And that has diddly squat to do with my response to your post. It has no bearing whatsoever.

I'm a man who obviously has better reading comprehension skills than you IF you think my post was challenging ANYTHING you know regarding transmissions.

Re-read my post again, Brent. My response had absolutely nothing to do with correctly diagnosing the OP's problem, and had everything to do with your aggressive posturing and challenge of Mark's 100% accurate information he posted, which may or may not best explain the answer to the problem the OP described, because there was FAR from enough info to make a 100% correct diagnosis.

You accused Mark of saying a slipping trans was ok. I corrected you inability to comprehend what he posted, and tried to help you understand what he ACTUALLY posted.

Now, I was late for a doctors appointment, so I forgot a few smilies. The crack about you loving that saying was supposed to be funny. There should have been a few smilies there to let you know that. I forgot to put them there. Apologies for that oversight.

Just so we're clear Brent, I didn't challenge your technical experience or knowledge. I merely tried to clear up your misunderstanding of Mark K's post.

Now, back to Transmission Help 101 presented by FTE and Mark K......

Stewart

 

That makes for a better engineer.

Stewart

 

I think I said essentially the same thing. I told the OP how he can diagnose a slipping clutch. Here it is again:

 

Yep, so lets wait to hear what he says.

 

First of all thanks for all the replies. Now I will try to explain best I can. The fluid is red looks normal. The tranny is slipping since the rpms go up and the speed goes down when it hunts from overdrive to next lower gear.
I pulled the trigger and called Brian's Truck Shop in Arkansas. I am going to limp it out there with OD turned off on April 2nd ( earliest date he had available) and get the last tranny the EX will need.
I understand I have done well to get 240,000 out of the original.

 

That's why I said lets wait and see what the OP has to say way back there.

 

Why did the tranny work ok for 787 mile after it first slipped? Then slip again and then quit slipping after I added fluid for another 285 miles. Then slip again?

 

Yes yes , your problem is exactly like mine , first I thought it was mechanical and actually I fully rebuilt it and change all the harnesses underneath the truck , changed the abs And speed sensors but still have the issue.
I asked mark about the low electrical could make the trans slamming and o/d flashing he answered me yes so I took his word and re check the alternator. It seems fine over 13.2 v but when it goes lower than that problems starts and i See
Some time slipping, slamming through gears , speed sensor stops, ABS sensor stops, o/d flashing .
Actually you can feels the truck is not normal. So check your electrical harnesses, connectors , sensors , alternator voltage, groundings , belt slipping.

I hope that will help you .

 

I just put a new alternator on the truck right before I left. A DC power 185. Maybe I have a loose ground or harness I will check that. Only problem is I did not get any codes when I hooked up the computer and the OD light never blinked.

 

Mark wasn't 100% right unless you consider going off on a tangent about a trans slipping before lock-up. The OP said his trans was slipping off and on when going down the freeway and that had nothing to do with pre-locked slippage in cold weather which is something that might occur for a few minutes and barely felt if at all (I never felt it), so that was my point. They were talking about 2 different things and I don't know why Mark even went on that tangent. Why is the OP going to complain about a slight or non-existent slippage that may last a minute if at all?

 

Me also didn't get any codes after I re do that trans that only codes I got is abs and speed sensors. Check the electric in the truck like check them all .harnesses And connectors under
The truck and alternator ans battery.

 

Mark went on a tangent because he hates people giving other people false information, for example Ford did not design the converter to not lockup until the PCM senses a certain temp. When we all know they did...

 

He went on a tangent right off the bat. The OP was talking about his trans slipping going up and down the freeway and Mark was talking about something that had nothing to do with it, and then they jumped on me for making my point. I never said anything about locking up.
From the OP:
Transmission, Slipping overdrive 2000 Excursion

I have an unmodified 2000 Excursion 7.3. with 239000 miles on it. My transmission started to slip in overdrive. I could turn off the OD and it would run fine. I was in upper Wisconsin headed home to Georgia and figured the cold had something to do with it. Drove sixty mile with OD off turned it back on shifted fine and drove 750 mile to Paducah, KY stopped to eat and it started down the road and it slipped again. Drove 45 miles stopped added 8 oz of tranny fluid and it drove fine back to a friends house and after I dropped him off and headed home it started again. The tranny is serviced every year, new filter, drained torque converter. I use Amsoil Synthetic ATF. I have used the truck to tow a 10000lbs trailer over 65000 miles. I was not towing when this occurred. Any idea what is going on? I guess what I am asking is my tranny about to become toast or am I looking at something that can be fixed easily. IE. is it time to head to Lead Hill Arkansas?

 

It's stupid to keep hashing this out. The OP really just wanted us to justify his trip to Lead Hill to get a BTS. So yes, you should go to BTS and get a new trans. Let us know how that works for you.

 

Yea OP, just get a new one......lol.