Loosing trans oil approx 1 pint every month.

[1988GTU]

I have a diff from a 95 4t60e gp (had the 3.4 lq1) forsale if you need one. Other than that, your seal(s) could have been improperly installed and therefore still causing you the leak. I have a buddy that installed an axle seal improperly and it leaked. After a second attempted, it was done correctly with no more leaks.

[IsaacHayes]

Adjustable one firms up the shifts if you adjust it to. Less wear on clutches and feels better. less sloppy long drawn out shifts. More quicker shifts.

[cutlass supreme FE3]

Adjustable one firms up the shifts if you adjust it to. Less wear on clutches and feels better. less sloppy long drawn out shifts. More quicker shifts.

looking at a pic of the adjustable one. how do you adjust it?
what is the part number i'm supposed to get?
thanks for all the valuable info you are providing.

[IsaacHayes]

The center part where you put the vacuum tube, you take that off and stick a small flat blade screwdriver and turn. Clock wise firms up the shifts. Just don't turn it all the way as it will strain the pump. If you hear the pump whining while at idle, it's up too high. I set mine at 4 turns from out of the box which is the max they recommend. I'd have to search to find the P/N. It's a pioneer one. Fits turbo 350/450/powerglide etc.

[cutlass supreme FE3]

The center part where you put the vacuum tube, you take that off and stick a small flat blade screwdriver and turn. Clock wise firms up the shifts. Just don't turn it all the way as it will strain the pump. If you hear the pump whining while at idle, it's up too high. I set mine at 4 turns from out of the box which is the max they recommend. I'd have to search to find the P/N. It's a pioneer one. Fits turbo 350/450/powerglide etc.

Am I supposed to have a TH125?

[IsaacHayes]

Hmm, an 88, possibly. Is it a 3spd? I think that's what a TH125 is. Either way the pioneer adjustable one will fit. Search for pcguys thread on it for a part number. Or go to Oriellys and ask for an adustable modulator for a turbo 350 trans... (TH350)


searching oriellys site:

PIONEER - Automatic Transmission Modulator
Item No: 747001

Its $12.50 which I paid like 15 after tax. That could be the one. Should work just fine. I did a look up for a 1969 camaro 350ci to find that. It will be smaller than your factory one but that's no biggie. Less clutter.

FWIW my factory one was not leaking but the spring was weak in it so even at WOT the shifts were not as strong and fast as they should have been. Turning the adjustable one firmer only affects shifts at part throttle, not WOT. But mine made it faster even on WOT shifts, which tells me the factory one was wore out. Car shifts like a dream now. Like new.

[cutlass supreme FE3]

no it is not 3 speed but a 4 speed with the overdrive.

[IsaacHayes]

Ah yeah, that's right, I think the TH125 is also called 4T60 (with no "E")

[gpse3400]

125C= 3T40 440T-4= 4T60

You have the 440T-4(4T60)

[cutlass supreme FE3]

is this a 4 speed automatic?

[gpse3400]

It most definately is. You have the 440-T4(4T60).

OD-4, D-3, 2-2,-1-1. And electronic Lock-Up Torque Converter.

[TurboGTU]

Yes sir, 440-t4.

[cutlass supreme FE3]

so it is a 440-T4 or a 4T60?
Where would I find the transmission code? Accessible from under the hood or beneath the vehicle?

[cutlass supreme FE3]

would this tell you what the transmission is??

[gpse3400]

...Like we are trying to tell you, you definately have the 4 speed....

440-T4 is the same as the 4T60. They changed the numbering later on.

MX0 is the RPO code for the 4 speed.