3.3TT Transmission and differential oil

[Jerry]

Have any of you change your oil for both of those yet? I wonder what is the mileage typically that I need to reach to change those. Also there is no transmission oil dip stick so checking it is annoying so I have not gotten around to that yet.

 

[CKeeler]

No need to check your transmission oil. It’s lifetime, unless you are in severe service. Severe service schedule is 50k miles.
I haven’t done the diff oil yet. Manual says it’s 75w/85 and to inspect every 36k miles if non-LSD. If you have the LSD replace it every 36k miles

 

[Jerry]

No need to check? Seriously reminds me of those old euro cars with the same set of instructions for transmissions and cracking them open after 100k plus miles the liquid has turn into sludge and it wasn't even driven that harsh compare to my weekend track sessions. Nothing last forever to be honest with you even with oem oil is not a magical unicorn juice meant to last forever. I am planning to change it early at 30k ish to be on the safe side as recommended by my mechanic friend. That is just my opinion if anyone here is more experience in this subject matter please contribute.

 

[oddball]

Modern synthetic fluids have come a long way.
100k miles is a reasonable expectation for current transmission fluid. More frequent if the car is regularly tracked or used for towing.
Same with the diff. Thankfully changing the diff is quite a bit easier.

There's no harm in doing changes early, just a waste of money. And it's a bit more annoying since there's no dipstick.

 

[Jonathan Lasich]

Tramamission fluid longevity is highly dependent on max temperature of the fluid. On a GT-R, 6 speed dual clutch transmission with synthetic fluid, if you exceeded 172F, it required an immediate fluid replacement. In Canada, taxes in and out the door, $1800!!! (10 litres of fluid @ $125/litre)

People who tracked their GT-Rs on a road course, shifting manually (usually not the most efficient way to shift), would regularly exceed 172 degrees F in one track day. People who tracked their cars usually added aftermarket transmission coolers to keep the temps down. If you don't track your car, temps won't get near that, and normally advertised longevity can be expected.

 

[Jerry]

Appreciated for the input yeah for sure I need to work on the cooling component next.

 

[Jonathan Lasich]

I believe that there is an aftermarket engine oil cooler currently available, but I haven't heard of an aftermarket transmission cooler for our car as of yet.

 

[ShannonC]

Same with the diff. Thankfully changing the diff is quite a bit easier.
.

Diff oil is easy to drain (as you would expect) however the filler is difficult to get to. I watched mine being changed and both mechanics said extremely fiddly with little room for access.

 

[AristotsirA]

Diff oil is easy to drain (as you would expect) however the filler is difficult to get to. I watched mine being changed and both mechanics said extremely fiddly with little room for access.

Do you know precisely where the filler location is at? I cannot see it.

 

[ShannonC]

Do you know precisely where the filler location is at? I cannot see it.

This may help >>

 

[AristotsirA]

That definitely helps but for the life of me I cannot see it from any angle. Guess I'll have to schedule an appointment at Kia.

Many thanks!

 

[AristotsirA]

Found it! But it's not something accessible. Drain plug for front differential is yellow "C" while the fill plug is in the front, yellow "D" and conveniently blocked by the power steering pump. Source of photo (minus my lettering) is here: http://www.kstinger.com/front_differential_carrier-548.html

 

[JSolo]

Is the fill plug the same 3/8" square plug cap as most diffs?

Filling the diff and 6mt trans on the G was a bit of a pain until I wised up.

With car on jack stasnds, long hose inserted into fill hole. Run hose through a wheel spoke (or just remove wheel), to side of car. Insert appropriate funnel into hose, slowly fill until it starts to drip out.

No dealing with any messy pumps or trying to angle container into hole. This takes a bit longer to fill, but works out well in the end.

 

[AristotsirA]

I couldn't even access the fill plug to remove it. Ended up pumping in new fluid from the drain plug.

Can't for the life of me actually find a bolt measurement (size and thread pitch) for the drain plug (Genuine OEM Kia Parts & Accessories - 5307039000). Would prefer to have something like a Fumoto valve in its place for the next round, might just have to order a replacement plug and take the measurements myself.

 

[General_Vodka]

I couldn't even access the fill plug to remove it. Ended up pumping in new fluid from the drain plug.

Can't for the life of me actually find a bolt measurement (size and thread pitch) for the drain plug (Genuine OEM Kia Parts & Accessories - 5307039000). Would prefer to have something like a Fumoto valve in its place for the next round, might just have to order a replacement plug and take the measurements myself.

Wait you have a gt2 so you have the lsd right? The plug is in a different spot then non lsd but if you use a small hose you can angle it in a way to use the fill plug. I got to my fill plug just fine

 

[AristotsirA]

Wait you have a gt2 so you have the LSD (Limited Slip Differential) right? The plug is in a different spot then non LSD (Limited Slip Differential) but if you use a small hose you can angle it in a way to use the fill plug. I got to my fill plug just fine

sorry, GT2 AWD, in reference to the front differential, not the rear LSD

 

[Ohiocruiser]

I have awd gt. Replacing front diff fluid is a pita, but doable. Drain plug is obviously is not an issue. But the fill one is something to get to. You can hardly even see it. I used 10inch extension. Also removed the front stabilizer bar, to get more room to get to the fill plug.

 

[dtrail7a]

I have awd gt. Replacing front diff fluid is a pita, but doable. Drain plug is obviously is not an issue. But the fill one is something to get to. You can hardly even see it. I used 10inch extension. Also removed the front stabilizer bar, to get more room to get to the fill plug.

This is definitely the way to go. Thanks for sharing. Changed mine this weekend with a buddy in less than an hour.

 

[JSolo]

I have awd gt. Replacing front diff fluid is a pita, but doable. Drain plug is obviously is not an issue. But the fill one is something to get to. You can hardly even see it. I used 10inch extension. Also removed the front stabilizer bar, to get more room to get to the fill plug.

Is the diff filled like any other diff? Proper level is to overfill it and let the excess drain out?

If so, then using gravity (not gravy!) is probably the easiest. Use a long hose & funnel. Route hose to outside of car (through a wheel or whatever is in the way). Filling is slow, but no monkeying with pumps or other pitas.

I used this method to fill the trans on the g37 (6mt), and the rear end. Both a pain to get at.

 

[Ohiocruiser]

Is the diff filled like any other diff? Proper level is to overfill it and let the excess drain out?

If so, then using gravy is probably the easiest. Use a long hose & funnel. Route hose to outside of car (through a wheel or whatever is in the way). Filling is slow, but no monkeying with pumps or other pitas.

I used this method to fill the trans on the g37 (6mt), and the rear end. Both a pain to get at.

That was what i did. Kept filling with pump, until it started to overflow. And the "hardest" part is not filling, but getting to fill plug, and than putting it back. But i am sure,when i have to do it again, it wont take more than 1/3 of the time, it took first time. Once a year i change differential fluid, and drain and refill the transmission fluid.