Hello oil fans,
I recently purchased a 2015 Ford Explorer 3.5L NA with 196,000 miles on for our high school kids to drive. One issue these vehicles have is that the Power Transfer Unit (PTU -think non-selectable transfer case to drive the rear wheels) fluid never gets changed because Ford calls it “lifetime”. The specification from the manual is synthetic 75-140W axle lubricant. Since these live right next to the cat, and the oil volume is next to nothing (18 fl. Oz.) , they routinely get very warm and the gear oil turns to pudding. Eventually internal gears/bearings/bushings fail or broken teeth bind gears up and blow the cases apart.
Sooooo, on the list of many things I’ve done to PM this vehicle, I changed the fluid. There’s no drain so it needs to be vacuum extracted. I was only able to remove about 8 fl.oz. so either I couldn’t get the tube to the low point or so much of it has already turned to pudding there’s not much “fluid” remaining. I refilled with Mobil 1 75W-140 synthetic. I recently noticed the tell-tale “propane” like smell that many have referred to.
Inevitably it will fail at some point as they all do unless they are taken care of from day 1. It’s not a cheap repair just for the PTU assembly, and stupid expensive if I don’t do the work myself.
My question is, can I save it, or prolong it for long enough? Over time with new fluid break down the old? I’d change it monthly if I knew that would happen and was working towards a clean PTU again. Is there any other product I could/should put in there to effectively break down the old pudding stuff? Fill it with some solvent and then drain/fill the next day? I read one guys claim he filled it with ATF, drove lightly for few laps around the dealership and then did a few drain/fills with cleaner fluid resulting each time.
Thoughts? P.S., I’m not interested in hearing “just replace it and be done”.
PPS, it's impossible to drain/fill while it's warm. The cat is about 1/2" away from the PTU. So close it's very hard to get hands and tools in to even get to the fill plug. Long term I suppose drilling and tapping for a pipe plug would be a good improvement.
Here are a couple of references in case you’re interested in reading up:
I recently purchased a 2015 Ford Explorer 3.5L NA with 196,000 miles on for our high school kids to drive. One issue these vehicles have is that the Power Transfer Unit (PTU -think non-selectable transfer case to drive the rear wheels) fluid never gets changed because Ford calls it “lifetime”. The specification from the manual is synthetic 75-140W axle lubricant. Since these live right next to the cat, and the oil volume is next to nothing (18 fl. Oz.) , they routinely get very warm and the gear oil turns to pudding. Eventually internal gears/bearings/bushings fail or broken teeth bind gears up and blow the cases apart.
Sooooo, on the list of many things I’ve done to PM this vehicle, I changed the fluid. There’s no drain so it needs to be vacuum extracted. I was only able to remove about 8 fl.oz. so either I couldn’t get the tube to the low point or so much of it has already turned to pudding there’s not much “fluid” remaining. I refilled with Mobil 1 75W-140 synthetic. I recently noticed the tell-tale “propane” like smell that many have referred to.
Inevitably it will fail at some point as they all do unless they are taken care of from day 1. It’s not a cheap repair just for the PTU assembly, and stupid expensive if I don’t do the work myself.
My question is, can I save it, or prolong it for long enough? Over time with new fluid break down the old? I’d change it monthly if I knew that would happen and was working towards a clean PTU again. Is there any other product I could/should put in there to effectively break down the old pudding stuff? Fill it with some solvent and then drain/fill the next day? I read one guys claim he filled it with ATF, drove lightly for few laps around the dealership and then did a few drain/fills with cleaner fluid resulting each time.
Thoughts? P.S., I’m not interested in hearing “just replace it and be done”.
PPS, it's impossible to drain/fill while it's warm. The cat is about 1/2" away from the PTU. So close it's very hard to get hands and tools in to even get to the fill plug. Long term I suppose drilling and tapping for a pipe plug would be a good improvement.
Here are a couple of references in case you’re interested in reading up:
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