Hi All,

This is a desperate solution for those who are suffering from a clogged internal (fluid pick up) transmission filter in their Honda/Acura. A clogged internal filter usually manifests itself by a complete loss of gears once the fluid is warm. DO THIS AT YOUR OWN RISK (but it can give you a few thousand more miles if you are desperate and you do not want your transmission rebuilt). DO NOT PM OR CONTACT ME if this does not work or if you ruin your transmission. This worked for me it may not work for you.

As you may know, your transmission has in internal filter that is known to clog up (starting at like 80k miles). The internal filter is built into the fluid pickup plastic assembly, at the bottom of the transmission. The transmission needs to be completely removed and disassembled for this filter to be changed. If you are desperate you can let all the fluid out, drill a hole from the bottom into the transmission casing, remove the filter element, tap the hole and put a screw in it (with some Teflon tape). Pick your own tap/bolt size and drill. I used an M10x1.5 tap (8.5mm drill bit) and a M10x1.5 bolt (with about 8mm thread – real stubby). I used Valvoline MaxLife Multi-Vehicle Full Synthetic Automatic Transmission Fluid (ATF) – I bought three one-gallon jugs at Walmart. This transmission fluid should cause no problems for your transmission (some even recommend it over the Honda fluid – but again you are doing this at your own risk). You want to make sure that your transmission is clean on the inside! YOU NEED TO UNDERSTAND WHAT YOU ARE DOING: you are going to drill a hole into the screen of the internal transmission filter. You need to do this without introducing any shavings/dirt into the transmission. From here on, you will not have a filter that filters the fluid before entering the transmission (and you know that this filter is needed as it has clogged with dirt). Your transmission after this may not be rebuildable and if you introduce dirt – it may not work for long. You can always replace fluid afterwards very regularly (3000-miles?).

Needed: shop-vac that can suck transmission fluid, drill bits, a large tap (for me: M10x1.5). 10qt of transmission fluid, transmission inline filter, pick.

1. Change the return inline filter (you can get the filter in Autozone; you can find plenty of YouTube videos that show how to do this).

2. Change the fluid twice
Remove the left side undercover after lifting the let front of the car. Remove the fluid drain plug (you need a 3/8 socket wrench) and let all the old fluid out in a container – you should get about 3qt. Remove the top fill plug (17mm) and rinse the transmission with a few ounces of new transmission fluid. Put the drain plug back in – fill the tranny with 3qt from the top (you can find plenty of YouTube videos for this. Drive the car in all gears for a few hundred feet. Repeat one more time. Drain the fluid.

3. Mark the new access hole’s location on your transmission. Drill a small (say 2mm) pilot hole paying attention to be perpendicular to the bottom surface (fluid is going to start leaking – put the shop-vac to it and suck out the fluid – suck it for a minute). Drill a slightly bigger hole (5mm), and finally finish with your pre-tap drill size (for M10x1.5, use 8.5mm). Drill carefully each time to just put the right size of hole – control your depth! Make sure that shavings from the drilling are dropping on the ground (that you do not introduce them into your transmission) – drill slowly. Use your shop-vac to collect even more shavings as you drill. After you drilled your pilot hole, transmission fluid will start dripping. You can use your shop-vac to suck out transmission fluid through the hole. If you marked it right – your hole should be right below the suction orifice of the filter, just below the filter screen.

4. Slowly and carefully drill through the access screen/filter. When you reach into the hole with a smaller drill bit/screwdriver, you should feel the soft material of the filter. Use your shop-vac when trying to remove as much of this as you can. Use a pick. You need to do this with a feel. Use your shop-vac generously.

5. Tap the hole with your favorite thread (again, I used M10x1.5) – use your shop-vac to suck away shavings. Prepare a stubby plug (I cut down a M10 bolt to about 8mm length). Put Teflon tape around the bolt thread. Rinse the tranny through your new access hole with about half a pint of fluid (introduced from the top filling hole). Suck on it again with the shop-vac.

6. Insert your newly made plug into the new access hole – tighten it appropriately (do not ruin your new thread).

7. Fill the transmission with about 3qts – drive and check fluid.

8. Assemble what you took apart (e.g., bottom cover).



Finally, the hole’s location: it should be 17mm towards the rear of the car from the center of the second bottom bolt (has a round channel on the casting) and 110mm towards the left of the car from the line where the two transmission case parts meet. While this hole location worked for me, a more precise location could be acquired by all of you who are doing this - chiming in (say: I think it was 2mm more to the right would be better). See picture:

 

An interestingly detailed summation of your endeavor, to say the least.
Although, I hope to never reach this level of desperation to employ such a perilous feat.

 

I had a 2006 CRV with the same problem - different tranny, but the filter was clogged. I was inspired by Transfix's can-do attitude to drill a hole in the bottom of the tranny and go for it. The rig is rusty, has 230K on it and as my local mechanic said: "the R&R alone is worth more than the car. What do you have to lose?"

I wasn't able to find an accurate location of the filter intake online, but got enough clues from the online parts manual and a replacement filter to get close. Missed the intake port, so just drilled a hole in the bottom of the plastic filter housing and through the filter material. it's very close to the bottom of the tranny, so easy to pick enough filter material out to clear a path for the ATF. A hemostat worked really well for grabbing little pieces and pulling them out. And I used a 1/4" pipe plug (the threads are tapered, so lock on their own) and sealed it with pipe dope.

A new filter ($15 from Amazon) was helpful for part identification, hole layout, port location estimation, drilling and filter fiber picking experimentation.

And... it shifts better than it has since I got it at 200K. Success!