C T D 518 overdrive ????

[Highbanked Hauler]

Recently my CTD 152K started coming out of overdrive at most speeds and will go  back in and out again. I am sure this isn't good for the trans. First time it was doing it at 70 mph. and  now it will do it at any speed it gets into OD . This is with no load and a fluid temp. of 160*. Fluid has less than 10K on it and it isn't slipping.  Ideas..

[Rolling_Thunder]

i remember someone discussing it somewhere on this forum but for the love of god I cant remember where or when...     not helpful I know but someone will chime in sooner or later.

[Challenger340]

Whats the vehicle application ? is there part-time 4wd involved ?

John Kunkel is the resident Tranni expert on here....FANTASTIC knowledge base....I'm sure he'll chime in soon.

just s "bump"

[John_Kunkel]

Is it the OD dropping out or the converter unlocking? What is the actual rpm rise?

If it's the converter clutch read this:

http://www.kentsoil.com/dodgebug1.htm

Converter unlocking can also be related to the TPS or brake light switch.

BTW, it's CTD not CDT.

[Highbanked Hauler]

  The truck is a 92 turbo,2 wheel drive. The trans is a 518 and the converter is a Hughes non lockup. At 70mph I gotta say the tach. hits 3K for a few seconds and it feels like you tossed an anchor out. It acts the same as if you were to hit the overdrive off button(maybe I had better check the switch) to see if anything is loose . When it does it at 40 or less I don't remember the rpm.  It usually does it when the engine is not pulling. I was wondering if the TPS  might be at fault. Cruise control works.. The reference to cdt is just brain damage showing up. 

  Challenger 340,  I use it to pull the car trailer for now and thinking about a camping trailer in the future.