Adjusting Camber & Toe on solid rear ends

[Sam_Q]

I have an ae86 with a T18 dif and I am looking to adjust my camber to -1 and possibly my Toe also to a simular amount.

So far I have heard of 3 different ways of doing this:

- putting the diff in a press and just bending it

- heating up a seciton on top of the axle tubes and quenching it

- chopping and welding


At this stage I am looking at the chop and weld approach using a jig that I will make myself.

I would like to heard from people who have done it, have a picture of it, know if toe in is good or just in general.

[jezza323]

how about floating hubs? ive heard that the axles/centre wont last as long if you dont go to a floating hub?

search on the IPRA forums, many of the rx7 IPRA cars run full floating axles

[merc-blue]

Sam there is a proper (and expensive) way to do it.
Bending the housing is asking for trouble IMO. axels wont like it a whole lot.

A full floating setup (or semi floating setup) can do it.
Anything where the Hub is independant of the housing. than a "ramp" plate is put in to adjust the alighnment of the hub. its a long fiddly process. and you must have a independant Axel/hub. the secret is that the Spline on the axel (hub end) has a barreled shape.
We run "ramped" full floaters in a few of our cars. and rear wheel alighnment can take over a day to do.
It is a expensive procedure and requires alot of custom fab. i will draw up some pics of how a "cheap" setup like this would look like

[Sam_Q]

jezza, got a link?

merc: I would like to see those drawings if you have some time.

I have heard that -1 degree is possible with a conventional setup without any long term problems, what do you guys would think would go wrong? bearings and splines flog out?

[LeeRoy]

You will flog out everything.

Bearings, splines, gears, probably the whole diff.

If you dont mind can i come round to your place? i'd like to watch you put a $1200 lsd in and have the whole diff implode.

[jezza323]

here is a bunch of links, just searched, dont have time to read through and sift out the relevant ones atm

http://www.techmasters.com.au/forum/...light=floating
http://www.techmasters.com.au/forum/...light=floating
http://www.techmasters.com.au/forum/...light=floating
http://www.techmasters.com.au/forum/...light=floating
http://www.techmasters.com.au/forum/...light=floating
http://www.techmasters.com.au/forum/...light=floating
http://www.techmasters.com.au/forum/...light=floating
http://www.techmasters.com.au/forum/...light=floating
http://www.techmasters.com.au/forum/...light=floating
http://www.techmasters.com.au/forum/...light=floating

[Smokey228]

I dont know much, but i do know you cannot just bend the diff! Thats the whole problem with welding, you have to be careful as it can warp the diff...

I cannot for the sake of me, think of anyway of attaining camber on a live rear end!? Though im sure there are some way, but perhaps for the money and trouble, it'd be easier and better off in the end to just go irs?

You cant bend anything, cause the axles need to be straight 100% of the time! They dont just bend and say thanks... Trust me

Cheers,
Jase

[Billzilla]

Well how about asking someone that's actually done it?

That's me, and the Datsun diff in my racing car has the rears running at 0.5° negative camber and a bit of toe-in as well, done by putting the housing in a big press and just bending it.. If you keep the angles small like that yuou will have zero problems. Much more than that though and I would recommend CV joints in the ends, like the V8 Supercar boys do.
Of if you want to do that cheaply (kinda) get the front diff out of something like a Suzuki Sierra.

[Cuzzo]

Can you remove and reweld the cups on the end which the axels bolts up to?

I believe that the commdores have a very slight neg camber from factory.

[Smokey228]

Bill, but if you bend the housing slightly, do the axles just bend to the weight and go okay with that? Or do you have to give them a 'cv' sorta thing???

And same if you were to just reweld the cups at the ends. Will the axles just accept the new forces being excerted on them or do they have to have a 'cv' stlye at the ends??

Cheers,
Jase

[Billzilla]

Bill, but if you bend the housing slightly, do the axles just bend to the weight and go okay with that? Or do you have to give them a 'cv' sorta thing???

And same if you were to just reweld the cups at the ends. Will the axles just accept the new forces being excerted on them or do they have to have a 'cv' stlye at the ends??

Cheers,
Jase

You find there's more than enough play in the spider gears to accomodate a good 0.5° (or even 1.0° on some centres perhaps) so that the axles are still straight and have no extra loading on them.

[oldcorollas]

Can you remove and reweld the cups on the end which the axels bolts up to?

I believe that the commdores have a very slight neg camber from factory.

no, you need to keep the bearing aligned with the axle.. or the bearing is not happy.
ie, axle, bearing and axle tube shoudl remain as an unaltered unit.... and realign that unit with the diff centre..

if you are going to bend etc, you want the whole axle tube to be at the new angle, and aligned with the centre of the differential itself.

main issue with small angles (assuming you have enough freeplay in the splines anyway), is that at as the axle rotates, the loading point changes from inner to outer part of the spline. basically, you are setting up a rotational reverse bending tester.. and testing how long the axle ssplines last when loaded in that regime

ie.. like this..

_\/________
..................|
__________|
............../\


as Bill said, with small angles it is not such a big issue... but if you have large angles.. and large power.. this reverse bending will almost certainly lead to failure.

to bend axle tubes may require large amounts of force. cutting and welding (if you do it accurately) should be more accurate, as the bend is put where you want it and reduces chance of nasty loadings on the axles bearings

so.. if you are going to bend housings, do it as close to the diff centre as possible. if you go to CV style driveshaft, then you can adjust the angle at the end of the axle tubes..


smokey, the axles aint gonna bend.. and if they do, they will break.. the misalignment is taken up by the slack in the splines between the axle and the diff centre.
if you reweld cups at the ends, you MUST have CV style.. otherwise you are only changing the angle of the bearing... with no effect on the camber or toe

[merc-blue]

I will try to find pics of a barreled axel floater.
Last time i was under a V8supercar its what they where running.
If i cant find any i will take some pics of somthing on a car here (although i will have to censor and blur some bits )
We have 2 of them in different cars and they work effectivly but haivng the ramp section cut correctly is a PITA.

[LeeRoy]

Ideally you need something like this if exerting any stress on the diff

[Matt-AE86]

I always had an idea of jacking the car up, puting some heavy duty stands under the end of each axle, wrapped heavy duty chain around the centre and then put a block and tackle bolted to the ground some how and keep pulling it tight and hopefully you would get some bend in the housing and give yourself some negative camber ?