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Hello I'm pretty new here and have a question about the trans in my truck. I have a 96 crew cab F350 with the 7.3 power stroke with 310k on it. The only mods done are the 10k mod, 6637, and bully dog muffler and cat delete. The last few days the transmission has started to act funny. If I take off from a stop fast it doesn't want to shift to second until I let off and let the idle come down. If I take off slow it shifts fine. It's normally warm when this happens. Also when I'm on the interstate and come to a stop it feels like it slips into first gear hard once I stop. I know it's hard to diagnose this without feeling it for yourself but and help would be appreciated. If you need any other info let me know.
Does it do this hot or cold or both?
Unfortunately when you add a little power to the engine (10k mod) the trans suffers from excessive heat. A bigger trans cooler is one of the best things you can do for it.
How's the trans fluid level & quality? If it's been a while since the fluid & filter was last changed now would be a good time to do it. Doesn't cost much and can't hurt.
All right cuda jim I have a question along the same lines. My truck is bone stock, and maybe once every 4months or so it starts to shift like a lenco, or like Warren Johnson. So I baby it for that couple of days, and then it starts acting fine again. But man if you're in the back seat you hit your head on the back glass if your not ready, because it shifts so hard.
But its done this about 3 times while Ive owned it, over 2 years. And it goes away. But I will say it seems it goes into highter RPM before it shifts. (just 1 or 2 hundred higher thn usual, but you can hear the difference).
I don't have a trans gauge so i don't know if the trans is hot but it starts to happen after I've been driving for 20 min. or so. The 10k mod was done after this had already started. The fluid level is good and does not smell or taste burnt. J/k on the taste. I'll start with the changing the fluid and the filter, like you said it's cheap and can't hurt. Does the tq have a drain on it also? Should I drain it if it does? Thank you Jim for your response.
My truck is bone stock, and maybe once every 4months or so it starts to shift like a lenco, or like Warren Johnson.
I'll bet your OD OFF light doesn't work. If it did it would be flashing when this happens.
When the PCM finds a trans problem it stores a code, flashes the OD light, and sets the pressures in the trans high to prevent additional damage. Get the codes read and the OD OFF light fixed.
My light works and the OD on/off function works fine. When this problem occurs I have yet to see if the light blinks. The issue happened last night and the light never came on.
All right cuda jim I have a question along the same lines. My truck is bone stock, and maybe once every 4months or so it starts to shift like a lenco, or like Warren Johnson. So I baby it for that couple of days, and then it starts acting fine again. But man if you're in the back seat you hit your head on the back glass if your not ready, because it shifts so hard.
But its done this about 3 times while Ive owned it, over 2 years. And it goes away. But I will say it seems it goes into highter RPM before it shifts. (just 1 or 2 hundred higher thn usual, but you can hear the difference).
Thanks ya'll
I agree with Mark, your OD light may not be working or you didn't notice it flashing. Get it scanned for codes for a definitive answer.
This has solved a hard shifting problem in the past, but not always:
You can remove and clean the Rear Antilock Brake Sensor, RABS, sensor on the top of the rear differential.
It also provides a signal... Vehicle Speed Sensor, VSS, to the Powertrain Control Module, PCM, to determine the shift schedule.
I don't have a trans gauge so i don't know if the trans is hot but it starts to happen after I've been driving for 20 min. or so. The 10k mod was done after this had already started. The fluid level is good and does not smell or taste burnt. J/k on the taste. I'll start with the changing the fluid and the filter, like you said it's cheap and can't hurt. Does the tq have a drain on it also? Should I drain it if it does? Thank you Jim for your response.
You need to taste the fluid to be sure LOL!
Yes, there is a plug in the TC, you need to rotate the engine by hand to line it up with the hole in the bell housing. IIRC you'll need about 16 quarts of fluid. Flush the coolers too.
The 10K mod may have finished off an already failing trans. A trans gauge would be a great investment since the e4od is such a crappy trans. Heat kills trannies.
Originally Posted by JasWood
My light works and the OD on/off function works fine. When this problem occurs I have yet to see if the light blinks. The issue happened last night and the light never came on.
Mark was answering Major94's question. It's strange your light didn't flash. Key on.....Push the button on the end of the shifter....does the light come on?
Here is the story folks. We were pullin across iowa, and next thing you know the speedometer quits working, and the OD OFF light is blinking. So we stop in walcot ( the home of the worlds largest truck stop) and got it scanned, the old guy there put in a new speed sensor oin the rear end. There for nomore OD OFF light flashing. ( that was a year or so ago)
Now the light works, I can turn it on or off at will, ( but I dont do it when driving). But when it shifts like a lenco the light is on and stays on.
Do you think the old guy who scanned it might not have cleared it or what do you think the deal is. Because my light works fine.
Now the light works, I can turn it on or off at will, ( but I dont do it when driving).
Why not? You can, you know.
Originally Posted by Major94
Do you think the old guy who scanned it might not have cleared it or what do you think the deal is. Because my light works fine.
Even if he didn't clear the code it will clear itself within a month after the problem is fixed. A code from a year ago is not in the memory any longer unless the problem is still there.
You need to have the codes read to see what's going on.