Borg Warner T10 vs Toploader

[Ghiblicup]

Dear Dan,
thanks as always!

I knew this chart from wasaac.org. What remains unclear is:

"B" gear sets are asid to be used in 260s and early 289s - but until which date? They were steel casings, correct?

"J" gear sets used potentially again in 260s and early 289s -> can we asume that there is no record on which car had which type?

Most importantly: Common literature knoweldeg seems to be most 289s used "M". Except "M" (Sebrings) were first available late 1963 only. That would mean around CSX2240?

<THE BIG QUESTION: Which casing (and gear sets) did standard 289s from CSX2075 to CSX2240 use? "B" or "J" or even other types?

Sorry for picking on this topic. But today so many 289s are described as "period correct t10 gearbox". I think that is not enough, if we consider for what period T10s had been built!!

Originally Posted by Dan Case

I am by no means a Cobra transmission expert but the expert had helped me and many other original Cobra owners. Cobras used a variety of T10 models. His notes are pages long. Short version.

Design wise think 1963-64 289 Ford Galaxie T10 physical dimensions. Early transmissions included cast iron main cases and tail shaft housings. After Ford created the aluminum main cases and tail shaft housings for the “lightweight” Galaxies, Cobras started using aluminum main cases and tail shaft housing. In the aluminum cases units more than one gear set was available, standard ones used Ford design all the way while a racing option used a GM input. When the GM input was used the engine installers had to remove the clutch disc Ford installed and replace it with a GM disc. Some street cars received GM input gear sets, my black car is one of them.

The aluminum tail shaft housings tended to break in any kind of competition so SAI sometimes replaced aluminum tail shaft housings with cast iron ones. They did this for their team cars sometimes and offered new transmissions fitted that way to independent racers.

A common point of confusion is the main case front flange. Cobras used five bolt engine blocks so their transmissions had the early narrow bolt pattern. 1965 and later Fords used six bolt engine blocks so a different aluminum main case was required for 1965-66 MUSTANG GT350s.

Tables don't paste in well so this will be jammed left.

B close (1962)* L & J close** M close*** K close (GM)****
1 36 1 36 1 36 1 36 (GM 1358577/Ford C3AZ-7100-F/BW T10-E12)
2 32 2 30 2 29 2 30 (GM 1358579/Ford C3AZ-7102-E/BW T10-E31)
3 29 3 29 3 27 3 29 (GM 1358576/Ford C3AZ-7B340-A/BW T10-E11)
4 26 4 26 4 26 4 27 (GM 9771377/BW T10-K16)
C 29-23-20-17 C 29-23-19-17 C 29-25-20-17 C 28-23-19-17 (GM 9771378/BW T10-K8)

* The B gear set was used on early Cobras.
** L gear sets are nickel alloy, J gear sets are not and the J sets were used in Hi Po 289 Fairlanes
and 390 Galaxies.
*** The M set is nickel alloy and also called the "Sebring" gears and was first available in 1964.
**** The K close ratio gear set is a nickel alloy gear set originally used in GM cars (Pontiacs) from 1957 to 1963 and it was used in some HP289 powered Cobras. A GM clutch disc is used because the GM input shaft diameter is larger. 1st, 2nd & 3rd gears in the K set are the same as used in the L ratio gear set.



Transmission case material. Not the documentation you would like but Dick Roush has known CSX2115 and CSX2165 since the 1960s he told me. CSX2115 had an iron case unit and CSX2165 had an aluminum case unit. The street car implementation date and or chassis of the family of aluminum cased transmission assemblies (more than one gear set version) is not known. Based on SAI photos for FIA registration the first LeMans Replica race cars in the CSX213x range received transmissions with aluminum main cases and tail shaft housings.