Hey all,

I apologize in advance for the long post and thank you for reading. I tend to ramble.

I drive a 2010 AT Fit sport. 165k miles and generally well maintained, with the exception of the transmission...

I purchased the car from my father who was the original owner at about 110k miles. At that point, he had never changed the transmission fluid, and by the time I got around to trying to change it, I was getting "oh if it's never been changed you shouldn't change it now" speech from shops. Well, at about 120k miles I had a strange leak that forced me to use some random gas station fluid instead of the recommended honda fluid. I took the car to the dealer and they could not find any evidence of leaking, and I chalked it up to a leak at one of the sensors that must have been real small and with the new foreign fluid it "sealed" itself. The dealer also told me at that time to not bother with a transmission flush.

Fast forward 45k miles of 0 leaks and extremely reliable driving, and I think my transmission finally gave up on me. I was driving on the highway two days ago hovering between 70-85mph (mostly 80+) for about 2 hours. I noticed that my RPMs were slightly above normal, although I wasn't accelerating. All of a sudden, my RPMs shot up to redline as if I was in neutral. I let off the gas and once the RPMs dropped, it seemed like the car tried to go back into gear but it felt like I "hit a wall" (much like the feeling of fuel cut). I immediately popped it into neutral to let it idle, while still cruising around 60mph. After a few seconds of idle, I put it back and drive and it went to redline again, then "hit a wall" once I let off.

So I pull over and just let the car idle. I could smell transmission fluid from inside the cabin. After a couple minutes, I put it back in drive and was able to get up to about 15 mph and it even changed gears. Luckily I was right at a rest area and was able to park and get towed home. I did check under the hood and I could smell transmission fluid very strongly, but the level was actually fine on the dipstick. Overfilled, even.

The next day, I started it up and drove down the block, getting up to about 30mph. I drove and shifted fine, but there was definitely a strange "whining" noise that is present no matter if I'm accelerating/decelerating/in drive/in neutral. Needless to say, I do not plan on driving it until getting it check out.

Here are a couple questions:

1) How hard is it to remove the transmission? (I'm pretty mechanically inclined, but it's been a while since I've worked on cars) I assume I will want to have everything inspected by a shop, and am willing to just bring them the tranny itself to save on some labor.

2) Do the synchros on these transmissions fail normally? If so, what is the likelihood that what happened to me is a busted synchro? Are there readily accessible upgrade options including a taller 5th gear for better cruising at highway speeds?

3) Could this be a faulty solenoid? At no time during any of this did my CEL come on or did the "D" flash showing me an error.

4) In the event I need a rebuild, what can I expect to pay a shop? I know transmissions are pretty expensive, but this is a 9 year old car with pretty high mileage. Doesn't seem worth it to invest more than $5-700.
4a) Anyone have experience with swapping to manual transmission? After a quick search, it seems like I can get a used m/t cheaper than an a/t. While I know this will be more work, it's something I am considering as I prefer m/t anyway.



Again, thanks for reading this far. I always tend to make these posts much longer than they have to be!

 

I have to preface the below suggestions with the fact that I am NOT a mechanic. This is merely a suggestion of what I would do....

If it were my car, I would drain as much fluid as possible and replace with Redline D4 ATF. I would then drive it gently to circulate the fluid and I would then drain as much as possible and replace with more D4. I would do this a total of 3 fills and then see how the transmission behaves.

If that doesn't fix it, I would source a used transmission from a junk yard that offers a short warranty and replace the transmission.

Honda has changed their fluid to help meet current EPA requirements and it's not the same viscosity as what came in your car from the factory. The Redline D4 is a closer match to what came in your transmission than the current Honda fluid.

Good luck!

 

I agree with GAFIT that probably cheaper to buy a used transmission (little grandmother drove to church) than it is trying to replace a synchronizer, etc. I have a '09 Civic and '11 FIT and I have used the HONDA DW-1 ATF (~$90 / case of 12 bottles) at about 30K mile intervals. Everything seems to be operating well at 117K - Civic and 73K - FIT.

Check the magnetic drain plug for metal parts. A buddy of mine ruined the 5th gear syncho on a '10 Sport MT (ineffective clutch activation system) and the dealer said that the part was not available at the time in USA, so, true or not, replacing with a whole use transmission (they want the old one - core charge) seems easier / quicker. Probably should check the AFT condition in the used one before putting any miles on it (is it full?) and then cycle out everything using the olde 12 x one liter bottle flush as described in the Maintenance forums here. Start out as new as possible.

Changing the ATF on the HONDAs is easy. The Tundra took 6 hrs of drain / fill / heat up / drain / etc essentially impossible for the common man.

 

I had to do a bit of research for this as I wasn't sure when the changeover happened...

'09 Fit as well as your '09 Civic call for Honda fluid Z1. In those cars I would use Redline D4. That is the correct viscosity.

Starting in 2010, Honda changed to the DW-1 spec which is thinner weight to help with fuel economy and emissions. Hopefully Honda also redesigned the transmissions for this new fluid. Honda says the DW-1 is backwards compatible, but a good friend of mine had immediate transmission problems when he switched. He started getting flares on gear changes. A switch to Redline immediately solved the issue. If your Civic is happy with the DW-1 than all is probably good.

That being said, if I had a Honda built in '09 or back, I wouldn't risk changing viscosity.

To the OP, it is highly likely that your top off with an unknown fluid is what caused this issue to come up down the road. Honda automatic's are very particular when it comes to fluids. Normally I would say Honda OEM fluid only and not recommend Redline. Only recommending Redline in this case because Honda no longer offers the Z-1 fluid.

 

Just did a bit more research...

It is rumored that DW-1 is semi or full synthetic. So, if you have a Honda automatic and it is doing fine with the DW-1, that is a good thing as DW-1 is likely a better fluid.

I only mentioned the potential issue since a good friend found his 2003 Civic didn't like the DW-1.

 

I thought the recommendation is to change the transmission fluid/filter at 120k miles?

In any case I would probably just trade the car in and play dumb about the tranny.
It isn't worth messing with them or getting them replaced. Transmission has its own computer that usually has to be programmed by the dealer.

 

Again, talking about my buddy's MT failure / swap out with a used one, it worked out for him. He had 150K-ish on his '10 FIT Sport (car is in perfect condition) and the dealer claimed that the used tranny had 37K on it and his total bill was around $2000 with returning the damaged one. I have no idea what and AT would do to the costs but I always look at these situations as "dealing with the devil you know versus dealing with one you don't". The next car, FIT or not, you buy might have a bum tranny in it and you're right back to the same place. I would nail down the costs of replacing your AT with a used one, sleep on it, and then decide.