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Hi All... just hoping to get some diagnostic input here.  This is an auto tranny in a Jeep Wrangler that has been acting up.  

A few weeks ago I stopped to fill up with gas, after filling up I dropped it in drive and nothing but revs.  Shifted from reverse to drive a few times... nothing. After playing with it and revving the motor a bit it dropped into gear and acted just fine.  No signs of weirdness leading up to that.

Since then, it's happened a couple more times.  I've found that revving it up good will drop it into gear.  Outside of this the tranny acts fine.  Shifts smooth, no slipping.

Sound like something sticking in the valve body?

Any thoughts appreciated.  

it will really really help..

with the year engine and possibly transmission type of your wrangler...

please post that info... as there are several different transmissions that could be in there..


have you checked it for fluid level...

have you done a transmission service on it lately.. with new filter... fresh fluid and a new pan gasket if its not one of the reusable versions..

post some more info on the year.. make model engine transmission..  

You either have the A904 or the 42RLE either way It sounds like a stuck pressure regulator valve.  When this happens you have no reverse either right?  

Ya, its the A904, aka 30RH bolted to a 2.5l.  185k miles.  After the first incident I changed the fluid and filter which was probably overdue and improved the general behavior of the tranny a little I think.

But yes, when this happens I have no forward or reverse.  

Yea it sounds like a stuck pressure regulator valve. With that mileage you probably have a lot of fine metal circulating around the trans and its starting to hang up some valves. Your governor valve will probably start sticking too. That will cause 2nd gear starts. Did you find a lot of metal in the pan when you changed the filter?  

There was definitely some material on the filter itself and in the pan.

I've got a spare tranny that I've already pulled the valve body out of.  If I go through it to clean it up, what's best to clean up the valves and body itself?

Thanks for the thoughts btw!  

hmm..

a spare laying around..

http://www.moparmusclemagazine.com/howto/5123_904_three_speed_automatic_transmission_build/index.html

http://www.4wdandsportutility.com/tech/0701_4wd_jeep_transmission_rebuild/index.html  

After that first incident I snagged a tranny from a guy who was parting out a Wrangler.  I'm was hoping to rebuild it, but might have to start with just borrowing the valve body.

Great links btw.  Thanks for the input guys... very helpful!  

If the torque convertor or any of the hard parts are damaged and creating metal then  the new valve body will get stuck in no time.