[BradC]

So this morning my truck decided to puke all coolant and transmission fluid while backing out of the driveway.

I have been very slowly losing a small amount of coolant (6 months give or take to drop from between the lines on the overflow to low). I have not noticed any increased fluid in the tranny, fill level has remained the same on the dipstick and no SMOD. When checking trans fluid level after coolant/fluid puke this morning, there was no trace of coolant on dipstick, just barely any trans fluid left.

Radiator is on order, going to swap it out tomorrow. Have an FSM, read the tutorials here, can't be too bad.

My concern is the transmission. What's the best course of action?

Fill it, run it a hundred or so miles and drain and fill?

Fill it and call it a day until next service interval (did an A136 maybe 20k or so ago, when the MM told me to)?

Something else?

Thanks guys!

 

[OhSix]

So this morning my truck decided to puke all coolant and transmission fluid while backing out of the driveway.

I have been very slowly losing a small amount of coolant (6 months give or take to drop from between the lines on the overflow to low). I have not noticed any increased fluid in the tranny, fill level has remained the same on the dipstick and no SMOD. When checking trans fluid level after coolant/fluid puke this morning, there was no trace of coolant on dipstick, just barely any trans fluid left.

Radiator is on order, going to swap it out tomorrow. Have an FSM, read the tutorials here, can't be too bad.

My concern is the transmission. What's the best course of action?

Fill it, run it a hundred or so miles and drain and fill?

Fill it and call it a day until next service interval (did an A136 maybe 20k or so ago, when the MM told me to)?

Something else?

Thanks guys!

So sorry to hear of the problem. Sounds like you caught things at the most opportune time. Other than loss of fluid and an unexpected expense and project, you may have escaped the most damaging affects of dreaded SMOD. Fingers crossed for you.

Having never experienced SMOD, I can imagine that coolant injected into the trans would result in significant foaming when the vehicle is operating at anything above parking lots speed. There's a whole lotta turbulence in the fluid path that causes the milkshake symptom to manifest. IF (big if) that imaginary scenario is true, you've safely avoided the worst case scenario.

If it were me, I'd take the requisite steps to make her drive-able again and take great care monitoring trans fluid for the first several miles. Several being your own definition. Example: I'd drive up my hill 1/10th of a mile and pull the stick. Repeat, repeat, repeat without leaving my neighborhood. If things are looking good, take a 3 mile drive to the grocery store, check the stick. Repeat in larger increments until I've proven to myself no coolant is in the trans. Even then, I'd drain it after X miles and fill er' up with new.

If you get away from this at the cost of a rad, fluids and a little driveway time, you've come out on top. Treat the tranny to a couple of drain/fills, smile and stick your middle finger in the air making sure the SMOD devil sees you. ;act028:

Report back your experience!

 

[Jonb]

I would drain and fill a couple times at least. You really don't want to drive it if there is any coolant inside the tranny or toque converter. I would drain and fill then move it back and forth in the driveway then drain and again move it back and forth then drain and fill. Then maybe around the block and drain and fill, then take it 25 miles or so then drain and fill. At the bare minimum I would want to do at least 4-5 drain and fill before I would feel comfortable.

 

[ridged]

I think that I would try to find a shop that can do a complete ATF exchange (not a pressurized flush).

 

[janimal]

Yep, gotta` drain and refill a couple of times. The coolant can react with the bonding of friction material on clutch discs,if left to sit, breaking the bond. The tranny may then only last a few months. My tranny cooler blew, and puked pink milkshake all over my driveway. Two flushes within a day or two and all is well 8 months later!

 

[BradC]

Thank you for the input so far guys.

I haven't ever experienced coolant and trans fluid mixing. When they say strawberry milkshake of death, etc, does it get foamy looking or what?

All of the fluid that has been set free is separated from each other where it pooled, i.e. - there are pools of trans fluid floating on ponds of nice fresh blue coolant.

I guess what I am asking is when looking at the transmission dip stick, is the SMOD something that is going to be obvious and clear as day?

 

[OhSix]

Thank you for the input so far guys.

I haven't ever experienced coolant and trans fluid mixing. When they say strawberry milkshake of death, etc, does it get foamy looking or what?

All of the fluid that has been set free is separated from each other where it pooled, i.e. - there are pools of trans fluid floating on ponds of nice fresh blue coolant.

I guess what I am asking is when looking at the transmission dip stick, is the SMOD something that is going to be obvious and clear as day?

Yep it does get foamy - and from what I understand it does so very quickly. I haven't experienced it myself but you'll find images on line.

Based on your description, it doesn't sound like coolant entered the trans circuit. The reason I say that is: trans fluid operates under pressure and is forced thru very small galleys which is one of the reasons the combined coolant/trans oil foams so severely.

You mention the trans oil was low but clear, it is my assumption that any engine coolant entering the trans circuit would instantly foam under pressurization and "cleaning out" the trans oil along the way - causing the foam.

But again, that's assumption. You gotta look out for your ride. Is it worth having her towed to a shop for a passive flush? Caution would say yes.

 

[BradC]

Based on your description, it doesn't sound like coolant entered the trans circuit. The reason I say that is: trans fluid operates under pressure and is forced thru very small galleys which is one of the reasons the combined coolant/trans oil foams so severely.

You mention the trans oil was low but clear, it is my assumption that any engine coolant entering the trans circuit would instantly foam under pressurization and "cleaning out" the trans oil along the way - causing the foam.

But again, that's assumption. You gotta look out for your ride. Is it worth having her towed to a shop for a passive flush? Caution would say yes.

That's the assumption I was operating under as well, but wanted outside opinions.

Thank you.

I really wish I would have let me talk myself into doing the radiator as PM when I did the timing belt a few months ago. It just seemed silly though.

Will update what I find once I dig into her Saturday.

Thank you again guys.

 

[OhSix]

That's the assumption I was operating under as well, but wanted outside opinions.

Thank you.

I really wish I would have let me talk myself into doing the radiator as PM when I did the timing belt a few months ago. It just seemed silly though.

Will update what I find once I dig into her Saturday.

Thank you again guys.

You've probably been looking around but just in case, the info in the video below might be helpful to your task at hand. The one thing I wouldn't do this fellow does is don't use air pressure to blow old trans fluid from the external heat exchanger circuit back into the trans.

First, no external pressure should be applied to the trans.
Second, he drained the sump, filled it, then forced old fluid from the external cooler into new fluid in the sump. Even though he's going to drain that fluid later, it makes no sense process wise.
Third, the FSM details a pressure method for the external fluid circuit, which I would do while you're under there.

BUT, using the trans as the pump makes perfect sense. And you'll have an eye on output. Best of luck!

 

[speedlever]

I really wish I would have let me talk myself into doing the radiator as PM when I did the timing belt a few months ago. It just seemed silly though.

It can be a tough call. But given the severity of the problem, I consider it relatively cheap insurance to just replace the radiator at the TB/WP service interval.

Seems to be a roll of the dice as to whether the tranny/radiator fittings will fail.

Good luck!

 

[Dnick]

Pay close attention to the old tranny fluid that you drain out. If it looks "pristine", then you're probably OK (tranny fluid went to radiator, but no radiator fluid to tranny).

If you see ANY signs of contamination, I'd be doing the multi-flush as others here have mentioned. I especially liked the recommendation for limited exercise of the gears (staying in driveway for example) vs. driving it at lenth, if you are trying to get rid of contaminated fluid.

 

[Carsmak]

Brad, from the various videos I've seen, I haven't seen a specific Honda SMOD video, unsure I'd call a Honda Cross contamination a true Strawberry color, which I believe is related to the source colors of coolant (when I did my initial discovery, the Coolant wasn't true blue and the ATF wasn't the true red the OEM ATF looks. Both looked dark, ATF dark red almost purple & coolant dark blue almost purple. When I started looking at the new OEM fluids I wanted to get as much out as possible good luck & keep us posted.

 

[IanRTL]

Make sure to take some pics of the old radiator fittings while you're at it. Live and learn with this sort of thing. The fact that it happened in your own driveway (and very abruptly) instead of on the highway is a minor miracle. You likely caught it in time before it became a huge problem. Once you do the radiator and get everything buttoned up and topped off there, I would pull the tranny drain plug. Let anything that may be left drain out. Then, fill with 3.5 quarts, start the truck, back it up to the end of the driveway and then right back to where you're working. The tranny will have sucked in that 3.5 quarts by then. Check the stick and add as much as needed to get back up to the top line. Start, back it up, pull it forward and check the level again. If it's low, top it off. If it stays at the same level, you now have the recommended level of fluid in the system (8.5 quarts). Since most of the fluid in the system will be fresh, I would recommend going on a very short drive around your neighborhood to let everything circulate. Try to go 2-3 miles and get into all gears if you can. It'll probably be difficult to get into 4th or 5th at lower speeds, but do your best. If everything feels normal after that drive, go back and do a drain and fill. Go on a longer drive then (10-15 miles) and get it up to highway speeds. If everything feels normal there as well, I would come back and do one more drain and fill. Then, just drive it for a few weeks an monitor everything. If everything is still normal, do one more drain and fill in 3-4 weeks just to be safe. You're going to have 12-16 quarts of DW-1 fluid in this, but it could have been MUCH worse. Best of luck and I'll look forward to hearing your results!

 

[BradC]

Ok guys, update time. For the record the truck has 125k and change. I've owned it since 70k and have kept up diligently with all maintenance.

Work was all completed Saturday, pretty straightforward until I got to the tranny. I do need to order some push pin clip/fasteners though...any ideas on a cheap source online?

Biggest PITAs:

• getting some of the clips on the splash shield to release without breaking. They seemed to release easier when I did the TB.
• getting the wire harness ties off the fan shrouds (broke them all)
• getting the A/C electrical parts off the shroud
• bottom fasteners on radiator shrouds (all were rusted and broke after 1/4 turn. Good thing I had a pile of parts from one of my Miatas I stripped after it was hit and had the right size bolts laying around)
• fluids everywhere! (frame rail/crossmember up front was full of fluid from when it leaked, seemed to randomly rain down from various points

Doing the actual radiator swap was pretty straightforward.

I usually struggle getting old rubber hoses off of their fittings, not sure why, but they always seem fused together. Had no such issues with this.

Lots of fasteners were rusted more than I expected. I live in PA, so I deal with salt and snow, but didn't encounter any that were this bad when I did the timing belt. Bottom fasteners on the fan shrouds and all of the fasteners on the radiator tie downs were crusty.

It ended up being a fitting that failed, as most expected. It was the fitting on the driver's side of the radiator. As I went to squeeze the clamp on that line to remove it, the fitting fell out of the rad. Pictures are of this fitting, both out and laid back in place.

After all was buttoned back up I drained the trans, and about shat myself. Hard to guess the amount, but maybe 1qt minimum of coolant (pure blue and pristine, not mixed with ATF) came out before the ATF. Uh-oh. Filled and drained and it was still ugly. Did one more and was out of fluid to try again. Should have bought enough fluid to do the bucket method but did not see that until after supplies were acquired. The last drain I did, did look strawberry milkshake-like. Honda type 2 and DW-1 do mix to turn pink I guess.

Had it towed to dealer (price I was quoted for full fluid swap wasn't much more than the fluid cost it would have cost over the counter). They ended up running through 24 quarts of ATF before it looked good, by their eye. $200.90 for labor and fluids. Picked truck up today and the fluid looked clean and no signs of coolant mixing. Drove it a whopping 10-15 miles so far, all seems well. ATF looked good still when I got back to work.

Going to monitor the fluid color and do another drain and fill when I change my oil next, maybe before then as I am at 90% oil life on the MM.

I understand fully how lucky I got that it decided to puke it's guts out in my driveway (aside from the ATF everywhere and the ire of the wife at the mess) and not on the highway, at work, or wherever with my 6 month old daughter in the truck. I know I'm not out of the woods yet regarding the tranny with how much coolant was in there, but here's hoping.

 

[IanRTL]

Wow. You absolutely made the right decision to have it towed. Because it was the inlet fitting that failed and the outlet fitting was still intact, the trans was sucking in the coolant rather than the tranny fluid being pushed into the radiator. This could have been WAY worse if you had driven it for even a half a mile without noticing the problem. I honestly think you're going to be perfectly fine with the measures you took. I would ensure to monitor the coolant as well for any signs of contamination. Doing one more drain and fill of the tranny fluid in 1000 miles or so and maybe even draining and filling the new radiator is a great idea. Just goes to show that this problem IS, in fact, a big problem that Honda needs to own up to. It's not just Honda that uses this design, but Honda cheaped out and used a mild steel belleville washer on those fittings rather than using brass, aluminum or stainless. All of this could have been avoided with a few extra cents in initial manufacturing cost. Nonetheless, here's hoping that everything works out well for you. These PA winters with the ludicrous amounts of salt used by PennDOT have the ability to eat a vehicle in not much time at all.

 

[speedlever]

Ian,

Yeah.. but look at his Belleville washer. It's not even rusted that badly. (we've seen worse) This looks like the dissimilar metals corrosion issue working from inside out to me. But the pics are kinda small so it's hard to see much detail.

 

[BradC]

Sorry if these are too big when embedded, but here are better resolution photos that I hosted on my Google drive so you can see the washer better.

Attached picture is the territory marking the RL did in our cul de sac. Glad we recently got the wife a '16 CRV, pictured, much happier I got to steal that for a few days vs. her Civic! New CRVs drive very nice.

Amazing how much of a mess this made. I had ATF in the overflow bottle and coolant and ATF everywhere in the engine bay.

PENNDOT sure does love the salt Ian, it sucks.

 

[IanRTL]

speed, looking at Brad's new pictures, it's certainly pretty bad. The dissimilar metals theory likely held true here, but the many years of PA winters did their worst on these fittings. No matter how tedious one is about spraying the underbody of their vehicle here, it gets everywhere. I'm extremely happy that I replaced my radiator when I did and even more happy for Brad that he caught it before it was too late. There have definitely been worse cases, but at least this one appears to have a happy ending!

 

[BradC]

Forgot to mention...

Please direct people to this post that balk at replacing the radiator when doing the TB service if they intend to keep the vehicle long term.

DO IT! I got LUCKY, you may not. DON'T HESITATE, SPEND THE $150 AND HOUR OF LABOR EXTRA. Hindsight being 20/20 and all, I would do it in a heartbeat now, LOL

 

[Dnick]

Yeah, that washer looks pretty bad to me. (yes, we've seen worse)