Thread: Selectable 4WD in LT95

just to be silly, I think I know of a way you could do it.....


But you loose the hand brake and this is soley in the relm of hypothetical engineering...

(you also need to use subaru parts or a ricer center diff)

remove the stock center diff and install the ricer diff in place machining up a set of collars with splines much like the selector in a fairy overdrive

the center diff would have the mod done as per the welding up for rear drive only but drive to the rear output would be via a sliding collar that would run into the back of the Center diff... actuation would be via an actuator where the parkbrake used to be....

right off the top the output shaft size of the center diff from one of the guys ricer might let you do it....


but that leaves the question of

Why would you want to front wheel drive 2t of off road vehcile?

Originally Posted by Blknight.aus

just to be silly, I think I know of a way you could do it.....


But you loose the hand brake and this is soley in the relm of hypothetical engineering...

(you also need to use subaru parts or a ricer center diff)

remove the stock center diff and install the ricer diff in place machining up a set of collars with splines much like the selector in a fairy overdrive

the center diff would have the mod done as per the welding up for rear drive only but drive to the rear output would be via a sliding collar that would run into the back of the Center diff... actuation would be via an actuator where the parkbrake used to be....

right off the top the output shaft size of the center diff from one of the guys ricer might let you do it....


but that leaves the question of

Why would you want to front wheel drive 2t of off road vehcile?

When can you have some ready I will gladly test one for you?
Every seccond rock crawling buggy in we-rock aus and Oz rock are running lt230s and pay over 1k for a rear disconnecting device which bolts onto the rear tailshaft to enable front digs.

(a front dig is when you need to do a really tight turn during a course, you disconnect rear drive, lock the inside rear wheel or chock it, turn the steering at full lock, and floor it which spins the vehicle on its axis). You can also do front digs with the center diff unlocked, and the handbrake pulled on, essentially disconnecting the rear drive, but as mentioned previously, your CDL wont last too long.

Originally Posted by Lotz-A-Landies

You would need to talk to them whether it can be reversed for front wheel drive, although you would want some pretty tough diffs up front for competition.

Diana

tough enough?




cheers,
Andy

thats what fiddle brakes are for leave all your diffs open lock the lefts with the bias favoring the rear then stomp the noise

what your calling a dig turn has been done in tractors for years and thats how some of them do it but they are normally 4 wheel or rear whieel drive.

the other method of doing that is even easier than using the diff like I suggested and is simply a case of putting a double dog on the output shaft which will let you unlock front, rear or both whenever you need to... the downside is it also costs you your park brake but then so did my hypothetical method.

The part time conversion would likely take out some of the drivetrain slop - at least the part caused by the center diff.........with the freewheeling hubs it would also take out the vibration coming from my front driveshaft which i really should have a look at......

Anything with a rear salisbury would be fine. I wouldnt do it to a RR with stock diffs.

I realise this is a very old thread but...I did this conversion last week and this thread was my inspiration.
I followed the instructions above almost exactly and used the same NTN 6207 bearing ($20 at CBC Bearings) I paid a local machine shop to do the machining and although it seemed simple, they charged a bit more than I was expecting. 4 hours plus some carbide because of the hardness of the side gear. Having said that, I know almost nothing about machining so maybe the price was fair.
What I did do differently was weld the rear side gear to the housing first to locate it properly (preheated in the oven to 200 degrees and then cooled it slowly in the oven afterwards). My wife wasnt too happy about finding a center diff in the oven but she got over it. I then put a largish washer under the rear side gear and welded the cross pins to the side gear as per the photos above. Because the rear output shaft comes very close to protruding through the rear side gear, I used a flap disc to take a mm or so off the end the of the rear output shaft to set my mind at ease about possible clearance and resultant diff preload issues. Even with the rear side gear welded to the housing, the cross pins are probably still necessary to act as a shear key between the diff halves and by welding the gear to the cross pins it provides a backup if the weld to the housing lets go. The side gear and cross pins weld easily, but the housing appears to be cast and doesnt take a weld as easily, although pre and post heat helps.
It all went back together with no issues.

I'll explain below why I did it and what my thoughts are so far.
Why:
I have a Nissan GQ diff in the front of my Perentie and an 80 Series rear. The reasons for this are probably a separate topic, but suffice to say I already have free wheeling hubs in the front. I also had a vibration issue in the front prop shaft which while not extreme, was annoying at certain speeds and probably not good for long term reliability.
I also hate the drive line backlash and potential weakness associated with a center diff. I'm a long term Patrol owner and am familiar/have no issues with part time 4WD handling and have had no issues with front diff or driveshaft longevity as a result of free wheeling hubs. If fact, quite the opposite, the Nissan GQ front prop and diff which I used were over 25 years old but were in as new condition with zero spline wear in the prop.(the vibration mentioned above was not the fault of the prop but more my backyard cutting and welding process as well as the new operating angles)
Thoughts so far:
Zero backlash. Its possible to stab the throttle on an off without inducing any clunk whatsoever. The rear LSD is pretty tight so this probably helps but it makes it so much more enjoyable to drive without constantly anticipating and correcting for backlash.
The transfer case and driveline is noticeably quieter. I'm not sure why, but it is, I suppose there's now less moving parts. The vibration is also gone.
Handling - its different, but I wouldnt say worse. The main thing was changing the front toe from 1-2mm out to 1-2mm in. This made a big difference to steering twichiness. Driven front axles need a bit of toe out as they tend to pull straighter and non driven axles need a bit of toe in. Windy roads and gravel roads feel fine to me. Having said this, I fully realise there will be situations where constant 4WD would be preferable but this a compromise I'm prepared to make. Possibly the longer wheelbase of a 110 makes it less of an issue also.

I accept this isnt for everyone but just thought I'd share my experiences in case anyone is contemplating it.

One question I do have is this: because the front output shaft in 4WD is now only driven by the locking dog, does this put more load on the dog than the constant 4WD setup when the CD is locked and the front output is also connected via the side gears to the center diff? Ie, now all front axle load goes through the locking dog only - is this the same with a part time set up and the CD locked?

Originally Posted by mark2

I realise this is a very old thread but...I did this conversion last week and this thread was my inspiration.
I followed the instructions above almost exactly and used the same NTN 6207 bearing ($20 at CBC Bearings) I paid a local machine shop to do the machining and although it seemed simple, they charged a bit more than I was expecting. 4 hours plus some carbide because of the hardness of the side gear. Having said that, I know almost nothing about machining so maybe the price was fair.
What I did do differently was weld the rear side gear to the housing first to locate it properly (preheated in the oven to 200 degrees and then cooled it slowly in the oven afterwards). My wife wasnt too happy about finding a center diff in the oven but she got over it. I then put a largish washer under the rear side gear and welded the cross pins to the side gear as per the photos above. Because the rear output shaft comes very close to protruding through the rear side gear, I used a flap disc to take a mm or so off the end the of the rear output shaft to set my mind at ease about possible clearance and resultant diff preload issues. Even with the rear side gear welded to the housing, the cross pins are probably still necessary to act as a shear key between the diff halves and by welding the gear to the cross pins it provides a backup if the weld to the housing lets go. The side gear and cross pins weld easily, but the housing appears to be cast and doesnt take a weld as easily, although pre and post heat helps.
It all went back together with no issues.

I'll explain below why I did it and what my thoughts are so far.
Why:
I have a Nissan GQ diff in the front of my Perentie and an 80 Series rear. The reasons for this are probably a separate topic, but suffice to say I already have free wheeling hubs in the front. I also had a vibration issue in the front prop shaft which while not extreme, was annoying at certain speeds and probably not good for long term reliability.
I also hate the drive line backlash and potential weakness associated with a center diff. I'm a long term Patrol owner and am familiar/have no issues with part time 4WD handling and have had no issues with front diff or driveshaft longevity as a result of free wheeling hubs. If fact, quite the opposite, the Nissan GQ front prop and diff which I used were over 25 years old but were in as new condition with zero spline wear in the prop.(the vibration mentioned above was not the fault of the prop but more my backyard cutting and welding process as well as the new operating angles)
Thoughts so far:
Zero backlash. Its possible to stab the throttle on an off without inducing any clunk whatsoever. The rear LSD is pretty tight so this probably helps but it makes it so much more enjoyable to drive without constantly anticipating and correcting for backlash.
The transfer case and driveline is noticeably quieter. I'm not sure why, but it is, I suppose there's now less moving parts. The vibration is also gone.
Handling - its different, but I wouldnt say worse. The main thing was changing the front toe from 1-2mm out to 1-2mm in. This made a big difference to steering twichiness. Driven front axles need a bit of toe out as they tend to pull straighter and non driven axles need a bit of toe in. Windy roads and gravel roads feel fine to me. Having said this, I fully realise there will be situations where constant 4WD would be preferable but this a compromise I'm prepared to make. Possibly the longer wheelbase of a 110 makes it less of an issue also.

I accept this isnt for everyone but just thought I'd share my experiences in case anyone is contemplating it.

One question I do have is this: because the front output shaft in 4WD is now only driven by the locking dog, does this put more load on the dog than the constant 4WD setup when the CD is locked and the front output is also connected via the side gears to the center diff? Ie, now all front axle load goes through the locking dog only - is this the same with a part time set up and the CD locked?

Load on the locking dog for the front driveshaft will still be the same as with constant 4WD Mark. Would you have any pics of the maching done inside the centre diff - I am presuming it is the side gear for the front shaft. Be interested to see how the bearing fits in there.