Differences between RB30 and TB42 driveline

[showtime393]

Hi there,
Do all petrol GQ Patrols share the same driveline?
Are gearbox and transfers the same, or does the rb30 have a lighter gearbox?
Are diffs, dif housings and axles the same?
I would imagine all driveline components mount using the same tie rods, control arms and mounting points in same locations?

[forkcy]

Hey mate

As far as i know RB30 and TB42 are a completely different gearbox don’t know much about the transfer, difference with the diffs is the ratios of the centres (which can be changed) as for everything else suspension wise all the same.

Luke

[showtime393]

Ok I'm toying with the idea of a rb25 conversion.
If I was to use a rb30 patrol, the rb25 should bolt strait up to gearbox and engine mounts?
If I use tb42 diff"s and run 35"s, how close to factory gearing would it be?

[tehekho]

There is a RB25 patrol floating around here. Hammers around the trails but it's a bucket of puss when it comes to crawling, and he has to charge everything.

AFAIK it was originally a RB30 pootrol and he just dropped in the 25, loom, ECU, fuel pump...

[turbo gu]

gearboxes are very different.
transfers are the same, just need to unbolt a alloy plate around the seal area if out of rb
rb30 had 4,3 or 4..6 diff ratios
td/tb had 3.9 or 4.1.
diffs are the same apart of pinion flange size. smaller on rb
I think they all bolt the trans cross member in the same spot

[showtime393]

Ok guys, thanks for all the replies.
Just trying to get my head around diff ratio's.
Is 3.9 - 4.1 or 4.3 - 4.6 a better ratio to run with 35's?
Or neither?
Because the rb's are a revy engine and not alot of talk, what would be good ratio's?

[turbo gu]

it depends what rpm you want the motor to sit on at 100km/h.
my gu with a 4.2td running 4.3 and 35s sits on around 2200rpm at 100km/h

[Nat84]

after have been there done that get the 4.6 diff had the rb30 gearbox rb25det cluch and flywheel RB30 engine mounts but need to cut the pass side as it hits the turbo

the GQ rb30 is the same gearbox as a R33 R32 VL just run a difrent ratio T/case it the same you can use a TB42 gearbox there a guy in vic that make the adaptor for about $900

[nicksamaniac]

i think youll find the rb30/rd28 use the FS5R30A 5speed trans, and the TD42/TB42 use the FS5R50A trans, they are different bellhousing patern, the 30A trans is pretty strong despite what people say, and alot more parts are available to strengthen them, (google PPG gearsets for FS5R30A) also if your going to use an RB25DET, it will bolt to a rb30/rd28 5speed, the rb30 diff centers are the highest ratio,
with an rb25,fs5r30a gearbox and 4.6(rb30) diffs, youll get 2500-2600rpm at 100kms.
i have and rb30 gq wagon, converted to turbo and the only driveline mod ive done is put in a button clutch. my gearbox has been copping my abuse for over 40,000kms sinse the turbo went on, and is 230,000km old now. and is still going strong.