Tenshi
Senior Member
- Joined
- May 8, 2018
- Threads
- 3
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- 132
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- Location
- Phoenix
- Vehicle(s)
- 2017 Honda Civic Si Coupe
- Vehicle Showcase
- 1
- Thread starter
- #1
Hello all,
I learned a lot from this community and wanted to do my part to contribute. I recently changed my manual transmission fluid on the 2017 Si. Like with the engine oil, I chose to change it earlier than what is recommended by Honda. I'll list a few reasons why I did this but this post isn't meant to kick the dead horse on the subject.
I want to share a few things I discovered while preparing for the job. There are a few helpful posts on the subject but I found them lacking some details. This is not a step by step guide by any means.
The 2017 Si has a limited slip differential. It is common for LSDs to require an additive packet for their gear oil. The Si has a Helical Limited Slip Differential that is gear based and does not require special friction modifiers or additives. The differential is built into the transmission and they share the same fluid and sump. By changing the manual transmission fluid, you are also servicing the differential. I wanted to change both the differential fluid and MTF and it was only after researching the car did I discover they are one in the same.
The drain and fill bolts are easy enough to find. The level check bolt was missing from the other write-ups on CivicX. Is it necessary to use the level check hole for the process? Probably not. The car requires 1.9 Quarts of Genuine Honda MTF and I doubt the jump to 2.0 would do any harm but my notes on the subject are below:
Drain bolt is easy to find. Round bolt with square socket and a 20 mm crush washer. 32lb/ft
Fill bolt is also easy to find. Directly behind/beneath the air box. It has the same square socket but no crush washer. No need to remove the air box, fill hole can be reached with a ratchet extension and a long funnel. 32lb/ft -Says to use liquid gasket to threads, I did not and no leaks yet-
Level check bolt: Allows excess fluid to drain out of the transmission. This allows the correct amount (1.9 qt) to stay in place during filling-car must be level or darn near. 6 mm crush washer 9lb/ft
Level check bolt Location: While under the car and looking at the transmission drain bolt, start counting the horizontal bolts holding the two sides of the transmission case together. These bolts form a line at the bottom of the transmission going from front to back on the car. Going forward, you should see 3 bolts in a straight line, right before the 4th bolt, there on the corner. There is a little nub of metal there as you round the corner and come to the 5th bolt.
Right next to that 5th bolt is a much smaller, 10 MM bolt head. This is your level check bolt. Here is a link to the crush washer replacement. This also shows a diagram of the transmission and helps with where you should be looking.
https://www.hondapartsnow.com/genuine/honda~washer~sealing~6mm~90442-r7g-000.html
Drain bolt crush washer is here: https://www.hondapartsnow.com/genuine/honda~washer~drain~plug~94109-20000.html?Make=Honda&Model=Civic&Year=2017&Submodel=&Filter=(bt=1,11;et=2,8)&Location=mt-clutch-case,3076250,10
Other notes and justification:
I had to go to the local Honda dealership 3 times for the correct washers. I was first given 18 mm crush washers. These do not fit the 20 mm drain bolt so I went back, bolt in hand, for the correct one.
Even after 3 visits I was not able to get the 6 mm crush washer. I ended up using the factory one- it was flawless due to the low torque on the bolt. I prefer to change it out so I did order some from the link above for next time.
Why did you change your MTF fluid at 5,000 miles Tenshi? Bumper sticker answer is 'Fluid is cheap, transmissions are not'. This is an entirely new system, first Si with a turbo and LSD. There is simply not enough data or history (yet) to determine how long this system will last. I made this choice for my personal vehicle and am not suggesting it is the right thing to do.
As with all things internet, I expect that if there is a mistake in here I'll be told about it. I don't mind editing this post if better information becomes available. This is for the fellow DIYers- I hope I saved you some time.
Thank you.
I learned a lot from this community and wanted to do my part to contribute. I recently changed my manual transmission fluid on the 2017 Si. Like with the engine oil, I chose to change it earlier than what is recommended by Honda. I'll list a few reasons why I did this but this post isn't meant to kick the dead horse on the subject.
I want to share a few things I discovered while preparing for the job. There are a few helpful posts on the subject but I found them lacking some details. This is not a step by step guide by any means.
The 2017 Si has a limited slip differential. It is common for LSDs to require an additive packet for their gear oil. The Si has a Helical Limited Slip Differential that is gear based and does not require special friction modifiers or additives. The differential is built into the transmission and they share the same fluid and sump. By changing the manual transmission fluid, you are also servicing the differential. I wanted to change both the differential fluid and MTF and it was only after researching the car did I discover they are one in the same.
The drain and fill bolts are easy enough to find. The level check bolt was missing from the other write-ups on CivicX. Is it necessary to use the level check hole for the process? Probably not. The car requires 1.9 Quarts of Genuine Honda MTF and I doubt the jump to 2.0 would do any harm but my notes on the subject are below:
Drain bolt is easy to find. Round bolt with square socket and a 20 mm crush washer. 32lb/ft
Fill bolt is also easy to find. Directly behind/beneath the air box. It has the same square socket but no crush washer. No need to remove the air box, fill hole can be reached with a ratchet extension and a long funnel. 32lb/ft -Says to use liquid gasket to threads, I did not and no leaks yet-
Level check bolt: Allows excess fluid to drain out of the transmission. This allows the correct amount (1.9 qt) to stay in place during filling-car must be level or darn near. 6 mm crush washer 9lb/ft
Level check bolt Location: While under the car and looking at the transmission drain bolt, start counting the horizontal bolts holding the two sides of the transmission case together. These bolts form a line at the bottom of the transmission going from front to back on the car. Going forward, you should see 3 bolts in a straight line, right before the 4th bolt, there on the corner. There is a little nub of metal there as you round the corner and come to the 5th bolt.
Right next to that 5th bolt is a much smaller, 10 MM bolt head. This is your level check bolt. Here is a link to the crush washer replacement. This also shows a diagram of the transmission and helps with where you should be looking.
https://www.hondapartsnow.com/genuine/honda~washer~sealing~6mm~90442-r7g-000.html
Drain bolt crush washer is here: https://www.hondapartsnow.com/genuine/honda~washer~drain~plug~94109-20000.html?Make=Honda&Model=Civic&Year=2017&Submodel=&Filter=(bt=1,11;et=2,8)&Location=mt-clutch-case,3076250,10
Other notes and justification:
I had to go to the local Honda dealership 3 times for the correct washers. I was first given 18 mm crush washers. These do not fit the 20 mm drain bolt so I went back, bolt in hand, for the correct one.
Even after 3 visits I was not able to get the 6 mm crush washer. I ended up using the factory one- it was flawless due to the low torque on the bolt. I prefer to change it out so I did order some from the link above for next time.
Why did you change your MTF fluid at 5,000 miles Tenshi? Bumper sticker answer is 'Fluid is cheap, transmissions are not'. This is an entirely new system, first Si with a turbo and LSD. There is simply not enough data or history (yet) to determine how long this system will last. I made this choice for my personal vehicle and am not suggesting it is the right thing to do.
As with all things internet, I expect that if there is a mistake in here I'll be told about it. I don't mind editing this post if better information becomes available. This is for the fellow DIYers- I hope I saved you some time.
Thank you.
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