2001 F250 transmission issue after rebuild

Nissan11

Nissan11

Well-Known Member
Joined
Nov 29, 2005
Location
Marston, NC
I have an 01 F250 auto with the 7.3. Last Sept the transmission went out in TX on a road trip towing a trailer. I had a shop in Sherman, TX called Alpha Transmission rebuild it. The price was $2800 with a heavy duty torque converter, brand unknown.
The truck has drove and shifted great for the most part every since. However, this winter I started doing some fishing and I noticed when the truck is on a steep incline of a boat ramp it will not move unless I give it a lot of gas, like the transmission is not engaging or something. I checked that the fluid level is at the top of the high mark. I put the truck on a hill at my house and it always takes about of gas and with a sudden jerk it starts moving. I am obviously not going to take the truck back to TX to let the shop look at it. Is there anything I can check on my own? Should I take it to a local trans shop and let them look at it? I am in Hoffman, NC.
 

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I would be curious as to what stall they put in it. Does it still drive fine everywhere else, only issue is on a grade? How is the fluid?
 
I'd check what @a_kelley said. I'd take it to a trans shop and have them put a pressure gauge on it after pulling the pan to check for obvious stuff.
 
I just called a transmission shop in Aberdeen. The guy I talked to said it sounds completely fine to him and that it sounds like it has a "high stall" torque converter. He says he is not worried because when on incline, once the truck starts moving it keeps pulling fine. He said he would be happy to drive it for me to be sure so I am going to try to get there Friday afternoon.
 
Nissan11 said:
I just called a transmission shop in Aberdeen. The guy I talked to said it sounds completely fine to him and that it sounds like it has a "high stall" torque converter. He says he is not worried because when on incline, once the truck starts moving it keeps pulling fine. He said he would be happy to drive it for me to be sure so I am going to try to get there Friday afternoon.
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didn't you say it was fine a year ago, and didn't do that?

Also who puts a higher stall converter in a diesel? Doesn't make too much sense to me..
 
a_kelley said:
didn't you say it was fine a year ago, and didn't do that?

Also who puts a higher stall converter in a diesel? Doesn't make too much sense to me..
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I have not had the truck on an incline until recently so I can not say how long it has been doing this. I also never had the truck on an incline before I rebuilt the transmission so I do not have anything to compare it to.

I have been reading about stall speeds online and I still do not understand something. If a truck has a stall speed of 1500 rpm then why does it start rolling forward on level ground at idle when put in drive?
 
Fluid friction. Everything is spinning, so there is a force being applied even at 1 rpm. The force just increases as the rpms increase.
 
Because the converter still transfers some force under the stall speed. Stall speed is where the torque multiplication comes in and keeps the motor from revving beyond that rpm until the input shaft starts turning.

To test stall speed, hold brake, apply wot. Do not hold wot longer than 5 seconds. Should be 2049-2381 for a stock converter.

It doesn't slam into gear on the incline, right? Just a smooth engagement?
 
a_kelley said:
Because the converter still transfers some force under the stall speed. Stall speed is where the torque multiplication comes in and keeps the motor from revving beyond that rpm until the input shaft starts turning.

To test stall speed, hold brake, apply wot. Do not hold wot longer than 5 seconds. Should be 2049-2381 for a stock converter.

It doesn't slam into gear on the incline, right? Just a smooth engagement?
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It does not slam but it seems jerkier than I would expect. I will test stall speed today. Thanks
 
On dirt, with the brake pressed hard, the rear tires break loose at 1400-1500rpm every time. I dont know how to get it to wide open throttle in gear without the tires turning.
 
Ok so, on flat ground, you got plenty of power at 1400-1500. So it should be the same on an incline.. check trans pressure on flat ground & incline & I'll almost bet the filter to pump is leaking air/cavitating/etc..
 
You could overfill it by 1/2-1qt and see if that makes a difference on the incline. If it does, you know it's sucking air, but usually the inlet is at the back of the pan.
 
What ever happened to @transman731 or whatever his username was?
 
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