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T-5 Tranny conversions?

51K views 135 replies 35 participants last post by  bearbvd 
#1 ·
Hello fellow Alfa owners!
I have owned and wrenched on Alfas for the past 15 years and am still learning, enjoying, and experimenting with this beautiful machine.

I have read hundreds of posts on the positives, and of the shortcomings in engineering design implementations of this automobile manufacturer.

One of my biggest areas of concern is how the power is transmitted to the rear end (transmission). There are questions of gear crunch, gear lightining, the proper way to shift an Alfa, no syncro downshift to first, and so on.

Personally, I'm working on a way to improve this area, permanently. These minor machining operations and misc available parts will allow the T-5 WC transmissions to be adapted to the Alfa bellhousing in a reliable and professional OEM type installation. The advantages are, and will be obivious. Imagine, choice of gearing, approx same weight as Alfa tranny, FULL,Positive, synchronization of gears - upshifting and downshifting very quickly, and the security of knowing replacement tranny parts are readily available if ever needed. The main part I will fabricate that will allow a sucessful and trouble free conversion is the machined aluminum adapter plate (attached to the Alfa bellhousing). I am using a '78 Spider as the test mule. I will thoroughly work out all the dimensions, fabrication details, and use as many readily available parts to make a troublefree install.

I will post my progress with text and pictures to share with the Alfa community --- Coming Soon !!!

flybird-T
 
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#2 ·
Hmm - interesting.

How will you handle the driveshaft? A conversion from the Alfa two piece, to a simple one piece driveshaft might also be an improvement. Like the transmission, the Alfa driveline is a weak area. The two driveshafts are sensitive to alignment, sensitive to balance, the U joints seem to fail frequently, ... A conversion using two U joints that are more robust and more available could be a real improvement.
 
#3 ·
I completely agree with all the points made in your post, ALFAJAY !!
The initial measurements from the tailshaft of the T-5 to the rear end, suggest that it is indeed doable with a 1 piece driveshaft, and maintain the same exact angle. Also using 2 real u-joints. I will be presenting this idea and dimensions to a shop here in the Bay Area for scrutiny.
Flybird-t
 
#5 ·
flybird-T:

Well, to keep the conversation going, I could throw out a few more questions:

- What sort of a car does a T-5 come out of? I am going to guess Ford, though this is just a guess. If the goal is to convert to something from the 21st Century, why not use a 6 speed box? Perhaps your choice was driven by expense, fit, or ...?

- How would your conversion handle the speedometer cable? Do modern transmissions even have a provision for a speedo cable?

- Will the hole in the tunnel for the gearshift need to be repositioned? The stock location of the Alfa gearlever is unusual in that it is so far forward. Most sporty cars have a shorter, more vertical lever, positioned further back. So, if the T-5 has a lever like this, it could be an improvement. However, that would complicate the conversion, due to the need to cut a new hole, fill the old one, and somehow modify the console.
 
#6 ·
- Will the hole in the tunnel for the gearshift need to be repositioned? The stock location of the Alfa gearlever is unusual in that it is so far forward. Most sporty cars have a shorter, more vertical lever, positioned further back. So, if the T-5 has a lever like this, it could be an improvement. However, that would complicate the conversion, due to the need to cut a new hole, fill the old one, and somehow modify the console.
I would say that for most of the Alfa market, the need to change sheet metal and/or the console would be an absolute deal breaker. For this to be a viable conversion it needs to be both bolt-on and 100% reversible.
 
#7 ·
Our race rules ( and a race car is the only old alfa I would think of doing this to ) allow changing the gearbox , which I've always thought odd -- but anyway, but the number of ratios must remain the same -- so 5 speed good.
BTW I have a ford paddle clutch in my race car and it ticks all the boxes much stronger, lighter and smoother than standard.
 
#8 ·
Alfajay:
Very good questions, and I have good answers; the T-5 was originall built by Borg-Warner, later sold to Tremec. BW was original supplier to many different car manufacturers (some are Ford, GM, Nissan,) so availablity is extremely good.
The choice for the 5 speed is expense and availibility. You will be able to use a 6-speed tranny also, but all my measurements will be surrounding the 5-speed. The taihousing from Chevy S-10 bolted to a main tranny box from a Ford Turbo Coupe, will provide stock location for the shifter,(no sheet metal modification) and provisions for a mechanical speedometer. The goal is to make the conversion as much bolt-on as possible. Keep in mind, there are instances where bolt holes would have to be drilled, and moderate mechanical skill and understanding will be necessary.
One post mentions; 100% reversibility--this is not a priority of mine, but It can be unistalled, and reconfigured to the original set-up.
 
#27 · (Edited)
Alfajay:
Very good questions, and I have good answers; the T-5 was originall built by Borg-Warner, later sold to Tremec. BW was original supplier to many different car manufacturers (some are Ford, GM, Nissan,) so availablity is extremely good.
What gearbox is in the BMW 2002?. My father had a 2002 Tii and notchy change compared to an Alfa ... I thought it was a BW something.

Anyway I'm keeping out of this thread. Too many people cannot accept old vintage cars as old vintage cars and for some weird reason want to make them as boring and easy to drive as modern cr@p ... :confused: ... have fun.
Pete
 
#9 ·
Hi all,
I am posting some pics below to show physical comparisions between the two trannies. On one pic you can see that the T-5 lends itself to a variety of different adaptable shift levers by the two bolt mounting (even a completely stock looking shift lever can be fitted). The difference from the stock location of the original shifter to the T-5 is approx. 1". This is an early type S-10 chevy tailhousing which moves the shifter to this ideal location. On a T-5,
mostly all tailhousings interchange to provide different shifter locations.
Now, ladies and gentlemen, I am going back into my work area to verify measurements and fabricate the adapter plate.
 

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#10 ·
T-5 Conversion

I heard of a T-5 conversion while racing at the VIR 50th reunion and tracked it to Ken Kneher. Ken uses the Alfa bellhousing but has come up with a custom rear housing to use the stock location of shifter and rear cross member.

The T-5 can be built using any number of ratios, with syncros or dog rings for racing. A complete syncro box was around $3500 if i remember correctly.
 

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#11 ·
Hi Dave,
I have heard of that conversion also. That is a very excellent piece of work by Ken. The T-5 shows its durability in the racing arena.
I will also be using the Alfa bellhousing, clutch slave, flywheel,etc. in the original location. However, the cost of this conversion to put the shifter in it's proper location will be approx. $50. to $75.00 using the tailshaft housing from the S-10. (located at any pick-your-part or just about any recycler!!) The rear tranny mount will attach to the original crossmember by way of a sturdy fabricated bracket. Most complete used T-5 transmissions can be had for approx. $80-$100 from recyclers. Again, very good post, and good pic Dave
 
#13 ·
T5 for the Alfa V6?

Cool idea!

Aren't there a variety of "T-5" transmissions out there? Isn't the T5 WC ("World Class") a bit of overkill for a 4-cylinder car, since it was fitted to V8 Mustangs. Aren't there other variants of the T5 fitted to V6 Mustangs, Camaros, Rangers, S-10s, etc.? Are they any smaller or lighter? Do WC gear sets interchange with lesser T5s?

Heck, as long as you're at it, what are the chances of developing a T5 adaptor for the Alfa V6. Seems like there might be a market for folks wanting to put a V6 in their Spiders and GTVs. The biggest challenge with those projects is finding a suitable transmission and fabricating the bellhousing.
Combine that with a set of motor mounts, custom headers and a custom sump, and it might become a marketable and cost-effective alternative to a TwinSpark conversion. Hmmm....

George
 
#14 ·
Hi gattia86,

You're right about there being a variety of T-5 transmissions out there. That's what makes this choice of conversion so tempting. This particular set-up will accomodate all T-5 transmissions with the Ford mounting pattern, but it will not be overkill. The main case and most internals I am using are from the 2.2L Ford 4 cylinder. The trannies are rated by torque handling capacity. The WC tranny backed, 4cylinders, 6 cylinders, all the way to beefy V-8s with over 300 lbs torque output. It all depends on what parts you use on the inside. Also the selection of WC means it is a later gearbox with improved internals(better bearings rather than bushings, composite faced syncros,
etc.). In my opinion the WC are more plentiful, affordable, and all WC internals interchange. The weights of the WC and non WC (earlier production) are aprox the same --give or take 2-3 lbs. Production of the WC came about 1987 -1988 to approx 1996 - 1999. The non WC was earlier. to answer your next excellent question -- I will be developing a conversion for the Alfa V-6. That idea is excellent, but will have to wait until this 4 cylinder project is realised, and thoroughly test driven.
Thanks for the insightfull questions -- I am glad and proud that so many members are really knowleable about the intricacies of Alfa mechanics. For more info, google 'T-5 transmissions'
Thanks,
Flybird-T
 
#16 ·
T-% W?C gear box for Alfa

We have t-5 boxs that fit Alfa, they use Alfa, bell house, trans support, shift leaver. The leaver comes up in the right spot and even use Alfa through out bearing. The street unit has many possable ratios and overdrive ratios. It curently uses carbon fiber syncrs.
The RACE ONLY box uses dog rings insted of syncros . Curently Im trying to source a .88-90 overdrive gear. Sooooooooon I sware, but just never gets done.
I can send pictures ETC.

Ken
SportscarworkshopS
1210 Myers st
Richmond Va 23230
1-804-539-2532
SportscarWorkshops
 
#17 ·
Transmissions For Alfas

While helping Krys Dean with her GT1 Camero I became too familar with her gearbox as it was not up to the task of 800+ HP and 600 lbFt tq.:rolleyes:
But the T5 based G Force Dog gear box would make a great small motor trans as the large gear 9310 shafts would last forever. The best part is gear ratios, price and the fact that the normal long tailshaft means you can use "typical" slip in u-joimt, single piece drive shafts, and forever be done with fricking giubos forever!

The ratios are available in syncro and dog engagement. 2.94/1.94/1.34/1.0/
.73 or.90 or 2.46/1.54/1.22/1.00/.73 or .90 or 2.92 / 1.99/1.34/1.0/.90 or .73
G-Force Transmissions and Long Shifters
Prices for the dog box was about $3500.00:p
 
#18 ·
More on T-5 conversions

Good Morning Alfa Fans!!
I'm back again with more info before I document the entire T-5 conversion on the Alfa BB. The pictures below shows the mock-up using the T-5 tranny and the Alfa 2000 bellhousing, the 1750 bellhousing should be the same. The dimensions and balance of the unit is very much similar to stock. This conversion will use the stock clutch slave cylinder, stock throw-out bearing, and stock pressure plate/w a 8.5 in. Ford clutch disc. The specialty item is the adapter plate which allows the T-5 tranny to fit directly onto the Alfa bellhousing. The list of the following Ford T-5 trannys will fit directly onto the adapter, and then onto the bellhousing; other T-5 trans will fit with slight mods as I will note later.

Following the source of the transmission, are the factory gear ratios;

1.Factory 94 Mustang 5.0 - 3.35 1.99 1.33 1.00 0.68 rev.3.15

2. Factory 94 Mustang 3.8 - 3.35 1.93 1.29 1.00 0.73 rev.3.15

3. Factory 94 1/2 Mustang 3.8 - 3.35 1.93 1.29 1.00 0.73 rev.3.15

4. Factory 94-97 Mustang 3.8 - 3.35 1.93 1.29 1.00 0.73 rev.3.15

242 Factory 94-95 Mustang Cobra 5.0 - 310 3.35 1.99 1.33 1.00 0.68
rev.3.1
 

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#19 ·
Yes very interesting You have my attention.
I would be interested in the V6 version for a couple of my cars.
John
 
#25 ·
Aren't the 'vette gearboxes a Tremec T56 with different rear section that incorperates a differential?
I believe these photo's are of the earlier/first transaxle 'vette gearbox that mistakingly had the clutch at the engine. After that I believe they changed to a rear clutch.
ALFAGTV6.COM • View topic - Front mounted tranny
 

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#24 ·
Looks great but I don't think it's going to fit in a stock tunnel, that box is very square on top, stock is not and very tight to start with. Cutting the tunnel is fine for a few, but most won't do it, leads to new problems like, the heater box no longer fitting, etc. etc.

Alfa Parts Exchange
 
#26 ·
Hello larry,
just read your post, and as usual, I respect your experience, and contributions you've made to the Alfa community. You may not remember, but we have had conversations in the past about misc Alfa parts. But in this instance, larry, I have done extensive research and mocking up of this endeavor, Just to try to reveal any shortcomings that I might experience before I give this project an OK. Believe me, I truly enjoy all the questions, opinions, and even questionable input into this conversion.
Now, to the reply to your post; the widest dimension of the T-5 measured at the top of the tranny is only 8.5 inches wide (suprising huh?) the spider's bottom measurement of the trans tunnel is 10+ inches, then mildly curves in toward the top of the tunnel.
MORE than enough room. Even if it were close - there always the technique of putting a hammer in the right place, before even considering cutting. Below I have posted a pic showing the top of the T-5 at it's widest point.

flybird -T
 

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#28 ·
I must say that Ken’s rear housing for the T-5 looks impressive (it almost looks like it would be the same length as the original Alfa gearbox, making it bolt right up to the standard engine and (maybe) prop shaft.

Judging by the photos of the T-5 on the Alfa bellhousing, I have to agree with Larry’s suspicions on the box’s overall height. Just for interest, I’ve included some photos of the Alfa gearbox compared to the Getrag 265, including the critical front-on shot which compares the height of each box using the input shaft as the standard reference point.

While they look nearly the same, by the time we made up a bellhousing for the Getrag and installed it, it struck the top of the Spider’s trans tunnel, and still had to go up another ¾ inch to locate the shaft in the stock, aligned position. By the time we cut two slots either side of the tunnel to square it off, then make up two patch panels and weld up four lines, we figured it would be less welding to simply cut and weld a new piece of sheetmetal to the top of the trans tunnel.

While the Getrag and tunnel mods will still allow us to install the heater box, console and side panels, there is really not much room to play around with – while the heater box sits in the location right above the bellhousing with around 20-25mm clearance from the standard trans tunnell (hint – don’t try and mess with the tunnel immediately above where the bellhousing would fit), you really can’t afford to raise the trans tunnel much more than an inch higher above where the gearbox would mount, or else getting the heater box in and out may prove either impossible, or very very difficult.

Anyway, it’s just my opinion – I guess that seeing as how Ken has fitted the T-5 to the Spider, he would really know the true answer as t how it fits the trans tunnel!

Good luck
 

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