[capt_slow]

My LCI REX is closing in on 30K and started looking into replacing the transmission fluid. Stumbled upon this really good DIY by evilchargerfan. The only problem is it was done on a early model car that still had a fill plug.

I've read you can fill using the breather vent at the rear of the tranny, but with the REX it's a tight squeeze to access the vent. Has anyone been able to do this service on a REX without removing the right-side output shaft?

[nilknarf]

I'm in the same boat. I have a 2017 rex and am now at 41k. Quite annoying that they removed the fill plug. Anxiously hoping someone has figured this out.

[Dafireman12]

Same boat. I’ve tried to locate the vent with no success…

[star63]

I filled mine through the drain hole. I used a pump that I normally use when filling oil to my outboard's lower unit. I bought a spare drain plug and drilled a hole for a fitting.

[star63]

[nilknarf]

star63, thanks for posting. I think your way is the answer. I found a video where a guy does the same thing, except it appears that he just wraps tape around the end of his hose and plugs it into the drain hole:

After filling, he then rips the hose out and quickly inserts his drain plug. The video doesn't actually show the filling process, but he describes it. If I were going this route, I'd probably try to find a drilled rubber stopper to put in the drain hole and run the hose through.


So star63, after filling, you had to remove the drilled plug and then insert the original plug, right? I'm trying to figure out how to do this with minimal loss of fluid. Was thinking one of these might do the trick, but will need to determine the correct size: https://www.valvomax.com/products/qu...il-drain-valve

With the failure rate of these transmissions and the amount of metal shavings I've seen on the magnetic plugs, I'd recommend changing this oil every 20,000 miles.

[star63]

Originally Posted by nilknarf

So star63, after filling, you had to remove the drilled plug and then insert the original plug, right? I'm trying to figure out how to do this with minimal loss of fluid.

Yes, I used my thumb to cover the hole when changing the plugs. I lost less than a spoonful of fluid.

The Quick Twist drain valve would make it even easier, I believe.

[nilknarf]

From what I've been able to gather, the plug appears to be 22M x 1.5. After giving the quick twist plug more thought, I don't think I want to lose the magnetic properties of the drain plug, since I've seen some photos with significant accumulation of metal particles on them.

Is the white fitting a swivel that you have on your hose?

Also, what fluid did you use? I have a extra bottle of Motul Gear 300 75W-90 and it seems to meet every spec of the BMW G1 fluid except its 90 instead of 85. Don't really think that should make much difference and I've seen that Liqui Moly recommends their 75W-90 for our transmissions.

[capt_slow]

It's as if we need a Fumoto drain valve that is magnetic.

[star63]

Originally Posted by nilknarf

Is the white fitting a swivel that you have on your hose?
Also, what fluid did you use?

No, it's just a universal hose fitting with M10x1 thread at the other end. I drilled and tapped the same size thread to my spare drain plug.

I used synthetic 75W-90 fluid but can't recall which brand.