Hi, 2 days ago I posted about ATF in the vacuum line to the front axle actuator. I went ahead and replaced that yesterday, and that part is good. the axle locks now like it should. At the same time I drained the excess ATF from the transfer case, because apparently the seal between the transfer case and the transmission is bad, causing the transfer case to over-fill. Everything seemed fine, so I didn't drive it anywhere yesterday.

Today: went to drive it, and when it is suppose to shift into 3rd gear, it just revs really high like it isn't catching properly. I went back and checked the fluid level in the transmission, and it was pretty low, I guess the transfer case must be full again. Filled it up.... no better. I find it highly unlikely that I could have burned out third gear in less than half a mile, sue to low fluid. It never did shift correctly.

Is it possible that I upset something in the vicinity of the transfer case vacuum switch? What causes the transmission to shift into the various gears?

I never had a problem with the transmission before yesterday. Gear 1 and 2 are fine. What should I look for next?

Please Help!

 

Very doubtful it was anything to do with the transfer case switch. The PCM controls transmission shift points.

Not shifting into 3rd, and slipping, the SES light should be illuminated and a DTC set in memory. Have someone retrieve the DTC's and post them here in the order they were retrieved. Check the transmission fluid in park with the engine at idle, when it's at operating temperature. If you check it when it's cold, make sure it's at least to the low part of the "safe" range. With cold ambient temperatures, it may take up to 20 miles before the transmission fluid is up to operating temperature. When was the transmission fluid & filter changed last?

 

The filter hasn't been changed since I have owned it. That has been about 4 years now. No idea before that. The check engine light is not on, but I don't have access to a scanner, so I don't know of any codes. I will call around tomorrow and see if anyone in town here can scan it at a resonable price, as the mechanic I usually use is about 50 miles away. It would take awhile to get it to him at 20mph. The strange thing is that it was totally fine before yesterday, and not fine today. The fluid is in the safe range, but wasn't when I first checked it.

 

Without an SES light, there will be no hard faults present, but there may be something in the pending or history files. You can try a fluid & filter change to see if that helps. Really should be done every ~36K miles. If it doesn't help, have a reputable transmission shop take a look at it.