[rhys bond]

ok so i have an sj40 sierra, fitted with a nissan a15 and 4 speed, just had a g16a dropped into my shed, it will need a new carby and tappet cover, rebuild, alt, so on, but the box on the back isnt like the sierra box with the external transfer case, so what do i do? do i find a g13a 5 speed and put that back in with the 16a engine, or does the conversion have the full box from the 16a put into the sierra, does the g16a bolt onto a g31a box? that's the main question really, does the 13 box go on a 16, cos that would save time

[Scrawny]

Yes, it most definitely will go on. But, you will need the adaptor plate from BenT- viewtopic.php?f=15&t=15009

[303zuke]

The 1.3 gearbox will fit to the G16A with the BenT kit (which is a very well made kit, better than most out of the US), but don't forget to find a 1.3 flywheel and clutch as the G16A flywheel does not fit inside the 1.3 bellhousing. Some people choose to retain the Vit gearbox and make a rear adaptor to mate to the Sierra transfer/jackshaft. That way you can keep the G16A flywheel.

But another question you should consider is the size of your transmission tunnel. If your SJ40 is a Type 1 or 2, you will have to massage the sides to fit even the 1.3 box. If you have a Type 3, a 1.3 box will go straight in without any massaging. The Vit box will require major bodywork to fit the T1/T2, while a T3 will need a couple of thumps with a hammer.

A Type 3 jackshaft will also fit the output splines in a 1.3 or Vit gearbox, while the T1/2 jackshaft won't.

I was also going to mention engine mounts, but after your Nissan conversion, there probably won't be much left of your oriiginal mounts.

Which model SJ40 do you have?

[rhys bond]

i dont know what one i have, i do know the vin so how can i tell?

[sideways]

If it's got a plastic dash you will be fine, depending on what they're done to fit the gearbox.

I'd just keep the A15. It makes the same power as a G16a and if it's already engineered that's a bonus. The biggest benefit would be the 5 speed.

You might be able to get a 5 speed for the A series (I believe they're pretty rare) but I don't know how much work it would be to fit. I looked at an LJ80 for sale with an A series and a 5 speed, they had to move the transfer case back to fit it, this resulted in a tailshaft about 30cm long flange to flange. I don't know if that was necessary, it was a dodgy clusterfuck of a vehicle so probably not. That gearbox certainly was very long though.

[rhys bond]

if i rebuild the g16a ive got a strong motor with plenty of after market parts, the 15a is so hard to get bits for and the 4 speed just means she screams her tits out to do 100km/h :/

[303zuke]

rhys bond wrote:

i dont know what one i have, .....how can i tell?

Type 1 has metal dash and drum front brakes. (Approx '81-82)

Type 2 has metal dash, 4wd light on dash near Ign Switch, and front discs. (Approx '83-84)

Type 3 has plastic dash, 4wd light IN the instrument cluster and front discs. (Approx '84-87)

A 1.3 conversion will require front discs, a 1.6 conversion will require front discs AND a brake booster.

[rhys bond]

ok thanks heaps, i have the type 3, 87. break booster. hmm thats a new one too me, needing one of those,

[sideways]

Is the A15 already engineered?

[rhys bond]

i wouldnt say engineered but its in there and running true,