a518 od problem

[chessman21]

I got a "92" d-250 recently an the trans would never shift into od.. I put a new dash od button, od solenoid, trans go shift kit, new filter and 10 quarts of atf+4 back in it and on the test drive it still wouldnt shift.. The otherday i got in it and droved to the store and it shifted into od!. At 45mph or so I could turn it off and on by the dashboard button so i kept on driving and it seemed to work perfect. I get it home and shut it off for several hours then i get back in and drive around and od now "wont" engage. The next day again It shifts into od but again after several hours or a total cool down it stops working.

I inspected the wires visually with a flashlight and the wires don't "look" bad or burnt.

Iv got the big blue wire on the black solenoid wire and the orange to the red on the solenoid. I assume this is correct (2 pin type)

Whats the sensor thing on the end of the trany by the mount for? The wires coming from it tie in with the od solenoid wires.

[Bustedknuckles]

Its the speed sensor. Its like a speedometer cable, but electric.

[chessman21]

Coming from the wire harness thats connects to the od solenoid I have two wires. One is larger than the other and is blue and the other is orange with a black line.. Which is the 12v?

[MIRADAMEGACAB]

Doesnt seem to be electrical related. I had one of these 518s in a Mirada and I could engage the OD at any time by feeding 12v to it. The polarity doesnt matter.

[chessman21]

Well the new od solenoid I installed has a red and black wire, red is pos and black is negative so says instructions, seems both wires would be black if they were uni polarity. As it is now I have the big blue harness wire connected to the black on the solenoid,, and the other smaller orange wire connected to the red on the solenoid. Mite the thicker blue wire be the pos??

[chessman21]

I managed to get the codes from the key and they are 36-37 and 45. Will 36 or 37 prevent the od from working? The valve body is the no-lockup type, I dont understand were the 37 even comes from..

One more question while im here,, Going "to" the od solenoid I have two wires. One is thick and blue an the other is skinny and orange with a black stripe. Which is positive?

[MIRADAMEGACAB]

You need a FSM (factory service manual) or Chiltons.

[chessman21]

I thought I had the proble solved (loose od solenoid connector)but its not working again. Now i have hooked a wire from the pcm ground to a test light.. The Light stays on till the truck reaches od speed then goes out, When i slow down to a stop the light comes back on or I can reech od speeds and illuminate the dash od button( od off) and the light comes back on .. The hot wire comes on with the key and stays on.. So I assume the od solenoid is getting juce as it should, Iv noted when the od "does" shift, and its not allways as soon as the light goes out. What else will prevent the od from shifting? Iv drove it around for hours and the od worked perfect, then i switch it off then switch it back on and no OD? The next day it may work again and may not.. The speedometer deosnt read nothing till abot 15 mph or so, dont know if this matters because the od solenoid is getting 12v and and the pcm ground which the pcm will only give a ground if the speed, throttle possision, crank, temp sensors check out. What else mite (sometimes)prevent it from going into od if the od solenoid is getting power?
Iv been reading and it says overdrive minimum/max pressure should be between 65-75/130-140... How do i check this and if the pressure is below 65 would that prevent the od shift?
Allso, i installed a Transgo shift kit (tfod-jr) and in the installation it said to back out one of the bolts till the spring flange is flush against the housing. I (think) it had something to do with pressure, its been awhile and im not a mechanic. Any how it never said nothing about readjusting it. Gears PRN123 shift well.

[B-300]

That's the pressure regulator adjustment. The shift kit uses a stffer spring and tells you to back that out for stage 1, I believe. This increases the line pressure for firmer shifts. It also increases the rpm of the 1st -2nd and 2nd-3rd shifts... The 3rd to OD is controlled by the PCM.
I know that later transmissions with lockup will shift out of lockup and OD if the brakes are applied. This is a problem if the brakelight switch is miss adjusted.
How many wire come out of the plug near the shift linkages? I ask because the valvebody appears to be an "re" type used in later models.

[chessman21]

The one pictured is off the internet, My valve body has an od(2wire)solenoid with no lockup. Now there is a 3 wire connection to the side of the valve body housing drivers side that iv yet to find out what it is, I assumed it was to a fluid temp sensor.

Thanks for the pressure adjusting info.

allso i came up with this from the ignition key odb

36= Speed controll switch allways high.
37=Torque converter cltch solenoid open or shorted ,CKT circit
45=Od solenoid circit shorted or open.

Havent figured out how to clear the codes yet, I assume the 45 is and old code because the test light hooked to the pcm ground and goes out (grounded)at od speed and comes back on (not sure)after slowing down as it would seem it should.

I havent located the T/c solenoid yet. Dont know if its anything to do with od.. Im a tranny noobie.

[MIRADAMEGACAB]

The one pictured is off the internet, My valve body has an od(2wire)solenoid with no lockup. Now there is a 3 wire connection to the side of the valve body housing drivers side that iv yet to find out what it is, I assumed it was to a fluid temp sensor.

The 3 wire connector is the neutral/reverse switch.

[chessman21]

ahh, the neutral/reverse works so I can iliminate that. Thank you.

[B-300]

The TC solenoid is on the same bracket as the OD solenoid on models with a lock-up converter.
The PCM won't shift to OD (or lockup the converter) unless:
1. The engine coolant temperature warm. (Above ~150 degrees)
2. The vehicle is going fast enough as measured by the speed sensor.
3. The throttle is less than ~ 2/3's open. (Not climbing a hill under load)

[chessman21]

Ok well, the valve body has the single od solenoid only no lockup.
Dont know how its showing code 37.

[B-300]

Try clearing the codes by disconnecting the battery and then depressing the brake pedal for 20 seconds... This discharges the internal capacitor in the PCM.
It's possible the transmission or PCM have been replaced with an incorrect one.

[chessman21]

Yea, im wondering if the trany was changed out.. Its jst kinna strange sometimes it works and when it does it works well till i switch off.
Iv spent $300 between two shops on diagnostics, the both said " The trannys fried and needed a total rebuild ($1800-$2500). This was befor the tranny shifted into OD out the blue one day. And as i said befor when it did the od shift it worked perfect for about 45 mintutes with me stoping and going stoping and going watching the od shift everytime perfect like there was never an issue. Wish I could figure it out. Thanks for your help guys
:1owned:

[RoadHogg]

"they both said " The trannys fried and needed a total rebuild ($1800-$2500). ""

I love that line. And so it costs the shop NOTHING to have mechanics that couldn't troubleshoot their way out of a wet paper bag! They have no trouble charging YOU $2500 to take a shotgun approach to fixing an issue they, the "professionals" don't have the skills of knowledge to find.

It's a pretty sad situation when the pinnacle of a modern mechanic's skill is finding the diagnostic connector.

Yea, im wondering if the trany was changed out.. Its jst kinna strange sometimes it works and when it does it works well till i switch off.
Iv spent $300 between two shops on diagnostics, the both said " The trannys fried and needed a total rebuild ($1800-$2500). This was befor the tranny shifted into OD out the blue one day. And as i said befor when it did the od shift it worked perfect for about 45 mintutes with me stoping and going stoping and going watching the od shift everytime perfect like there was never an issue. Wish I could figure it out. Thanks for your help guys
:1owned:

[chessman21]

Agreed,, I had one order a new solenoid for me wich he did and wanted $375 to put it in. He said he would do it after he droped the pan. He said the pan had to much metal grime not shavings in the pan and he wasnt gonna mess with it. I think they were scared of it not being and transission spacific shop. Being the
'for sell" sighn had '92 d250 with od" and I asked the man point blank if the truck had any problems and he said no I decided befor I drop $2500 I would try to figure out what else it could be first. I started with a new factory ordered:rocket: od dash switch. $80 didnt fix it. Then I figured I would put the new od solenoid in. I was told or read in a forum that while i was there it would be best to install a corrective shift kit (TFOD-jr $35)while I had the valve body down. I did that put in 9 quarts of atf+4 in it and still no od. Convenced the mechacnics were correct i parked the truck. Jumped back in about two weeks later and it shifts into od. I go into town and back and it was shifting smooth as butter. I could slowly accelerate and od would shift at about 35 or I could from a stop accelerate kinna fast and od would shift at about 50mph. And after it shifts into od I could turn it on an off with the od dash switch, I must have done it 10 times. As i said it seemed to work perfect. Get it home and park it. I get back in the next day... No od.

Is it possable the pcm is not grounding the solenoid "well" enough or is there such a thing? Does it get a little ground from each sensor temp/speed/throttle to make a full ground? as I said i have a test light hooked to the od solenoid while im riding down the road and the light indicates that the solenoid is getting juice when od is needed and ungrounded when the truck slows down to about 20. Im assuming its grounded, the test light goes out.(one test light wire on frame and the other test light wire spliced into the ground/pcm wire) When the od is off the test light comes on. When i reach od speeds the light goes out(grounded). Slow down/ stop, light comes back on. With me? I will try clearing the codes as instructed by B-300 and see if i still get the code 45.
I may brop the pan again and see if the pressure regulator is accesable without droping the valve body again and if so giving it 2-3 turns off the spring retainer counterclock wich should incress pressure.
The temp gauge wire was loose but I stuffed the wire back in the little clip its allways read 3/4 to the hot when warm has from day one.