Hey, I'm new here and just bought an 1978 FJ40 (1 Viewer)

[DeadguyLLC]

It has a Turbo 400 transmission and a Chevy 454 big block swapped in. I installed a truck avenger Holley carb, a new MSD distributor and wires, and the engine seems to be running fine. I'm having trouble shifting though. Does anyone know these transmissions? Everyone I've had before this was manual.

The big problem, is when I am in Drive, it doesn't seem to change gears, it just revs high like it is still in first or second. It's a three speed, so if I shift down to second, or sometimes first and them second, it seems to pop up to higher gearing. Or if I shift to second, them pop up to third (drive). But if I start in drive, it doesn't seem to get there. It has a B&M proshifter on there, BTW.

 

[SuperBuickGuy]

a couple thoughts... first, the basic - those shifters are a PITA^2; couple that with a manual valve body and it would do something similar to what you describe.

If not that, is the kick-down wired? how about the vacuum? if those are all fine (and the transmission isn't a manual-valve-body (which means you have to shift it to go to the next gear), look at the governor (it's on the side) - if that is sticking, those issues could happen. Also Turbo 400s can get sticky valves in the valve body. I had a transmission that got water in it. It took 20 or so miles of driving to get it to shift correctly. One thing to caution about that - be very gentle to the transmission during it's time to get the valves working again, you could easily burn up the clutches when it doesn't get full pressure to the clutch packs.

If none of those work, I'd drop the valve body - but before, I'd check the oil to be sure it's not already burned up.

The good news, though, is that turbo 400s are dirt-cheap to rebuild and if you ever wanted to learn how to do it; rebuild kits and the few specialized tools you need (including the GM rebuild book - seriously, the one from GM) - you'd have about the same dollars in the transmission as if you took it to a shop to be rebuilt except that you'd now be able to rebuild it yourself.

 

[DeadguyLLC]

a couple thoughts... first, the basic - those shifters are a PITA^2; couple that with a manual valve body and it would do something similar to what you describe.

If not that, is the kick-down wired? how about the vacuum? if those are all fine (and the transmission isn't a manual-valve-body (which means you have to shift it to go to the next gear), look at the governor (it's on the side) - if that is sticking, those issues could happen. Also Turbo 400s can get sticky valves in the valve body. I had a transmission that got water in it. It took 20 or so miles of driving to get it to shift correctly. One thing to caution about that - be very gentle to the transmission during it's time to get the valves working again, you could easily burn up the clutches when it doesn't get full pressure to the clutch packs.

If none of those work, I'd drop the valve body - but before, I'd check the oil to be sure it's not already burned up.

The good news, though, is that turbo 400s are dirt-cheap to rebuild and if you ever wanted to learn how to do it; rebuild kits and the few specialized tools you need (including the GM rebuild book - seriously, the one from GM) - you'd have about the same dollars in the transmission as if you took it to a shop to be rebuilt except that you'd now be able to rebuild it yourself.

Thanks for the input. I know it shifts Park, Reverse, and then Neutral. I would guess it then goes Drive, Second, First. How can I tell if it's Manual Valve body or not? I can start it in First or Drive, but it seems to hold it's gearing until I shift.

 

[shawnfj40]

You may have a "reverse" shift pattern valve body and a straight pattern shifter. just change the numbers and letters

 

[DeadguyLLC]

So, tomorrow I'll pull the governor and take a look. Can anyone tell me what i am looking for? Like I said, I've always dealt with manual transmissions in the past.

 

[Mace]

You may have a "reverse" shift pattern valve body and a straight pattern shifter. just change the numbers and letters

This,

If you put it in what you think is the "first" gear (not drive) does it shift?

Also, you need to see what the electronic downshift solenoid is doing.

 

[DeadguyLLC]

So, It turns out I have a turbo 350, not a 400. The transmission fluid was very low. I refilled it, but can't take it for a test drive until I get some fluid in the front diff. (I drained it, and then found out the fill plug was stripped).

 

[SuperBuickGuy]

low fluid would cause your problems (as would overfilling, actually).
Hope it was just fluid....

 

[Fast Eddy]

You only need fluid in the front diff if you're using 4wd. In 2wd with the hubs unlocked, nothing in there is turning.

 

[Mace]

Buy a quality double flare tool, and go to town.