Engine/Transmission (1998.5 - 2002) NO lockup

[MAngelotti]

Took off this morning after usual warmup routine and no lockup in od. Was fine last night with no possible cause in mind. Have read a little and am leaning toward od/lockup solenoid, any suggestions before I drop the pan. Any help would be appreciated as I am supposed to be leaving in the am for the great north woods and would love to get this straight asap.

Thanks

 

[RAJohnson]

Sounds like your on the right track.

 

[JJPage]

When I was having lock up issues with my 48RE, it turned out to be my gear selector sensor. My front band adjustment stud was leaking transmission fluid, it had the gear selector sensor plug drenched, the pins were shorting out and causing all sorts of wierd behavior.



I repaired the leaking stud, unplugged the sensor and cleaned it all up with can of airesol cleaner I got at radio shack, then coated it all with dielectric grease and plugged it back in, problem resolved.



Just something to check... .

 

[FourBarR]

How cold was it? There is a thermister switch in the transmission that prevents it from going into o/d below a certain temp. If not temp related maybe the switch is defective .

Hope this helps.

 

[John - K5AWO]

When I was having lock up issues with my 48RE, it turned out to be my gear selector sensor. My front band adjustment stud was leaking transmission fluid, it had the gear selector sensor plug drenched, the pins were shorting out and causing all sorts of wierd behavior.

I repaired the leaking stud, unplugged the sensor and cleaned it all up with can of airesol cleaner I got at radio shack, then coated it all with dielectric grease and plugged it back in, problem resolved.

Just something to check... .

Ditto on this. Pull the sensor out, clean it good, and put it back in.
Quick 10 minute check to see if all is well.

Then after you drive it again, decide if more sleuthing is necessary.

I ended up eventually with the mods in my signature on the transmission.

 

[MAngelotti]

Thanks for the responses, sorry I did not respond sooner. Well I had a friend pull the pan at his shop due to my taking off for a little fun in the snow and this is how it stands. He found a snap ring in the pan from who knows where. He hooked up the scanner and found that the pcm was powering and grounding the solenoid as it should. This worried me so I had him change the solenoid anyway. This brought no change or so he told me. I picked up the truck last night thinking ,well I'll just drive it for now w/o lockup until I do some more tinkering and make a decision on what to do with the situation. On the way home I was pleasantly surprised as the truck went into lockup as it should. I did have him check connections and all and am now wondering what to think. Truck was fine all the way to work this morning so it looks to me like TDR fixes another one. Thanks for the help!

 

[PhillipFleming]

Finding any "hard part's" in the pan is not cool! the first time i had the pan down in my old dakota (it had the 46RH aka 518) i saw a chunk of what i thought to be bearing race. After i dissassembled it to overhaul it the o/d support bearing had busted off a chunk of the bearing cage and fell into the pan. Driving around with out any lockup isnt a great idea, that will heat up the trans to dangerous temps in no time. Id want to no where that snap ring came from. Any chance you got a pic of the snap ring chunk? i chuld probbly tell you where its soupost to be. my spelling stinks sorry.

 

[cerberusiam]

Snap ring chunk is probably from the OD direct clutch pack. Since lockup wasn't activating in OD a good bet the pressure drop is effecting it. Could have a leak on the direct release that is going to cause some issues. About the only fix is pull it down and rebuild it.

 

[MAngelotti]

Bad news , as many of you probably suspected no lockup again. Weighing my options for a fix. I'm creeping up on 200,000 mi so I guess I've gotten all I can out of the stock transmission. Money is tight so I'm gonna take her for ll shes got. I'll take it easy and keep from towing anything for now. Thanks for all the responses.

 

[Devil Black Diesel]

Ditto on this. Pull the sensor out, clean it good, and put it back in.

Quick 10 minute check to see if all is well.



Then after you drive it again, decide if more sleuthing is necessary.



I ended up eventually with the mods in my signature on the transmission.

Where is this sensor located? is it easy to get to? Anyone have a photo of where it's located? So just disconnect, pull out, clean, and replace?



Thanks

 

[JJPage]

Where is this sensor located? is it easy to get to? Anyone have a photo of where it's located? So just disconnect, pull out, clean, and replace?



Thanks

It's a round plug on the driver's side of the transmission, just to the rear and slightly below the front band adjustment stud. It is just a connection, harness to sensor, the sensor stays in the trans case.



After disconnecting, clean both ends, I used a dry contact cleaner in a spray can from Radio Shack, then a bit of dielectric grease on both ends and plugged it back in. Do not use no-ox, it is conductive and will cause shorting between pins.

 

[cerberusiam]

It's a round plug on the driver's side of the transmission, just to the rear and slightly below the front band adjustment stud. It is just a connection, harness to sensor, the sensor stays in the trans case.

The neutral safety switch doesn't have anything to do with lockup, all it does is make sure the truck won't start in gear and turn on the backup lights. The 2nd gens don't have a range sensor box like the 3rd gens do.



Lockup is controlled by the TCM portion of the PCM and thats in the trans control harness plug about the middle of the trans. Check that plug and make sure there is no fluid in it and it is making good contact.

 

[JJPage]

Lockup is controlled by the TCM portion of the PCM and thats in the trans control harness plug about the middle of the trans. Check that plug and make sure there is no fluid in it and it is making good contact.

Cerb, this is the plug I'm referring to... the one with pins 1 thru 7, looking at a picture of a 47RE, other than the wires being different colors, it looks alot like mine. Or am I missing something? wouldn't be a first :-laf.

 

[cerberusiam]

Cerb, this is the plug I'm referring to... the one with pins 1 thru 7, looking at a picture of a 47RE, other than the wires being different colors, it looks alot like mine. Or am I missing something? wouldn't be a first :-laf.

The one slightly below and to the rear of the band adjuster is the neutral safety switch isn't it? The one right above the pan rail?



What threw me is you said range sensor plug which is in the place of the neutral safety switch. Maybe you meant the trans control harness and not range sensor??