[DeTomaso] Trans cooler

[MikeLDrew at aol.com]

In a message dated 8/9/12 6 20 55, adin at frontier.net writes:


> I can't remember which years which cars had trans failures at LeMans 
> (Mike Drew, do you remember?) but I would guess if a ZF would ever overheat, it 
> would have been at LeMans.
> 

>>>No Panteras ever had ZF failures at Le Mans.   They just blew up their 
engines with regularity.

Only one GT40 ever suffered a ZF failure--the Ford France entry, prepared 
for them by Shelby American.   It was GT109, one of the four GT40 roadsters.  
 Nobody today seems to know WHY the gearbox failed, but it was the first 
GT40 ever to be equipped with a ZF.   Significantly, the GT40 roadster 
bodywork is different from the coupes, and lacks the side scoops on the flanks 
which directed air into engine/gearbox oil coolers, and the rear brakes, on the 
regular cars.   I have a copy of a road test of GT109 prior to the race, 
when they were shaking down the new drivetrain combo, and it doesn't appear to 
have any gearbox cooler.

Stories of GT40 gearbox failures center around non-ZF units.   Originally 
the GT40 was supposed to have the first ZF gearboxes, but Ford issued a 
request for proposal and then failed to follow up and forgot to pay to have work 
start!   So nine months later, they went to pick up their gearboxes from ZF 
and ZF said, "what gearboxes?   We haven't started work yet because you 
never issued the formal go-ahead and paid for the work!"

DOH!

So the GT40 started racing with an Italian Colotti four-speed, which was 
woeful thing, totally unsuited to the task at hand.   They failed left and 
right.   Eventually ZFs appeared and then all was well.

Ford engineers calculated that the ZF wasn't up to the job of handling the 
torque of the big-block 427 which would first be used in test cars at the 
'65 Le Mans, but would be the main tool for the job for the '66 races.   So 
Ford had Kar Kraft (a wholly-owned Ford custom shop that did little custom 
jobs for Ford, such as building the Boss 429 Mustangs etc.) tool up to produce 
the T44 transaxle, which was a transaxle made using almost entirely 
production components from the Ford Top-loader four-speed gearbox as used in 
Mustangs, trucks etc.

Some clown at Kar Kraft forgot to heat-treat the gears!   So although the 
prototype big-block GT40s set the pace and were leading for the first few 
hours of the '65 race, both succumbed to gearbox failure.   But once that 
detail was sorted out, they became unstoppable, and they creamed the rest of the 
field in '66.

By '68 the big blocks had been outlawed, Ford had largely pulled out and it 
was down to privateers such as John Wyer, whose Gulf-liveried GT40s pulled 
out upset wins in both '68 and '69 (same car used both times, P/1076).   
Those were running Dash-0 ZFs with the gearbox cooling pump and cooler that I 
mentioned the other day.   I don't know of any ZF failures in any race--they 
were pretty sturdy pieces, and the Dash-2 most of us have is better still.

Mike