Transmission, Transfer Box and Diff types

[Warthog]

Have done the intro, but figured this art of the forum would be the right place to ask if anyone knows what manual transmission, transfer box and diffs are fitted to the Y61 4.2 / 4.2TD
The 1999 Y61 I have has a dead (again) RD28ETi motor in it, with a FS5R30A 5 speed manual transmission, a TX12A transfer box and H233B front and rear diffs.
Does the 4.2 have the FS5R50B transmission fitted (I would assume stronger/different ratios?) and the codes of the transfer box and the diffs.
I have a workshop manual for the Y61 GU but it only covers and gives info for the 2.8, so would much appreciate if anyone can assist!!
Many thanks

[Bigrig]

Have done the intro, but figured this art of the forum would be the right place to ask if anyone knows what manual transmission, transfer box and diffs are fitted to the Y61 4.2 / 4.2TD
The 1999 Y61 I have has a dead (again) RD28ETi motor in it, with a FS5R30A 5 speed manual transmission, a TX12A transfer box and H233B front and rear diffs.
Does the 4.2 have the FS5R50B transmission fitted (I would assume stronger/different ratios?) and the codes of the transfer box and the diffs.
I have a workshop manual for the Y61 GU but it only covers and gives info for the 2.8, so would much appreciate if anyone can assist!!
Many thanks

Someone will be along to assist with this one mate - I've seen similar topics before, so someone will have the info - just a matter of getting past the Sunday morning scratch and brekky and they'll be around no doubt!!! LOL

[YNOT]

Y61 TD42 has
Transmission; FS5R50A
Transfer case; TX12A
Front diff; H233B
Rear diff; H233B

Tony

[Warthog]

Asante Sana (Thanks very much in Kiswahili)
The question I'll now what to ask is what is the difference between the 30A and 50A gearbox?
I guess is chunkiness and the max torque it was designed to have put through it? I have seen similar topics on the GQ where folks have said the bits aren't interchangeable, it would be better to change the engine transmission and diffs but I have had one chap in YUK tell me that there is a spacer in between bell housing and flywheel housing on the 2.8 (as it has a dual mass flywheel) which if removed allows the 4.2 to fit the same gearbox (with mods to mounts and pipework)
I also assume that different ratio diffs are available/fitted for the different engine types or are they a standard ratio for all the diesel GU patrols?

[YNOT]

They are 2 completely different gearboxes. The 30A is an alloy case gearbox and is the same as the Skyline/300ZX gearbox. The 50A is a much bigger cast iron case box much better able to handle the higher torque outputs of the bigger TB and TD series engines. If you have a TB or TD engine I would be staying with the 50A gearbox.

Diff ratio's for diesel Patrols (going from memory here)
RD28T; 4.3:1
TD42; 4.1:1
TD42T; 3.9:1

Tony

[Warthog]

So that be me looking in the Dark heart for an engine, transmission and 2 diffs as appears only common thing is the transfer unit! :-(

[YNOT]

What engine, gearbox, diff combination do you currently have and what are you trying to achieve?
It looks like you want to swap out you dead RD28 for a TD or TB42. If that is the case you will need the 50A gearbox to suit the bigger engine. The transfer case as you stated is the same. The diffs are the same except for different ratios. The minor difference in ratio's (4.3:1 v 4.1:1) is not worth worrying about. You could go up 1 tyre size (from 31" to 33") and it would put the gearing back to standard.

Tony

[Warthog]

As in the intro, currently have a stock RD28ETI engine (just done it's second head in 2000 miles, first time my good lady was driving it and it was a long steep incline coinciding with the viscous coupling on the fan dying...... so bad luck and when she stopped had she not switched it off probably would have helped a little. This last time 2 days ago my brothers apprentice mechanic was taking it for a customs inspection and should have know better, radio up probably texting or on the phone, being a 20 year old, the first thing he knew was the car behind flashing as it had a windscreen full of coolant!) so it has a 30A gearbox with standard transfer and diffs.
I can either throw another $1500 at it for another head and leave it as a 2.8 and always wonder in the bush out here if it will get me home, or can swallow with pain and fit a 4.2/4.2TD with all the right bits and know it will get me home!
Any ideas/suggestions would help!

[Warthog]

Sorry, is a 99 GU Station Wagon

[YNOT]

If it was me I would drop in a TD42 and 50A gearbox (not quite as easy as it sounds - the engine mounts need to be moved etc) and leave the diffs as they are.

Tony

[Warthog]

Moving the mounts isn't such a hassle, have done a couple of Mazda SL35TD engine conversions into Range Rovers in my younger days, concern with leaving the diffs as is would be fuel consumption over long distances, the lower ratio in the diff on the 2.8 will mean the 4.2 sits at higher rpm for given speeds, this can be solved in the Land/Range rover with the choice of transfer boxes there are, but I can only find one T/box for the GU Patrol, so no ratio changes....

[Acko]

Hi guys, Does anyone know the stock diff ratios for an 85 MQ shorty, L28?
I just bought it & intend to do it up with 35's, lift kit, V8 & an auto.

Bjorn.

[James112]

Great info guys. I thought Y61 had H260 rear?

[jackal2828]

Hey guy's I am looking for some info , I have recently blown the OD gear and main shaft on my 1999 td42 with FS5R50B gearbox apparently they are known to give a little trouble ,looking guys that have done the rebuild on the box and need some info , manual and trixs to strip the gears off the main shaft