Transmission flaring meets Temporary fix.

Hi all. I see a lot of people are having trouble with the transmission flaring when shifting from third to fourth gear on their first run of the day. A friend of mine had the same problem. It was bad. I checked his transmission fluid, the manual way, and the level was spot on. Having an idea that there may some air getting introduced into the hydraulics when the fluid contracted, I overfilled his transmission 1/2 quart. He hasn't has a flair since. I wonder if this is a good solution or if it could cause any problems.

 

Has anyone else tried anything like this?

 

to get a accurate reading the trans temp has to be 102 degrees. the the temp of the fluid off your reading was off

 

I was at 105 degrees when I checked the fluid.

 

ok

 

Thanks for looking out though.

 

@gearcruncher is there any downside of overfilling an AT with the correct fluid?

 

I think so, excessive pressure on the main seal

 

Jus an FYI: the transmission was an ac60F

 

Hi. Are you a trans or Toyota tech?

 

no but looked into this with my old truck when I was doing a tranny flush and looked up some info and thats the info i ran across.

 

Interesting. Thanks!

 

IS gearcruncher a Toyota tech?

 

IDK, but he knows a TON of things about Toyota transmissions and transmissions in general.

 

Thanks for the heads up. I am looking forward to some good information.

 

It seems this gearcruncher knows what is wrong with this transmission. It was s exactly what I thought.

 

I checked this morning and my truck has the same flare when shifting from third to fourth gear. This sucks.

 

Only issue I've heard of on over filling (and I'm thinking more like a quart or two over) was it could cause the fluid to foam and possibly starve the VB at times.

 

Thank you for your input!

 

http://www.sonnax.com/parts/2277-o-ringed-end-plug-kit

This is a good read. While this in not an AC60F transmission (the one in the TRDOR) It is a similar Toyota valve body, and I think the principles are the same. I bet air is being drawn in through the stock bore end caps as the transmission fluid contracts due to cooling down. I would bet that the Rev1 TSB transmission software patch runs some code to try to purge out the air, that got drawn into that circuit, before the valve body relies on that circuit to control the transmission's function. Just my speculation..... Any thoughts @gearcruncher or any other whizzes?