I just purchased a used 32' fifth wheel and while bringing it home, I found down shifts to be very rough.
Running in over drive on level, hit a hill and when it down shifted it went to third and was really rough and then back up to fourth. I wasn'nt really into the throttle hard at all. If I locked in 4th, the down shift went a lot smoother.
Is this normal? My old f150 just shifted along smoothly loaded or unloaded.
Thanks for your replies Hammer

 

I don't understand what you mean by the difference of locking it in 4th and downshifting, vs it down shifted.

It shouldn't be harsh or rough at any rate.

 

Thanks Aldridge: If I push the button on the shifter and lock out the overdrive, it doesn't seem to be as rough of a downshift. But if I leave it off, then it shifts really hard (very little modulation) . By looking at the on line manual, it appears there was only a 4 speed and a 6 speed available. I just bought this truck and thought I counted 4 shifts. I'll check it out today. Thanks again. Hammer

 

OK: I have a 4 speed with an o/d clutch. So it shifts out of O/D and into 3rd very hard.And then shifts back to 4th. If I lock out the O/D the shift to third is not as harsh.
These are the only shifts that seemed harsh. I have only pulled the trailer 150 miles on Interstate. Thanks again for any thoughts. Hammer

 

BUMP! something is wrong if it's shifting like that... TPS, something - I'm no diesel expert but the PCM thinks you're smashing the gas or it thinks the engine is working a lot harder than it really is.

Might want to ask this in the 7.3 forum...

 

You have a four speed with a lockup torque converter clutch. 4th gear is an overdrive gear ratio.

O/D and 4th are the same thing. When you lock out O/D it will be in 3rd, not 4th. It seems that maybe your harsh shift is the torque converter unlocking, or the shift into 2nd gear.

Harsh downshifts are unusual in the 4R100 trans in your truck. I don't know what's wrong with it.

 

Mark, it might not be the tranny at all, but the PCM thinking something else is up.

I'll repeat my suggestion that the OP posts in the 7.3 forum about this

Matter of fact, I'll MOVE this thread there...

Thread moved ...

 

Sucks when you are in the boat and the paddles go floating by. If HE doesn't know what's wrong with it.....

I was thinking the same thing, that rough downshifts seemed very rare. Are all the upshifts ok at heavy throttle? Perhaps you don't notice what is in general a rough shift because you are not giving it as much throttle on the upshift, but since the down shift is coming from heavy load/throttle it is more noticeable.

 

I wonder, is it a used truck?

I wonder if someone put a shift kit in it?