BG Tranny Flush - Lost Calibration? (1 Viewer)

[100s]

Cross posted over on clubLexus. Should have probably done it in my own garage after this insanity.

Dropped my 2022 Gx460 with 46,977 for a transmission flush (they use BG) at the dealer at 8AM this morning. At 4:30 the service manager called me to inform me that they needed to keep the car until tomorrow because they suspect that the calibration is off on the tansfer machine and they aren't sure that they put enough or too much fluid in my rig. I tried to keep it together, knowing that the service manager or advisor probably doesn't know much. From what I know, the BG system uses the rigs own transmission pump to exchange the fluid in most cases. My fear here is that the trans was over or underfilled while it was running at temp. I pressed the service manager as to if they had follwed the FSM procedure and he didn't really know much. I am going to ask to talk to the tech tomorrow. Exceptionally nervous that they may have run my trans with low fluid. When I look a that unit, it seems pretty simple with just pressure gauges and a sight glass to determine if the fluid is "clean". I know on the A750F you really don't want to run it much more than a quart low.

Thoughts? Opinons? Anyone familiar with the BG flush on the A760F?

 

[Rednexus]

That's quite a strange response from the dealer. As far as I know, the A760F has a level plug on the transmission pan, just like the A750F does. They should be able to open the level plug and quickly tell if the transmission is under or over filled (fluid flows out if it's over-filled, if it's under filled, nothing comes out).

If it's under-filled, they can easily add transmission fluid via the 24mm fill port on the PS side of the transmission, until it starts flowing out the level plug. That's how I do it on my A750F when I DIY transmission fluid exchanges. On a lift (which the dealer has), it would be 10 minutes of work to check the level plug and top off the transmission. The only reason I can think they might need to keep the rig overnight is 1) they don't have a pump for manually adding trans fluid via the fill port or 2) the calibration issue was uncovered late in the day and they weren't able to check the level and top off prior to the shop closing.

In terms of running it under-filled - probably not an issue unless it was way under-filled. I'd quiz them in terms of how they checked the level, how much it was under-filled, how they added additional fluid, and why it was necessary to keep the rig over night. Then, see what they say, and how much sense it makes.

Not the first time I've posted this - and probably not the last time - but it's pretty darn easy to DIY the fluid exchange with a Motive Power Fill (note the 460 procedure is a bit different if you don't have an external cooler, and the 460 also has a thermostat that needs to be pinned open).

 

[100s]

They did call me an hour before closing. I did get an alert that my doors were unlocked and front windows were down usually indicating it was in a stall, and then another when the hood was opened. Wish I would have captured the exact time on those. The app says 17 hours ago, so that would put the hood at about 4PM, In a stall at 1PM. I would hate to think that instead of "we ran out of time" this whole calibration and fluid level issue was devised. I watched the instructional videos on the BG exchanger and there (as far as I could tell) is no indication other than color and pressure of fluid for status what-so ever, no volumetric measure of fluid in/fluid out. I know this is used all over the place (one of my 100's has had its A750F exchanged this way several times) so I'm assuming they must have to check the fill level plug intermittently during the service since it is "sealed".

 

[Rednexus]

They did call me an hour before closing. I did get an alert that my doors were unlocked and front windows were down usually indicating it was in a stall, and then another when the hood was opened. Wish I would have captured the exact time on those. The app says 17 hours ago, so that would put the hood at about 4PM, In a stall at 1PM. I would hate to think that instead of "we ran out of time" this whole calibration and fluid level issue was devised. I watched the instructional videos on the BG exchanger and there (as far as I could tell) is no indication other than color and pressure of fluid for status what-so ever, no volumetric measure of fluid in/fluid out. I know this is used all over the place (one of my 100's has had its A750F exchanged this way several times) so I'm assuming they must have to check the fill level plug intermittently during the service since it is "sealed".

That's certainly a strange explanation. Something not adding up. IMO it's almost negligent to do a fluid exchange on a Toyota and not check the level at the end via the overflow plug. Again it takes minutes to check and top off. Otherwise the process relies on both 1) perfect accounting of fluids in and fluids out and 2) the pre-exchange level being perfect.

I'd still quiz them on what happened, what they did, and DIY your own level check at home.