lockers and LSDs

[ntsqd]

The couple of them that I saw at Weddle Engrg worked very much like the OX or ARB selectable lockers. They are either an open differential or they are a spool. Nothing in the middle, no "limited slip" function is available.

Both work on the premise that if one side gear is locked to the diff case then the other is as well via the spider gears. The way that this is accomplished is that the case has an array of holes in it that are parallel to the axle centerline and radially arrayed around the axle centerline. Then one side gear has a matching set of blind holes in it too. There is an assembly with a series of pins that fit into these hole(s). On the end opposite of the pins there is a groove very much like what the shifter forks ride in within the transmission. The bell housing casting was modified to have a "shifter fork" assembly in it. Slide the fork one way and the diff is a normal open differential. Slide the fork the other way and the pins lock the side gear to the case, making the diff act as a spool.

The reason for the vacuum actuator is that the holes don't always align. By using something with some 'give' as the actuator the system can wait until the holes do align without putting something in a bind. If you go with a Morse cable type of actuation you will need to finesse the alignment by loading the lever in the locked direction and then creep the vehicle enough for the the pins to drop into place. The same holds true for unlocking. When locked it is very likely that the pins are in a bind. Some motion of the case while trying to unlock the diff may be required. The 2nd gen cable shifted OX shifter solves this by using a big spring in the shifter assembly. The ARB uses compressed air to lock and hold the locked position. Venting the compressed air allows a spring to unlock the differential.

Some of this type of locking diff use a splined coupler instead of pins and holes, but they work and function exactly the same.

Clear as mud, or in need of a graphic?

[ntsqd]

BTW: OX Lockers

[fusername]

so spool=fully locked axle
I thought a spool was an open diff that when there was a difference in speed past a certain threshold it then LOCKED fully the two wheels togeher. sounds squirrly but thats what I thought it was.

the system makes sense. for every other description of a locker i had to look up a pic, this is the first that made sense. If I had my actuating cable spring loaded so it would simply keep pressure on it untill it popped into place, that should cover me. Can't wait till it comes in the mail. Xmas present for myself.

[Bruce2]

so spool=fully locked axle
I thought a spool was an open diff that when there was a difference in speed past a certain threshold it then LOCKED fully the two wheels togeher.

No, a spool is just a solid block that connects the ring gear to the axles. Nothing magical happens at any speed or load.

[ntsqd]

Mark Williams Ford 9" Lightweight spool:

[Bruce2]

Could be lighter if it was made from aluminum.

[ntsqd]

They offer it, but the picture was nearly as zippy looking.

[fusername]

so is there anything that locks fully during excessive slippage? it sounds moronic as it would have crazy handling characteristics, but I have to ask.

now here is my question on application. I am getting a locker from a syncro trans (094?) and next summer I will have a 091 without a home, and will tear into it to replace wear parts and put in the locker if it fits. the diff is the same on a 091 and 094, so that should be simple, the acuating parts will be the trick. How different is an 002 trans? If I wanted to put this locker in a 002 can that be done, not that I have one. what about a single side cover beetle case, as I hear they are extreemly simliar to a 002.
now if you have a locker/lsd for a early IRS trans, will it fit a SA? I am curiuos what trans share the same diffs, but maybe this belongs in another thread.

[fastback]

the syncro 100% locker fits the 091/002 , BUT u have to weld and machine the case to make it accept the vacumactuator and mechanism that engages the locker.
u shoul also take the bearing covers from the syncro diff.
the late beetle tranny is only sharing the (splined)gears and mainshaft with the 002 tranny
and the seal for the inpushaft
maybe some other hardware too
but
the R/P , diff , case, bellhousing, nosecone shifter mechanism etc is different

[fastback]

to do it easier a ZF LSD from a vanagon fits straight in the 091/002 tranny
it has 40% "locking" as stock but can be adjusted to 60-80%

[fastback]

syncro 100% locker

[fastback]

094 ZF LSD vs 002 stock

[fusername]

so what vanagons came equiped with the LSD? I didn't know they were available.
I will email the guy I am getting the locker from, any other parts I should ask if he has?

[Bruce2]

All Bus diffs fit all Bus gearboxes from 1968 to 094s. Any Bus 'box prior to 76 needs the bearing supports, bearings, and flanges from a later gearbox in order to fit a later diff.

A Bug diff NEVER fits a 68 and later Bus 'box.
A Bug IRS diff can't be made to fit with swing axle type axles.

[ntsqd]

From what I saw of the disassembled locker assembly at Weddle, the bell housing is unique to the Synchro locker. It has the needed bosses etc. to carry the locker shifting mechanism. The b/h may or may not be longer. If it is, then you'll want the input shaft to go with it.