Diff gears, LSD, stall - Page 2

**Stav** · 22-08-2008, 10:46 PM

Modern torque convertors have electronic lockup for light cruise and then you mash the throttle and the rpm slips up the rev range to flash speed lockup. The only issue i have heard is for stall speeds above 3000 that for some reason the lockup at normal driving speeds is compromised. I suppose there is only one way to really find out...try it. Also many seem to have problems with limp home mode once stall speeds reach those rpms.

Sox · 23-08-2008, 07:36 AM

Quote:

Originally Posted by Stav

Modern torque convertors have electronic lockup for light cruise and then you mash the throttle and the rpm slips up the rev range to flash speed lockup. The only issue i have heard is for stall speeds above 3000 that for some reason the lockup at normal driving speeds is compromised. I suppose there is only one way to really find out...try it. Also many seem to have problems with limp home mode once stall speeds reach those rpms.

Ya I know they lock up at light throttle, though I didn't know the high stall units did on the AU's.
I still think that 3k stall would be boarder line on being a pain in the bum, but I'm just guessing as I haven't driven one.

5.0 ED · 23-08-2008, 08:50 AM

logic says though, that if the stall speed is higher, than the lockup won't last as long, more rpm difference = more friction when locking up, also worth mentioning is that if you increasing your stall you should be increasing the transmissions cooling to cope with the extra heat produced from the hi stall when unlocked and on flash point.

The Monty · 23-08-2008, 10:19 AM

I just put on a MASSIVE tranny cooler, the stall retains 3rd and 4th lock up as per a normal AU.

**Stav** · 23-08-2008, 11:20 AM

Theres lockup for easy driving .It is electrically controlled from memory by one of the gearboxes solenoids.

The other lockup is the hydraulic lockup when we hit the throttle the stall spins ,the tranny fluid gets flicked outwards/inwards causing the internals to lockup. Truth is that because of its nature it never truly locks up solid and hence why manuals put out up to 10rwkws more.

The Monty · 23-08-2008, 05:48 PM

Ill tell you all how it goes when its in.

In the mean time, anyone up here in Brisbane know how to put one in, for some cash of course, Im good at handing the wrong spanners too.

Sox · 23-08-2008, 06:46 PM

Quote:

Originally Posted by Stav

Theres lockup for easy driving .It is electrically controlled from memory by one of the gearboxes solenoids.

Yep, that's how understand the Ford setup to work (and others), though see below.....

Quote:

The other lockup is the hydraulic lockup when we hit the throttle the stall spins ,the tranny fluid gets flicked outwards/inwards causing the internals to lockup. Truth is that because of its nature it never truly locks up solid and hence why manuals put out up to 10rwkws more.

And this is how normal convertors work.

So how does the electronic side of things 'lock-up' the convertor if the box is essentially 'after' the convertor in the chain, if you know what I mean.

blackers10 · 23-08-2008, 09:31 PM

my brother is currently attempting to fit 3.45 gears to his 3.08 forte live axle
and they are binding up and it just doesnt move at all
is there ANYTHING else that could be causing this issue??

tried a set from an IRS diff and the gears out of a live axle diff
(swapped the crown AND pinion)
i was under the assumption that you could just bolt the gears straight in and use the same shims(the ones that go between the outter bearings and the housing and its all good??

or is there other shims we dont know about between the pinion and crown mounts??

Sox · 24-08-2008, 07:39 AM

Quote:

Originally Posted by blackers10

my brother is currently attempting to fit 3.45 gears to his 3.08 forte live axle
and they are binding up and it just doesnt move at all
is there ANYTHING else that could be causing this issue??

tried a set from an IRS diff and the gears out of a live axle diff
(swapped the crown AND pinion)
i was under the assumption that you could just bolt the gears straight in and use the same shims(the ones that go between the outter bearings and the housing and its all good??

or is there other shims we dont know about between the pinion and crown mounts??

As far as I know they go in without a hitch.
Have you got the shims on the correct sides? That is, you didn't mix up the left and right shims?
And how tight do you have the pinion?

**Stav** · 24-08-2008, 10:02 AM

Quote:

Originally Posted by Sox

Yep, that's how understand the Ford setup to work (and others), though see below.....

And this is how normal convertors work.

So how does the electronic side of things 'lock-up' the convertor if the box is essentially 'after' the convertor in the chain, if you know what I mean.

Yep.I know what you mean.The modern convertor has a clutch which eliminates the free wheeling of convertors in the past. s7 solenoid in the box being on and off determines when this happens. This is for light throttle driving only though.At 80 kays letting off the throttle makes it unlock then reapplying throttle locks it back on. At full throttle though things revert back to the old way of convertors.

I think that it must use hydraulics to activate the light throttle cruise lockup clutch