Center diff lock swap?

[nonipotent]

I currently own a 1988 GL-10 Turbo with a center diff lock and a 1990 Loyale with a 5sp dual range transmission out of a 86 GL.

I've found myself wondering if it would be possible to take the locking differential out of the GL-10 and transplanting it into the transmission my Loyale to mimic the coveted RX transmission. Any thoughts?

[el_freddo]

You need an AWD dual range box to achieve what you’re wanting to do. 

The single range AWD gearbox is a solid upper shaft and the bottom lay shaft is a tube that has the front pinion shaft run through it. 

AFAIK the dual range 4wd gearbox uses a setup with the drive gears mounted on the pinion shaft for the front diff. 

I know more about the AWD L series box with the locking centre diff than the specifics on the dual range 4wd pinion shaft setup as I’ve not pulled that section apart. 

We’re lucky in Oz because our market came with dual range AWD gearboxes right into the late naughties. These parts are somewhat interchangeable with that locking centre diff gearbox you have. 

For example: my L series “Ruby Scoo” runs a bastardised locking AWD gearbox with the following setup: 

- phase 2 front cases with matching drive gearsets 
- L series 1.59:1 low range 
- L series locking centre diff pinion shaft - modified for 4.111:1 diff ratio 
- matching rear locking centre diff housing, shift linkages and tailshaft 
- oil “feeders” over the low range gearset to lubricate and keep cool on long climbs.

The key is a phase 1 dual range AWD gearset - if you manage to score one of these it will fit into your L series front cases. The low range hub internally will need a small amount of machining to fit the EJ upper gearset shaft. There are threads around that explain this. 

Your biggest hurdle is the EH dual range gearbox/gearset if you’re in the states. 

[Numbchux]

I'm ASSuming the GL-10 is a manual. If it's an auto, no. Just no, but I don't think there was one marketed as a locking center so I'm assuming manual.

 

The input shaft is different depending on single or dual range. The latter being 2 piece for the extra gearset, and the former being one continuous shaft from the clutch disc through all 6 gears (don't forget reverse). The DR transmission case has a bunch of extra machining for the low range. It looks to me like the casting is the same and theoretically this could be duplicated, but would require some serious machine work.

The Output shaft is different depending on FT4WD/AWD or PT4WD/FWD. The former being hollow so the pinion shaft can spin independent of the output shaft, the latter being one piece, pinion and output shaft.

 

So in theory, you have an example of each. BUT (and it's a big one), these 2 transmissions have different ratios, so both would have to be disassembled and parts swapped for it to work. The 1st, Reverse and 2nd drive gear are part of the input shaft. So you would need to be able to put the associated driven gears from the PT4WD output shaft onto the FT4WD, the other 3 gearsets could be used from either, as long as it's a matched set, but 5th is very short in the turbo cars, so I would assume you'd want the non turbo set.

I have not seen anyone try to swap them. I do know that all the bearings that those gears ride on are different part numbers between them.

 

I got 98% done assembling an RX box with non turbo low range and 5th gears, EJ 4.444 ring and pinion and AWD center diff. I also wanted to use a Carbonetic clutch type front LSD, but it crashed hard into the low range gears, then the rest of the car didn't pan out.... But the EJ pinion gear does fit the EA82 FT4WD output shaft perfectly and then the EJ center housing bolts to the back of the EA82 front case.

[el_freddo]

You don’t need to machine a single range casing for the AWD dual range - just use the PT4wd front cases. 

Really to achieve this the easiest way possible you need to import an EJ dual range gearbox or at the very least the internal gearsets minus the front and centre diff.

[Numbchux]

5 hours ago, el_freddo said:

You don’t need to machine a single range casing for the AWD dual range - just use the PT4wd front cases. 

Really to achieve this the easiest way possible you need to import an EJ dual range gearbox or at the very least the internal gearsets minus the front and centre diff.

We must not be thinking of the same thing. The dual range main case halves have considerably more machine work than the single range ones. You cannot just lay a dual range input shaft assembly and idler gearset into single range case halves. When I talk about the machining, I'm not talking about the transfer or extension housing.

You can put FT4WD/AWD dual range input shaft and idler gear into a PT4WD DR case. But that's not what he has.

The OPs question involves using what he has. I'm fairly certain importing a transmission from overseas is not what he's looking for.

[el_freddo]

12 hours ago, Numbchux said:

You can put FT4WD/AWD dual range input shaft and idler gear into a PT4WD DR case. But that's not what he has.

The OPs question involves using what he has. I'm fairly certain importing a transmission from overseas is not what he's looking for.

Sorry I misinterpreted what you were saying. And yes, you’re right about what I was saying with the first quoted paragraph above. 

I get that the OP wants to use what he’s got, however I think this is not possible without other parts. The time and effort to machine bits to make them fit the Single range AWD gear to make it a dual range would be better spent earning the coin to import the parts that will make it happen.