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R151F gearbox: Lower Gearing

Posted: Tue Sep 11, 2007 1:34 pm
by gotoy
Hi,

I need to know what transfer case I have on a R151F gearbox.

The gearbox came from a halfcut with a 1KZ and R151F gearbox, Landcruiser, Jap model.

Hope someone can point me in the right direction.

Posted: Tue Sep 11, 2007 1:50 pm
by gotoy
From searching, here and net, appears its RF1A. How can I confirm this?

FYI I want to put a lower gearing on the 2L/4L.

Posted: Tue Sep 11, 2007 2:25 pm
by dumbdunce
take a picture of it and post it up is the easiest way. it is probably as you say, ort the split landcruiser transfer case. it will probably have 2.3:1 low range gears already; lower gears are available from Marks Adaptors.

Posted: Tue Sep 11, 2007 2:30 pm
by gotoy
dumbdunce wrote:take a picture of it and post it up is the easiest way. it is probably as you say, the split landcruiser transfer case. it will probably have 2.3:1 low range gears already; lower gears are available from Marks Adaptors.
Thanks dumbdunce. Actually its Marks who are asking about it.

Posted: Wed Sep 12, 2007 6:33 pm
by gotoy
Marks Adapters say they don't carry low gearing for R151F gearbox.

Anywhere else to go? Or perhaps some kind dude who ahs already done a lower gear conversion can point me in the right direction?

Posted: Wed Sep 12, 2007 6:58 pm
by dumbdunce
gotoy wrote:Marks Adapters say they don't carry low gearing for R151F gearbox.

Anywhere else to go? Or perhaps some kind dude who ahs already done a lower gear conversion can point me in the right direction?
R151F is pretty low to start with, 4.8:1 1st gear I think? anyway it's not the gearbox you would put the gears in, it is the transfer. again, post a photo of the transfer, even from underneath, and I should be able to tell you if gears are available and where to get them.

to start with, are the two outputs both offset to the right side of the vehicle, in line with each other, or is the rear output centered and the front output off to the right?

a picture will really really help.

Posted: Wed Sep 12, 2007 7:06 pm
by dumbdunce
does it look like this
Image






or like this (ignore the gearbox, that is a H55F)


Image

your transfer will probably be the second one, it is unlikely to be the first given the vintage of the engine/vehicle it came from.

Posted: Wed Sep 12, 2007 7:32 pm
by gotoy
Apolgises, can't take a piccy as well away from home for a while.

From your piccies, its the 2nd one.

Posted: Wed Sep 12, 2007 10:09 pm
by dumbdunce
http://www.marks4wd.com/products/gearma ... -gears.htm

these are the gears you need. choose your ratios and tell them it is for a bundera turbo diesel, these had the same combination of R151F and split transfer case.

Posted: Wed Sep 12, 2007 10:48 pm
by dumbdunce
remember even the 3.08 gears are only 34% lower than your existing 2.29:1 gears, you have to decide if that sort of reduction is worth your $1800.

eg if 2000rpm in low 1st before was 10km/h before it will be 6.5km/h after the swap.

Posted: Thu Sep 13, 2007 1:32 am
by Tapage
Most common BF1A ( split case ) gearing it's the 1.96 ( here in Panama ) and few ones come with 2.28 ( talking about cruisers )

Posted: Thu Sep 13, 2007 12:29 pm
by gotoy
dumbdunce wrote:remember even the 3.08 gears are only 34% lower than your existing 2.29:1 gears, you have to decide if that sort of reduction is worth your $1800.

eg if 2000rpm in low 1st before was 10km/h before it will be 6.5km/h after the swap.
The price is quite steep and I am also now questioning the cost. For starters I am not a rock crawler. Yes we do some hard trails sometimes but thats only a few weekends a year. The rest of the time its mild to medium.
For that $1800 I can practically buy a recon gearbox...or be there anyway.
For $1800 I can intercool my recently installed 1KZ and still have cash for an entire respray.
For $1800 I could do a hell of alot!!!!!!
That 1800 would also see me having a front ARB locker and many others....

Not such a simple case of replacing a gear cog at a few hundred $$

Posted: Thu Sep 13, 2007 8:15 pm
by Frankenyota
Can you fit the lower first gear as per a dyna / marks gearbox?
Or lower your diff ratios, say 4.88 as a different option.
May work out cheaper than $1800.

Matt

Posted: Thu Sep 13, 2007 8:26 pm
by gotoy
Frankenyota wrote:Can you fit the lower first gear as per a dyna / marks gearbox?
Or lower your diff ratios, say 4.88 as a different option.
May work out cheaper than $1800.

Matt
I am already running 4.88 diffs.

Posted: Fri Sep 14, 2007 2:26 am
by Tapage
Up R&P ( instead t-case ) give us a little % of CR .. you need to go up to 5.38 ( if we had this option ) from 4.88 to try some % of reduction comparable to 3.08 low gears on the t-case ..

Not to discus if you really need it or not .. or it are your taste or not .. it could only can be determinated by yourself ..

I found in my case 4.88 or 5.29 ( hard to install in a SF Cruiser axle ) are not enought reduction for me ..

With one gears i found hi reduction that I need, low reducction and peace of mind that still have strong pinion with 4.56 ..

Posted: Fri Sep 14, 2007 2:12 pm
by gotoy
I am running 35" XT on standard 4.88 diffs. Engine 1KZ to R151F gearbox.

I was just after some lower gearing for 2nd low gear. The 1KZ/R151F halfc ut came with 4.11 ratio axles, however I have maintained the 4.88 ratio's....to date anyway.

Posted: Fri Sep 14, 2007 6:22 pm
by Frankenyota
Dump the cruiser case and go dual hilux transfers. A bit of work but a larger choice of ratio's.
I love my dual cases :cool:

l have duals with v6 and auto and 4.88 diff ratios.

Matt

Posted: Sun Sep 16, 2007 7:58 pm
by dumbdunce
Frankenyota wrote:Dump the cruiser case and go dual hilux transfers. A bit of work but a larger choice of ratio's.
I love my dual cases :cool:

l have duals with v6 and auto and 4.88 diff ratios.

Matt
it's a bundera, there is no space for duals

Re: R151F gearbox: Lower Gearing

Posted: Tue Mar 15, 2011 6:21 pm
by DOZER
gday guys, im after some help. The pictures above show two transfer cases. My hilix is in need of a replacement and i cant find it, my T case is the top shifter case in the first picture but has 6 bolts attaching it to the gearbox.

No wreckers or Transmission joints can help me identify what T case this truck is out of?

I have been told that the gearbox in my 2.8 D 1995 hilux is not the original and is a R151F box, but i have my doubts as it does not have the rubber plug under the bellhousing so im at a loss of what the gearbox is and what the Tcase is.

My transfer case has the following features.

21 spline, top shifter, 6 bolts to mount to gearbox, and both the flanges are round unlike the one square one in the above pic.

Any help would be great, been searching for about a week now and even a dedicated hilux wrecker can not help me.

Cheers

Re: R151F gearbox: Lower Gearing

Posted: Wed Mar 16, 2011 10:43 pm
by blackarrowilly
Hey dozer it could be a R151 box as you have to run a bellhousing of a LN130 surf to make them bolt up to 2.8 motor.

Re: R151F gearbox: Lower Gearing

Posted: Thu Mar 17, 2011 8:34 am
by DOZER
Thanks for the info bud.