Transmission leaking after tow

I have a 2007 4wd with an automatic transmission that has 110,000 miles on it. I had my transmission flushed at a non-Toyota shop about 3 months ago; I had it flushed just for maintenance not to address any problems. Prior to my flush I towed a 4000 lbs travel trailer with no problems. Yesterday I towed for the first time since the flush but it was only an approximately 1800 (RZR4 on a flatbed) for 400 miles. I felt no problems in the power delivery, nothing seemed out of the ordinary. I went to unhook my trailer and I felt oily fluid (it was night). I grabbed a flashlight and observed that my rear axle, springs, and part of gas tank, also had fluid on them. I noticed that my transmission was coated on both sides with a thin layer of fluid; this coating covers 90% of both sides and also around the transmission pan. I don't believe the pan is leaking that is just where some pooling occurred on the lips of the pan. I don't know much about "sealed" transmissions. It is my hope that there is a vent and my transmission was overfilled during or after the flush by a technician who does not know about "sealed" transmissions. My fear is that I blew a seal that might be at the top of my transmission where I cannot see.

After I unhooked I went out and tested the drive. All the shifting was normal, and reverse engaged normally. If i did not see fluid I would not know anything happened.

I only have the stock transmission cooler and all the lines to and from the transmission are fine.

Any help or suggestions would be great.

 

I think the first step is to check the AT fluid level.
Then, see if you can locate the exact source of the leak. Assuming that the fluid is, in fact, ATF, it could be coming out the dip-stick tube, or maybe the vent, if there is one.

Since ATF is used in the power steering system, check that level, as well.

 

The 2nd gens have a trans pan that unbolts correct? Maybe the tech didn't properly torque those bolts and the heat from towing caused fluid to get past the gasket.

 

I don't have a dip-stick to check the level but I am not sure about a vent. I checked the other fluids and everything else looks good.

 

Yes it does have a pan but the tech did not remove the pan, he just hooked into the cooler lines for the flush.

 

He didn't replace the filter in the trans?

I'm not sure, it could've been overfilled.

 

He did not replace the filter. I am hoping it was overfilled and the heat caused it to overflow from a vent. I just don't know if there is such a vent and I can't seem to find a simple way to check the fluid level. The fluid appears to be coming from the top area of the transmission where I cannot clearly see. I hope there was not so much pressure that the fluid forced out the pan gasket. I am hoping someone knows if there is a vent and might be able to direct me to where it is.

 

there has to be a vent, the trans can't operate as a closed system, but I don't know where it is.
Someone who knows more 2nd gen stuff should chime in soon.

 

I just found a thread with a possible location behind the left cylinder bank at the firewall; I'm checking now. Thank you for your responses.

 

http://www.villagetoyotaparts.com/s...sembly=356173&ukey_make=1021&ukey_model=14412


Part # 3510-4B

 

I was able to locate the vent and it does look like it was the source of my leak. I am going to install a larger transmission cooler and take it to the dealership and pay them to check my fluid level. Thank you for the chart it helped.

 

I had a very similar experience - I found fluid on my trailer chains and looked underneath to find a thin coating on just about everything. There were a few drips coming from different places, so when I got home I wiped everything off and let it sit overnight and checked it again in the morning - nothing. No drips. The A/T fluid level is good, so there must be a small leak somewhere that only happens under stress. I don't want to pay someone to look at it and do a bunch of unnecessary work, so I think I will just keep an eye on it, especially when I am towing a trailer.