Trans problem (long)

[kjscorp]

Hello all,
Just picked up a 97 explorer sport xl 4.0 w/4r55e at auction, and have run into some problems. Known problems: no speedo, no OD light, no cruise, no backup lights. When the truck is put into drive it seems to start in 3rd, and will not upshift or down shift automatically, however if pulled manually into 2nd it will downshift to 2nd. If put in 2nd to start, it starts in 2nd and stays in 2nd. If put in 1st, it starts in 3rd and stays in 3rd. It will not upshift automatically at all. If you start in 2nd and manually shift to 3rd, the trans shifts with a firm clunk into what feels like 3rd lockup. At aprox 60 mph its turning about 3k, so I believe its still in 3rd, not OD. After getting home and letting it cool, did a little exploring and found the trans wiring harness (both connectors) not connected at all. Also both O2 sensors were not plugged in. Re connected the trans harness and O2's, then replaced the vss. This solved the backup light prob. but I still have no speedo, cruise, or OD light, and the trans still has the exact problems as described. Also changed the tps (had a bad spot). I was told buy a good friend whos been rebuilding trannys for 20 years that the trans was in limp mode, due to no speed sensor input. Also found a 2 wire sensor on the top of the trans just aft of the bellhousing, seems to be just above the pump, both wires have been snipped (converter lockup? ) Any help would be fantastic. Thanks so very much

 

[Opera House]

Well, this has a history. Those two wires above the OD section are for a speed sensor that detects shift problems. The Later version of the 5R55E doesn't have this sensor. This transmission may have been replaced with a later one or the wires connected together to get rid of (fool the computer) a tranny code. The wires should be connected together. Have you found the real VSS? Should be last sensor on the transfer case if 4WD. You need to get that going. This transmission has a lot of problems with the vqalve body gaskets blowing out. I bought a spare 99 for parts with a bad gasket and it had only 52K. This generally affects the low/reverse servo and the overdrive. This includes the L/R servo cover. You will likely find several valve body bolts loose. Changing the VB gaskets will likely solve your low problem. Check the bracket that holds the EPC solenoid for cracking and backing out. I love auction cars. That is where I get all my vehicles. This will take less work than you think.

 

[kjscorp]

Thanks for the reply Opera House, was hoping you'd respond. The wires on the OD speed sensor are not connected now, just snipped. You're saying I should just jump them together? I was going to strip them back and try plugging them in to the sensor. The real vss? are you talking about the speed sensor at the very back of the transfer case just below the output yolk? isnt that a hall effect pickup? I replaced the vss that is geared to the output shaft on the transfer case (has a hole where a cable would be if used on a older model). I have the truck at the stealer getting codes pulled. Should know something by fri. mid day. Will pull the vb and check all bolts for backing out and then change the gasket. Where is the EPC solenoid located? Also could the speedo prob be due to a bad RABS sensor in the rear diff? Thank you so very much for your input and advise.

 

[Opera House]

If the two wires aren't connected together it will give a sensor fault. You are probably better off connecting them than using the sensor. That is the VSS on the transfer case and I believe that it is still a coil. Believe this was eliminated about 99 and the now use the differential sensor. Of the group of four solenoids, the one closest to the front is the TCC, last is the EPC, the two in the middel and the two on the other side are the SSA-D solenoids. Get the gaskets from the dealer because of updates. They probably won't sell you the gaskets without the updated seperator plate. I generally don't recommend pulling the VB without a manual. It can be done, just don't tip it over because things will fall out. Not a big deal because you probably haven't made this a daily driver you depend upon.