TIGEROOTES@aol.com wrote:
> Jarrid,
> What is the difference between the early and late overdrive adapters
> ("doughnut spacers")? You said there is an additional oil passageway. I
> have seen many units with an outboard copper tube plumbed across the spacer,
> and I believe it was a factory update. Is this the equivalent of the oil
> passageway?
> Jim
The overdrive adapters are about 4 inch extensions of where the
tailcase would have been mounted on standard transmisions.
Early and late look almost identical, except that late ones have
a 3/8 or so extra drain hole towards the bottom, which appears
to let tailcase oil drain back into the gearbox, perhaps fixing
a design flaw with the early tranmisions (who knows).
The gaskets between the gearbox and the apapter/tailcase tell the
whole story. Get one of each and compare.
There had been problems with some sort of a pressure buildup in the OD
unit, which somehow blew the gearbox oil out the tail section of the OD.
I dont think the add on tube was a functional equiv to the later
oil return as the od adapter has no seal in it, and therfore
wouldnt contribute to a pressure buildup in the OD.
The fix was to put a balance pipe "probably what you have seen"
escentially across the overdrive unit.
Seemingly dumping any pressure buildup back to the gearbox,
or nulling out a pressure differential.
The funny thing is that although it was afcatory fix, most later ODs
dont seem to have the modification.
Not sure under what circumstances the oil departed, or if there was
a more appropriate internal fix, but the fact remains that many if
not most survining ODs dont have the fix.
The rebuilt OD trans on ebay doesnt seem to have the balance tube,
and its an all-sync.
Anyone know why Rootes stopped the pressure hose mod?
Seems to be a rootes only problem as the other laycock
overdrives that used the flange type output didnt seem to have
this mod.
Jarrid Gross
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