When my Excursion sits for a while, the transmission slips a lot at first till it builds up pressure. Is this a problem? It seem fine other than this.

Perry

 

You are checking fluid levels while it's running and in park, correct? If fluids are proper and at proper levels, it's not a good sign.

 

It's not a bad sign. The problem is most likely the leakdown check valve for the torque converter is leaking. The ONLY problem that will cause is that the transmission will appear to be slipping for a while after the trick sits for a while. It isn't slipping, it is the torque converter that temporarily becomes a high stall converter until it fills up with fluid again.

The way to diagnose this is to check the transmission fluid level after the truck sits long enough to have the symptoms. Check the level BEFORE starting the engine. If it is really high it's because the converter has halfway drained into the pan.

 

^^^ Mark would know! ^^^

 

Yes mark would know. He has saved my backside on here before. Any harm in letting it stay this way a while? I also have the heat shield rattle that I think is coming from the transmission. I am wondering if it might be time to replace the torque converter. I assume this is a simple job once the transmission has been removed? Should I replace that main seal with a better one? Any suggestions there?

Thanks

Perry

 

It won't harm anything, it's just annoying.

 

I just started noticing this since I had not been daily driving mine for the last 3 years. In the last 6 months or so I noticed when I drove it once a week or every two weeks the first hit of the throttle would feel like it was slipping. In the last month I've been daily driving it again and this has not happened once since I started driving it every day. Now after it sits I keep my foot on the brake and drop it to first and back to D before taking off and that seemed to remedy it also.

 

The reason that works is that you're giving it more time to refill the torque converter.

 

I figured it was something like that

 

Anybody have a diagram or pic showing this TC leak down valve ?

Where is it located ?

 

It's in the pump body. I don't have a diagram.

 

Cool thanks.

Sounds like my trans is coming out for a look see

I don't drive mine very often so I do not have an idea of how long it takes to leak down to the point "slipping" on start up but now that I have a good idea of the cause maybe I will use it for a few weeks and check it out.

Anything in particular that causes this valve to stop functionally correctly ?

 

Sometimes it is just a small piece of debris caught on the valve.