Careful attention should be given at the end to measuring the tranny oil level with the motor warm and running. It is really easy to get the level way off if you measure it cold with the engine off - you could be 2-3 quarts low. I think that was also an issue with my explorer and may have contributed to the noise, the trans level was at least 2 quarts too low.
Cheers,
Martin
This is just to add on refilling the tranny and checking the fluid level properly and what can happen if it is not filled to capacity or full.
A couple of months ago, I took my vehicle into a local tranny shop to have a tranny tune-up done, new filter installed and drain the tranny pan fluid (6-7 quarts of new fluid). I paid for the service ($150) with another guy who disappeared right after that. While the tech worked on my truck, I sat in the front lobby/office of the shop. I couldn't see him visually because of the coverings on the office windows, but I could hear him working on my vehicle with the vehicle lift going up and my engine off. Next I heard him taking the pan bolts out with an air ratchet. Then it was kind of quiet for a bit and then I heard the tech re-installing the pan bolts. Next I heard the lift coming down and he started my engine up and brought out my truck saying " you're all set" and he never took it for a test drive, which I thought was quite strange. Most tranny shops I have been in over my 3+ decades of driving always test drive the vehicle after service has been done to the tranny. I asked the tranny tech if he found any problems in my tranny or anything in the pan and he said "no", "everything looked great in there". So I took my vehicle up the street for a test drive to make sure everything is good, it wasn't! As soon as I started picking up speed on a bridge on ramp, the tranny slipped from 2nd shift into 3rd and I said "WTF"! I drove the vehicle down to the next off ramp and turned around and headed back to the shop, not happy but keeping my cool. The tech who worked on my vehicle was there by himself and I told him that the tranny slipped up the road from there. He looked surprised, sort of, then took my vehicle back into the shop and I went and sat in the office again, same place as before. I heard him raise the lift with my engine running this time (which he didn't do the first time, engine was off the first time as he worked on it), then I heard the tranny being shifted thru each gear (which opens that solenoid for each gear and allows more tranny fluid into the tranny/solenoids) and the engine revving up a bit. A short time later, he drove my vehicle out of the shop. A few minutes later, the tranny shop owner showed back up saying he just test drove my vehicle and everything seems fine now. He first tried telling me that when you drop the tranny pan, you only need to refill what you lose from the pan drop, not true! Fluid drains from the solenoids as well when the pan is dropped. They need to run the engine and shift the tranny thru the gears to fully fill the tranny. He said problems shouldn't arise just from the pan fluid swap. I told him the tranny ran fine prior to coming to his shop and he then admitted they had to add an extra 2 quarts or so of tranny fluid after I brought it back to them the 2nd time. The tranny has been working fine since.
This goes to show you that being 2 quarts or so low on tranny fluid can cause "slipping" and it also shows how or what to look out for if you take your vehicle into a tranny shop for this type of service or if you do it yourself. Make sure you/they refill your tranny with the engine running (up to operating temp) and someone shifting the tranny thru each gear to fully refill the tranny with fluid.
The $150 I paid for this service was well worth it for me, other than the under fill BS I had to deal with at the shop. I didn't have to lay on the cold ground, under my vehicle getting oily and dirty and the little money I would have saved doing it myself wasn't worth the hassle of running for the oil and filter parts and setting everything up.
