I am experiencing hard shifts as though the vacuum is not fuctioning properly. 1-2 at 30 mph and 2-3 at 50 mph.

I checked the vacuum and its pulling 24" constantly. So its not the vacuum pump.

I verified everything else that is run off vacuum and they are all at 24" ish. No leaks...

When I connect the vacuum gauge to the trans side of the VRV it shows 14" at idle. If I run the throttle the vacuum decreases to less than 14" the more I increase the throttle.

Is that normal? I am starting to think it could be the VRV? Should I adjust the modulator on the rear of the trans?

Thanks
Thad

 

You should get around 20in out of the VRV at idle. Maybe try adjusting it.

 

14" is max. I have tired to go higher but thats it. It goes way lower than that too!

Thad

 

I assume that you checked that you are getting 24in at the inlet to the VRV? If so it would seem likely that you need to replace the VRV.
Never heard anyone mention it but I wonder is it possible to service one, just a thought.

 

Yup...might have to spend more cash...

I plan to install a vacuum gauge soon too. Maybe Monday.

Thad

 

Is your kickdown linkage well lubed and moves freely?


When I bought my motorhome back in 2000, the man was told by a shop it needed a new tranny as it was shifting at max RPM for each gear.


When I got home with it, first thing I checked was that kickdown rod, and yup, it was stuck down, making the tranny think it was being given full throttle all the time. Good can of WD40 fixed that!

 

My kickdown rod is not installed. Which way should the kickdown lever be (on the trans) to ensure that this isnt an issue?

Thad

 

Ah, theres your problem

Having no kickdown rod won't do any bad to the trans, but it will make it shift at max RPM's!



And it's to dark now to see tonight, but if no one knows by tomorrow, I'll run out to the van and check for ya.

 

With a properly adjusted vrv you do not need a kickdown rod. I took mine off because it was still allowing the trans to kickdown too soon for my liking, I like more of a forced kickdown to where I have to deliberatley put the smoke pedal in the rug to do so, that way I can use the lower end power of the motor. The lever on the trans should be forward and up, try tipping the vrv towards the front of the truck a little and see if that doesnt help

Oh and you should be able to pull the lever down by hand and it should spring back up.

 

This is true. The vrv can be used to adjust the shift pionts as well. There are 2 7/16" head bolts that hold it down tight. I played with mine over a 10 mile back roads run and got it to shift right where I wanted it to shift.

 

I bypassed the VRV and ran vacuum straight to the modulator and now it shifts...but super early. I also put a purple stripe modulator (they didnt have a black one) that I used to further isolate the problem.

At this point it seems to be the VRV and I have one on order. Should be here in a few days. I will shift manually if I need to use the rig over the next few days.

Thanks
Thad

 

I've got some questions, I'm having the same problem exactly as what the op described. I just don't know what I'm looking for. I know when I brought it home I whent under and pulled the hose off the thing at the back end of the tranny and there was just a small drop of oil in there, what is the thing that had the hose on it called and does oil in it mean it's shot?

Also my kickdown is a little rusty I'll check that out today, how do I know if the kickdown is working properly?