What you need to swap a 3650 into a 96-98 car. t-45 to 3650

Discussion in 'Drivetrain' started by ScottyDsntKnow, Jun 3, 2014.

  1. ScottyDsntKnow

    ScottyDsntKnow Well-Known Member

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    I just got done with this swap because I was able to get a brand new fresh rebuilt 3650 with no core charge for $1060 to my door from a transmission shop in Minnesota. I know its not a very common swap and ppl get skeered of the VSS to OSS speedometer thing but its not a big deal.

    You will need:

    -3650 from 2001-2004 (note ALL 02-04 3650s have a .62 overdrive vs .68 for the 01 and the T-45 if that matters to you)
    -79-95 style trans mount
    -Stiffler's T-45/3650 Crossmember for 96-98 Click me
    -3650 shifter
    -Shifter pivot ball cup if your 3650 doesn't have one (ebay)
    -OSS sensor
    -Reverse switch from your T-45
    -Dallas (dallas not FRPP) speedcal

    A new OEM/McCleod/DD TOB is always a good idea when the trans is out.

    Pull the t-45 and install the 3650 on the block like normal. I had to put a block of wood under the front of my oil pan and tilt the motor as far back as it would go to get it in there because the 3650 case is a little bigger than the T-45. Then, bolt on the trans mount and install the crossmember like in the instructions but WITHOUT the spacer. NO idea why they have that spacer in there but all it does it push the trans up against the tunnel. One might be asking, why not use the stock crossmember? Well, because it wont' clear the 3650 case, even if you grind off the casting tab at the bottom of the tailshaft housing. The actual body of the case itself sits down on the crossmember and the 96-98 style mount won't fit the 3650 at all. The bottom of the mount does not clear the case either. I suppose one could use a Cobra crossmember setup and then toss a 94/95 hangar plate onto the 3650 which moves the mount itself back an inch and a half or so. That would be what I would do if I had a 96-98 Cobra and was doing this swap.

    Anyway, after the crossmember shenanigans, the driveshaft is a direct bolt in, install your OSS sensor and wire in your speedcal if it isn't already. My car had it wired in by the previous owner so don't ask me about it lol. Also install your reverse light sensor (teflon or rtv on the threads) at this time. Button the exhaust back up and everythign else that you need to do, fill with 3.2 quarts of fluid through the shifter hole (3.2 NOT 3.8, 3.8 is the old fill and is too much), install the pivot ball cup onto your new shifter install the shifter into the 3650. The 3650 has internal stops so do NOT set the stops if your shifter has them, you can damage the transmission if shifter stops prevent it from engaging fully. I removed the stop bolts completely on my Tri-Ax.

    Now, onto everyone's favorite part, the dreaded VSS to OSS. It is stupid easy. You multiply your current rear tire's revolutions per mile, (look it up on discount tire direct) by your rear gear ratio by 12. 12 is the number of OSS pulses for the 3650. Once you have said number, plug it in here in the "current setup VSS pulses per mile" block. The extended range speedcal number it spits out is your switch setting . 1 is up and 0 is down. All new and newer Dallas Speedcals are extended range so unless you have a really old one you will be good. I was able to get my speedometer dead on accurate the very first time and it really is that easy.

    Now... break it in for 1000 miles, change the fluid out if you want to and have fun with your trans. For fluid, I use Pennzoil Syncrhomesh, its like mother's milk for the 3650.

    Hope this helps anyone wondering about this swap. I sure as hell got fed a TON of bad info such as grinding off that casting tab, being able to use the stock crossmember/mount and seems everyone is scared to death of the VSS to OSS thing. Yes I understand the T-45 that is built properly with the single rail design is going to shift better. I am into this transmission fully for under $1200 shipped to my door after I just sold my shifter for $100 and I still have the t-45 core I can get a few $hundred for as well. It shifts smooth the .62 overdrive is great for 4.10s and I'm not trying to set the world on fire right now with this thing. Any other questions or if I left something out just ask. I also did use Cobrabob gaskets on the shifter and its nice and quiet.
     
  2. Cpotts13

    Cpotts13 Well-Known Member

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    Do you have any pictures? Maybe if you edit it and put it in a 1, 2, 3 step format it could be stickied.

    Sent from my SAMSUNG-SGH-I337 using Tapatalk
     
  3. ScottyDsntKnow

    ScottyDsntKnow Well-Known Member

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    I am actually going to swap the junk $12 trans mount out today or tomorrow with an OEM one I got from LRS so I can get some pics of the crossmember but that's really the only thing I can think of as far as pics. It looks damn near identical to the T-45 in there and IS for all intents and purposes.

    That's another thing... the mount... I highly HIGHLY recommend an OEM rubber mount. The prothane ones tend to cause vibration issues and also the holes are a hair off requiring one to have enlarge the crossmember slots a bit which kills the adjustability feature of the stiffler's and also takes off the coating too. I've found from over a decade and a half wrenching on these cars that the best combo for mounts is a good set of energy suspension poly motor mounts and a brand new OEM Ford rubber mount. I only had the aftermarket rubber one in because the crossmember got here stupid fast and I had a lift available that weekend so I ran to the parts store and got what they had. One of the studs was spinning in the rubber during install so I'm getting my money back for it and also illustrates why one should stick with OEM. It was serviceable to do an initial very easy road test though.
     
  4. ScottyDsntKnow

    ScottyDsntKnow Well-Known Member

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    Some pics after I had it on the lift.

    [​IMG]

    Can see from this pic below the tab I was told to ground which you can see did NOT need to be ground

    [​IMG]

    And you can see here why you need this swap crossmember.

    [​IMG]

    The stock crossmember goes straight across and bangs right into the bottom of the case.

    [​IMG]

    In the above pic you can see how close even the stiffler's unit is but obviously not close enough to be a problem.

    The ONLY issue I ran into with this swap crossmember is I had to take a cutoff wheel to the BBK exhaust hanger pegs because they were hitting the crossmember and preventing the exhaust from tucking up to the floorboards like it should. You can see in the first pic where the paint got rubbed of from the left one. Once I cut them off I put a jack under the exhaust and pushed it up till it was against the crossmember again and tightened the crap out of it. It lowered about 1/4" after I removed the jack so clearance is great and its very close up to the body of the car as well.

    [​IMG]

    Like I said I don't think a how-to is required for those who have done a trans remove/install in a SN95 or Fox. Everything is the same minus the stiffler's crossmember, the mount and the VSS to OSS.

    edit: Please excuse the crap looking grinding job I did. I was in a hurry and I eventually will go back and smooth it all out. It is not hurting anything though and I will likely get to it later rather than sooner...

    edit2: Yes I know I need subframes.