Transmission repair/replacement

Removed transmission from f150 to be rebuilt, after getting it back and reinstalling it as well as the other components we filled it up with ATF fluid let it sit so the ATF could circulate after that we tried to take it for a test drive but when I put it into drive it would not move forward so I tried reverse and still would not move, i went back under the truck and went through everything again to make sure that I hadn’t forgotten anything and could not find a problem

That’s a tough one. Suggest to post make/model/year of vehicle and the nature of the problems.

Is the fluid at the proper level?

After I turned it off I checked it and was a bit low but topped it up and tried again but still nothing

That’s not the proper way to check the fluid level. The engine must be running, the transmission fluid must be warm, and vehicle must be level.

That symptom is consistent with not enough transmission fluid. It may take several times of running the engine, stopping, and checking the fluid level and topping it off again to get the torque converter & all filled again. It is probably possible to check the transmission fluid pressure at a test port. That’s probably the next step. May require a visit to a shop for that. If that’s ok, check that the linkage from the shifter the driver uses to set D,R, N etc is actually moving the shift levers on the transmission like it should, assuming that’s the way it works on your transmission. What else? hmm… Does it use a vacuum modulator? Try disconnecting the vacuum source (plug it on the engine end so it doesn’t create an engine vacuum leak), see if that has any effect. Are you getting any diagnostic codes?

Can you put a gage on it to see if the pump is working?

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See if the shifter selector linkage is hooked up to the transmission.

When you placed the torque converter into the transmission,was it properly seated ?

When you installed the transmission with the torque converter properly seated in the transmission into the truck, did the bell housing sit flush with the engine before tightening any bolts ? or did you have to tighten the bolts to get it to pull together ?

After the transmission was bolted to the engine did you slide the torque converter forward to bolt it to the flex plate ?

i might ask why did the trans fail? than ask how much rebuild was. $600? or $1800? what did shop find besides worn clutches and leaky seals/orings? anything big broken? if it was a minor parts overhaul than thats one thing. yes, its possible you have a TC issue but most folks know about seating convertor.

Got the truck moving in drive and reverse now I’m having a problem with drive dosent seem to have enough power to go forward on it’s own unless I press on the gas but even then it’s still sketchy. Reverse thought has no problem going backwards?

Do you have enough fluid in the transmission? Does it read in the normal range with the engine running? The transmission should take 6 to 8 quarts of fluid.

Yes fluid is good but still being difficult

Have the test port pressures tested. If they all test ok either you got a problem (in this order of likeliness) w/the install, or with the valve body, or with the clutches/bands/planetary gears mechanisms.

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What year is the truck? If it’s an oldie, the transmission bands may need to be adjusted.

Have the truck towed to the rebuilder. Let him figure it out.

If this was a complete rebuild with a new torque converter, it may take a number of tries to get the TC completely filled with oil. In the mean time you will have air in the TC which makes the coupling very spongy. Ask the rebuilder if they installed a new TC and if there is a process to complete fill the TC fully with transmission fluid only.

I was wondering how the air gets out the TC. I guess when the engine is turning and the pump is filling the TC, the air is at the hub in the center. The air must come through the hub to the driven element of the pump; back around the hub; between the outside of the hub; and exit between the hub and the bushing supporting the TC hub into the transmission. All this time the pump is pushing oil into the TC. So the best way to bleed the TC, is to run the engine in neutral while monitoring the soil level until it stops dropping.

Silly thought, but is the parking brake off?