Hello everyone. I'm new to Honda's and this forum.

I searched a lot on this forum and some others for a description of the transmission problem that I am experiencing but I haven't found one that mentions what I am experiencing.

The car has 159K miles on it and the atf isn't bright red but it still has a red cast to it on the dip stick. I plan to replace the atf.

The problem that I have is that after I drive the car for a while, it will begin soft-shifting between 1 & 2 and then it will progress to slipping in the other upshifts until the car will not move at all. The downshifts seem to be normal (I guess as I wrote this car is new to me). Now, for the puzzle. I found that when I turn the engine off and let it sit for a minute that I can restart the engine and the transmission will shift "normally" again.

I'm suspecting that this problem is not internally mechanical at this point and must be electrical since turning the engine off and then restarting it would appear to reset something to make it shift normally again.

What is the consensus here regarding my experience and what should I do to remedy it other than replacing the atf since I have no idea either when it was last change or what fluid is in it now.

 

It's the sump filter, it is non serviceable. There is no pan to remove to gain access. This is why it is critical to replace fluid at specified intervals.
What is happening is the fluid is pulled through the filter and with it all the junk suspended in the fluid. This junk impacts onto the filter screen and blocks flow enough to cause low/no pressure. No flow, no go. Usually you will notice a whinning or whirring sound coming from the torque converter area as well, this is due to the ATF pump and TC cavitating. When the engine is turned off the pump is stopped, this stops the suction and all the junk at the filter screen disperses into the sump fluid. It needs to be removed.

With only 159K miles I suspect the fluid has never been changed. Do a service of draining > refilling > driving ~ 30miles going through all the gears 1-4 and reverse. X3. I would suggest to use whatever cheap Dexron II/III is available from the local store for the initial drain and refill, usually sold by the gallon. Buy three gallons. Your gonna toss this stuff anyway, no need to waste money with Honda ATF on a cleaning. I would also suggest adding SeaFoam Trans-Tune(or equivlant) to the refill process as well. It is a hydraulic cleaner. DO NOT USE 'SLIP FIX' OR 'STOP LEAK FIX' IN THE TRANSMISSION. Stop leaks will just clogged up the trans, ports, and filter screen exacerbating the problem. When you have gone through the cheap stuff and the fluid is now a nice clear red/pink, drain > refill > drive X3 using Honda ATF, and I would suggest adding more cleaner as well.

I would suggest that you park the car with the left side higher than the right and let it sit before draining, this may help drain more of the heavy junk out. During the first change add SeaFoam Trans-Tune(or other hydraulic cleaner) to the refill process to aid in breaking down the goo and removing it through the drain & refill process. And only drain and refill, no 'flushing' or using the pump to drain the trans via the cooler lines, your current problem is the sump filter screen is impacted with gunk and you want to draw that away from the filter. The only way to do that is through the draining process.

From now on adhere to fluid change intervals. Doing a simple drain and refill of the sump every 10-15K miles keeps the fluid fresh and the transmission shifting smoothly as well as making the process easier/quicker.

 

Thank you for the response MAD MIKE!

Your explanation makes a lot of sense. I did not think that it was an internal mechanical problem yet. I'm going to begin the cleaning process this evening. I have to drive a little less than 40 miles round trip to work everyday so I should be ready to put some new keeper ATF in it this weekend.

After I have done the 3X cleaning should I also do the 3X exchange with keeper fluid or should I do an exchange using the cooling line?

 

His explanation is very well written. My 1990 Honda Accord automatic transmission is one of the loudest whining automatic transmissions I've ever had out of all the 90-93 Accords I had. But the trans never slips or has trouble downshifting. I've even taken this car with 240k miles on it for 12 hour trips of straight running and driving not one slip or hesitation. After you do what Mike told you to do post back and tell us how it went. Does the S light on the dash ever blink while all of this is happening? If so you should check the TCU for codes.

 

No there is no blinking S light or D4 light.

I forgot that I had some Auto-RX in the cabinet. I'm going to use that in lieu of the Sea Foam.

Then I plan to do a full fluid exchange using the coolant line method. I'll report my results on this thread.

 

Always drain and refill with Honda ATFs. There is no pan or readily accessible area to clean so the only way to pull the junk out is through the draining process. This also draws any junk that may have migrated over near the sump pickup out towards the drain plug. It's not just about changing the fluid, it's about getting the particulate matter from worn discs, clutches, and contamination out of the trans and away from the sump filter. Using the cooler line drain method would just exacerbate the impacted filter issue.
Pulling a cooler line off to allow the trans to self bleed may seem like a nice/easy way to do it, but you will never get all the fluid out and the heavy junk and ferrous material attached to the drain plug magnet will never be removed if only the cooler lines are. Drain and refill are the best options with the Honda ATs.

An auxillary cooler and filter can be installed. A proper filter would be great as the 'filter' on the AT is not really a filter but a metal screen, so smaller particles can still be recirculated through the trans causing wear.
Honda ATs are low pressure transmissions ~ 130psi max, so a standard quality oil filter(Mobil1/K&N) should be able to survive without worries of bursting.

I have no experience with Auto Rx.
IF it is a hydraulic cleaner for use in ATs, then it should be fine.
IF it is a slip shift/leak fixer then NO. This will just compound the issue if it has sealing goop in it.

'Tyler' did this with his non functional trans... https://honda-tech.com/forums/honda-.../#post50667457

It directly attacks the problem, but I am a bit concerned due to the AT being so low that if hte plug were to catch something it could break the case. I would prefer a flat or flush mount plug.

 

H4A(90-97 Accord trans) does not have any pressure sensors, so no codes would ever be set. It only has the three speed sensors for the main(NM), counter(NC), and final drive(VSS) shafts.

 

Thanks again for the additional response.

My questions about do the fluid exchange was after the 3X drain and fill to eliminate all of the dirt and sludge as possible. I was asking if it would be appropriate to do an exchange through the coolant lines to insure that all fluid that was used in the cleaning drain and fills was out and only fresh Honda ATF was in the tranny.

I am definitely going to take your advice on the drain and fill..

Auto-RX is a cleaner only that can be used in transmissions, engines, PS systems, etc.

 

Cooler lines are 'filtered' and would be the clean side of the system.
Sump > Filter > Pump > Cooler(line/cooler/line) > Transmission circuits > returned to Sump.
You would basically be skipping the dirtiest part of the transmission, which is the part you want to clean.

 

Well now I have a dilemma.

I added the Auto-RX trans cleaner (not conditioner or anti-slip) to the transmission before I did the first drain and refill thinking that I could get a better cleaning with the first drain. I guess that was a stupid idea.

I was going to drive the car a mile or so to get the cleaner circulated and then drain it. The transmission initially went into gear but then I lost all gears. Fortunately I had not gotten off my street when I lost them. I turned the car off and then back on as I had before but still no movement from the transmission. I did this again and let it sit a little longer and still no forward gears. I was able to finally get reverse and was able to back down the street to my drive way but the transmission would not even pull the car up the small incline of my driveway.

I now have an immobile Accord. I fear that the cleaner may have emulsified some of the gunk and it was immediately drawn on the the filter screen and now I have no pressure at all. It was running and shifting fine earlier today when I drove it.

I may have to resort to Tyler's modification to get the dang thing moving again. I really hate the idea of taking it to the shop to have the tranny dropped just do that the sump filter screen can be cleaned. I really can't afford that expense at this time and I need my transportation.

HT please help if you can!

 

Yeah I would have drained the old stuff first and then added the cleaner with fresh fluid. The new fresh fluid would have been able to absorb more of the contamination, with the cleaner helping to break down the larger blobs and allow it to drain out. What most likely happened is the cleaner broke down the junk in the sump and on the magnetic plug and set it free in the system. Let it sit for an hour or so, get it back in your drive way or parked on the street and drain the contents of the sump. Before putting the drain plug back in pour in a bit of fresh ATF via the dipstick and see if it is just clear red or it flushes out some more gunk. Do that til it is mostly clear to remove the heavy deposits. Reinsert the drain plug, refill and try again.

When the '95s trans started to act up I could drive it about a mile and then it would stop, it then became progressively worse. It got to the point where I could only move the car a few hundred feet before it would act it was in neutral. Already had a replacement transmission lined up, so I didn't spend much time on diagnosing at the time. When I drained it before pulling quite a bit of junk came out of the trans. It smelt fine, but was mostly grey gloppy gunk, like that magnetic putty but in fluid form. At the time I didn't understand what was causing the problem as the Honda AT gunked up sump is pretty unique among typical car transmissions. Every other car has a removable pan with serviceable filter.

 

Thank you for your response again Mike. I was hoping to that you would respond.but I wasn't expecting to hear from you so quickly.

I'll do as you recommend while holding my breath and keeping my fingers crossed. If that doesn't help my problem and get it moving again then I'm going to try fabricating a spray tube out of something and see if I can get to the screen through the drain hole. I have an inspection cam that I hope that I can use to get a look inside once I have the nastiness drained out. As a very last resort I may attempt Tyler's trick. I sent him a message via email asking if he had precise measurements as his post only showed the measurement from the end of the case.

I did get it back into the driveway last night and have it parked on the level ground.

Thank you so very much for your excellent guidance and taking time to help me out by responding. I'll keep this thread updated.

 

When I finally got the drain plug out is was covered with gunk that looked like thick liquid graphite however there was no globs of gunk that cam out with the old fluid. The fluid was very dark appearing black while draining but did not smell burnt at all.

I poured some new fluid into the tranny and it flowed out red so I filled the tranny and started the engine. The car is still on jack stands. The wheels still did not move in any gear. I could hear a whining sound coming from the transaxle area under the hood but it was not loud. I ran the stick through all of the positions and I believe that the whining got more quiet but there is still no movement of the wheels.I drained the new fluid and there was some additional gunk on the drain plug but nothing noticeable in the fluid. I'm not using a clean drain pan so I can't really determine what if anything is suspended in the new fluid when it is drained out.

May be time for more drastic measures.

 

Clutch material is probably what is now stuck in the filter screen, unlike the goo it will not be as willing to settle back to the bottom of the pan.
Fill the sump and see if the clutch material will disperse into the fluid, but the fibrous material is probably impacted and caught in the screen of the sump pickup.
The whining is the pump/TC cavitating, there is no flow and no lubrication, so don't run the engine. Over fill the pan by about a quart to make sure the sump and surrounding area is submerged in fluid. Let is sit for as long as possible(day if not more) and drain. I would raise the right side of the car to promote any heavy deposits to sink towards the drain plug. Hopefully you will be able to extract material from the sump filter.
Othwerwise you will need to pull the case apart or use 'Tyler's method.

 

Put 4 quarts of fresh ATF in with another dose of cleaner in Thursday night. It's been sitting and soaking since then. I am about to drain that fluid out and refill with correct amount of ATF and hope for the best.

If this doesn't get the tranny to start shifting then tomorrow I will apply the Tyler procedure to the case and try to spray clean the filter screen with brake cleaner or similar solvent. Really have nothing to lose at this point. The case can always be repaire with JB Weld or the like.

I'll post back the results.

While tranny was draining I ran a code dump and I need some help figuring these out. I read the FAQ post but I'm confused.

CEL only code is 12

S light has the following code in this order:
1
2
3
7
8
14
15

 

1. Solenoid Valve A Lockup Control
2. Solenoid Valve B Lockup Control
3. TPS*D4 may or may not light*
7. Solenoid Valve A Shift Control
8. Solenoid Valve B Shift Control
14. FAS-wire *D4 does not light*
15. NM sensor *D4 does not light*

If the car was ON at anytime you disconnected a sensor/wire harness this would have set a code in the TCU.
Check your wiring harness and connection between ECU and TCU.
Verify no sensor/solenoid is unplugged.
If the wire harness is not damaged or dislodged, check the TCU for any leaking capacitors and/or burnt resistors.
Clear the memory and recheck. If the codes immediately come back there is most likely a problem with the wire harness or TCU.

 

Thanks for the code definitions Mike.

I removed and tested both of the shift solenoids and checked the screens. All 4 of the solenoids functioned when 12V was applied and all were at 15-16 ohms. There was not debris on any of the screens. I cleaned all electrical connectors with brake cleaner and re-installed the solenoids.

I removed the TCU and opened it to examine the circuit board. There did not appear to be anything that would indicate a component failure; no dark or burned looking marking and all components appeared normal. I re-installed the TCU.

I filled the sump with 2.5 qts of fresh ATF and started the car. Still no movement in any gear. Both wheels were off the ground on jack stands. I checked the fluid level and it was most of the way up the hash marks on the stick.

I listened but did not detect a whine coming from the transmission area.

I suppose I have eliminated all possibilities at this point with the exception of a clogged filter screen or a dead transmission. Tomorrow I apply the Tyler method. I figure that I have nothing to lose at this point.

There was a fair amount of goo on the drain plug when I performed the first drain and refill but nothing of any significance was washed out of the case. When I inserted my endoscope camera in the drain hole the bottom of the sump looked pretty clean.

I reset the ECU and TCU and read codes again after re-installing the solenoids and ATF and starting the engine and putting the shift lever through all of the positions. The only code that was returned after clearing the stored codes and reading them again after starting the engine was a 41.

I really bummed out at this point because I'm beginning to believe that the tranny has taken a dump on me.

I'll post again when I have drained the case and attempted the Tyler method. I have a question regarding the picture of the filter screen posted in Auto Trans Experts or at Least Experienced Tech Advice. Does the filter screen extend past the opening into the filter housing of is the extent of the screen mostly what is visible in the picture? I am curious if I need to attempt to clean the screen that may not be visible in the picture since Tyler mentioned a spray straw that CRC makes the sprays out of the sides of the straw instead of just the end.

 

I believe it does, if you were able to prise back the lower lid you would find the screen goes over the whole section of the pickup. The various dips and bumps are to prevent starvation of fluid in the transmission when going up and over hills/bumps/pulling Gs around a corner. It keeps the trans fed. But I think the main culprit with the starvation issue is that little 1" x .5" opening is what collects most of the clutch material and blocks flow.

This is why it is critical that the fluid is drained/refilled. You want to extract the clutch bits out. Metal bits will sink near the drain sump, ferrous bits will stick to the magnet, gunk will stick to whatever but its the clutch material that will screw ya. I don't think I have heard of a 90-97 Trans actually dying because of clutch wear slippage. It either dies flat out from the pump starvation issue or someone thinks the trans is dead/dying due to a sensor/solenoid issue or blames the trans for acting up when it is in limp mode from an engine issue.

 

The "Tyler Method" has saved another transmission and me several hundred dollars in turn either having the transmission replaced or rebuilt.

The method was easier that I expected.

I used a 1/2-13 steel alloy set screw as the p[lug for my access hole It works well and is flush against the bottom of the case. I just need to seal the threads with some hi-temp RTV or I may have some gasket maker from my days of working on VW engines.

The transmission is shifting great now in all modes. It took about 3.5 qts of ATF to bring the sump up to the full mark after the procedure.

I was confident that the procedure had worked when after I began to spray the brake cleaner into the access hole a gush of clean ATF poured out of the hole. When I first looked into the hole before cleaning the screen I couldn't even tell that I was looking at a screen. After spaying it repeatedly with the brake cleaner it was then obvious that it was indeed a screen that I was seeing through the hole.

i drilled my hole using the measurements and pictures that Beocop post on his thread. I drilled my access hole that the edge of my hole was just a hair past the flat surface on the edge of the slope on the TC.

All-in-all a great an inexpensive repair of a flawed design by the Honda engineers.

My grandfather used to say, "if they made the engineers actually work on the equipment that they designed they would design them differently". He was referring to the old oil filler holes at the base of Briggs & Stratton vertical shaft lawn mower engines. Those old enough to remember will understand.

Thank for all of the time that you took to respond to my posts Mad-Mike.

I love Honda-Tech!

I forgot to mention also that the ECU code 41 was from the O2 sensor not being connected because I forgot to plug it back in after testing the shift solenoids.

 

Well, I'm back again. Since the last post I had to perform the screen cleaning again about two weeks ago and just this morning the tranny began to show symptoms of the clogged pick up screen again.

I'm going to try cleaning the screen again when the rain stops. I live in Jacksonville, FL and we're waiting for hurricane Matthew to pass.

My question is whether anyone else has had to perform the screen cleaning multiple times?

Is this an indication that the tranny is on its last leg?

 

If the trans was not drained and cleaned of old fluid then the old clutch material may still be floating around. Or the new fluid has aided in removing deposits stuck in other areas of the trans and they have come free and it needs more draining/refilling. Drain and refill again as the dipstick may show clean fluid but there really may be gunk and junk in the sump still getting kicked up.

 

Thank you for the reply Mad_Mike. I have done several drain and refill cycles since I began this journey. This will be the 3rd time to clean the pick-up screen. I have been using Valvoline Maxlife because it is cheaper than anything else that I can get; even Super Tech.

Once Matthew passes today I'll drain the sump, clean the screen, and refill once again. Fortunately I already have the screen access hole.

A note on the access hole - the aviation gasket material never fully sealed the threads on the set-screw plug that I am using but black Permatex did seal it completely after the second screen cleaning. Just FYI.

 

I think you should try to use Honda ATF instead of Maxlife. Before my transmission problem started, I always used Honda ATF Z1. After replacing the ATF with Valvoline Maxlife, my transmission problems started. I don't know if it's related to the Maxlife ATF used since many have used Maxlife without problems. I've gone back to Honda ATF (DW1). My upshifts are great. The transmission still "clunks" when shifting down during deceleration to a stop. I haven't experienced any transmission problem since the "Tyler Method". I've also installed an in-line transmission filter. Maybe Maxlife is linked to your excessive clutch wear. I suggest using Honda ATF just be sure that the ATF is not the problem. To prevent possible damage to the transmission, maybe you should also install an external filter.

 

Thank you for your reply beocop. I was using the Maxlife with the plan to change over to DW-1 after I was sure that the filter clogging problem had been resolved.

I can say that there was not as big a gush of ATF when I cleaned it the second time and I used compressed air though the drain hole to the access hole that I drilled in an effort to get as much stuff out of the sump as possible. There was a thin coating of gunk on the drain plug magnet at the last cleaning but not much at all. I have also never been able to seen any apparent filings or sludge in the fluid when drained out.

I will have to use the Maxlife one more time on Saturday when I do the cleaning but I plan to get some DW-1 next week and do the 3x drain and fill then.

 

How that story ended?