MR2 Roadster Owners Club

The Workshop => Performance Related => Topic started by: 777Rav on March 4, 2018, 06:40

Title: Hybrid Corolla/MR2 box.
Post by: 777Rav on March 4, 2018, 06:40
Morning.

I've trawled the forum and am struggling to find a comprehensive step by step write up on how to build a hybrid box using FL 6 Speed MR2 box and a Celica box to end up with 1st-5th Corolla ratios, longer 6 speed and LSD.

I know all the info is out there spread across the net in dribs and drabs but does a full write up exist? (preferably with pics....me being a simple chap  ::) ) Most descriptions I find are modifying the Corolla or Celica box using reverse lock out kits etc. There seems to be a few people on here that have done it but regrettably no write up..... :'( or at least that I can find.

Thanks.

Title: Re: Hybrid Corolla/MR2 box.
Post by: shnazzle on March 4, 2018, 10:40
Building the box is generally something others have left to pros as it isn't quite as straightforward.

I know of one who did it himself...@manos3003 how did that work out for you? ;)

BUT having said that, he might be able to put together a how to.
Title: Re: Hybrid Corolla/MR2 box.
Post by: 777Rav on March 4, 2018, 11:08
I've stripped boxes in the past so have no issue giving it a go, I think specialised tooling is often the thing that stops people attempting it but from what I have read so far it doesn't actually seem "that" involved. The hardest bit seems to be the diff preload which  I gather doesn't need to be done if you're building the box up in this fashion. Although I may be wrong.........

Having said that, maybe it's something that will eventually get farmed out to someone else who has the first hand experience. I guess I'm just surprised that someone who has done it hasn't written a "how to"......
Title: Re: Hybrid Corolla/MR2 box.
Post by: mattbrown82 on March 4, 2018, 16:25
This link may help. It covers a rebuild of the 5 speed box. Also has info on the diff preload.

http://www.tcorolla.net/overhaul-1203.html
Title: Re: Hybrid Corolla/MR2 box.
Post by: m1tch on March 4, 2018, 17:00
If you need to upgrade the gearset you can get a JUBA 3rd and 4th which are the same as the 2zz Celica- be aware that 5 and 6 speed boxes have different width gears.
Title: Re: Hybrid Corolla/MR2 box.
Post by: JoeCool on March 4, 2018, 21:31
I think your easiest route to do this is:

Use the Celica Gearbox. Split it open. Change the 6th gear for the MR2's 6th (it's the first gear on the stack and therefore the easiest to change)

Then, pull the Helical core of the MR2 diff out, and fit it into the crown wheel of the Celica Box. That's the final drive retained but with the helical diff in place. And yes you'll need to set preload correctly althogh I don't know how to achieve that.

Then, use the 6 speed shifter shaft from the MR2 gearbox, along with the reversing linkages that you'll have to drill holes in the Celica casing to fit the brackets for.

Sorry if that's teaching you to suck eggs. It's what I had done to my Corolla gearbox, minus the 6th gear swap which I regret not doing.
Title: Re: Hybrid Corolla/MR2 box.
Post by: MrT on March 14, 2018, 22:53
Interesting you asked this question, I've just been thinking similarly. I'm interested in the c60 (USDM) box with a c66 final ratio and helical differential. Same sort of thing I think you want. I prefer the spread of ratios in the c66 box.

Does anybody see why this isn't feasible?

And would it be better to build the gearset into a c63/6 gearbox housing to suit the mounts and bracketry?

Thanks
Title: Re: Hybrid Corolla/MR2 box.
Post by: 777Rav on March 22, 2018, 05:11
Thanks for the responses.

So just to be clear, swapping the 1st to 5th gearset from the Corolla box along with the pinion into the 6 speed MR2 casing is not an option? What is it that prevents this being possible?