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Moving front diff forward for 32s

Posted: Tue Nov 06, 2012 1:44 pm
by dean zuk
Hi all,

Im having to move my diff forward on my nt sj413 to fit a set of 32x9.5 super swampers i've got after already extending bumpstops, steering lock and smashing inner guards.

I understand how to do it (redrill spring plate and diff locaters further back) but i'm not sure how to measure how far forward i need to go with it? :?

If anyone knows the best way to go about measuring that would be great, or better yet if you could tell me a measurement :mrgreen:

Current specs to help out:
Narrow track diffs
32x9.5 super swamper tsls (sit flush with guards so ??? offset)
50mmish suspension lift
Bens power steering kit (steering box 20mm forward)
1 inch body lift very likely

Cheers in advance
Dean

Re: Moving front diff forward for 32s

Posted: Tue Nov 06, 2012 3:04 pm
by zukmeista
Just measure from the center of the existing hole I would have thought? Keep in mind that by moving the diff forward, youwill get more firewall clearance, but then the tyres will rub behind the headlights instead.

Re: Moving front diff forward for 32s

Posted: Tue Nov 06, 2012 3:29 pm
by dean zuk
zukmeista wrote: by moving the diff forward, youwill get more firewall clearance, but then the tyres will rub behind the headlights instead.


This is the problem i'm trying to avoid, ideal would be to miss both but i'm trying to find the happy place in between, preferably without having to redo it.
In saying that I would prefer if it rubbed on the nice round headlight bucket than ripping the tyres on the bottom of the firewall :|

Re: Moving front diff forward for 32s

Posted: Tue Nov 06, 2012 3:45 pm
by zukmeista
Do what I did, take to the firewall with a BFH! :twisted: Easiest way to fix the problem.

Re: Moving front diff forward for 32s

Posted: Tue Nov 06, 2012 3:52 pm
by dean zuk
zukmeista wrote:Do what I did, take to the firewall with a BFH! :twisted: Easiest way to fix the problem.


Done that :roll: Wasn't enough

Re: Moving front diff forward for 32s

Posted: Tue Nov 06, 2012 3:55 pm
by zukmeista
Get a bigger hammer? :lol:

Re: Moving front diff forward for 32s

Posted: Tue Nov 06, 2012 9:09 pm
by Bruiser70
Gota go up deano!!!! I think you'd be surprised the difference a 25mm body lift makes to your minimal clearance :lol: thats if you ever put those swampers back on! I think your having way to much fun on the wee tyres!

Re: Moving front diff forward for 32s

Posted: Tue Nov 06, 2012 9:33 pm
by Rotazuk
On a standard 413 you can move the diff forward 20mm , then the tie rod hits the drag link . With the drag link moved forward 20mm you could go to about 40 mm but I would expect you would be rubbing the light box .

The light box can be cut back a reasonable amount thou . You are going to hit somewhere on 32's , I say trim the headlight box area over a lift .
Chris

Re: Moving front diff forward for 32s

Posted: Wed Nov 07, 2012 2:15 pm
by Swamped
I did 15-16mm, can't remember. I measured from the edge of the existing hole on the bottom plates, taking into account the diameter of it and drilled a pilot hole. Welded up the old hole and redrilled the new one in the right place. For the spring perches I cut and welded on new ones with the holes in the right place but I was swapping in wt diffs.

The diff moves forwards under compression so if you miscalculate the shift forwards the tyres could eat the front of the guard rather than just scuff em a bit :lol:

With that tyre/offset/diff/lift combo is it real tippy? My rims stick outside the body maybe 90mm on stock diffs and with wt's its even further. I know its a lot of pissing around but a guard chop might be a better option if your planning on holding onto it for a while? A strong wind on the open road makes em feel like they are gonna flip. Even old feisty laid his over doin a skid on gravel.

Re: Moving front diff forward for 32s

Posted: Wed Nov 07, 2012 6:02 pm
by COILY
RUF will help.

Re: Moving front diff forward for 32s

Posted: Wed Nov 07, 2012 6:44 pm
by UBZ
COILY wrote:RUF will help.

will still only give you 15-20mm depending on what springs you use .
any more and you will have to move the shock mounts on the chassis .
Beating / cutting the firewall to much will result in Accelorator pedal issues .
The bottom Headlight bucket ,as Rotazuk said can be cut quite alot and easily .

Re: Moving front diff forward for 32s

Posted: Wed Nov 07, 2012 6:54 pm
by dean zuk
8) Thats the kind of info i'm after.

Swamped wrote:The diff moves forwards under compression so if you miscalculate the shift forwards the tyres could eat the front of the guard rather than just scuff em a bit :lol:


Thats what i'm worried about :oops: . At the moment the tyre collects from the firewall to almost the center of the wheel arch under compression. The ideal would be to get the middle of the arch at full compression.
My plan was that if i could do that, then a small (1 inch)body lift would allow me to be able to turn the wheel at compression :roll: , also it would help to avoid a bit of rub in the back.
This is all ideal world type stuff though :roll:

Swamped wrote:With that tyre/offset/diff/lift combo is it real tippy? My rims stick outside the body maybe 90mm on stock diffs and with wt's its even further.


I haven't driven it offroad with these tyres on yet, so not sure how bad it will be, seems ok on road though. Not too sure how much worse a 1 inch bodylift would effect it? :|

Cheers for the help
Dean

Re: Moving front diff forward for 32s

Posted: Wed Nov 07, 2012 7:23 pm
by Swamped
I think your offset may cause your front tyres to drag on the chassis too with 32's and nt diffs. I've never tried mine on stock rims but Id expect it might. I wouldn't go with a body lift due to the already poor center of gravity but they aren't hard, esp if you get the kits that are about with the long nuts? Don't know if thats what they are called.

Are you running stock gearing?

Re: Moving front diff forward for 32s

Posted: Thu Nov 08, 2012 4:11 pm
by dean zuk
Swamped wrote:I think your offset may cause your front tyres to drag on the chassis too with 32's and nt diffs.

The big lugs on the tyres (every 5th? on the TSLs) were clipping the springs on full lock so i spaced the steering stops out a tad.
Also the rims are 15x7s, and come to just inside the plastic flare so the tyre ends up just outside that, so 20mm maybe past body :? . Surely that a bit wider than standard, but i quite like the skinny inner track so i dont sit in ruts :mrgreen: .
Anyone know the height of a standard 413? im starting to second guess how much of a spring lift i actually have as they're bastard spring packs i made up out of the standard springs and a set of second hand lift springs due to the lift ones being filling loosening hard. Theres 80mm to the std bumpstop at the front.
Swamped wrote:Are you running stock gearing?


I was waiting for this :lol: At the moment i just have a 410 tcase in there to make it onroad driveable for cert etc. Currently just wanting to get it legal to get out to the river to go fishing then look at a set of gears (eyeing up 4.9s)

Cheers
Dean

Re: Moving front diff forward for 32s

Posted: Thu Nov 08, 2012 4:53 pm
by BlakeJ
would be real interested on how you get on dean, im putting 32.4" on my samurai this summer, was gunna bring diff forward about 18mm, guard chop and cut as much out of the firewall as i can without causing accelrator problems. will be running a rock lobster on it aswell for gearing.
cheers
blake

Re: Moving front diff forward for 32s

Posted: Thu Nov 08, 2012 5:59 pm
by dean zuk
BlakeJ wrote:would be real interested on how you get on dean, im putting 32.4" on my samurai this summer


At this rate i might end up copying what you do :lol: :roll:
How wide are the 32s you're putting on? I thought it may be easier with 9.5s but it would seem its still not ideal :x

Re: Moving front diff forward for 32s

Posted: Thu Nov 08, 2012 6:53 pm
by Ben
I have moved my front diff forward 20mm. My 32x10.5 Simex's occasionally just touch the firewall and just kiss the headlight bucket at full flex and max compression, so I'd call it pretty centred in the wheel arch.

Ben

Re: Moving front diff forward for 32s

Posted: Thu Nov 08, 2012 6:58 pm
by dean zuk
:D Thats awesome to know Ben.

Have you cut/ bashed anything in the guard? or just the usual seam bashing?

Re: Moving front diff forward for 32s

Posted: Thu Nov 08, 2012 7:39 pm
by BlakeJ
dean zuk wrote:How wide are the 32s you're putting on? I thought it may be easier with 9.5s but it would seem its still not ideal :x


they are 33" silverstones, but from the old mould so actual diameter is 32.4 or 32.3. 10.5 wide, going on a 7 inch rim

Re: Moving front diff forward for 32s

Posted: Thu Nov 08, 2012 9:30 pm
by PuddleJumper
I went forward 16mm on mine. I run 31" Silverstones on 15x7" rims with 0 offset (lugs on the inside of the tyre touch the chassis on full lock) Dont forget a spacer for the drive shaft too.

Re: Moving front diff forward for 32s

Posted: Fri Nov 09, 2012 8:06 pm
by Ben
dean zuk wrote::D Thats awesome to know Ben.

Have you cut/ bashed anything in the guard? or just the usual seam bashing?


No cutting or seam bashing. I'm SPOA with a 2" body lift, but the springs are well used stock springs that are flat to inverted, so its not as high as you'd think. It measures 550mm from axle centreline to the lip on my 413's plastic flares.

I also have widetrack diffs, but narrow track spring spacing.

Ben

Re: Moving front diff forward for 32s

Posted: Mon Dec 17, 2012 11:09 pm
by dean zuk
:) Well they're on there and not catching, but still not totally ideal.

I've made the bumpstops a bit longer (40mm extended in front, 20mm in back) and done a bit more bashing of the firewall, concerntraiting on the bits where it clipped worst.

Couldn't quite fit my finger into this gap at full compression
Image

Pretty happy with the rear, extremely tight fit but seems not to be rubbing
Image

Overall flex is ok, tossing up doing a RUF now just to try and squeeze a tad more out of it and maybe a softer ride, or leaving as is and get it legal.

"flex" shots
Image
Image

Re: Moving front diff forward for 32s

Posted: Fri Aug 01, 2014 4:00 am
by slidenyo
after reading heaps of interweb dribble,
there seems to be two trains of thought on bringing the diff forward in our sj413 ute.
one being use a swb rear top leaf,
two being a re drill on the perch's and skid plates
and as a side note being able to use a rear prop on the splined section to gain the inch and a half shift.
currently I've returned it to standard shackles ,no lift, patrol bumpstops (brackets modified) on the front, longer shocks in the rear.
all to try fit 31" swampers with a big offset rim and no lift.
will obviously need a front tubbing and guard chop if I can get the springs to let go of some more droop.
Suzuki masters shed your knowledge for me please.
this is a cheap build so trying to utilize 2nd hand parts and manual labour to achieve the results

Re: Moving front diff forward for 32s

Posted: Fri Aug 01, 2014 6:28 am
by 3VILC
I've put 31s on mine. No brakes yet so havnt done a proper flex but a test flex pulling one wheel up with the engine crane. The front inner guards are gone and firewall moved back and the rear wheel wells are widened and higher. Standard ride height. Looks like I may get a tiny bit of rub at the top of the rear, fronts are going to clear all the bodywork but hit the chassis rails. Crap offset tho some bigger offset rims or spacers should be fine. Probably just weld up a couple of steering stops for the time being. Rears will see how it goes, discs might be just enough of a spacer, could drop the bump stops a fraction, but then I've just left my wife so a set of new rims could be on the shopping list when I sell the house haha

Re: Moving front diff forward for 32s

Posted: Fri Aug 01, 2014 4:14 pm
by QUADRACER
Don't forget to space your drive shaft the same distance

Re: Moving front diff forward for 32s

Posted: Sat Aug 02, 2014 7:25 am
by slidenyo
^ yeah understandably, ill go have a hunt at admirals to make sure theres no factory shaft a little longer to suit.
might also look at finding a shorter pitman arm with the same spline to pull the draglinks away from each other