trans shudder

what would cause the trans to shudder when pulling
a hill with a boat its okay without the boat and it stops
when the converter unlocks but after the converter locks up
and it starts to strain it will shake the truck I have a 93 w150
4x4 318 also what trans fluid is correct atf +4 or atf+3
thanks

Don't pull anything in overdrive.

A trans shudder happens when the TCC is goin from lockup or to lockup.
If it shudders or misses after lockup check engine running.
And like was said no towing in overdrive.
MT

Thanks for the reply .I do not pull in overdrive this happens
when converter is locked up and it is not engine miss when driving
and start to give it gas like going up hill it will shudder if I tap
the brake which will unlock the converter it stops and when it locks
back up it will do it again I can also let off the gas a bit and it will stop but will lose speed also of course.

A engine miss will do the same thing.
It is hard to a engine miss from a converter shudder.
Has the trans ever been seviced?
If not service the trans filter and fluid.
Also lube gard has a good additive for TCC shuder.
Mt

It's probably the infamous Dodge "Torque Converter Shudder" My '97 did it from the day we bought it, with 88k miles on it. And it didn't seem to make much difference if we were towing or not. Several fluid changes, and a host of different additives later, it was still doing it when I sold it.

From what I've heard (From Dodge Techs.) and from misc. postings. It's not a major prob. more of an annoyance. (And it is an annoyance.) I've read several postings where people have installed new converters, only to have the problem come back within a couple of thousand miles.

Here's a real good article about it - http://www.allpar.com/fix/torque-converter.html

-Gary-

Thanks for the reply