The other day, the transmission has been acting up on my 2001 7.3. Everytime I take off though 1st gear it would rev up to 3000 Rpms until it would shift to 2nd and from all the other gears it would shift irregularly. I'm wondering if anyone has any suggestions on what the problem is. In the morning I'm gonna change the tranny fluid and I hope it makes a difference but I know on diesels it's not that simple I would appreciate any suggestions. Thanks

 

I had a similar issue on the same year truck and it ended being the mechanical diode curse of the 4r100 transmission. It was toast (I know, probably not what you want to hear). You can see if your truck has the mechanical diode by determining the build date. This link has instructions. Look around for a real transmission rebuilder (not just someone who swaps them, definitely not Aamco). I got an upgraded torque converter, better valve body, upgraded shift solenoid, a better warranty, and some other goodies for about the same price as the OEM replacement and labor.

If you can, take your truck for a drive again and count the gear shifts carefully, there should be 4 (1-3 and then OD). Also, watch the gear selector lever. Is the "Overdrive" indicator blinking?

 

It's drivable and it shift but the shift points are very hard and they shift in high Rpms and the over drive indicator was blinking when the problem started but I hit the truck off and started it back up and it stopped. But the transmission just feels weak now and doesn't have very much power behind It

 

Yea, it is time to get it rebuilt. Like he said, don't take it to Aamco! The light blinking is your engine light for the transmission. If the light blinks on and off then there should be a code tripped and will tell you what is wrong if you get it scanned. Just did mine 2002 at 260,000. Got some good life outta that 1st one!

 

The thing is that I took it in the other day and he scanned it but there weren't any codes for the transmission but when he drove it he said the clutch was slipping pretty bad. So there isn't anything besides getting it rebuilt

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And I also only have 130,000 miles on the truck which is the really said part about it. I don't understand why it went bad

 

Unfortunately, that is just what my rebiuilder said! He has seen them go with only 150,000! Not really anything to do with how you drive it! It is that faulty, corrupted, disfunctional 4R100 transmission! When you drive it again, watch for the blinking light, then have it scanned! You reset the code when you turn off the truck, that is why he did not get any codes on his scanner. Sure sounds very similar to what my issue was. If you drop the pan and change the filter or fluid you will see the magnet is covered with small filings! All kinds of parts in there with friction, bearings, races, planet gear. I kept my planet gear as a reminder! Hope this helps it go down easier!

 

Yea. I replaced the fluid and filter right after this all happened and the only thing that was bad was te oil was very dark so it must have over heated

 

Yep, definitely need to get that burned oil outta there. New filter and fluid should be good to go! Transmission, gears, clutch, all those parts and pieces, do not do well with burnt fluids. The blinking light is where I would focus my attention though! That's a warning for you!