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FL5/DE5 Transmission fluid reference

Blindeye_03

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The airbox in these cars comes out ridiculously easy compared to almost every other car I've ever worked on.

Remove the sensor and pull it back, release two snap-in clips for some other wires, four 10mm bolts, a 5.5mm bolt on the hose clamp, and it's out.

You will waste far more time than that attempting to pump fluid in through that tiny hole with a syringe. I believe the threads are M6?

If you are serious about doing this and want to spend some money and effort to gain any sort of efficiency, I would recommend purchasing something like this:

1772151082454-rc.webp


That could be threaded into the check hole. You'd want to add a rubber washer or similar to form a temporary seal. And double-check what the treads actually are, both size and pitch.

And then getting what you need to hook that up to a fluid transfer pump of some sort. This could be as simple as a repurposed brake bleeder with a large enough reservoir, for example:

https://www.rennline.com/schwaben-3-liter-european-pressure-brake-bleeder-sku-sch-2774831/

You would want to be very careful to measure out the exact right amount of fluid so you don't underfill or overfill. This would take some trial and error at first, doing things with the car completely leveled out. But once you figure it out, you could fill the trans from the check plug with only the front of the car elevated, since you will be putting in a measured amount of fluid.

I do not think this is worth it. There shouldn't be a need to change your transmission fluid every two oil changes. Track use changes things, but using a more appropriate viscosity fluid and making cooling system changes would be a better way to handle that - if the fluid is getting cooked on track, that's never a good thing no matter how often you change it out.

We are somewhat lucky with our cars in that they already at least have a cooler (or warmer, depending) for the trans that exchanges heat with the engine coolant. It's a matter of plumbing to adapt this into a dedicated trans cooler, and the transmission already has an internal pump.

Blackstone will do UOA of transmission fluid. This will give you an idea of how the fluid is performing.

So if you have something to pump or long enough of a hose to fill the transmission via the check hole - what is the harm in doing that? Every single car that I have owned long enough to change the transmission oil I have done this way. Since the extra oil is supposed to drain out of it anyways it seems like the logical place to refill it from.
 
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Are all 3 plugs loosened and tightened the same direction, so loosen clockwise and tighten counter clock wise? or vise versa? Sorry if it was in OP, did to see it.
 
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Spart

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So if you have something to pump or long enough of a hose to fill the transmission via the check hole - what is the harm in doing that? Every single car that I have owned long enough to change the transmission oil I have done this way. Since the extra oil is supposed to drain out of it anyways it seems like the logical place to refill it from.
Quite a few manual transmissions will have a fill hole that serves as the check hole.

Our cars have three, and the check hole is significantly smaller than a fill hole ordinarily would be. That's what makes it difficult to execute. The threads are M6 - not large at all.

Are all 3 plugs loosened and tightened the same direction, so loosen clockwise and tighten counter clock wise? or vise versa? Sorry if it was in OP, did to see it.
All are conventional.
 

Blindeye_03

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Quite a few manual transmissions will have a fill hole that serves as the check hole.

Our cars have three, and the check hole is significantly smaller than a fill hole ordinarily would be. That's what makes it difficult to execute. The threads are M6 - not large at all.



All are conventional.
Ah well then that makes sense now. I remember changing the trans oil on my EP3 and using the fill hole up top too.. Then on my Fiesta ST I filled it on the side/check hole. I didnt do my trans oil changes/flushes on my own when I had a FK8 but I want to on the FL5. I just have to figure out how to get the car lifted and not be deathly afraid of being under the car. I have driven cars off of ramps and thats a legit fear I have along with being squished.
 

Cueyo

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So I did my transmission fluid change with the OEM fluid and was wondering if what I'm experiencing is normal.

Did the drain and fill and refilled with the 2.32 quarts, waited for the oil coming out to be a dribble, then buttoned everything up.

For the first two days after the change the shifts were smoother than they were prior, then end of yesterday and today they've been harder. Not super hard, but definitely notchy, like 3-4 isnt smooth, can feel the gates.

Wanted to ask whether this was normal before I go and check the level.
 


AspecR

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So I did my transmission fluid change with the OEM fluid and was wondering if what I'm experiencing is normal.

Did the drain and fill and refilled with the 2.32 quarts, waited for the oil coming out to be a dribble, then buttoned everything up.

For the first two days after the change the shifts were smoother than they were prior, then end of yesterday and today they've been harder. Not super hard, but definitely notchy, like 3-4 isnt smooth, can feel the gates.

Wanted to ask whether this was normal before I go and check the level.
Difficult to say exactly, but when you say harder do you mean the shifts are harder now than before you did the fluid swap? If so, then that's not normal, the feeling should be consistent with how it felt previouisly.
 

Cueyo

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Difficult to say exactly, but when you say harder do you mean the shifts are harder now than before you did the fluid swap? If so, then that's not normal, the feeling should be consistent with how it felt previouisly.
Yes, they're definitely harder than before, just weird that it took a few days to get to that point.

Does Honda have any additives in the factory fill? My 3-4 was the biggest difference, previously I could just bump it into 4th, now it's conscious effort.

There's the smallest chance that maybe I let too much dribble out? If the level is fine do you have any suggestions? I can't remember if it felt like this when I bought it, the transmission definitely got smoother over time though.
 
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Spart

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So I did my transmission fluid change with the OEM fluid and was wondering if what I'm experiencing is normal.

Did the drain and fill and refilled with the 2.32 quarts, waited for the oil coming out to be a dribble, then buttoned everything up.

For the first two days after the change the shifts were smoother than they were prior, then end of yesterday and today they've been harder. Not super hard, but definitely notchy, like 3-4 isnt smooth, can feel the gates.

Wanted to ask whether this was normal before I go and check the level.
Should've done Red Line or ACDelco. :dunno:
 

AspecR

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Yes, they're definitely harder than before, just weird that it took a few days to get to that point.

Does Honda have any additives in the factory fill? My 3-4 was the biggest difference, previously I could just bump it into 4th, now it's conscious effort.

There's the smallest chance that maybe I let too much dribble out? If the level is fine do you have any suggestions? I can't remember if it felt like this when I bought it, the transmission definitely got smoother over time though.
Hmm, Unless half a quart dribbled out then no, you don't have anything to worry about on that end. Only suggestion is to drive it some more and shift slowly. Next time use higher quality fluid than OEM like AC Delco, Amsoil, Redline or Motul.
 

BgeezySGP_FL5

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I was told that any other fluid other than OEM will void the warranty on the transmission and the synchros warranty any validity to that?
 


AspecR

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I was told that any other fluid other than OEM will void the warranty on the transmission and the synchros warranty any validity to that?
That's inaccurate, you can use any transmission fluid from a reputable manufacturer outside of the OEM as long as it is a GL-4 grade fluid and it meets/exceeds similar specifications to the OEM fluid.

Redline MTL/MT90
Motul Gear 300
AC Delco(GM) Sychromesh
Amsoil 5W-30 Manual Synchromesh
Driven STF Synthetic Synchromesh

The above list is what owners have recommended over the OEM fluid, I have Redline MT90 in my car. AC Delco Synchromesh is an OEM fluid for GM vehicles and has been used with great success across the board. A dealership cannot deny warranty service for swapping to a different fluid unless that fluid was a lower grade than OEM and directly caused an issue within the transmission
 
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BgeezySGP_FL5

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That's inaccurate, you can use any transmission fluid from a reputable manufacturer outside of the OEM as long as it is a GL-4 grade fluid and it meets/exceeds similar specifications to the OEM fluid.

Redline MTL/MT90
Motul Gear 300
AC Delco(GM) Sychromesh
Amsoil 5W-30 Manual Synchromesh
Driven STF Synthetic Synchromesh

The above list is what owners have recommended over the OEM fluid, I have Redline MT90 in my car. AC Delco Synchromesh is an OEM fluid for GM vehicles and has been with great success across the board. A dealership cannot deny warranty service for swapping to a different fluid unless that fluid was a lower grade than OEM and directly caused an issue witrht the transmission
Awesome thank you!
 

Cueyo

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Hmm, Unless half a quart dribbled out then no, you don't have anything to worry about on that end. Only suggestion is to drive it some more and shift slowly. Next time use higher quality fluid than OEM like AC Delco, Amsoil, Redline or Motul.
So how was the factory fill so smooth? I understand replacing with a better fluid, but the car shifted like butter 90% of the time.

I will note that it's fluctuated in feel over the last day, and the longer drives get, the worse it feels...

Throwing her up on the lift tomorrow and double checking...
 

AspecR

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So how was the factory fill so smooth? I understand replacing with a better fluid, but the car shifted like butter 90% of the time.

I will note that it's fluctuated in feel over the last day, and the longer drives get, the worse it feels...

Throwing her up on the lift tomorrow and double checking...
Good question, I have no idea. Best to just check it like you’re already planning
 
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Spart

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So how was the factory fill so smooth? I understand replacing with a better fluid, but the car shifted like butter 90% of the time.
I did not find the factory fluid to be smooth, in fact it felt like there was inconsistent and excess synchro effort.

Switching to Red Line MTL made all of that go away.
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