[DarkHorse]

Hey guys,

Hoping to get some guidance on gearbox options, and hopefully build up a bit of a knowledge base about motor/gearbox/transfer combinations across the various generations.

To get the ball rolling, my scenario is that I have a very noisy manual gearbox on my SV620. Prognosis is that the gears have been hot due to running dry at some stage, so simplest/cheapest option is just to replace it. Following my general philosophy to upgrade rather than just replace, I have read that the later GV gearboxes are built stronger. I also have the pipe dream of an H27A conversion in my brain, so hopefully those two considerations work out with the current H20A motor. To complicate matters I have a geared SE transfer that I want to keep. It obviously bolts onto the current SV gearbox, but will it bolt to a later SQ gearbox?

So:
Which gearbox should I be looking for? GV H25, or XL7 H27?
Will either/both bolt to the H20 and the H27?
Will they need input shafts swapped, or re-splined?
Any electrical issues with reverse lights, or ECU management?
Will Will my G-series transfer bolt up to either/both?

Feel free to elaborate for any other G16/H2* combos...

Cheers!

[atari4x4]

GV gearbag & transfer combo are longer than the SV combo from memory, there is a thread somewhere on here with pics showing the 2 side by side. trying to remember who it was that started the thread.

[atari4x4]

this is the thread i was thinking about, i did have a pm from techedge that had pics... that pm is long gone.

viewtopic.php?f=5&t=38531&hilit=v6+vitara+gearbox+swap

[atari4x4]

i just googled it....








































google says AW4

[Zook_Fan]

I don't think the G series transfer will bolt to a H25a gearbox. The output shaft seems much longer than the pictures I have seen of the vitara transfer.

In saying that I do actually have one of each here, I just haven't separated the Vitara transfer and gearbox to see what is inside there and what actually would be required for adapting.

[DarkHorse]

Google can

But in the spirit of considering all options - will it fit the various combinations I'm chasing, just make sure the bellhousings suit? Will it be stronger than just replacing the H20 manual? Would it mean swapping the complete ECU? Requires addition of TCU, trans cooler... anything else?

The techedge thread raises a few issues Although I'm a little confused about why he went through it all when he was replacing the motor as well...
- different sized gearbox input shafts - could the box shaft be swapped (along with various gears, bearings and seals I'd imagine?) or would the crank shaft of the motor need to be changed? Either way it's probably a deal breaker for me given the current circumstances, but interested for the sake of future reference...
- clutch slave cylinder on the opposite side - just a plumbing and real estate thing? He mentions he bolts the H20 clutch to the H25 box, and the flywheel spiggot bearings are apparently the same.
- different stick positions and driveshaft lengths more an annoyance than anything - 50mm I could deal with.

Thanks Gus.

[DarkHorse]

Zook_Fan wrote:

I don't think the G series transfer will bolt to a H25a gearbox. The output shaft seems much longer than the pictures I have seen of the vitara transfer.

In saying that I do actually have one of each here, I just haven't separated the Vitara transfer and gearbox to see what is inside there and what actually would be required for adapting.

Despite bolting straight up to the H20 box with absolutely no modification? That sucks...

If it's just a shaft length difference would it be a fairly simple solution to just get the shaft cut down?

You planning on splitting the Vit cases any time soon? Would love to see the results.


Given that if I was to do an engine conversion it would be to the H27 (I wouldn't bother with the time and expense for an H25) is it even worth considering H25 boxes or would the hassle of fitting one just need to be repeated when the XL7 motor goes in?

[Zook_Fan]

That is my guess from eyeballing it and the pictures online, I might be wrong. If you were to need to cut it down it would be a respline job as well.

I do plan on doing it soon, either this afternoon or tomorrow morning. Depends how carried away I get. Will post the results in my build thread and here.

Huge assumption but I would guess that the H25 and H27 manuals would be the same.

[got_bar_work]

I have a 1.6 manual with gears and a j20 auto gv sitting on the ground if u need any pics or measurements. Will be splitting apart to put my duals on the auto and hopefully the gears in a auto gv when I find one.

[Zook_Fan]

If you can get a measurement of the diameters of the input spline that would be great along with some pics.

Here are some side by sides of the GV and Vit cases, the browner box is the Vit:

[Zook_Fan]

I think I've been going about this all wrong in my head. Here is an okay picture of the vitara transfer I found online:



The splines look to be the same as the GV one I was looking at and from what I can count it has the same tooth profile.

If it is just the length of the input that changes then it is the extension housing on the front that needs to change to mount the two together. The vitara gearbox is a very different bolt pattern on the housing to the transfer, could someone please get a picture of the 2L gearbox?

Alternatively, a smaller custom housing could be machined from aluminium to suit the two bolt patterns just narrower which would theoretically allow the use of the smaller input on the 2.5L box.

In this scenario for a GV the front and rear driveshafts would require small modification to take up the differences in transmission length and the tunnel would require manipulation. This would however make an almost bolt in option for 2L V6 Vitara's.

The other option is to add a small male to female shaft in between the boxes. It would only be roughly 150 to 200mm long I believe and would have a male end to go in the 4.24 input gear and a female end to go on the gearbox. It would not really need to be retained as long as it was the correct length. I'm going to order the 4.24 gears, design up the various options and get some costings for machining done. For a GV the cheapest way forward would probably be the extra shaft, for the 2L's the new housing is probably the better option.