need the timing belt?
At our shop we replace accessory belts with a timing belt job, and they generally start looking bad around the time it's due for a timing belt.
(I'm not searching through all your posts to find the answer LOL)


If you mean like foot on the floor maximum power, I've never noticed it myself... but because cool air is denser than hot air... to a certain extent this is probably quite real and apparent to a few people.

However, modern fuel injection makes the differences much less noticeable.

If you had a basic non-feedback carburetor on the engine you might really be able to tell a difference.

Drag racers tend to go faster at night, engine can make more power as the air gets denser.

Wankenstein

I was going to buy accessory belts at the time of the head gasket and timing belt kit but, I wanted to make sure it was running okay before investing more money in it ($48 total for OEM A/C, PS, ALT belts on Amazon).

In hot, humid weather it seems idle lower and not as smooth under load compared to cooler outside temps.