Hi guys, here's my latest and greatest issue.

Took the ram for few hundred kilometer trip and encountered the following:

Start truck, lock out OD, enable OD when cruising at highway speeds, when entering a town and locking out OD the transmission would shift late and very hard.

So it seems that the non-OD shifts are harder after overdrive has been engaged and then disabled. I was experiencing this hard shifting after getting off the highway and I turned off and on the engine and it shifted fine after that with the OD locked out.

Hopefully I've explained this well enough but basically after getting off the highway and locking out the OD I experienced late and hard shifts but only after using and then locking out OD.

Any thoughts? Couldn't find anything on google or searching DF.

 

On your truck, it just shouldn't matter. 1-3 are purely mechanically governed, there is no electronic input at all. The trans simply shouldn't care whether O/D is enabled or not.

You are probably going to have to put some gauges on it, and see what pressures are doing under various conditions.....

 

Yeah that's why I find it very odd that it shifts differently from 1-3 after driving with OD engaged on the highway and then reverts back to shifting fine from 1-3 after restarting the truck.

 

I don't have an explanation for that one.

 

Are you sure you have an RH transmission?......The RH can be identified by a three wire solenoid connector near rear cooler line....As stated, there are no electrical inputs for the 1-2-3 shift....Now you may have an RE transmission, which has an 8 pin connector near the rear cooler line....That unit has a governor sensor and solenoid that is a part of the shift controls for all shifts....

 

He has a 94, so, unless a previous owner did some major changes.... it's still an RH.

 

Late and hard shifts on the RH is usually caused by high throttle pressure or low governor pressure....I would attach a 0-100 psi gauge to governor pressure port and make sure pressure corresponds roughly with vehicle speed.....If it does,then the problem is throttle pressure....

 

Thanks I'll be sure to check when I have a moment.

And if it's a throttle pressure problem, then what?

Thanks,
Scott

 

High throttle pressure after transmission reaches operating temperatures usually indicates that the throttle valve in the valve body is not stroking correctly...Visit sonnax.com and look at your valve body for common wear areas that cause these issues...