Straight_LineMTB Posted November 8, 2024 Share Posted November 8, 2024 (edited) Hey all. I was installing my rear lift springs and noticed a leak of red tranny fluid. What had me confused is the drip migrated to passenger side frame. Drip collected a few inches ahead of muffler on frame. There's a plate covering wiring and I felt up there and wires seemed wet with fluid. Only owned this a few months and seems it just recently started dripping. Not sure where to start. Any advice is appreciated. 2001 LE 4x4 167k Edited November 8, 2024 by Straight_LineMTB Link to comment Share on other sites More sharing options...
Slartibartfast Posted November 9, 2024 Share Posted November 9, 2024 That spot's never gonna rust! I'm not super familiar with the underside of the R50, but I see some plumbing in that picture. If those are the transmission cooler lines, they would be my first suspect. Could be where they connect to the trans, could be a spot rubbed or rusted through, could be a loose hose clamp, could be a rubber section giving out. If there's tranny fluid on top of that plate, I would expect to find the leak somewhere over it, or somewhere uphill of it, probably running down a harness or a hose to get there. If there's so much muck everywhere that you can't tell, clean the area as much as you can, run it for a bit, and see what gets oily again first. A friend of mine had a hell of a leak on her Dodge that turned out to be the park/neutral switch. The switch itself was leaking around the electrical connections, and fluid was running from there to the side of the case, down to the pan, then dripping onto the cooler lines, and finally dripping on the exhaust. I was starting to suspect the pan gasket was bad until I unplugged the switch and found ATF behind it. Link to comment Share on other sites More sharing options...
Lock Posted January 23 Share Posted January 23 (edited) Take that heat shield off next to the resonator and underneath you'll find the auto trans & transfer case connectors. I bet that like Slart said one of the connectors is leaking at the trans, and the trans fluid is going along the piping and coming out at that junction area. When I was doing my auto-manual swap I noticed like half of the connectors there were damp with trans fluid. I think when the auto trans get old the sensor seals start to fail and trans fluid just starts to seep along the wiring, but yours looks pretty bad. It could be just transfer case sensors leaking, they are easier to get to and replace but I don't recall them having tubes just bundled wires so it's probably trans wiring. As for how to fix it, I guess it depends which connector is leaking. The one that was leaking for me I think was the torque converter RPM sensor. You'd have to pull the trans to replace it. So if you can't get to it without pulling the trans, you could possibly fill up the connector hose with RTV and hope that holds the fluid back. Edited January 23 by Lock Link to comment Share on other sites More sharing options...
Straight_LineMTB Posted January 23 Author Share Posted January 23 1 hour ago, Lock said: Take that heat shield off next to the resonator and underneath you'll find the auto trans & transfer case connectors. I bet that like Slart said one of the connectors is leaking at the trans, and the trans fluid is going along the piping and coming out at that junction area. When I was doing my auto-manual swap I noticed like half of the connectors there were damp with trans fluid. I think when the auto trans get old the sensor seals start to fail and trans fluid just starts to seep along the wiring, but yours looks pretty bad. It could be just transfer case sensors leaking, they are easier to get to and replace but I don't recall them having tubes just bundled wires so it's probably trans wiring. As for how to fix it, I guess it depends which connector is leaking. The one that was leaking for me I think was the torque converter RPM sensor. You'd have to pull the trans to replace it. So if you can't get to it without pulling the trans, you could possibly fill up the connector hose with RTV and hope that holds the fluid back. Thank you for the tips. I had seen a couple others with similar leak state it's the sensor on top of tranny. Plug closest to front of car seems to have the drip. I saw one guy hole saw a spot under dash to get to thst sensor to replace. Seems like that could be a bit of an easier if not messier route to address it. I'm thinking of going that route to save the headache of dropping transmission. Leak isn't super bad currently so kinda holding off for now but I know it's inevitable. Tranny slips into 3rd gear when cold and have the rear main seal leak so the trifecta is nearly complete lol. 1 Link to comment Share on other sites More sharing options...
hawairish Posted January 26 Share Posted January 26 Given the saturation, I'd say it's probably a sensor atop the transmission. There are no fluid lines in that area, so it has to be travelling down the loom. Guessing that's the only sign of saturation. There are two sensors on top. Hopefully it's the revolution sensor at the rear end of the transmission and not the turbine revolution sensor at the front of the transmission. Older/OE turbine revolution sensors had a rubber/plastic boot that can crack at the top and allow ATF to be expelled; replacing it requires dropping the transmission because the sensor is ridiculously long. The rear sensor is much shorter and more accessible, but also just uses an o-ring to seal. Keep in mind your transfer case uses ATF, too, and is in that area. Since you have the LE, you have the full-time ATX14A transfer case and I'm not sure what sensors exist there. Doubt it's the breather on top of the rear section of the case, but wouldn't hurt to inspect (it points in the wrong direction of your leak and likely not a factor unless you regularly park on an incline). If the ATX14A is like the TX10A at the tail of the case, the fluid line is relatively low in that area when the truck is level, and there's a baffle plate inside that prevents fluid from being slung directly into the tube. Of course, usually helps to power wash the area as best you can and try to see if/where a new leak/drip develops. Link to comment Share on other sites More sharing options...
Straight_LineMTB Posted January 27 Author Share Posted January 27 Thank you for the feedback. When looking at the leak. The drip is coming off the small burgundy colored plug on end closest to rear of car. Very slow but drips a drop or 2 a day. Link to comment Share on other sites More sharing options...
hawairish Posted January 28 Share Posted January 28 Dude...your reply struck a total déjà vu moment...except it really happened! In fact, exactly one year ago, I replied to a thread on the Club Frontier forum about this exact same issue where ATF was unbelievably dripping from wiring insulation. I had forgotten all about the leaking through the insulation, only recalling the general nature of the failure. While I was typing my reply there, the topic starter had posted that he found the same issue on the Club Xterra forum. All these trucks use the same transmission, of course. This post shows the failure at the tip of the sensor. So, my money's on that sensor. Unfortunately, if it is that sensor, it's not cheap and not easy to replace. Unfortunately, part two, I decided to crawl under my truck to see what plugs are visible to confirm if I could see what you see. I see that my harness also shows a layer of grime on it...which is highly unfortunate because I just had the transmission down in 2023 and didn't notice it. 1 Link to comment Share on other sites More sharing options...
Straight_LineMTB Posted January 28 Author Share Posted January 28 I'm debating on just hole sawing into the floor board to replace that sensor. I mentioned before someone had similar issue and just cut into floor board to get to that sensor to replace. If my leak gets worse I'll just do that. Just not sure how to run the new wire since it won't be in that wrapping. Link below Link to comment Share on other sites More sharing options...
hawairish Posted January 28 Share Posted January 28 Can't say it's something I'd ever consider doing. That guy seemed to do a great job of figuring out where that hole needed to be. You're going to hate it if you miss the mark, though. Maybe if you're able to cut a large piece from a donor truck to use as a proper cover. This idea doesn't sit well with me. Your truck, of course. I'd sooner buy the transmission jack and drop it all down. Especially if you already have a leaking RMS. Changing the RMS is a bigger pain in the... Link to comment Share on other sites More sharing options...
Slartibartfast Posted January 28 Share Posted January 28 A friend and I hole-sawed his S10 Blazer's firewall to get to a bellhousing bolt. Then we did it again, a few inches over, because that's where the bolt actually was. Not our finest moment. (Or Chevy's finest moment, either, but that's the S10 for you.) If you do go for the hole saw, make sure you measure better than we did. Also make sure the hole saw and/or pilot drill aren't going to take out the harness when they break through. I've got a trans with this sensor in the corner, waiting to go into my '93. I think I just found something else to check before I install it! 1 Link to comment Share on other sites More sharing options...
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