OD Shenanigans - Dodge Diesel - Diesel Truck Resource Forums



1st Gen. Ram - All Topics Discussion for all Dodge Rams prior to 1994. This includes engine, drivetrain and non-drivetrain discussions. Anything prior to 1994 should go in here.

OD Shenanigans

Reply
 
 
 
Thread Tools Search this Thread
Old 09-23-2012, 09:21 PM   #1  
Registered User
Thread Starter
 
Join Date: May 2011
Location: Colorado
Posts: 29
Unhappy OD Shenanigans

I am stumped on what is causing my OD issues. My truck will intermittently not shift into OD or will shift out of OD at highway speeds. I bypassed the TPS with a POT and that worked for a few days then the problem came back. I hooked up a switch to the OD solenoid and grounded it at highway speeds and still no OD. Please help point me in the right direction.
Ghosthider is offline   Reply With Quote
Old 09-23-2012, 09:33 PM   #2  
Registered User
 
j_martin's Avatar
 
Join Date: Nov 2011
Location: Isanti, MN
Posts: 4,322
Quote:
Originally Posted by Ghosthider View Post
I am stumped on what is causing my OD issues. My truck will intermittently not shift into OD or will shift out of OD at highway speeds. I bypassed the TPS with a POT and that worked for a few days then the problem came back. I hooked up a switch to the OD solenoid and grounded it at highway speeds and still no OD. Please help point me in the right direction.
The OD solenoid is powered by the A21 splice (same power as the FSS) and grounded by the PCM.
The solenoid in the transmission has to be good.
Connections have to be good.
Inputs to the PCM to calculate OD shifting have to be good:
TPS
CPS
VSS
Engine temp
Transmission temp
Power and ground to the PCM have to be good.

<edit> didn't see you had tried to ground the solenoid. If you have power and ground to the solenoid and no OD, you have internal trouble in the transmission.

hope it helps
John
j_martin is offline   Reply With Quote
Old 09-24-2012, 07:41 AM   #3  
Registered User
Thread Starter
 
Join Date: May 2011
Location: Colorado
Posts: 29
Thanks for the help! I was thinking it was in the tranny. I am just unsure if its the OD solenoid, or something else. Looks like I have a trip to the tranny shop in the future.
Ghosthider is offline   Reply With Quote
Old 09-24-2012, 08:34 AM   #4  
Registered User
 
Tuckerdee's Avatar
 
Join Date: Apr 2003
Location: Brighton, CO
Posts: 760
I just had this problem. Turned out for me it was the crankshaft position sensor going bad. Would cut in and out when it heated up to operating temp. The computer couldn't see that the engine was running so it wouldn't send a signal to shift the OD.
Tuckerdee is offline   Reply With Quote
Old 09-24-2012, 08:52 AM   #5  
Registered User
 
j_martin's Avatar
 
Join Date: Nov 2011
Location: Isanti, MN
Posts: 4,322
Quote:
Originally Posted by Tuckerdee View Post
I just had this problem. Turned out for me it was the crankshaft position sensor going bad. Would cut in and out when it heated up to operating temp. The computer couldn't see that the engine was running so it wouldn't send a signal to shift the OD.
Tucker, if you had grounded the solenoid, it would have shifted to OD. Different problem.
j_martin is offline   Reply With Quote
Old 09-24-2012, 08:57 AM   #6  
Registered User
 
Tuckerdee's Avatar
 
Join Date: Apr 2003
Location: Brighton, CO
Posts: 760
Yeah, you're right j_martin. I just thought I'd share what happened to me to let it sink into the collective consciousness of the board.
Tuckerdee is offline   Reply With Quote
Old 09-25-2012, 08:54 PM   #7  
Registered User
Thread Starter
 
Join Date: May 2011
Location: Colorado
Posts: 29
Just wondering if doing a transmission flush and adjusting the bands would help or if it going to require a full rebuild. There is no shudder and it shifts nice and firm, it just wont go into OD or if it does it will slip back into 3rd on the highway.
Ghosthider is offline   Reply With Quote
Old 09-26-2012, 06:24 AM   #8  
Registered User
 
j_martin's Avatar
 
Join Date: Nov 2011
Location: Isanti, MN
Posts: 4,322
Quote:
Originally Posted by Ghosthider View Post
Just wondering if doing a transmission flush and adjusting the bands would help or if it going to require a full rebuild. There is no shudder and it shifts nice and firm, it just wont go into OD or if it does it will slip back into 3rd on the highway.
It would be very unusual for those symptoms to be internal to the transmission. If you're not up to systematically testing the wiring involved, you need to get some help. Guessing is the most expensive and least effective path to a repair.
j_martin is offline   Reply With Quote
Old 09-26-2012, 11:02 AM   #9  
Registered User
 
ChrisLib's Avatar
 
Join Date: Dec 2003
Location: Boerne, TX
Posts: 1,508
I went thru pretty much the same thing with my pile of junk, this was the fix for me...
https://www.dieseltruckresource.com/...oo-t74673.html
ChrisLib is offline   Reply With Quote
Old 09-26-2012, 01:09 PM   #10  
Registered User
 
SORTIE's Avatar
 
Join Date: Jul 2009
Location: METRO USA
Posts: 532
Quote:
Originally Posted by Tuckerdee View Post
The computer couldn't see that the engine was running so it wouldn't send a signal to shift the OD.
what computer?
SORTIE is offline   Reply With Quote
Old 09-26-2012, 09:20 PM   #11  
Registered User
Thread Starter
 
Join Date: May 2011
Location: Colorado
Posts: 29
For ATF fluid is it best to avoid ATF +4? I have read that ATF +4 can cause issues. What would be the right fluid to use?



________________________________
92 W250 LE Regular Cab
Ghosthider is offline   Reply With Quote
Old 09-26-2012, 10:14 PM   #12  
Registered User
 
Join Date: Oct 2006
Location: Indianapolis, Indianna
Posts: 701
Quote:
Originally Posted by Ghosthider View Post
For ATF fluid is it best to avoid ATF +4? I have read that ATF +4 can cause issues. What would be the right fluid to use?
DEXRON III is the factory suggested fluid. I susect ATF +4 would make it shift smoother but i have never tried it.
Rampage1967 is offline   Reply With Quote
Old 09-26-2012, 10:51 PM   #13  
Registered User
 
j_martin's Avatar
 
Join Date: Nov 2011
Location: Isanti, MN
Posts: 4,322
Quote:
Originally Posted by Rampage1967 View Post
DEXRON III is the factory suggested fluid. I susect ATF +4 would make it shift smoother but i have never tried it.
My factory manual says ATF plus, with Dexron II an allowable substitute if ATF plus isn't available.

When my transmission was overhauled/upgraded, Kole put in Amzoil Synthetic Multi Vehicle Transmission Fluid. Says he wouldn't warranty it with anything else in it.
j_martin is offline   Reply With Quote
Old 09-29-2012, 08:42 AM   #14  
Registered User
 
DodgeFreak's Avatar
 
Join Date: Mar 2006
Location: Iowa
Posts: 665
theres a pressure port on the left side of the trans put a gauge on it jack it up and run it untill its supposed to go into od. we had one that wouldn't go into od all other gears worked fine and we put a gauge on the od port we found we had 26psi when it tried to shift into od, found the seal was bad on the od piston, we just replace the seal and od clutches and we were good to go.
DodgeFreak is offline   Reply With Quote
Old 09-29-2012, 04:45 PM   #15  
Registered User
Thread Starter
 
Join Date: May 2011
Location: Colorado
Posts: 29
Well I took it to a Tranny shop this morning All the way there the OD bypass switch hooked up worked and it would go into OD but it was cold. The tranny shop put it on a scanner and told me to check the wiring. Brought it home dropped the pan and changed the filter and fluid. Everything was tight , no lose OD solenoid. I checked the blue wire going to the OD solenoid again and it was going from 13 volts to 0 volts to 5 volts. I am guessing that the blue wire should have 13 volts constantly when the truck is running. And that is why my bypass switch is intermittently working If thats true where does that blue wire go? I am unable to find it when it goes up above the tranny. Thanks for all the help!!

__________________________________________________ _______________
92 W250 LE Regular Cab
Ghosthider is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Shenanigans,Really? irocpractice Political Discussion 2 11-06-2012 03:16 PM
Fuel gauge Shenanigans barngal6 2nd Gen. Dodge Ram - No Drivetrain 5 04-14-2007 03:45 AM


Tags
1st gen, diesel, od solenoid, overdrive, transmission

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 10:35 AM.


Copyright 2017, DieselTruckResource.com
We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.