Mythbusters - S and T series diff strength

[o_man_ra23]

How did this become a for sale section for a G series?? Its a discussion about the strength of common diffs, not a thread to do with conversions. I dont think this post is really warranted in this conversation.

Oman

if anyone wants a G series - i have one out of a hiace for sale...5 stud so no mods needed.

[crowncustom]

I will say that it is most centres that break under extreme conditions.Normally its the sun gears that break most of the time.But axles do break once in a while also.
I had a 1966 RT 40 Corona 1600S which I had put a 18RG into and for memory it ran a S series diff 4.11:1 ratio.This car was no sloutch when it came to grunt so not long after the conversion was done I decided to see how good the diff was.Popped the clutch at about 5000-6000rpm and bang broke an axle.The diff was fine but axle was broken inside the sun gears and would not budge.Never used that diff again.And the motor that was in it prior to the RG was a fairly well worked 1600 and that rear end took alot of punishment with the 1600 but the with the RG it lasted about a week.And the 1600 motor was put into another RT 40 1600S I had and I also broke an axle in this car.So yes axles will break.
Cheers Brett.

[oldcorollas]

if anyone wants a G series - i have one out of a hiacebvlah blah blah.

please delete your post.

[Dimitri]

dam you hen. now the kids giving away their S series rear ends are going to know theyre giving away spares for their new T diff!

2 things to add. if youre running a locked diff. you need to let it warm up before you thrash it. properly warm up with a solid 10 minutes of driving before you do skids.

also if youre welding your S series. obviously you need to lock the gears by pouring weld into the inspection holes in the side of the centre. but you also need to weld the "hat" onto the centre aswell. when you have it apart itll be obvious what i mean.

[rolleraction]

Anyone heard of full spools being available 'off the shelf' for S or T series diffs??
If so, where and how much?
Cheers

[Dimitri]

www.peterdmotorsport(s?).com mini and full spools in chro-mo and al'. i have 1. not installed though, but looks nice .

for zenki only.

[truenosedan]

i completely agree with what hen said,

but also agree with the ke70 borg warner diffs being fucking strong

i have done prolly 20,000 kms now on an old shit ke70 diff, as in 280,000 open in the hands of some granny, and now 20,000 locked, it has had the shit thrashed out of it,,, now behind turbo... some welds are loose in the diff now... but still sweet

[SLO-055]

dimitri raises a good point, one i've often pondered, at our workshop and with all my friends cars i've found a few things, the shorter of the two axles usually breaks, most possibly because it has less give, therefore this means the longer axle lives ... well longer cos it can twist more, so therefore, when the metal of an axle is hotter, it's easier to bend, therefore should break less. jus a theory tho.

[myne]

Makes sense.

Axles have some twist in them, and it makes sense that the longer one can absorb more twist before breaking.
If they both twist 1degree over the whole length of the shaft, the shorter one is going to have relatively more twist per length.

[ra23celica]

I have nothing technical to add any more than my std. T series diff in my RA23 has developed a whine after 1 too many hard starts behind my 1G-GZE.
Time to start that rear disk conversion on my G series Hilux axle and bolt that baby in...

[oldcorollas]

Makes sense.

Axles have some twist in them, and it makes sense that the longer one can absorb more twist before breaking.
If they both twist 1degree over the whole length of the shaft, the shorter one is going to have relatively more twist per length.

not really???

they only twist as much as their material properties let them... if one axle was twicw as long, it would have twice the twist??

is the short axle on driver or passenger side?... ie.... the side being pushed down or pulled up?

[RobertoX]

^^ agreed, they should fail in torsion for the same load regardless of length, its just that for a given torque the longer one will twist more, (twice as long, twice the twist).

AFAIK the effect of pushing down and pulling up of wheels wont apply to FWD since the torque to be resisted is not around the longitudinal axis of the car (and short/long axle pairs are found on FWD mostly)

Could it be because the longer axles take act like a softer spring when they have shock loads applied making them take shock load a bit better than the shorter axle? (just a thought)

[oldcorollas]

i thought we were talking about RWD solid axles.. not FWD??

there is a possibility that a longer axle could experience more windup.. and when it lets go (during tramp/loss of traction), the whole grip and slip situation is magnified as the longer axle loads and unloads more....

perhaps


but anyway... back to the thread

so if people usually break centres.... are aftermarket LSD centres significantly stronger in terms of the pinion gears etc??

[SLO-055]

i'm full of crap...talking bout that whole 'hotter the metal, more give it has', was playing around with the leaf set up on my car last night, had it up on the hoist, and while staring at the diff, i realised i always put a fair bit of that moreys additive into my diff oil (makes the oil tackier, and also takes alot of the heat out of the oil). so don't listen to me...loser
anyway that more windup theory works, you snap less axles when using a tyre with a higher profile/sidewall, as it can flex more, causing less stress on the axle.