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T5 with a 1725 motor

Discussion in 'Modified Alpine' started by Mag0152, Jan 16, 2022.

  1. 260Alpine

    260Alpine Silver Level Sponsor

    Easy way to remember, 94 and up V8 and V6 have the longer input shaft. You can swap input shafts as long as they are the same first gear. You could also use a spacer pilot bushing like Dan has made for the V6.
  2. 260Alpine

    260Alpine Silver Level Sponsor

    You can change the OD ratio by swapping to different pairs of cluster and main OD gears. This thread has a good explanation. Lots of later long shaft Mustang V6 T5's on car-part. com for average of $400.

    BritishV8 Forum: Changing 5th gear ratios on Ford t5
  3. spmdr

    spmdr Donation Time

    I'll use the short input boxes because that is what I already own.

    Also, long input shafts for the 2.95 box are odd ducks for sure.

    And I would not count on future availability for Odd Ducks.

    I'll mod the bellhousing as needed to use what I have and what is more common (short input 2.95 T5s).

    Having said that, If you are looking for a T5, get what suits your needs.

    DanR, what mods are needed to the trans tunnel to put a T5 behind a V6?

    Last edited: Jan 21, 2022
  4. 260Alpine

    260Alpine Silver Level Sponsor

    I think the 2.95 long input is aftermarket only.
  5. DanR

    DanR Diamond Level Sponsor

    Dan, I believe that you may get by without any cutting if you go with the Alpine engine, bellhousing and related clutch components.

    The only reason to modify the Alpine tranny tunnel when doing the V6 with the T5 is because of the need to utilize the Mustang II Bell housing and it has an external "Bell Crank" that is needed to activate the release bearing for the clutch.

    I did the modification to several of my Alpine V6 Conversion before I realized it "may be possible" to forgo the widening of the tranny tunnel if you elect to utilize an internal hyd release bearing.

    I am currently restoring my 1965 late Series IV ST OD Colour code 70 Alpine. As soon as I get an opportunity I will measure some of the engine, bell hosing and transmission components and compare with the T5 if you are interested.
  6. DanR

    DanR Diamond Level Sponsor

    Jim you may be correct. I just had a T5 from a 3.8 V6 1352-238 rebuilt and changed the input shaft to the 2.95 1st gear. The outfit that did it for me is AllTrans, Greenville, SC. They have been very nice to deal with over the years and have built several T5 and recently an A4LD.

    I believe they said the input (new) was the last one available. It was a tad expensive but better than some trannys off the WEB.
  7. spmdr

    spmdr Donation Time

    It looks like the shifter position of the AMC and Chevette tailhousings are close to the Alpine shifter position.

    And the short Chevette T5 is close to the overall length of an Alpine trans as well.

  8. DanR

    DanR Diamond Level Sponsor

    Another consideration will be the location of the universal/yoke position. Does it fit in the x-frame?
  9. Gumby

    Gumby Donation Time

    This is a fascinating discussion on the introduction of the BW T-5 Five speed into an otherwise Stock Alpine. I am "Hoping" that a "definitive" solution will become clear through all of this, leaving only the gear ratios to personal choice. Doing NO sheet metal work on the car is the ultimate goal here. There are so many combinations discussed already, it's impossible to determine WHICH parts do I need.

    Physically fitting in the car is the first order of business. What fit's in the space we have (Stock 4 cylinder Alpine). \i.e., tail shaft length that fit's within our X-frame and existing trans tunnel and stock shifter location?

    Second, input shaft length so that it will actually bolt up with an adapter plate and not jam in to the end of the crank, or fall out of the pilot bushing.

    Third, clutch components... What works with the existing flywheel, pressure plate (cover), and throw out bearing we already have? The Transmission doesn't care about these but the disk itself may have to be a different one base on splines and diameter. OK fine, what will work with our existing set up? Clutch disks are all pretty close to the same thickness from one application to another (yes I am speaking in general), so inner and outer diameter to match the flywheel's surface and cover's plate are critical, as is the spline and shaft diameter. Again, there should be a definitive choice here. Material would be next, standard, kevlar or ceramic pad style. mostly personal choice here. What works?

    If the clutch parts must be changed, again, what works? Aftermarket over the shaft hydraulic throw out bearing? are they adaptable? Other clutch covers? Does the flywheel need to be drilled or modified?

    Finally is the gearing, within the units that fit (shaft length) shifter location, tail shaft within the X-frame). Of the ones that fit, which models (stamped ID's) have the ratios we can select from.

    The Adapter Plate itself, unless someone here has a CNC Mill and can reproduce multiple plates, will have to be fabricated as needed.

    That's what we need. A definative list of this "KIT" we can assemble to give our cars that desperately needed overdrive 5th gear using American parts. I don't really want to use a Toyota 5 speed.
  10. Bill Blue

    Bill Blue Platinum Level Sponsor

    A lot of interesting questions, especially the ones about the clutch. No help here. However, there is one item that can be scratched off of your list of concerns and that is tailshaft length within the X-frame. Based on my car with the engine setting within a quarter inch of the firewall and a looong A4LD transmission, I can say absolutely no problem.
    BTW, I seriously doubt a CNC mill would be necessary to make up a batch of adapter plates, especially if both transmissions use concentric ring and bore to locate the bell housing. If they do, plates could be made with a manual lathe and drill press. No magical machine work required. Some drawings would be helpful to fully assess the problem.
  11. Barry

    Barry Platinum Level Sponsor

    No matter which unicorn tailshaft housing or shifter setup is used, installing a T-5 transmission in a factory manual transmission Series Alpine requires widening the left side of the transmission tunnel in the vicinity of the accelerator pedal. It's a simple modification, but one that is absolutely necessary in order to put a T-5 transmission in a factory manual transmission Series Alpine.
    Last edited: Mar 15, 2022
  12. Bill Blue

    Bill Blue Platinum Level Sponsor

    Most, if not all of the widening is to accommodate the Ford external clutch actuating components, which can be eliminated with aftermarket coaxial hydraulic thrust bearing.
  13. Alpine 1789

    Alpine 1789 SAOCA President Diamond Level Sponsor

    Or by starting with a SIV automatic. ;)
    Last edited: Mar 15, 2022
  14. Barry

    Barry Platinum Level Sponsor


    I have had three different T-5 transmissions in my S-V and the left side of the gear case (not the bellhousing and not the clutch linkage) of all three interfered with the left side of the transmission tunnel in the vicinity of the accelerator pedal. Have you installed a T-5 transmission in a factory manual transmission Series Alpine without widening the left side of the transmission tunnel in the vicinity of the accelerator pedal?
  15. Barry

    Barry Platinum Level Sponsor


    Did you miss the part about "... in a factory manual transmission Series Alpine"?
  16. Alpine 1789

    Alpine 1789 SAOCA President Diamond Level Sponsor

    I did. And for some reason, the smiley face I added after my smart-assed comment got dropped. I just fixed that.
  17. Barry

    Barry Platinum Level Sponsor

    NBA rules; no harm, no foul. In any case, you are right about the transmission tunnel for a S-IV automatic chassis being wider (to accommodate the BW automatic transmission) and eliminating the need to modify the transmission tunnel for a T-5 transmission. The S-IV auto trans mount is different (neither good nor bad), but that is also a minor issue.
  18. Alpine 1789

    Alpine 1789 SAOCA President Diamond Level Sponsor

    Even more minor after Dan started making a bracket for the Auto/T5 combination. Jim Ellis spent an entire day putting manual mounts on my SIV automatic (one stock and one fabricated by Jim). The car now has both sets, but I will use Dan’s bracket and the original mounting points.
  19. spmdr

    spmdr Donation Time

    When I did the Tiger T5 kits, I used as much stock Tiger stuff as possible.

    Going on that same theory, you could use the stock 10 spline clutch, with some mods,

    along with it's stock activation.

    This assumes a Mustang/Ford T5/input shaft.

    BUT, with a new-tech trans, why not a better clutch activation?

    However, having not put a T5 into an Alpine, I'm curious what the minimum mods are necessary

    to put a (modified) T5 into an Alpine.

    Here are mods I see, from a distance, so far:

    1) pilot bearing (or trans input shaft)

    2) Clutch (or trans input shaft)

    3) Bellhousing

    4) Transmission mount

    5) Drive shaft

  20. spmdr

    spmdr Donation Time

    So, what would a modified, for an Alpine, T5 look like?

    Here again, How close to a "stock" T5 do you want to stay?

    1) Main case, Ford type. (this may change depending on Bellhousing mods)

    2) Tailhousing, easiest would be an S10, would require a custom shift linkage to move the shift lever back.

    3) Input shaft, Ford 10 spline, with pilot bearing and spline sized to Alpine dimensions.

    4) Input shaft cover, shortened to clear Alpine TO arm, Bellhousing locating OD sized to Bellhousing mods.

    5) Speedo cable mods


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