The wife and I took a 120 or so mile drive around the back country in the Explorer last week. Going through Ramona, the transmission pressure started jumping all over the place, with no rhyme or reason. I am thinking, great, just great. I pull into a parking lot and start looking over everything. Crawl under the Explorer, and there it is; the wire for the pressure gauge sender is missing the retention nut. I stop by Tractor Supply and purchase a four pack of M4 nylon lock nuts. The pressures have been fine ever since. I think the pressure variations I saw on the Mojave Road trip were from a loose wire nut. All that worry due to a 25 cent nut.
The Explorer has had a slight driveline vibration at freeway speeds for a few years now, but I just figured it was the price paid for having a awesome off-road Explorer. I noticed the vibration I felt on the way home from the Mojave Road trip was there. Much more pronounced than before. Starts at 60 MPH on the dot, on up to about 75 MPH, which is as fast as I went. I put the rear axle on jack stands and pulled the rear drive shaft so I could see if I could feel any movement in the pinyon or transfer case output shaft. They are solid. I pulled the slip-yoke off the drive shaft and it was full of water. Must have been from crossing the Mojave River. The U-joints looked and felt okay. I had that drive shaft built several years ago when the transmission/transfer case went in, and I did not realize the builder used grease-able U-joints. I never use them because they are weaker, usually very difficult to service, and don't seem to last as long. The double cardan centering ball was completely dried out. Ordered three Spicer 1310X U-joints and centering ball rebuild kit. Parts arrived on Thursday, I put it back together same day. I drilled a small hole in the slip-yoke boot to allow it to drain if it gets water in there again and greased the heck out of the yoke with synthetic grease. I did not have time to take it for a test drive.
Today I went out to SMOG it and pay my outrageous registration fee through AAA. When the guy was driving it into the bay to test it, I noticed the brake lights were not working. The wiring for the brake lights is not OEM, I had to modify it for towing behind the RV, and for the transmission torque converter lockout relay. I pulled the side off the center console for access and messed with everything I could think of; relays, fuses, wiring, etc., before realizing it was not my doing but the brake light switch itself that was not functioning. Replaced it in the Autozone parking lot in about five minutes, after I put all the stuff I pulled apart back together, works great.
Finally got on the freeway and the driveline vibration is completely gone. I am very relieved, because all I could think about was TurboExplorer chasing his driveline vibration for a long, frustrating time.
If you are in the market for driveline parts, check out drivetrainamerica.com. I am not affiliated with them in any way, but their customer service is outstanding. I purchased the U-joints from Rock Auto, they were the best price on-line. I located the centering ball rebuild kit at Drivetrain America. It was a $12 part with a total order amount of $20. The next day, I realized I needed the rubber boot that goes over the ball. I emailed their customer service asking if they could add it to my order and I could pay the difference, or cancel my order so I could reorder with all the parts I needed to avoid extra shipping. I got a reply the same day telling me the boot was added to my order at no charge and thanking me for my business. It was only a $5 part, but it was 25% of the entire cost of the order. That is great customer service. I am planning on rebuilding my front driveshaft just because its been a long time, and am going to order all the parts from them.
