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InNeed f5m31..


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Can anyone could tell me if i could put a tranny out a 2.0 in a 2.4 nonturbo spyder or where i might be able to find a f5m31 tranny mine took a hit not rebuildable

IIRC the n/t Spyder trans is slightly different, should bolt up but I believe you have to clearance an area inside the bell-housing. @twicks69 or @pauleyman might be able to clarify what will/won't work.
Also I believe what you're actually looking for is an f5m33, not 31 (some parts on the 33s will say 31). The top trans engraving on the bell-housing should read F5M33.

The F5M31 is only used in the 2.4L nonturbo spider. Your clutch and flywheel are interchangeable with turbo FWD components as well as swapping in the F3M33 2g turbo FWD transmission. Shift cables are the same, I am not 100% certain on the axles; they are 27 spline on the 2g F5M33. Check the spline count on your inner axle cups.

The F5M31 transmission is pretty weak, the F5M33 transmission has a better gearset.

You could probably get that welded but if you can find a new one than right on .

Did you notice that you posted in your build thread? You might get more answers on the tech question part of the forum

o0GuitarKid0o said:

You could probably get that welded but if you can find a new one than right on .

Did you notice that you posted in your build thread? You might get more answers on the tech question part of the forum

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Only way that is being welded is by completely disassembling the trans, then degreasing, washing, bead blasting and then cleaning again before preheating and TIG welding. There is an input shaft seal behind the snapped off TOB sleeve as well as a bearing race and shaft bearing. Would not be a good idea to weld ever assembled. The bellhousing chunk would need the same thing done. Grind surfaces, and then TIG.

Personally it is not worth it for a 2g F5M31 trans that is a pile of junk in the first place.

Much better off simply finding a 2g F5M33 turbo trans.

You can't use the 31 axles in the 33 trans you have to find turbo axles if you go with the turbo trans the 31 is smaller where it goes into the diff.

twicks69 said:

Only way that is being welded is by completely disassembling the trans, then degreasing, washing, bead blasting and then cleaning again before preheating and TIG welding. There is an input shaft seal behind the snapped off TOB sleeve as well as a bearing race and shaft bearing. Would not be a good idea to weld ever assembled. The bellhousing chunk would need the same thing done. Grind surfaces, and then TIG.

Personally it is not worth it for a 2g F5M31 trans that is a pile of junk in the first place.

Much better off simply finding a 2g F5M33 turbo trans.

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Yeah seems like a better idea to grab a new trans unless buddys a welder and knows a transmission guy

The Motor mounts might be differnt for the fm33 also and flywheel and starter.

i know this is an old thread but i just came to say, i unknowingly swapped an f5m31 into my GST that originally was automatic.

now i see you guys saying the axles aren't the same between the 31 and 33 and that may be true, but i can personally verify that the axles that were being used on the old automatic went right into the f5m31 and worked just like they're supposed to... now im bummed i got the 31 and not the 33

The spline count difference between “31 and 33” is generally taking place in the realm of 2G manual transmissions, where the F5M31 (paired with the 4G64) has 25 splines at the differential and the F5M33 (paired with the 4G63) has 27 splines at the differential.

Your swap isn’t as common. And as you’ve found, the automatic FWD turbo transmission (F4A33) has 25 splines at the diff.

It’s important to know a little more information past “31” and “33”.

btw i cleaned the case more on the transmission, the bellhousing actually has a f5m33 stamping (followed by more letters/numbers) while the case behind the bellhousing is stamped f5m31.. rtv between the two doesn't look oem either, im guessing someone put this thing together to work with their swap... i stumbled on it at the junkyard a few years ago

2gGSTsquared said:

btw i cleaned the case more on the transmission, the bellhousing actually has a f5m33 stamping (followed by more letters/numbers) while the case behind the bellhousing is stamped f5m31.. rtv between the two doesn't look oem either, im guessing someone put this thing together to work with their swap... i stumbled on it at the junkyard a few years ago

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Its an F5M33 most likely. All the gearcases I have seen have F5M31 cast into them.