Chrysler Town & Country van "shakes / misses" under load?

A friend has a 1993 Chrysler Town & Country van.
We thought that the tires were out of alignment, as the van
would shake as if there was a bad tire, or an alignment
problem. After having the tires rotated and balanced,
the problem continued. We thought it could be motor
mounts, but that was not the problem either. After test driving
it again, it seems that the van shakes when under a load. That is,
when you are climbing a hill at 60 MPH & the engine is under a load,
the car shakes as if it had a bad tire. However, when you are accelerating
on a down hill, or simply let off the gas, then there is no shaking
whatsoever.

Conclusion: the engine must be missing, or similar.

I am not familiar with this van.
Would someone please suggest a 1,2 3 solution. That is,
what do we start replacing, checking, etc. to fix the problem?
My first thoughts are to change out all filters, injector cleaner,
new plug wires and plugs.

THANKS in advance for your suggestions
My email is:

Gene

 

You could have a bad axle(s), another thing is an over/improperly torqued
front wheel, or corrosion where the hub and wheel mates causing the front
wheel(s) to not seat correctly, or the mounting plate on a front rotor could
be bad.
Larry

 

Thanks Larry.
We had the tires & wheels, etc. checked.
It definitely has something to do with the engine
"missing" when it is under a load. The engine
idles & runs up just fine without a load. Put the
engine under a load, and it "runs rough".

Gene

 

Does the transmission downshift?

 

No

 

So when you brake-torque it in the driveway it misfires? Or is this only
something that happens when it's on a roll?

--Geoff

 

This is typical of bad inner CV joint on one of the axles. A good mechanic
would be able to take it for a test drive and determine which axle was the
problem (or both!).

 

Try moving the gear shift to downshift (OD->D in a 4 speed), and see if it
continues.

 

Does the van shake side to side? Or is it a shudder. If it's side to side
get a new mechanic that knows FWD vehicles. If it's a shudder it may be
torque converter shudder. Did your friend have the trans fluid
flushed/changed recently? If so did they use +3 or +4? If not than they need
to have it flushed back to +3 or 4 and PRONTO.
Larry

 

I had the exact same symptoms, it was a plug wire, but I see you've
already thought of that.

Lisa