I drove my wife’s 2005 Jeep Liberty to work last week and when I got several blocks from my destination, the engine started to rev up even though my speed did not increase. Yes, the transmission started slipping! We’d had the car several years with no previous problems and even though it had 160,000 miles on it, it appeared to have been well cared for and had been reliable.
Having little experience with automatic transmissions, I had it towed to a well established transmission shop that had been around ever since I can remember. A few days later they called and said their diagnosis was that it needed to be completely rebuilt and the cost would be between $3,300-3,400. That was a shock to the system and more than I was prepared to pay. I figured now was when I was going to learn how to rebuild an auto trans.
After doing a lot of reading and using my trusty scan code reader, I found that the symptoms were consistent with a plugged filter. Every gear was throwing a code that the sensed speed of the output was inconsistent with the input speed. It made more and more sense that this was simply the pump was starved for transmission fluid.
I went online to my AMSOIL account and ordered 5 quarts of Signature Series Multi-Vehicle Synthetic Automatic Transmission Fluid (ATFQT) and a filter. When it arrived the next day,
I jacked the Jeep up and put it on a jack stand and dropped the pan. The fluid looked more like motor oil in the bottom of the pan, not the clearish red that showed up on the dipstick. The filter had bits of RTV and a thick film of crap covering it. Whomever last pulled the pan used way too much sealant and it was coming off in chunks and clogging things up.
I reinstalled the filter and pan. I let it sit for 24 hours per the instructions on the sealant tube just to be sure there were no leaks. Then I filled it with the correct Automatic Transmission Fluid (ATF).
The results, the transmission shifts and pulls better than ever since we purchased the vehicle! The moral of the story is you might well be able to save yourself some serious money if cover the basics yourself. Do not rely on the “Pros” unless you have a trusted mechanic that you know is honest, too many are out there to take advantage of us all.