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6 speed manual to suit 4jb1-t

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6 speed manual to suit 4jb1-t

Postby Rocher » Sat Sep 24, 2016 11:24 am

Hey guys,
New on this forum and was hoping someone may be able to help me out.
Looking to swap a 4jb1t into my upcoming fj40 project, but have been unable to find a part time manual 6 speed gearbox to suit, or find anyone who has mated a 4jb1 (or similar) to one.
This is the last thing I need to sort out before I can get all the engineering, etc sorted so I can start the project.
Also I haven't been able to find much about the differences between the old and new engines other then a slight change to piston design. Is there any benefit to the old vs new or vice versa. Engine age shouldn't be an issue as it should fall under the year of the 40 series body (pre 4jb1t production)

Fyi the plan is a lengthened fj40 body on a cut down j90 prado chassis (~100" wheelbase) with a 4jb1t engine and some kind of 6 speed gearbox with a part time transfer case.
Thanks
Luke
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Re: 6 speed manual to suit 4jb1-t

Postby geeves » Sat Sep 24, 2016 5:07 pm

Im not aware of many 6 speed 4wd gearboxes. Not sure why you would want one.
It could be argued that with the 2 speed transfer case that the mua box normally found on the 4jb1 is actually a 10 speed although high 5th is so close to high first that its rally a 9 speed. Early fj40s had a 3 speed gearbox.
Life would be much simpler just using the 5 speed MUA box. The outputs from the box are pretty much where you need them and this combo is in quite a few Hiluxes. The 4jb1 is a very flexible engine with good power from 2000 all the way to 4000+ as long as you run a 2.5 or bigger exhaust a free flowing air filter and a minor fuel tweak.
Sanding your knuckles before starting work can help. That way you cant skin them
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Re: 6 speed manual to suit 4jb1-t

Postby Rocher » Sat Sep 24, 2016 8:12 pm

Was hoping for the 6 speed to get a slightly lower gear (for towing my track car) and slighter taller top gear (better highway fuel economy).
Plan is relocate the oil filter so I can fit a 3" exhaust with a WTA intercooler and a mechanically (boost) controlled vnt turbo from a zd30. And then up the fuelling to suit
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Re: 6 speed manual to suit 4jb1-t

Postby MUVIT » Sun Sep 25, 2016 7:11 am

Toyota prado's had a 6 speed manual
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Re: 6 speed manual to suit 4jb1-t

Postby stardog » Sun Sep 25, 2016 2:54 pm

I had a old landcruiser Ute with the 3 speed gear box and i dropped a Holden 253 v8 in it back in the early eighties use to tow the boat from MT Isa up to karumba and back no problems.
Even done a few trips up to Darwin and back in her was a bit thirsty on the fuel but was a great tow vehicle.
No gas conversions back then for them but it was great Ute to drive with the v8 in her I think I still have some photos of it somewhere o them memories .
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Re: 6 speed manual to suit 4jb1-t

Postby Rocher » Mon Sep 26, 2016 11:50 am

MUVIT wrote:Toyota prado's had a 6 speed manual

The Prado's aren't a part time gearbox, nor are the 6 speed hilux's unfortunately
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Re: 6 speed manual to suit 4jb1-t

Postby MUVIT » Mon Sep 26, 2016 1:00 pm

Part time?
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Re: 6 speed manual to suit 4jb1-t

Postby geeves » Mon Sep 26, 2016 2:45 pm

Prado etc are full time 4wd and dont have a reputation for reliability. However it is possible to swap the transfer case out of an earlier hilux onto the box. Still have the issue mating it to the 4jg2 though
Sanding your knuckles before starting work can help. That way you cant skin them
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Re: 6 speed manual to suit 4jb1-t

Postby Rocher » Fri Sep 30, 2016 2:17 pm

I know the old 5 speeds could be mated to the hilux part time transfer case, but the new 6 speeds are full time on both the prado and hilux
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Re: 6 speed manual to suit 4jb1-t

Postby geeves » Fri Sep 30, 2016 2:58 pm

Have a look at the ratios They might not be sufficiantly different to our 5 speed to justify the hassel
Sanding your knuckles before starting work can help. That way you cant skin them
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