Outer Limits 4x4 Board

Haven't been able to find any info on diff pumpkin sizes and clearances. Just interested to get an idea what clearances are between different 4wd's. Ie it *looks* like a Zook on 235/75R15's has about as much clearance as a Patrol on 31's, but I've never had the chance to measure up.

I guess we gain a bit of clearance on trails too by riding the centre ridge slightly due to narrow wheel track, but I'm ignoring that in this comparo.

Anyone know any stats?

Am scratching my head and wondering whether it's possible to shave the Zook diff pumpkin for a bit of extra clearance when I'm doing lockers and RUF...

where are ya gwagon?

Moph wrote:I guess we gain a bit of clearance on trails too by riding the centre ridge slightly due to narrow wheel track, but I'm ignoring that in this comparo.

I think this is one of the most important facts about zooks this makes a massive difference driving in ruts as i found after flipping my rims and then realising i cant drive any of the tracks i use to due to my diffs hitting everything eg. ive got 31"mtrs on flipped rims, front locker yet a stocker will kick my ass along the mudtracks out in sawyers. But the extra width does keep the side of my 4x4 from gettin rooted so...

my dad has a GU patrol on 33s and i have a sierra with 235x75r15 tyers so ill measure the difference tomorrow and let you no, there isn't much in them hers some pics





cheers scott

Dont know how true it is but the rumour I have heard is a Trol on 35's equals a Zook on 31's

VR Rodeo wrote:Dont know how true it is but the rumour I have heard is a Trol on 35's equals a Zook on 31's

thats when you shave i believe ... i was looking into a couple of months ago

mate has a lux. He has 100series front diff, gu rear(small type)

Mine on 33's(32) is better clearence then his on 35's. like 20mm..

a Zook on (true)33,s is the same as a GQ on 36,s !!

OK i measured the hight from the bottom of the diff pumpkin to the ground, this is what i got

Suzuki sierra 235x75r15

23cm front and back with 22psi in tyers

GU patrol with 285x75r16 mtz

24cm front and back with 40psi in tyers

so only 1cm higher

cheers scott.

DavePatrol wrote:OK i measured the hight from the bottom of the diff pumpkin to the ground, this is what i got

Suzuki sierra 235x75r15

23cm front and back with 22psi in tyers

GU patrol with 285x75r16 mtz

24cm front and back with 40psi in tyers

so only 1cm higher

cheers scott.

Cool. 235/75R15 has overall diameter 733mm. 285/75R16 has overall diameter 834mm. So diameter difference is approx 100mm, and radius (ie ground to centre of hub) is 50mm.

The GU is sitting on tyres 50mm taller to the hub, but only has 10mm more clearance - so the GU diff must be 40mm deeper than the Sierra (WT obviously - NT would gain even more). So a GU needs tyres 80mm taller (3.2") than the Sierra to maintain the same clearance

Which means a Sierra on 32" tyres should have slightly better clearance than a GU on 35s

Im running 32 mungrals (measure approx 31.5"), and it has pretty much the exact same diff clearance as my mates patrol with 35's. Oh, and when i went lux diffs, i only lost around 12mm of clearance

get it up there wrote:Im running 32 mungrals (measure approx 31.5"), and it has pretty much the exact same diff clearance as my mates patrol with 35's. Oh, and when i went lux diffs, i only lost around 12mm of clearance

by shaving would that almost come back to even

What is diff shaving?

cutting the bottom off the diff housing so instead of being round its a flat bottom... can gain up to 1" of clearance. IMO if you're shaving zuk diffs you have other issues to deal with first... lol

Shaved Sierra rear and 9/34 swampers = 31cm

How difficult is shaving the diff, cj? Any pics from when you did it?

My shaved diffs give me 300mm on 32" Simex's. Same as Hilux on 35" Simex's

BenT wrote:My shaved diffs give me 300mm on 32" Simex's. Same as Hilux on 35" Simex's

Damn.. thats madness. Did you do it yourself??

i plan to do that to my lux diffs soon

11_evl wrote:i plan to do that to my lux diffs soon

x2!!!!!!!!!!!!!!!!

i just measured a 60 series diff with worn 750 R 16's (31-32 inch) 240mm
and i measured a standard wide track with 30x9.5 15's 230mm

rough measurements of clearance between ground and bottom of pumpkin.

Tim D

can this be put in the bible? under diff shaving/ clearance

get it up there wrote:

BenT wrote:My shaved diffs give me 300mm on 32" Simex's. Same as Hilux on 35" Simex's

Damn.. thats madness. Did you do it yourself??

Yep, did it myself. No too big of a job if you allready have the housing out and stripped. I just cut a small amount off the bottom, then put an old diff head in to gauge the amount to take off, and kept cutting till close to the ring gear.
I had previously checked the angle that the housing sits at when installed, so that I could get the bottom paralell to the ground.
Then I cut out a cardboard template till it fitted in the hole and then cut that shape from steel and welded it in.
I had to trim a little off the flange of the diff heads to match the new housing shape, but there's still heaps of sealing area.

The trussing on the other hand... took ages. Wouldn't be so bad if using a plasma cutter, but I cut and shaped everything with a 5" grinder.

Now I have no drain plug, but I just take out the bottom two bolts to drain the oil.

I used to run 31" Kumho's (true size probably closer to 30"), and with stock diffs had 255mm clearance.

Ben