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So I finally got round to making the appt for the tr6 to go in for it's planned engine rebuild. I'm getting the guy to box in the diff mounts at the same time and install the LSD - I figure he may as well since the old one will have to come out before the welder gets fired up.

So now I'm back to the last thing that needs attention before I can stop - the gearbox. It's false economy not to change the clutch, so regardless of anything else I have to do that.

I'm still trying to decide (obsessing more like) whether to have an o/d fitted or a 5-speed conversion.

Now, I really like the TR6 box - it just has a nice feel when you get used to it. The trouble is I'm doing all this work so I can bolt a supercharger on, and I'm worried the o/d won't be able to cope with the extra power. It's also not an inexpensive conversion, although it does increase the desirability of the car and retain some vestige of 'originality'.

The other two choices I know of are the HVDA-type celica box or the Ford type-9 (UK Ford Sierra). I know the celica can handle anything I could put through it, but the alloy boxes are hard to find. For that reason I'm wondering if anyone has experience with the Ford box.

Finally if I do (can) stick with the original box, has anyone used the TRF 'magic' kit? I *know* this is a stupid question, but does the use of a t/o bearing here remove the auto adjustment from the clutch? If so then I'm not interested.

TIA as always, Alan
 
Alan,
In your decision making process for which way to go for your tranny, o.d. or true 5-speed, consider the one thing that the purpose of that fifth gear is really all about. Saving your engine. I had the J-type overdrive unit installed on my stock 4-speed and have never regretted it. When I get up to cruising speed I just drop her into overdrive and listen to my engine hum. Yes, there are those who make their Laycock overdrives act like 6 or even 7-speeds but my arm would be sore doing all that shifting. I play in the 4 gears between traffic lights or on a nice curvy road then I settle down with the lower rpm's and listen to the music.

Bill
 
I installed a Jtype in a GT6 and it was an excellent choice, IMHO. I drive the car somewhat conservatively, no racing, hole shots or racing. Sure, I rev it up occaisionally, but overall I'm easy on the car. The OD is a good choice for such drivers.

If you dog the car, race/autocross it, or drive hard consistently, the OD may not be the best choice for longevity. If you drive it like you stole it, the five speed is a better choice because it can take abuse much better than the OD box.

There's really nothing that performs like the J-type. It effectively gives you a six speed gearbox and it's a real pleasure to drive. It's also correct for your car, which is more important to some than others. If you carefully rebuild/restore the OD box before installing it, and maintain it carefully, it will last for many, many years.

So, consider your driving style and habits, then decide.

Good luck in your choice, and let us know!
 
Oh I do drive it like I stole it and that's the problem right there. Currently I have a regular 4sp box with a second gear synchro that isn't 100%. Ergo I'm considering dropping the cash to do a conversion to a J-type, or to a 5 speed. All up parts are about the same (at least for a celica box - I have no clue about the Sierra conversion having only heard of it yesterday).

I'd really like to have the J type for the sake of originality, but I'm not sure it's up to the job, hence my dilemma. There is something about a modern 5-speed with the old engine that bothers me, in an odd way that I can't define. I know I could get my 4sp uprated, but that's not the object of this exercise. I want to be able to do 80 (legally of course, I'd never speed on public roads /ubbthreads/images/graemlins/nonod.gif /ubbthreads/images/graemlins/nonod.gif /ubbthreads/images/graemlins/nonod.gif) and have a conversation over the sounds of engine and exhaust.

I guess what I really want is someone to pull out a magic uprated overdrive system, but then as the song goes - you can't always get what you want.

Anyway, anyone know anything about that type 9 conversion, or can offer advice about the other one. Or does anyone have a magic wand...
 
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I want to be able to do 80 (legally of course, I'd never speed on public roads /ubbthreads/images/graemlins/nonod.gif /ubbthreads/images/graemlins/nonod.gif /ubbthreads/images/graemlins/nonod.gif) and have a conversation over the sounds of engine and exhaust.


[/ QUOTE ]

Where can you do that in the US? /ubbthreads/images/graemlins/wink.gif

Have you thought of a "retro" overdrive for your '73? If your worried about the J-Type giving up under power, the A-Type is stronger.

I'm not sure I understand your reservations about the modern transmission. Aren't you putting in a modern diff as well. You've already changed the suspension a lot so why not keep going?

Not criticisms either. My 6 is well modified and I'm not done yet. /ubbthreads/images/graemlins/cheers.gif
 
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I want to be able to do 80 (legally of course, I'd never speed on public roads /ubbthreads/images/graemlins/nonod.gif /ubbthreads/images/graemlins/nonod.gif /ubbthreads/images/graemlins/nonod.gif) and have a conversation over the sounds of engine and exhaust.


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Where can you do that in the US?

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Rural Texas? See:

https://en.wikipedia.org/wiki/Speed_limit

but I'm in no position to try it myself... but Italy and Germany are closer....
 
Well in the UK, you have a lot more roads for the enthusiast - the M23 on the way down to brands hatch and the A303 down to Yeovil, the A14 - the road that cops forgot and my own favourite, the north half of the M25. Not exactly legal, but precious few Gatsos. Since you are further north, the M18 btw Doncaster and the Humber bridge also springs to mind. Little old ladies in Ford Fiestas are doing a ton on it.

Sorry, back to why I'm feeling odd about a 5 speed. I will be keeping the old diff so it's a relatively quick job to switch it back in. All the other stuff could be reversed too. The gbox is a bit more aggravation - doable, but more trouble. I think it's more that you can't see the diff, but the 5 speed is there in your face. I guess I'm just odd that way.

I did think about the A type, but it's non-original too, and all those stories I read about the lurching as it engages put me off (and did I mention that it's non-original).

The more I think about it, the more I know I ought to get a 5 speed and stop whining. It's just that it seems like sacrilege to shove something japanese (or worse ford) in there.
 
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I want to be able to do 80 (legally of course, I'd never speed on public roads /ubbthreads/images/graemlins/nonod.gif /ubbthreads/images/graemlins/nonod.gif /ubbthreads/images/graemlins/nonod.gif) and have a conversation over the sounds of engine and exhaust.


[/ QUOTE ]

Where can you do that in the US?

[/ QUOTE ]

Rural Texas? See:

https://en.wikipedia.org/wiki/Speed_limit

but I'm in no position to try it myself... but Italy and Germany are closer....

[/ QUOTE ]

Oops! Read the footnote to that article James. The Texas legislature has made it possible for an 80mph speed limit hav the Highway Department yas yet to post any 80pmh speed limits. They are still studying the possible effects. Besides, my comment was ment to be tounge in cheek. /ubbthreads/images/graemlins/smile.gif
 
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The more I think about it, the more I know I ought to get a 5 speed and stop whining. It's just that it seems like sacrilege to shove something japanese (or worse ford) in there.

[/ QUOTE ]

Odd comment from someone who was toying with the idea of a V8 conversion into their TR6. /ubbthreads/images/graemlins/blush.gif

Just giving you a hard time Alana, I understand the struggles of some of these decisions. /ubbthreads/images/graemlins/cheers.gif
 
Shawn, you are right - I was thinking about a v8, but then I was going to go totally non stock and not care about any sort of originality - or resale - at all. I'd still put one in if I had the time and space (and competence).

As that's not an option, I'm keeping it (somewhat) close to stock and just trying to get it to go with a little more enthusiasm. I'd like to stay as close to original as I possibly can, or at least be able to return it back if I ever felt the need. For some reason the 5-speed crosses the line.

I'm obviously not a concours fanatic and have no logical reason for feeling like this. In fact since I'm shoving a Nissan diff in I can't even defend my position...

So my own oddness aside, J type is out. A type is possible. 5-speed; has anyone done the Sierra conversion, or is it Celica/Supra all round?
 
5-speed is easily reversed, nothing is cut during the install. Plenty of Celica/Supra or Toy pick-up 2wd trannies around too. I've got one of each in the 3A and 4A and both are aluminum cased. Also for the HVDA kit, you eliminate the slave cylinder and associated problems; the hydraulic t/o bearing is a nice feature. You retain the original shifter so unless you look under your car alot, you'll soon forget that it's not original ... until you shift to 5th that is!
nfi but Herman is a great guy and makes a great product. The two times I emailed him with questions, he's personally called me from CA on his nickel. Can't say enough about it. Hope this helps. PeterK.
 
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I'd like to stay as close to original as I possibly can, or at least be able to return it back if I ever felt the need. For some reason the 5-speed crosses the line.

I'm obviously not a concours fanatic and have no logical reason for feeling like this. In fact since I'm shoving a Nissan diff in I can't even defend my position...


[/ QUOTE ]

I feel much the same way in that I don't want to modify my TR6 beyond what can't be brought back easily to original. Basically bolt in/bolt out mods. I know that would have to include repainting to the original, or an original, color in my case which doesn't bother me.

As stated in the previous post, AFAIK the Toyota conversion does not modify any part of the car to preclude swapping back to original TR transmission. Much like how Richard Good modifies the differential to fit the car and not the car to fit the differential.

IMHO these types of mods, that increase performance without changing the character fall into TSOA type improvements. I also see it as a "tuner" version of improvement that the factory could not do because of cost accounting etc... For instance, 5-speeds were available in the sixties but were primarily in high end vehicles like Ferrari and Aston Martin.

/ubbthreads/images/graemlins/cheers.gif
 
After installing a supercharger more power is only a set on pullies away. For the same money I think I would go with the 5 speed so you can run a lot more power in the future.
I had around 600 HP in my TR6 and what am I doing now? putting on a turbo and increasing the power.
 
hey,
check out dellow automotive in australia. they do a toyota supra, all alloy, conversion for less than hvda and that box can take serious hp and abuse.it also weighs less. that is the one i am planning for my 62 tr4 sleeper (looks original but has the devil inside)
rob
 
This crew do too. You are looking at $3500 for a supra box from them though. Mainly though because USD is worthless currently. At the 2.5:1 it was when I was there in '99 it would be a much better prospect.

https://www.conversioncomp.co.nz/

btw: I emailed Herman about his kit. His reply today implies that I could use the W58 box. If that's the case (and of course I will double check) then I'd want a very compelling reason to import essentially the same kit...
 
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