Transmission issues again
 

My transmission has really been acting up on me lately.
The first shift is good. Sometimes but rarely the second shift doesn't work right. The problem is mainly with the 3rd shift. I'm guessing into 3rd gear?
Going around 45 - 50 mph it won't upshift. RPM's go up to 4600 and still no shift. If I drop it into neutral and back into drive it will go into gear. But if I let off the gas or if the rpm's drop it will drop out of gear. Not drop down a gear drop out of gear.

I have to keep putting it into neutral and back into drive to get it to shift.
This only happens when it's really hot out because I don't ever have any trouble in the morning getting to work with a 20 mile or so drive. Like this morning it ran fine.

Transmission fluid is bright red, no signs of going bad. It was changed with a filter about 2 years ago when I bought the car. I think I put Mobile 1 synthetic in it.

I did replace the B-2 piston about a 3 months ago. Here's my other thread about this:
http://www.peachparts.com/shopforum/diesel-discussion/224516-transmission-problems.html?highlight=piston

These problems only happened after I started towing my jetski around.

My plan is to put some Trans X in it. Then do another fluid & filter change. Hopefully that will fix it.

Anybody have any other ideas what could be the cause of these issues

Danny

TransX will make your seals swell and make things worse.

So what do you suggest?
Just do a fluid change & filter without it?

I'd just replace the filter and fill it back up with fluid. If I were you I wouldn't use synthetic in a old tranny, it can only make things worse.

Why can synthetic tranny fluid "only make things worse"? I've been using synthetic in my old Dodge pickup (206,000 miles on the original tranny) for quite awhile now an not had an issue I could relate to it.
Have you experienced something you could trace to synthetic trans fluid?

The problem of course is if you've got a trans with say 250,000 miles and you put in synthetic fluid and the trans fails who is to say it wasn't going to fail with conventional fluid anyway? If I had a brand new trans (or say 60,000 miles even) and I put in synthetic and it failed well I'd think it might have been the fluid but automatic transmissions are complicated and its hard to say what makes one fail...

-Curt

Sounds like a vacuum modulator issue. Check the vacuum line going from the transmission to the valve cover.

Try disconnecting your kickdown switch under the accelerator pedal. Could be locked up or broken, telling your trans to be in a gear lower than it should be.

I thought about disconnecting it but it seemed to work fine when I hit by hand. Maybe I'll just disconnect it anyway. Or at least test it with a meter.