BritishV8 Forum

Hi all,

I previously posted asking for opinions on the Toyota V161 but would also like to know how those of you who have installed the T56 feel about its performance, strength, availability and cost for rebuilt or new units.  I've read a lot of your project posts and it seems that your putting a lot of HP through them some in race cars too.  There are some really nice cars that you've built here.

For those of you who use the T56, how does it rate for smooth shifting?  Is it notchy, clunky?

I know they're in a lot of high end cars Viper, new Camaro as well as the Aston Martin.  So it must be pretty good.

I'm considering the Toyota trans because of the strength and the fact that it's a very smooth shifting unit.

The tranny will be going into a TR7 with a Rover V8 and approx 250-300hp and around the same torque output - no turbo, SC nitros etc. just normally asp. MPEFI.

Must be streetable but also be strong enough for track days.

Thanks,

Trip

Trip, I think you should take a look at what's being used in these race cars:
http://www.britishv8.org/MG/LesGonda.htm
http://www.britishv8.org/MG/KeithBurnett-MGBGTV8.htm

If you want a six speed for bragging rights or fuel economy that's perfectly cool, but your 300hp, <2500#, TR7 V8 for track day use won't really "need" a T56 for durability or performance. The extra overdrive would be nice to have on long highway trips... but for track day use you can save some money with a transmission that's significantly lighter weight and also physically smaller.  I don't have a current article on Jerry Richards' MGB GT V8, but I was surprised when I spoke with him at V.I.R. earlier this summer that he's a big proponent of the old Muncie 4-speed for these cars. According to Jerry, it's quicker shifting than the T5 and even lighter weight. I grant that Jerry is a pretty radical thinker, but he's very quick!

Thanks again Curtis,  I'll read the articles you suggest.  

A Muncie, huh?  Interesting idea.  

You're right though, it would be nice to have the OD for long weekend trips.  Or at least a 5spd.

Trip

I ran a Muncie in my BV8 for 16 years. Very reliable, light weight, strong transmissionn. Switched to a T-5 for the over-drive, which I like much better for highway cruising.
If I was building a race car, I'd give the Muncie some consideration.
The T-56 is stout for sure, but as Curtis said its overkill for the application. They are heavy also. 5th and 6th gears in a T56 are both overdrive.

Bill

Thank you Bill.

I'm definitely not in the same class as you guys and your race cars.  I would like to get it out to track days but it won't be a full out race car like yours.

Trip

Trip-
The T56 is a pain in the ars! I helped out with a set up and it took too many attempts to get it right and the bell housing is a custom unit that in our case was not perfectly machined and scewed the transmission causing it to let go. You also have to use a hydraulic collar for the throw out bearing that takes a lot to get it adjusted right. It is finally working and is a nice set up but the effort involved was time consuming. The T5 is the way to go if not the LT77 Rover 5-Speed.

Hello Mike.

I was actually hoping to keep the clutch as hydraulic.  From personal experience, I find that I like the connected feel of hydraulic as opposed to the vague feel of a cable.  I've also stretched - adjusted - stretched a few cable clutches too.

Your nightmare experience with the T56 is making me rethink the whole thing, however.

I have an LT77 currently in my 7 but either it will need a rebuild or it's just naturally a notchy, clunky tranny(?)

But I actually have it - rather than having to hunt for another trans. so maybe I should be considering it too!  

"You also have to use a hydraulic collar for the throw out bearing that takes a lot to get it adjusted right."

What you said about the collar and adjusting it is a troubling thought.

Thank you for your insights, Mike

Trip

I'm with Curtis on the trans choice. You can build a pretty sweet T5. Here's a pic of mine:



rrrrrrrreeeeeeeEEEEEEEEEE! bang! EEEEEEEEEEEE! bang! EEEEEEEEE! LOL.

You can start to spend a crapload of money pretty quick though. I've probably got about $1500 into this one. You can build a pretty bitchin' Muncie for less and they are 10 lbs. lighter than the T5's insanely light 70 lbs. That said, I'm a huge fan of the T5 for 300ish hp. 4 gears for speed and one to cruise. Cool.

No experience with the LT77. Sorry man.

Did you actually rebuild that T5 yourself?  Tranny buildin's definitely one for the list... way down the list, of course.  

Gots to learn the weldin' first!!! zzzzzzzzzzap!

Trip

Building it was EASY. The dog-rings really helped that though. WAY fewer parts. Just stay organized. It does help to have a press to get the gears off the mainshaft to change the syncs though. The other thing is a decent robust snap-ring expander. A couple of the retainer snap-rings are pretty stiff.

Don't you also need micrometers, an end-play guage and other measuring instuments?

BTW. What are "The dog-rings"?

I take it that you'd also need the press to install the gears, too.

Trip

There is available a T56 to GM 4 speed bellhousing adapter:



http://www.thegearbox.org/catalog/item/3838217/4803441.htm

What problems could be expected when bolting this up to a 215 4-speed bell?  (Other than physical size).

Greg

I set the preload on the bearings with feeler gauges. Works fine. It doesn't hurt to have a mic set though..

Dog rings take the place of the syncros. Here's a modified pic of the one I posted. I painted out the selector hub to make them easier to see. They're those notch looking things. I circled under the blue spot where the 1st/2nd dog ring is engaged with the 1st gear. The other circle is the 3rd/4th gear selector. You can see the dogs on that one too. It's a REALLY basic design. You pretty much just bash them together and they're engaged.



Syncros use a similar tooth like structure but they are much smaller and there are a bunch of them all around. Between the selector teeth and the teeth on the gear is a fluid clutch. As the selector teeth are moved toward the gear teeth the fluid clutch squeezes the gear oil out causing friction and matching the speed of the intermediate shaft (under the gears in this pic) with the speed of the Main shaft gears before engaging the teeth. Pretty damn smart design. You can feel it working in a regular syncromesh trans. You push it into gear and it gives you resistance for a moment.

You got to be pretty positive that your changing gears with a dog-ring setup but there is absolutely NO transition. The trade off is you can make really quick gear changes. BAM BAM.

Thanks for the explanation and visuals, Nicholas.  I think I understand now.  Sychros ease into the gear while dog rings are either engaged or not.... no clutch action.  Must be great for drag racing but not so much for stop and go traffic.

Trip

Hi Greg,

It depends on which T56 trans - LS1 Viper or LT1 - you're using.  There will be additional costs involved to get the correct  bushings, input shafts etc.  The Viper T56 is also a stronger unit and harder to source, therefore a more expensive unit.

It also seems that the trans. mount point may move due to the changed total length including the adapter and T56.  Keep in mind, the T56 is wider and heavier, too.

It may actually be more cost effective to swap the bell housing.

Trip

Nic, I think your showing us a T5 converted to "spur-cut" aftermarket gears/dogs? I bet itsa brute "whiner". Looks like no one wants to consider t-axels in front motor-cars? Better weight ditribution, aerodynamics?,value?, reduced shift times-clutch at t-axle, space utilization? Oh well, roverman.

Hey Art,

I'd consider a transaxle for my TR7 V8 project when it actually happens    

I know the later Vettes have it but I haven't seen any TA/IRS out there.  The Porsche TAs are big bucks.... Even Boxter.  Would be a nice project, though.  Maybe I can find some info.

Also some set-ups (Porsche 928, 944 and 968) have the clutch at the engine/flywheel and then transfer power to the rear TA via a "torque tube" ... Just a fancy German name for a driveshaft, tho.






Here's a vette C5 Ls motor and TA from a Philly Co.

Looks like it may be a squeeze to fit under a TR7 tunnel.  Might have to modify the gas tank too.




Trip

I recently saw a rolling C6 chassis on ebay for $5k!! Here's another one for about $9k. Still a frakin' great deal:

http://cgi.ebay.com/ebaymotors/2005-C6-Corvette-Rolling-Chassis-LS2-Engine-50k-Miles_W0QQcmdZViewItemQQ_trksidZp3286Q2ec0Q2em14QQhashZitem4836291838QQitemZ310146308152QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

Crazy good deal for the turnkey LS let alone the rest of the chassis. Even if you could only use the engine/trans/brakes $9k is great. Really not a big fan of the flappy paddle thing though. My problem is I've never had the foresight or bank account to buy something all together.

I will admit all the building I've done as a result has been really fulfilling. I sure learned a crapload about the Buick/Rover. For me the history of it has got that sort of gateway to mystery story. I had no idea that Rover continued to make the 215 after '64 until I found out about while researching. I still remember the sense of discovery. It was uncovering a conspiracy or something. My imagination was totally set ablaze.

I guess that's been the tone of my whole project. I bought my '73 Vega GT after seeing an add in the local car shopper rag. The title was '73 Vega GT 215 V8. I thought: That has got to be a misprint. I've never heard of a V8 with that CID. Thinking I've got the edge on some other buyer that wouldn't know better, I call the guy. He assures me it is correct. So I go take a look. There it is, all aluminumy, I had to get it. $2200 later I'm driving it home. The rest has been nonstop discovery. Seriously fun.

So I guess, since I'm in a momentary lapse of catharsis, I wouldn't really change a thing. All the mistakes and redirections have been an exciting thrill ride for me. Good times...

WOW I'm way off track now. Sorry guys. Focus! Dammit, Art! This is your fault! With your constant 'out of the box' posts! Seriously, sometimes I'm like: Where the hell is he coming from? Then, after reading the post a couple times I'm like: Uh huh, uh huh, Yup. OK, I'm on board... LOL.

Yes, Art, it's a G-force gear set. Really beautiful parts. I can't wait to run it! Ever since I read the chapter in Carroll Smith's "Race to Win" about dogboxes I've wanted to own one. I've spent the last few years driving heel/toe into every corner, my hands at 9/3 with my thumbs locked only taking my hands off the wheel for the time it takes to switch gears, all just to build the muscle memory. Now I've had a few chances to actually use it on the track in my SRT 4. I can't wait to try it out with the Vega.

That's patterned after a bike transmission, which we all know how those shift, even without the clutch. That's what Nick has for his car only with a different gear selector. Same principle, same effect. About 3 decades ago an early pioneer was making this setup for the Muncie by milling down the sliders and welding a piece on the synchro nose of each gear.

Jim

I didn't know you could actually buy an entire Vette rolling chassis.  This is nice to know.  I'm really not sure that my current 7 will be my dream TR7 V8 project car, but down the road, the idea of something completely unconventional is a really cool idea.  

I wonder how much better the weight distribution would really be?  

The only thing about that set up that I'm not to keen on is the lack of inboard brakes (sprung vs. unsprung).  Convert to inboard???  I guess anything's possible if you know how to fab the needed parts.  once I learn to weld and fab... the sky's the limit!

Or, if you use really light high end racing brake components, you could significantly lower the unsprung weight.

BTW. Nicholas what's a "flappy paddle thing"? do you mean paddle shifter?  If so, I agree, the whole idea for me is to actually drive the car and traditional H gate shifter is the most fun way to go IMHO.

I do think sequentials are neat, tho and have their appeal especially in some racing apps.  But to me it's like sitting in a video game and not having full control over the car. Like Formula One has become... Launch control, ABS, traction control, computer controlled sequential semi-automatic transmissions, computerized active suspension etc, etc... What's next, driver's sitting in front of a video screen in a Ferrari warehouse in Modena, sipping ice cold Brio chinoto? Please!

Jim, if it's patterned after a bike tranny, it has the best of both worlds.  bike type shifting as well as manual gear selection, rather than the sequential ratchet type from a bike.

Trip

Nic-et all... "Where de hell is he comin frumm"? We'll see how you spew after YURR alien abduction!. focuz, focuz,If I were to consider, semi-shiftless( paddle), I'd sooner go CVCT... in a T-axle, yeah thats-it !  Tripp, many irs's and t-axels can be converted to inboard disk, ie. C-5 has potential with approx 10.5" disk, billet rear cover doubles as caliper mounts. Aluminum metal matrix rotors=1/3 the weight. This set-up is going in my 69 AMX. Nearly all caliper mounts/adapters can be machined from alum. billet = lighter and best heat dissipation, 7075- T6= approx 105 ksi. ut. Guy on craigslist now has (2) Boxter "S" t-axles, asking $1,600 ea.1 with 200 mi.orig.These are holding 280 hp. in std form. I paid $1,200 for C5, b.h. thru compl. t-axle and suspension clip. The deals are out-there, you just have to dig for them. Happy Hunting, roverman.

Art,

"Aluminum metal matrix rotors=1/3 the weight. This set-up is going in my 69 AMX. "  Nice - That's definitely going to be something to see!!  Hope you'll post some pics or at least a link to your site when the car's done or even as the project advances!!!

"many irs's and t-axels can be converted to inboard disk, ie. C-5 has potential with approx 10.5" disk" Now... that's cool :0  

"billet rear cover doubles as caliper mounts"  Okay, now I'm totally fascinated!!  I'm going to search and see if I can come up with some more info now that I know it's possible.

Trip

Trip,
Getting back to the original question, "opinions on the T56", I can say I've  probably let 20 people drive my LT1 6 speed TR6 and nobody has ever complained about it shifting in a notchy or clunky manner. This was the first T56 I ever used and I was suprised at how easy the clutch and transmission was to work. You're right, they put heaps of them out there for all sorts of people to drive so you would think they would try to make them comfortable.

 Curtis is right though, you won't "need" one for durability or performance with your track use. Bragging rights? Sure, then you can do something silly like state it on your licience plate. Fuel economy? That's probably why the manufactureres put them in there. Cruising at 1,900 RPM doing 90 MPH is kind of neat.

 My engine came with the T56 hanging off the end of it so I just jammed it in there as is. I don't think I'd go looking for one though.

Ken

Hello Ken

Not sure how we got so far off topic.... Thanks for bringing it back to T56.  

Thank you for the first hand insight about the T56.  I've driven some of the older American cars - Mustang, Camaro, Trans Am etc with 5 spds and they all had that notchy, clunky feel. I wonder if those were older Tremacs or even T5s?

"This was the first T56 I ever used and I was suprised at how easy the clutch and transmission was to work." That's really nice to hear.  I've been thinking that it probably must be pretty smooth because they use them in Aston Martins, too.

"then you can do something silly like state it on your licience plate."  You did that, didn't you - That's okay, it's a pretty cool mod to be able to brag about!

Fuel economy is a factor as I would like to be able to take it on long road trips not just cruising around town.  I figured it's a transmission that can handle a wide range of uses ie: the best of all worlds.

"Cruising at 1,900 RPM doing 90 MPH is kind of neat."  I totally agree with you, especially since the LT1 is a torquey motor with lots in the low end.

Trip