Foxbody trans swap

jimendo20 · May 30, 2026

I just got a foxbody. Dream car. Starting project ran and drive for a while 3rd gear gave out. Getting stuck. I got a used trans but I believe its from sn95. Did swap left bellhousing attached to car just swapped transmission.
It started and died out wont crank over again.

Any thoughts?

AeroCoupe · May 30, 2026

A T5 from a 94/95 car will not bolt up if you used a Fox bell housing. This is due to the input shaft being longer. You would need to swap the input shaft from the Fox T5 into the 94/95 T5 and shim it according to end play.

Have you checked for codes? Check engine light (CEL) only illuminates for emissions related codes so other codes can be present and you will not see a CEL flash.

jimendo20 · May 30, 2026

Havent checked codes. I guess its mixed matched then. It bolted on just fine. Sorry. Completely new to all this. Car used to be a 4cyl. Previous owner did swap to 5.0. Got it as is.

KRUISR · Jun 2, 2026

If the trans still has the tag on it, check that. Since your car used to be a 4 cyl, check the tag on the old trans too. What you are looking for is the 1352-xxx number on the second line. It will identify what the trans was originally built for (not that it couldn't have been rebuilt at some point in its life).

Here is a pic of the tag...

This is a 96-98 V6 trans I have.

The reason I ask you to check the old trans is some folks have used a 4 cyl trans behind a 5.0 - not recommended to any kind of spirited driving.

Mustang5L5 · Jun 2, 2026

Do you have a photo of the trans? Or maybe at least one under the car? Might be some visible clues to ID it.

So car is no crank right now? DO you hear the solenoid clicking? Does the starter at least try?

jimendo20 · Jun 4, 2026

Mustang5L5 said:
Do you have a photo of the trans? Or maybe at least one under the car? Might be some visible clues to ID it.

So car is no crank right now? DO you hear the solenoid clicking? Does the starter at least try?

the one it had ans the one I installed. Does not crank. Solenoid wont click. Starter wont make noise at all. Tried to crank over engine with a braker bar. Seems locked. But was running just fine before installed. After install, it ran, died out and just didnt crank anymore.

jimendo20 · Jun 4, 2026

KRUISR said:
If the trans still has the tag on it, check that. Since your car used to be a 4 cyl, check the tag on the old trans too. What you are looking for is the 1352-xxx number on the second line. It will identify what the trans was originally built for (not that it couldn't have been rebuilt at some point in its life).

Here is a pic of the tag...

This is a 96-98 V6 trans I have.

The reason I ask you to check the old trans is some folks have used a 4 cyl trans behind a 5.0 - not recommended to any kind of spirited driving.

This is what I had on

KRUISR · Jun 4, 2026

The photo of the tag in the car says its a 99 WC trans with electronic speedo. You can see the sensor in the same pic just in front of it. The gearset in that trans should be the same as a 90-95 5.0 WC trans - 300 ft/lbs rating.

Can't tell exactly what your old trans is internally. What is the measurement of the length of the bearing retainer and/or from front of case to tip of input shaft. I have a 96 V6, 94 GT, 00 V6, 04 V6 and an 88 4 cyl T5 handy in front of me for the next few days and can compare measurements if needed.

Best way to tell if its the trans or engine is causing your locking issue would be to pull the trans (leave the bellhousing and flywheel/clutch in place) and try turning the motor over with a wrench.

Mustang5L5 · Jun 5, 2026

Yup. that's a 99-04 T5 that put in.

Old trans says Borg-Warner, so it's pre-1998. Top cover does look like it has the provision for the NGS, so it's likely a Fox trans.

Assuming no parts have been swapped on these trans, the 99+ T5 will have an input shaft that sticks out 3/4" longer. I wonder if it's what's jamming your engine up.

Jack the rear end up. Put the trans in gear and have someone push the clutch in. Can you spin the rear wheels and get the driveshaft to turn?

With the clutch in, can you turn the engine over with a breaker bar

Loosen the 4 trans bolts. You don't need to remove it but back the bolts out far enough the trans can slide back (might need to loosen trans mounts as well). Does this free anything up?

AeroCoupe · Jun 5, 2026

That appears to be a Fox bellhousing based on the clocking of the clutch fork. If that’s the case Inwould think that the longer input shaft would physically keep the bellhousing from being flush with the block.

Mustang5L5 · Jun 5, 2026

Yeah. Not quite sure where the extra length is being that it all looks flush. Someone could have converted that 99+ trans.

But based only on appearance it shouldn’t work and I wonder if it’s the cause of the issues

AeroCoupe · Jun 5, 2026

Does a modular T5 case bolt up to a Fox bell housing?

Mustang5L5 · Jun 6, 2026

Yes.

I have one right now in my basement on an engine stand bolted to an 83-85 bell

The T5 only came on the V6s from 96-10, they never bolted to a mod motor

AeroCoupe · Jun 6, 2026

Ah I did not know that. I do remember now that the V8 mod motor got the T-45 so learned something today.

jimendo20 · Jun 10, 2026

Mustang5L5 said:
Yup. that's a 99-04 T5 that put in.

Old trans says Borg-Warner, so it's pre-1998. Top cover does look like it has the provision for the NGS, so it's likely a Fox trans.

Assuming no parts have been swapped on these trans, the 99+ T5 will have an input shaft that sticks out 3/4" longer. I wonder if it's what's jamming your engine up.

Jack the rear end up. Put the trans in gear and have someone push the clutch in. Can you spin the rear wheels and get the driveshaft to turn?

With the clutch in, can you turn the engine over with a breaker bar

Loosen the 4 trans bolts. You don't need to remove it but back the bolts out far enough the trans can slide back (might need to loosen trans mounts as well). Does this free anything up?

So, removed trans today. Piece of the sleep of input shaft got stuck in the throwout bearing and fork. This is hour it came out

jimendo20 · Jun 10, 2026

jimendo20 said:
So, removed trans today. Piece of the sleep of input shaft got stuck in the throwout bearing and fork. This is how it came out

Shaft is same size. Sleeve is longer? Idk. Didnt check the bell housing length. I’ll check that tomorrow.

Mustang5L5 · Jun 11, 2026

Sn95 bearing retainer is longer than Fox. I have one kicking around that I can measure later, but it's looking like that was an SN95 trans without mods. That input shaft should be about 0.65" longer than the Fox one.

If oyu have your old trans still, measure from the case to the tip of the input shaft and see if there is a difference between the two. Likely there is.

You might have to pull the clutch off and inspect for damage to the pilot bearing or other components in there if this is the case

KRUISR · Jun 11, 2026

If you have the transmission out of your car, check at the top of the bellhousing. A 94/95 bell has 5.0 cast into it. Fox bellhousings do not have this. V6 bellhousings have a 3.8 cast into them.

As mentioned above, the mod motors never used a T5 but an aftermarket bell is available to have that combination.

If you have the input shaft out (not mounted in the trans) look at the splined section length and the smooth section back to the bearing area. On a Fox input shaft, the two lengths are the same or slightly longer splines. On an SN95 the smooth section is clearly longer.

An image I found on the internet but shows the difference. The smooth part back to the polished tapered section.

My collection of spare T5s...

Starting top left - 96 V6 (1352-238) with a newer top cover (likely rebuilt at some point), 94GT in the middle, 00 V6 (1352-260) and 99 V6 (1352-260).

Your top cover looks like the 94 GT, shaped like the Fox with neutral provision, but not the sensor. So likely yours is a 94-98 (V6 or GT).

jimendo20 · Jun 11, 2026

Left is the one it had. Right is the one going in. Bell housing is taller but does not align with engine from 3.8.

Mustang5L5 · Jun 11, 2026

The top cover that says Tremec is the post-98 T5, however the two input shafts appear to be the same lenght. So possible that was swapped

Fox shaft should be 7.1” long and sn95 is 7.9” long.

However, it seems they reused the sn95 bearing retainer and didn’t cut it down??

Foxbody trans swap

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lube between the nut and the face. I know my lubes

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That is…until I whipped out my Bissell

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New Member

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That is…until I whipped out my Bissell

lube between the nut and the face. I know my lubes

That is…until I whipped out my Bissell

lube between the nut and the face. I know my lubes

That is…until I whipped out my Bissell

lube between the nut and the face. I know my lubes

New Member

Attachments

New Member

Attachments

That is…until I whipped out my Bissell

New Member

Attachments

That is…until I whipped out my Bissell

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