Inline transmission filter after rebuild - how important?

Joined
Mar 20, 2021
Messages
4
Points
1
Make
Kia
Model
Forte
Year
2018
Miles
10,391
Engine
Hyundai Nu 2.0L CVVL (G4ND) MPi
Kia Forte 2018 - 2.0 L Sedan Automatic.

I recently replaced my transmission with a manufacturer rebuild/remanned (direct from Kia). Job went fine mechanically,
but I have yet to program it with my Autel and fire it up. Want to make sure I have this right first.

This is my first transmission replacement job and I am hearing that adding an inline filter is a decent idea to protect from fine particles that can form during break-in of a remanufactured transmission. I have spoken with others who are members of Kia Optima communities who have had significant success with installing a Magnefine filter on their Kia Optimas with long-term success. This allows for a serviceable filter that can be changed during transmission fluid changes. Modern kia's don't have a pan that you can drop. There is a real filter inside the AT case (not mesh, a real filter) but it is non-serviceable, only changeable during a rebuild.

As much as I would like to do this, the situation is different on the Kia Forte. There isn't much room at all between the send/return lines coming out of the transmission and the warmer/cooler attached to the front of the transmission case. Each hose is not much more than perhaps 6 inches in length. I've attached an image showing the two hoses. There's just not enough space to fit the 5" length magnefine, I've cut the hoses and tried, it's just too tight, it's not going to fit.

MVIMG_20210812_234048.jpg

Now, the only other option I have found is a comparable Honda filter that also has 3/8 inch barbs, and it is about 3" in length (while the magnefine is a larger 5"). That two inch difference would certainly allow me to squeeze that filter into one of these lines. The magnefine was close, but the smaller Honda filter should fit nicely. In addition, it also has a relief valve just like the magnefine in the event that the filter clogs. I've attached a picture of that Honda filter as well, including an image from a Honda forum showing the valve inside the filter (someone cut one open).

61+WbKL51bL._AC_SL1500_.jpg
Honda 25430-PLR-003 AT Filter 4.jpg

Honda recommends this inline filter for all of their Accords and Civics from 2003 up to 2017, which includes everything from 4-speed, 5-speed, and CVT transmissions. It's recommended for all of them, so it seems like a fairly multi-purpose AT filter.

Now, of course, I don't have a Honda. I have a Kia forte. But the Civic is the same class of car as a Forte (for whatever that is worth) and this filter they sell is meant to cover a wide variety of transmissions. My Kia has a 6-speed AT. In addition, as stated, the Honda filter includes a pressure relief valve, just like the magnefine.

Is it a gamble to try and use a Honda AT filter on my Kia, even if the spec may be similar?

Or is it better to take the more conservative route and say "let's not mess with it" and simply forgo the filter altogether?

Of course, Kia service information does not recommend a filter, but it's my understanding many rebuilders do and it is a common practice for transmission longevity.

This would allow me to change the filter every 25k miles along with the fluid, which I had planned on doing.
 

billr

wrench
Staff member
Joined
Mar 12, 2007
Messages
7,331
Points
63
Since these are slip-on hoses (barbs/clamps), you should be able to use new, longer, hoses and put in just about any type or size filter you want, located wherever it is convenient. Hose is cheap (clamps, too, but existing can re re-used). What am I missing?

I don't think an add-on filter is necessary, but agree that it is convenient for changing periodically. I, though, would be looking for a spin-on filter/base to plumb in there.
 
Joined
Mar 20, 2021
Messages
4
Points
1
Since these are slip-on hoses (barbs/clamps), you should be able to use new, longer, hoses and put in just about any type or size filter you want, located wherever it is convenient. Hose is cheap (clamps, too, but existing can re re-used). What am I missing?

I don't think an add-on filter is necessary, but agree that it is convenient for changing periodically. I, though, would be looking for a spin-on filter/base to plumb in there.
I'll admit, I never thought of that. Now it seems like I just need a mount point. Thanks.
 

bp042665

transmission guy
Joined
Nov 26, 2012
Messages
743
Points
18
Location
Iva South Carolina
yes in line filter is great we do them at my shop put it on the return line in a easy location you can mount it anywhere just add more line and make sure it is transmission line just not any will do
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
12,273
Points
83
Location
St-Hyacinthe, Quebec, Canada
just because I have time off I looked into a few mounting kits, this one looks good for your forte

this one comes with the filter and hosses so hence a bit more expensive, but should save time for the 20 bucks more.

link here
 
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