[UBZ]

So i want to run 235/85/16s (32s) on my LJ Bush truck and looking for peoples experiences in terms of drivability using different gearing options

I want to set the truck up for a Mud / Rock mix . So needs to be able to crawl as well as spin tyres to clear mud .

I have a Stock LJ80 with 205/R16s (29's) and love the way the gearing works in low range , only thing is it would be nice to have 1 gear lower than first for the slow stuff.

It will be a trailer queen , so hi range gearing not to much of an issue , would be nice to be able to drive it in the high though.

F10A 970cc Engine with a LJ80 4 speed gearbox (want to use this for ease of installation and weight)
Gear Box Figures
1st = 3.835
2nd = 2.359
3rd = 1.543
4th = 1.00
Rev = 4.026

Diffs will be LJ80 Housings - Cromo Axles and CV's Eventually

Current thoughts are to fit a Clocked SJ transfer and aftermarket gears , So I have been comparing low range crawl ratios .

Stock LJ80 - 4.56 Diff gears and 2.571 Stock Transfer
1st = 44.92
2nd = 27.63
3rd = 18.07
4th = 11.71

LJ80 Gbox - 4.56 Diff Gears and 4.16 Transfer
1st =72.68
2nd = 44.71
3rd = 29.24
4th = 18.95

LJ80 Gbox - 4.56 Diff Gears and 4.9 Transfer
1st = 85.61
2nd = 52.66
3rd = 34.45
4th = 22.32

LJ80 Gbox - 4.56 Diff gears and 6.5 Transfer
1st = 113.57
2nd = 69.86
3rd = 45.69
4th = 29.61

So based on the above figures 4.16 transfer gears are going to move 1st low to 2nd low position , but will do nothing to help spin the approximately 20% larger than stock tyres tyres .

4.9 Transfer gears look about right , with a little extra gearing for the tyres .

I know i could fit 4.88 LJ50 R&P or 5.12 Super Carry R&P to help with the tyre size , but both are very hard to find here in NZ and I all ready have a decent supply of 4.56 LJ80 Diffs .

My question is , will the 4.9 Gears be enough for the 32" Tyres ? 6.5 gears look to low to me , meaning constant shifting into high range which I would like to avoid .
Current thoughts are to set it up with 4.56 LJ80 gears and if required change to LJ50 4.88 gears when $$ allows / can find some

Any input or suggestions appreciated .

[zukmeista]

Pretty sure LJ50 transfer cases are lower geared than LJ80's?

[UBZ]

LJ50 Transfer Cases have a low range of 3.013:1 which isn't enough gearing for 32s

[Highway-Star]

Mine is 31's with an F10, 4 speed, 4.9 transfer, and I have run 4.8's and 5.12 diffs.

Ample crawl, most of the time only light acceleration is reguired. I do notice the difference in 2nd low with having now gone back to 4.8 diffs (as I couldn't hold the 5.12's together in the front); preferred it with the 5.12's as it never ran out of puff on hills in 2nd, but the 4.8's are still enough. If you want to stick with the 4.5 diffs, I'd be looking for the 5.1 transfer gears. I reckon the 6.5's would be too low (might be OK with 4.1 diffs?), unless you are planning on putting a ring ding engine in it at some point, in which case I would use them. Also I still find myself swapping to high range allot in between worthwhile tracks with my gearing.

[3cyl]

I can definitely recommend using a Sierra transfer ( tipped over to keep the output shafts in the centre to still use proper diff housings) and some creative stick bending for the shifter. Tanshi, Highway Star and I all have this setup. We all mounted them a little differently but can post pics if you need ideas. Tanshi has 33s, I run both 235/85s and 7.50/16s and we both have 2strokes and find 6.5s work pretty well, mostly because high range isn't too much higher. Highway uses the 4.9s and his gearing is pretty much spot on with his 31s and f10, I think it would still be fine on 32s.
By the way my low 1st is 121:1, 2nd is about 77:1, 3rd is about 44:1 and 4th is about the same as high 1st.

[sideways]

3cyl wrote:

I can definitely recommend using a Sierra transfer ( tipped over to keep the output shafts in the centre to still use proper diff housings) and some creative stick bending for the shifter. Tanshi, Highway Star and I all have this setup. We all mounted them a little differently but can post pics if you need ideas. Tanshi has 33s, I run both 235/85s and 7.50/16s and we both have 2strokes and find 6.5s work pretty well, mostly because high range isn't too much higher. Highway uses the 4.9s and his gearing is pretty much spot on with his 31s and f10, I think it would still be fine on 32s.
By the way my low 1st is 121:1, 2nd is about 77:1, 3rd is about 44:1 and 4th is about the same as high 1st.

Yes please!

[UBZ]

Cheers for the replys guys , your LJs are my inspiration fro this project.

Highway-Star wrote:

I do notice the difference in 2nd low with having now gone back to 4.8 diffs ; preferred it with the 5.12's as it never ran out of puff on hills in 2nd, but the 4.8's are still enough.

This is the drivability info I was after
So basically to run a 31" tyre or above , ideally I need to use LJ50 4.88 R&P to avoid running out of "Puff" on long hill climbs. It also should reduce the stress on the drive train a little . I need to use the 4.88 R&P in a 4.11 or 4.56 carrier ?? Correct?

Highway-Star wrote:

If you want to stick with the 4.5 diffs, I'd be looking for the 5.1 transfer gears.

Ideally I would prefer not to use the 5.12 Calmini Gears ....... Have heard a local horror story of the case harding wearing off with only a little abuse . I aslo have had experience with their badly fitting gear in the past .

3cyl wrote:

I can definitely recommend using a Sierra transfer ( tipped over to keep the output shafts in the centre to still use proper diff housings) and some creative stick bending for the shifter. Tanshi, Highway Star and I all have this setup. We all mounted them a little differently but can post pics if you need ideas.

Pictures please . . I have seen Highway-Stars Barbecue plate mounting design and was planing something similar , but more ideas / options would be awesome. Did you guys reinforce the chassis after cutting out the stock transfer cross member?

3cyl wrote:

Tanshi has 33s, I run both 235/85s and 7.50/16s and we both have 2strokes and find 6.5s work pretty well, mostly because high range isn't too much higher. Highway uses the 4.9s and his gearing is pretty much spot on with his 31s and f10, I think it would still be fine on 32s.

I chose 32's purely because I like the profile of the 235/85/16s . Skinny tyres work so much better on the track, easier on the arms without power steering and should clear the drive train nicely .
31's would be big enough for most of our tracks here , especially with the tiny LJ 3rds . But a 10.5" Profile is too fat IMO.

7.50x16 SATs are still available here in NZ 2nd hand , but 8-10 ply side walls are off putting ..
I have noticed that Maxxis make the M8090 Creepy Crawler in a 7.00 x 5.5 Profile , but again an 8 ply side wall.
My Current favourite contender would be the Pirelli Scorpion in 235/85/16 , they only measure up as just over 31 and have nice soft side walls . but im also really loving the Maxxis MT762's that i'm currently running on the Land Rover . arg damm tyre choices .

[3cyl]

Don't have too many pics these days but these may help. The rubber mounts are spring shackle rubbers, 2 on the driver's side and 1 on passenger. Used one of those spine strengthening plates as part of the mount. Made a low profile removeable crossmember and keyed it in with the old tube (sorry, no pics of that unless I pull off the bash plate) Had to raise the tunnel to fit it in due to no bodylift and a spaghetti bend in the shifter to bring it out the top. The rear output is in the same spot as the original and needed a 25mm tail shaft extension for the front.

[Highway-Star]

UBZNZ wrote:

Cheers for the replys guys , your LJs are my inspiration fro this project.

Highway-Star wrote:

I do notice the difference in 2nd low with having now gone back to 4.8 diffs ; preferred it with the 5.12's as it never ran out of puff on hills in 2nd, but the 4.8's are still enough.

This is the drivability info I was after
So basically to run a 31" tyre or above , ideally I need to use LJ50 4.88 R&P to avoid running out of "Puff" on long hill climbs. It also should reduce the stress on the drive train a little . I need to use the 4.88 R&P in a 4.11 or 4.56 carrier ?? Correct?

Highway-Star wrote:

If you want to stick with the 4.5 diffs, I'd be looking for the 5.1 transfer gears.

Ideally I would prefer not to use the 5.12 Calmini Gears ....... Have heard a local horror story of the case harding wearing off with only a little abuse . I aslo have had experience with their badly fitting gear in the past .

It probably wouldn't run out of puff on long hill climbs with 4.5's.... BUT, you would probably have to keep the revs up a bit more, which combined with higher gearing to start with, may be a tad on the speedy side? Thats what I was getting at with the difference between the 5.12 and 4.8's anyway, the 4.8's require more speed to keep the torque up, which is a bit faster than I would sometimes like to go on a steep hill with bump ups etc. 1st gear is so low either way, diff gearing is near moot.

You mean for the 26 spline side gears? Yes use a 1L or stockman rear carrier inside the 4.8 crown wheel. Stockman carriers are stronger (have seen a 1L carrier fail due to what I see as a Sierra specific design flaw), but 1L ones accept lockrights (if thats on the cards for you?). Keep the 4.8 pinion in its LJ50 pinion housing, the LJ50 rears have that thrust bolt, which nothing else short of a Jimny front has. None of us have killed a 4.875 R&P yet (except for other failed parts taking them out in 3cyl's car); I am amazed how much abuse they can take, yet the 5.12 Super Carries were like pretzels (but only in the front, where they run backwards).....

OK, I have never run the calmini 5.1's; just sounded good to me in theory.

UBZNZ wrote:

3cyl wrote:

I can definitely recommend using a Sierra transfer ( tipped over to keep the output shafts in the centre to still use proper diff housings) and some creative stick bending for the shifter. Tanshi, Highway Star and I all have this setup. We all mounted them a little differently but can post pics if you need ideas.

Pictures please . . I have seen Highway-Stars Barbecue plate mounting design and was planing something similar , but more ideas / options would be awesome. Did you guys reinforce the chassis after cutting out the stock transfer cross member?

I actually managed to put a slight bend in that BBQ plate on the weekend . I am suffering one notable side effect from my transfer conversion which is getting enough adjustment in the gearstick adjustment plate to keep it in 2nd and reverse under load... Just something I should have put more thought into when moving that part of the tunnel.

[UBZ]

Highway-Star wrote:

You mean for the 26 spline side gears? Yes use a 1L or stockman rear carrier inside the 4.8 crown wheel. Stockman carriers are stronger (have seen a 1L carrier fail due to what I see as a Sierra specific design flaw), but 1L ones accept lockrights (if thats on the cards for you?). Keep the 4.8 pinion in its LJ50 pinion housing, the LJ50 rears have that thrust bolt, which nothing else short of a Jimny front has.

I have a lockright 1520 to put in the rear diff.
but I thought a stockman carrier was the same as a 1ltr and would fit a lockright......


So rear setup is LJ50 4.87 Housing & Pinion , 1 Ltr Carrier / 26 Spline Side gears and 4.87 ring gear.

Front Setup - stock LJ50 4.87 front diff with 22 spline side gears . when I want to upgrade to cromo axles n cvs , I will have fit a 1 ltr carrier and 26 spline side gears ?

Thrust bolt in the LJ50 rear ?? 1st I've heard of this .
Are the 1ltr and stockman 26 spline side gears the same?

[Highway-Star]

UBZNZ wrote:

Highway-Star wrote:

You mean for the 26 spline side gears? Yes use a 1L or stockman rear carrier inside the 4.8 crown wheel. Stockman carriers are stronger (have seen a 1L carrier fail due to what I see as a Sierra specific design flaw), but 1L ones accept lockrights (if thats on the cards for you?). Keep the 4.8 pinion in its LJ50 pinion housing, the LJ50 rears have that thrust bolt, which nothing else short of a Jimny front has.

I have a lockright 1520 to put in the rear diff.
but I thought a stockman carrier was the same as a 1ltr and would fit a lockright......


So rear setup is LJ50 4.87 Housing & Pinion , 1 Ltr Carrier / 26 Spline Side gears and 4.87 ring gear.

Front Setup - stock LJ50 4.87 front diff with 22 spline side gears . when I want to upgrade to cromo axles n cvs , I will have fit a 1 ltr carrier and 26 spline side gears ?

Thrust bolt in the LJ50 rear ?? 1st I've heard of this .
Are the 1ltr and stockman 26 spline side gears the same?

Most Stockman carriers have 6 round holes on the crown wheel side (some variants), 1L has 2 long slender ones. Thats the quickest and easiest way to ID them. The internal dimensions must be different; 3cyl tried running a 1520 in a stockman carrier and it went bang first day out, his 1520's in 1L carriers lasted ages until he put the bigger tyres and 6.5 gears in, then he started breaking rear lock rights. I haven't gotten too into the detail differences though, as I was hoping the super carry air locker solution would work long term....

Yep, you have those 2 diff configs sounding right. You could use a stockman rear carrier in the front if its not getting a lockright also.

Thrust bolt was only on the rear diff. Its in the pinion housing, and when adjusted correctly helps to prevent crown wheel deflection under load. They deleted it on very late LJ50's I believe, and hence ever after...

Side gears are not the same. Stockman ones have a squarer tooth profile, the 1L ones have a smoother more rounded profile. I believe its a case of use the 1L ones with the 1L carriers and lockright, and the stockman ones with the LJ carriers.


I'll just add a bit of a disclaimer... late model Stockman's are a bit of a grey area, and I have pulled some Stockman diffs apart finding some different variants on the above mentioned carrier info (even noticed 2 different 4.5 crown wheel designs, but thats getting off topic). But this would be 2 diffs out of about 8 or 9 I have played with.

[303zuke]

And the Stockman/1.0lt side bearings and adjusters are larger to clear the 26 spline axles. If you are going to use a Stockman centre in an LJ50 diff, make sure you also use the Stockman adjusters or you won't fit the 26 spline axles.

[sideways]

Highway-Star wrote:

UBZNZ wrote:

Highway-Star wrote:

You mean for the 26 spline side gears? Yes use a 1L or stockman rear carrier inside the 4.8 crown wheel. Stockman carriers are stronger (have seen a 1L carrier fail due to what I see as a Sierra specific design flaw), but 1L ones accept lockrights (if thats on the cards for you?). Keep the 4.8 pinion in its LJ50 pinion housing, the LJ50 rears have that thrust bolt, which nothing else short of a Jimny front has.

I have a lockright 1520 to put in the rear diff.
but I thought a stockman carrier was the same as a 1ltr and would fit a lockright......


So rear setup is LJ50 4.87 Housing & Pinion , 1 Ltr Carrier / 26 Spline Side gears and 4.87 ring gear.

Front Setup - stock LJ50 4.87 front diff with 22 spline side gears . when I want to upgrade to cromo axles n cvs , I will have fit a 1 ltr carrier and 26 spline side gears ?

Thrust bolt in the LJ50 rear ?? 1st I've heard of this .
Are the 1ltr and stockman 26 spline side gears the same?

Most Stockman carriers have 6 round holes on the crown wheel side (some variants), 1L has 2 long slender ones. Thats the quickest and easiest way to ID them. The internal dimensions must be different; 3cyl tried running a 1520 in a stockman carrier and it went bang first day out, his 1520's in 1L carriers lasted ages until he put the bigger tyres and 6.5 gears in, then he started breaking rear lock rights. I haven't gotten too into the detail differences though, as I was hoping the super carry air locker solution would work long term....

Yep, you have those 2 diff configs sounding right. You could use a stockman rear carrier in the front if its not getting a lockright also.

Thrust bolt was only on the rear diff. Its in the pinion housing, and when adjusted correctly helps to prevent crown wheel deflection under load. They deleted it on very late LJ50's I believe, and hence ever after...

Side gears are not the same. Stockman ones have a squarer tooth profile, the 1L ones have a smoother more rounded profile. I believe its a case of use the 1L ones with the 1L carriers and lockright, and the stockman ones with the LJ carriers.


I'll just add a bit of a disclaimer... late model Stockman's are a bit of a grey area, and I have pulled some Stockman diffs apart finding some different variants on the above mentioned carrier info (even noticed 2 different 4.5 crown wheel designs, but thats getting off topic). But this would be 2 diffs out of about 8 or 9 I have played with.

IIRC the one 3cyl blew on the first day was in a LJ50 centre, not a Stockman one. There's a few people on LJ10.com running 1520s in Stockmans and 3cyl recently said to me they work in a Stockman 3rd so they must work.

Either way, next on the list after my engine rebuild is putting a 1520 into a Stockman diff so we'll see how that goes.

[3cyl]

The one I blew years ago on it's first day out was LJ50. Don't recall putting one in a Stockman, well not blowing one anyway. Of the 10 or so that I've done, 1 blew in a LJ50 carrier, running 235/75s behind a 2 stroke, 1 snapped the bearing journal out of the centre of the crownwheel side of the 1 litre carrier and busted it and the other was at Glasshouse, both the last 2 were in 1 litre carriers with 6.5 gears turning 235/85/16s the first and 7.50s the second. Also mick broke 1 in a 1 litre doing a rollback and sidestep. A lot of these were probably in part caused by worn side gears. Still haven't broken a welded yet.
Pretty sure the manual says about the different dimensions of the Stockman centre and you should bench test them anyway.

[Highway-Star]

3cyl wrote:

The one I blew years ago on it's first day out was LJ50. Don't recall putting one in a Stockman, well not blowing one anyway. Of the 10 or so that I've done, 1 blew in a LJ50 carrier, running 235/75s behind a 2 stroke, 1 snapped the bearing journal out of the centre of the crownwheel side of the 1 litre carrier and busted it and the other was at Glasshouse, both the last 2 were in 1 litre carriers with 6.5 gears turning 235/85/16s the first and 7.50s the second. Also mick broke 1 in a 1 litre doing a rollback and sidestep. A lot of these were probably in part caused by worn side gears. Still haven't broken a welded yet.
Pretty sure the manual says about the different dimensions of the Stockman centre and you should bench test them anyway.

Rightio, my mistake. So 1520 may work in a stockman carrier then?

[3cyl]

Highway-Star wrote:

3cyl wrote:

The one I blew years ago on it's first day out was LJ50. Don't recall putting one in a Stockman, well not blowing one anyway. Of the 10 or so that I've done, 1 blew in a LJ50 carrier, running 235/75s behind a 2 stroke, 1 snapped the bearing journal out of the centre of the crownwheel side of the 1 litre carrier and busted it and the other was at Glasshouse, both the last 2 were in 1 litre carriers with 6.5 gears turning 235/85/16s the first and 7.50s the second. Also mick broke 1 in a 1 litre doing a rollback and sidestep. A lot of these were probably in part caused by worn side gears. Still haven't broken a welded yet.
Pretty sure the manual says about the different dimensions of the Stockman centre and you should bench test them anyway.

Rightio, my mistake. So 1520 may work in a stockman carrier then?

To be honest, I've always had 1 litre stuff laying around and being the cautious type.... I MAY have put one in a Stockman for Mick, not sure now. I'd be DEFINITELY bench testing the carrier if I did though. Meh, I'm over Lockrights anyhow and once I've given the Rover some love I hope to be rid of them (lockrights, and stupid welded too for that matter) though I have been thinking of using a Vit rear 5.12 in the rear.

[tanshi]

plans are afoot for something even better,

watch this space

[3cyl]

tanshi wrote:

plans are afoot for something even better,

watch this space

Hoi, you... fess up, you know I got no patience.

[Highway-Star]

3cyl wrote:

tanshi wrote:

plans are afoot for something even better,

watch this space

Hoi, you... fess up, you know I got no patience.

Hamster in a wheel in the centre, and pool noodles for shafts. Should work a treat in an LJ

[TZAR]

Hydraulic pump attached to motor then a hydraulic motor attached to front of transfer case so you can get maximum torque at 1 rpm of the transfer case??????

[3cyl]

TZAR wrote:

Hydraulic pump attached to motor then a hydraulic motor attached to front of transfer case so you can get maximum torque at 1 rpm of the transfer case??????

Oh I was hoping it would be those odd looking but cool snow ski track bogey thingies I saw on youtube.

[UBZ]

Great Tech Guys .

I think I will use a 1 Litre Carrier , as the 1520 Lockright is Designed for It ... and they are cheap and plentiful here .
I will try to get some comparo photos of the Different Carriers and Diffs for reference to add to this thread .

Does anybody know what the length differences are between LJ and NT SJ40 (SJ410) drive shafts?
Given that rebuildable LJ80 Drive shafts are had to find and that the front will require a spacer ,I am considering modifying some SJ40 ones to the right length .

Also have you guys had any issues with Axle Tramp ? Considering all the reduction gearing .

[3cyl]

Never noticed tramp but in some pics in the Ripley wheeling thread I seem to have some mild wrap. Mine's a little stiffer sprung than some too as I'm not competing in unlocked competitions.

[tanshi]

mine wrapps a bit but nothing i worry too much about.
Just replace your springs often.

[Highway-Star]

UBZNZ wrote:

Great Tech Guys .

I think I will use a 1 Litre Carrier , as the 1520 Lockright is Designed for It ... and they are cheap and plentiful here .
I will try to get some comparo photos of the Different Carriers and Diffs for reference to add to this thread .

Does anybody know what the length differences are between LJ and NT SJ40 (SJ410) drive shafts?
Given that rebuildable LJ80 Drive shafts are had to find and that the front will require a spacer ,I am considering modifying some SJ40 ones to the right length .

Also have you guys had any issues with Axle Tramp ? Considering all the reduction gearing .

Not off hand sorry. But the 1L shafts would definitely need shortening. By how much I am not sure. I still have stock Stockman shafts in mine, but the front one really is on as much stretch as I would like due to the Sierra transfer being shorter, and my front diff being a little bit forward (jackshaft and rear tailshaft are good).

My 80 decimates front springs (and Sierra thickness U-bolts for that matter). Not conventional spring wrap I don't think though, more a combo of a bit more travel than stock, and aggressive left foot braking. Rear springs seem to last very well in it though (total opposite of my Sierra..... go figure ).