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Re: Tremec TKX new 5 speed

PostPosted: Thu Jan 21, 2021 1:58 pm
by Frogelan
Very impressive work Greg and the TKX seems to be very well adapted indeed.

I hope you will give a summary of the parts (I got a little lost) when it is up and working.


Re: Tremec TKX new 5 speed

PostPosted: Thu Jan 21, 2021 2:26 pm
by h20hamelan
Worth mentioning, as I think CABC26 was the first to do this T5 (though he never posted anything)
I believe the speedo is in the wrong/inaccessible spot. Maybe Greg can comment?
I have not finished my T5 swap yet, planning on GPS driven speedo, also because of tyre size (cant recall, there are two suppliers in N America fit original Smiths).

Hope to have LSD, T5 and Fi Lotus/Ford +2 soon :D

Steve at TCSc has done them too, so probably 4-5 out there so far.

Re: Tremec TKX new 5 speed

PostPosted: Thu Jan 21, 2021 2:39 pm
by gjz30075
I think TomR was the first but using a Ford 2.3 SVO (I think) bellhousing and S10 tailshaft. I was able to watch the
progress of Cabc26's T5 install at a local shop and that inspired me to move forward on mine. I
already had the RWD bellhousing; just needed a kick in the butt to get started :-)

Speedo output on the tailshaft is irrelevant because it's plugged, I use the Speedhut Speedbox mounted
in the glovebox to drive the oem speedometer. I prefer to mount it with more of a straight shot (for the
cable) to the speedo, like 1 owner69 did, but I'm going for oem / stealth look.

I'll take this further. My gearbox mount is using the oem mount turned backwards. Hopefully
the picture can depict this. No exhaust yet. Because the tailshaft mounting holes are up against
the frame tunnel, I made a mount that 'cantilevers' forward, then the oem mount mounts to it. There
are rubber pieces in between the two. The cantilever mount is 1/8" steel with two ribs for strength.

We're going off the rails a bit here but to answer the op's question, although the TKX box is smaller,
it's not an advantage that I can see, as long as the T5 fits.

I should probably start a thread with the trials and tribulations with this mod :-)

Re: Tremec TKX new 5 speed

PostPosted: Thu Jan 21, 2021 5:09 pm
by prezoom
Silver Sport Transmissions seem to be the vendor of these transmissions as seen in an ad in Hemmings Daily's postings. Nice video explaining the new version of the T5 mentioning multiple shifter locations, and indicating they may be able to accommodate most any location. The box comes with two speedometer options, mechanical and electronic. Also two different overdrive options.

Re: Tremec TKX new 5 speed

PostPosted: Thu Jan 21, 2021 5:33 pm
by nmauduit
gjz30075 wrote:Nick, the best pics I have that shows anything significant is the shifter location.

thank you, that seems very promising indeed, I'll certainly keep that in mind (I would opt for annular clutch, which I find easy and reliable enough so far) , so the rest of the mods certainly seem reasonably mininal considering the swap itself would be only justified by a more powerful powerplant, at least in my case...

please keep us posted !

Re: Tremec TKX new 5 speed

PostPosted: Thu Jan 21, 2021 5:50 pm
by gjz30075
I'm using a Tilton annular throwout bearing. Their recommendation is the 60-6104 for an 8 1/2" bent
finger diaphram pressure plate. This is what I'm using and had in the car with the 4 speed. They also
recommend using a 3/4" master. I changed mine to 3/4" and the feel is a bit heavy but no heavier than
when I was using a standard, 5/8" master with the 4 speed.

There are plenty of options out there for annular throwout bearings. The face of the Tilton is flat, which
goes against the recommendation of having curved face for the diaphram clutch without the platen. Seems
to work pretty good, so far.

Re: Tremec TKX new 5 speed

PostPosted: Thu Jan 21, 2021 8:05 pm
by 1owner69Elan
I should probably start a thread with the trials and tribulations with this mod

Further elucidation of the fitting of a T5 (presumably applicable to the TKX) would be very useful to the community. A viable alternative to the Voigt T9 could be helpful. Be useful to see how much modification/fabrication is needed for both options. Also, cost comparison.

If the TKX fits, seems a downside might be the weight (99 lbs). The 600 lb-ft torque capacity is certainly overkill for the Lotus, but this rating may be using a larger diameter clutch than we have.

I have the Voigt T9 with a Close ratio gear set with a 0.75 fifth and I am overall quite happy with it. But, a more "mainstream" and modern TKX adaptation, as opposed to a custom designed and fabricated low volume Voigt T9 unit, would be worthy of consideration.

Re: Tremec TKX new 5 speed

PostPosted: Thu Jan 21, 2021 8:11 pm
by mbell
The concern for the T5 for me was that you needed to get the right combination of parts for it:
- Bell housing
- Gearbox (Input shaft and ratio)
- Tail housing (S10)

All of these are likely second hand and can't just be ordered from a supplier I believe. The TKX probably doesn't solve this but allows purchase of new gearbox with correct input shaft, ratios and tail housing (assuming it fits). If you have easy access to the T5 parts then the advantages are minimal. If you don't then buying the correct TKX is probably a lot easier (but more expensive) than trying to get the right T5 combination of parts.

The rest of the problems fitting a new gearbox remain with the TKX (bell housing, pilot bearing, clutch plate, clutch hydraulics, gearbox mount, speedo drive, prop shaft)

Re: Tremec TKX new 5 speed

PostPosted: Thu Jan 21, 2021 8:17 pm
by h20hamelan
I paid $300, for 6 boxes.
3 S10 and 3 mustang
They are still available, people are buying them for their Volvo’s (2 are for my Volvos which I use for towing bikes) and the other for +2. The S10 boxes are more rare, and many people use them for their hot rods because they are longer than the Mustang camero. I do have an extra S10, dont think I want to part with.
The RWD bell was less than $200 shipped
The Saab annular/concentric clutch slave was about $70
PP (8” works fine) and clutch $120
These are Cdn prices, or about 1/2 that £, 2/3 USA$

No frame mods needed

Re: Tremec TKX new 5 speed

PostPosted: Thu Feb 04, 2021 2:14 pm
by TomR
I have posted some detailed threads in the now far past on putting a T5 into an S4. I used a short tailhousing for an S10 truck and a Mustang SVO/TBird 2.3L bellhousing. It is not bolt-in at all but doable.

The TKX probably fits in general but I'm not sure about available tailhousings. Also, you'll need to use a digital speedo (I used a Cobra replica).

On the other hand, it has beautiful ratios (2.92/1.94/1.34/100/0.82) and is very light. Plus it shrugs off the 170ft-lb from my 2L Cosworth:-)

Re: Tremec TKX new 5 speed

PostPosted: Thu Feb 04, 2021 3:26 pm
by disquek
It seems like folks are seeing the TKX as smaller than the T5. It's not.

It's smaller version of the TR3550 (a different American muscle car transmission).

The standard (even the Z) T5 is seen as too light duty for a well tuned V8. The TR3550 is far heavier duty than the T5, but also far larger.

I have a '65 Mustang Fastback Restomod. I recently bought a T5 with a custom gearset from GForce. The T5 will fit in a Gen1 Mustang without modification to the transmission tunnel. A TR3550 requires major surgery to the tunnel. A TKX requires a less major surgery in moving the factory bracing rearward in the tunnel.

My point is that the T5 is the smallest 5 speed American gearbox. The TKX is not a smaller version of the T5. It' a smaller version of the TR3550.


Re: Tremec TKX new 5 speed

PostPosted: Thu Feb 04, 2021 9:10 pm
by TomR
Ah, good point Kyle. I only read about ther TKX on some hot rodder site and got the impression it was similar to the T5 (not smaller, not especially larger) and of course the internet is never wrong

You sure don't have much room to give up on the sides in the standard chassis - I cut a few small relief holes on the sides near where the housing ends and tailshaft begins although a hammer might have sufficed as it is close. And a TTR reinforced chassis requires some actual work to get the T5 to fit at all. I had Tony make up a reinforced version of my standard chassis (including a relief for a mechanical speedo at the time) but completely neglected the interference between the angled reinforcements on either side of the top inside of the tunnel. Had to make up indented patches and weld them in as I couldn't bring myself to leave holes in the reinforcements

Re: Tremec TKX new 5 speed

PostPosted: Thu Feb 04, 2021 9:22 pm
by disquek
I'm very bummed that this came out like a week after I bought my GForce T5. The GF T5 is a nice box, but one of the trick they used to get the torque rating was to reduce the helix angle. So it's LOUD in 1-3.


Re: Tremec TKX new 5 speed

PostPosted: Sun Feb 07, 2021 10:33 am
by gav
Hi all

Late to the party but on the dogleg ZF S5-18 box - I used to run this with a 4.3 diff in my Sprint.
It is the overdrive box rather than the 1:1 box that the elites use (more desirable for racing) and was known as the noddy box.
My TC was running 150 BHP/129 ft/lb and the box hardly noticed it. I subsequently changed to a Zetec and a Sierra box - engine is great but the box is definitely a retrograde step because first is pretty hopeless. The ZF has a positive change which I really like and the power delivery was great in that set up.
The downside was that the tower for the gear lever intruded into the tunnel just behind the dash. I was looking for some photos but haven't found any yet but will add if they appear. I hid it with a carpeted casing that lessened the impact but if you want to keep the original interior, the change mechanism will need some clever re-engineering.
The box is destined to go into my competition car - unless I change my mind again - choices, choices.
Good luck with the project.

Re: Tremec TKX new 5 speed

PostPosted: Fri Feb 12, 2021 3:11 pm
by cabc26b
Also late to the party but will ad my comments having fitted the Tremec T5Z to the elan.

First off, once the dimensions showed it would work out , the rest was of the process was easier than i expected. To address a comment made earlier - with the exception of the transmission mount ( fabricated ) all the associated parts were bought as new parts - bell housing, clutch disc, transmission, tail-shaft , shifter, yoke to driveshaft etc.

There were minimal modifications requited to the frame , both stock and TTR , with reinforcements . The TTR frames are not "drilled" for the motor mount so there better placement once you get it sorted. Yes the shifter worked fine in the stock frame , the MDL shifter has minimal slop.