Potential transmission problem?

[DaveN]

I was talking to a guy that does transmission work (I don't know if he's good or not) but he was saying that there is a problem with the auto trannies in the CTD's. Apperantly (according to him) the oil does not pump through the trans unless it's in gear, and that if you plan on leaving your truck idle for more than a few minutes you should just shut it down. I don't know anything about the guts of auto transmissions, but is this correct? I haven't heard anything about it on the forums..... anyone ever heard of this?

 

[Bigramguy]

The pump still works,just the trans cooler flow is very low when the vehicle is in park,which isn't really a major problem. If you tow heavy or work the truck hard,don't idle it in park,let it idle in neutral to help the trans cool better. Also if you have problems with convertor drainback in the mornings,idling in neutral will help that also.

 

[DaveN]

Thanks for the response, what is the difference between park and neutral? I thought they were the same except park engaged the pawl...

 

[Bigramguy]

When you move the shifter,it moves a control valve or manual valve in the trans valve body. The factory valve and passages seem to allow more flow in neutral than in park. I believe most of the aftermarket upgrade valve bodies have addressed this with increased cooler flow in park with a redesigned manual valve.



Here is a link with some info about the valve body and manual valve.



http://www.dieseltrans.com/DTTech/valvebodys.html

 

[DaveN]

Thanks, I think I've got it!