Outer Limits 4x4 Board

I have 80series with 4" lift and 33" tyres. I fitted caster correction plates recently to fix up on road handling, while caster plates fixed up the handling the change in pinion angle has caused front prop shaft to bind and shudder severely (I have the front shaft out of the car so I can still drive it)

I am planning on cutting diff housing and rotating steering knuckles so that I can remove caster plates and restore factory spec caster angles and eliminate binding in the front shaft

I want on road handling to be as good as possible and want to be able to keep full time 4x4 and am not interested in fitting double cardin or cv joints to front shaft coz I am told these will only help for short term and wear quickly, also I want to be able to keep wear parts (unis and bushes) stock if possible.

I have read through the topic on this in the Bible, this topic only seems to refer to SOA conversions on earlier models.

Once I have worked out how much to rotate knuckles I am planning to remove diff housing from car to make it easier to work on.

I guess I am looking for a heads up from anyone who may have already done this. I am a pretty capable tradie (well not pretty) and have my bro who's a panel beater helping and I have a mate lined up with 3phase mig for welding back together.



OK time for 20 questions

Is there any traps to watch out for?

With the car resting at normal onroad ride hieght should the diff pinion be pointed in straightest line to transfer case pinion?

do coil spring/shock mounts need to be shifted too?

Should I strip the diff to do this?

What caster angles did you go for? (Toyota manual says 3 degrees +/- 1degree for other than 31" tyres)

Are there any issues with clearance to tie rods, sway bars under body etc?

Afterwards has there been any other issues?

would you do this again?



Thanks in advance

Dave.

hi bud, i have never done this to a 80 but have done it to my old hilux diff but with the same setup as a 80 steering and pinion wise.

you are rotating the knuckles not the diff housing itself so it will not change pinion angles.

one thing to watch is the clearance from the tierod to trailing arm, as you rotate the knuckles rearward it lowers the tierod closer to the arms.

it is best to strip the diff (at least all the cv joints and hubs, king pin bearings, centre can stay in) as you will more than likely need to replace the axle oil seals after welding., mark the knuckle and the diff tube (to get where it is placed now) then cut the knuckles with a 1mm cutting disc just behind the factory weld, cut into this 3 to 5mm depth (you will see the join) around the diff tube, once done, shove a jack handle through the king pin holes and lever towards the rear to move the knuckle to your desired degree. once done use a grinding disc to v out the cut and reweld.

cheers mark

it is just so much easier to partime the thing.

udm wrote:it is just so much easier to partime the thing.

bwahahhahahhaha you think.
i went through this toady, marks4wd dont seem to want to answer the phone, 4wd systems do not have any in stock, ebay the4wdshop will not get back to me as to why he doesnt have them on there anymore (even though there is a link), and the wreckers want a fortune for the dx tcase and rear shaft..

man i hate constant 4wd......

cheers mark

I thought this are a important issue with the front DS .. coz if you gonna keep the single u-joint you need to keep the geometry ( parallel lines in the t-casae and at the pinion ) parallel to the ground of pinion and the t-case outpup front flange ..

But if you are trying to rotate the front housing the theory claims for CV in the t-case output and the pinion oriented to the t-case ..

From experience and talking to suspension professionals, it is my understanding that castor plates which are usually around 5degree are too much for a 4 inch lift. Generally, a 4 inch lift only requires 3 degree bushes, not 5 degree plates. They are good for around a 6 inch lift. Because you have the plates, your driveline angles in the front are now excessive and are causing bad tailshaft vibes.

If you go to 3 degree bushes, you will maintain handling and reduce your vibes to tolerable limits. I'm running 2 degree bushes in my 40th anniversary with 3-4inches of lift and it drives great with no vibes in the front end. Make sure you dont have any dents in your front shaft.

cheers for great feedback mud4b

I realised after reading your reply I dont need to change pinion angle at all, there was no vibration in driveline before I fitted caster plates.

udm wrote:it is just so much easier to partime the thing.

cost of marks adapter + freewheeling hubs $500-600
plus open up transfer case to swap it all over

versus

two new oil seals 9 bucks each
plus partially strip diff, a little grinding, a little welding
plus I get to keep fulltime 4x4, std bushes, and unis

A weekend spent working on the truck either way.

IMHO fulltime 4x4 has definite advantages and not many disadvantages.

I reckon 80s handle and corner better on road in fulltime mode. ive been driving mine as rear wheel drive for a couple of months now and reckon it was way more surefooted as fulltime 4x4.

So for me its a no-brainer.

carts wrote:From experience and talking to suspension professionals, it is my understanding that castor plates which are usually around 5degree are too much for a 4 inch lift. Generally, a 4 inch lift only requires 3 degree bushes, not 5 degree plates. They are good for around a 6 inch lift. Because you have the plates, your driveline angles in the front are now excessive and are causing bad tailshaft vibes.

If you go to 3 degree bushes, you will maintain handling and reduce your vibes to tolerable limits. I'm running 2 degree bushes in my 40th anniversary with 3-4inches of lift and it drives great with no vibes in the front end. Make sure you dont have any dents in your front shaft.

with 5degree plates my 80 drives beautifully on the road. I could not fault it at all as far as the way it steers and handles in all conditions.

Drive shaft has no dents and new unis

You loose 1.7 - 2 degrees of caster each inch of lift ..

You can handdle your 80 series so far so good at least with .2 degrees of positive caster ..

The apropiate caster are around 2 degrees of caster.

80's_delirious wrote:partially strip diff, a little grinding, a little welding

i understand where you are coming from, but, its not that easy, the diff housing is really thick where the knuckles are pressed into and then they get welded, it would be a big task to pull them apart, set them (castor and camber) and then weld PROPERLY... and most importantly, u dont want a steering knuckle to seperate while driving.

udm wrote:

80's_delirious wrote:partially strip diff, a little grinding, a little welding

i understand where you are coming from, but, its not that easy, the diff housing is really thick where the knuckles are pressed into and then they get welded, it would be a big task to pull them apart, set them (castor and camber) and then weld PROPERLY... and most importantly, u dont want a steering knuckle to seperate while driving.

Hey udm I know I have understated the work involved in both parts of my comparison, but I have given this a lot of thought. There is a good thread on this mod in the toyota bible if you are interested

http://www.outerlimits4x4.com/phpBB2/vi ... 084#194084

I also know that 4x4 specialist fabrication/suspension shops are doing this mod with good success.

Im confident resetting caster angles will not be a problem with some careful measuring and marking etc. Between myself, my brother and mate who will help, we have four different trades and all pretty switched on, and definitely not the first time for ambitious car mods.

Have a good quality 3phase mig on standby so weld quality wont be an issue. Definitely wouldnt do this if I thought weld quality would be suss. Lost a front wheel at 80-90ks recently!! definitely not fun!!

SHould have this done by sunday arvo ready to drive to work on monday.

i will try and take some pics of this.

well, make sure you take heaps of pics

udm wrote:well, make sure you take heaps of pics

will try to. greasy mits and digital camera prolly not a good combo

good to hear your having a go..

the knuckles are not that thick where they weld on, like i said only 3 to 5mm..

camber is not a problem as they are pressed in and at a very reasonable depth so you would seriously have to stuff up to change that.once you start doing it ,it really does not seem like a huge task and step by step is easy once your doing it, when you get to the other side it takes half the time again since you know what to look for and know what your doing.

one thing i forgot to mention is once one side is done and you set the other side up also just measure between the 2 to make sure they are spot on or your housing is not twisted..

get with the pics and dont worry about the grease on the camera...

cheers mark.

hey guys

thanks for all the good info. will let everyone no how it goes.