Close ratio gearboxes for TR6
>A few weeks ago I posted a note that
I had traded a TR6 for a retired
>(rusty) old TR4A SCCA car. It was purported to have (among
other goodies) a
>straight cut close ratio transmission. I am disassembling
the car, and
>removed the powertrain tonight. I opened up the tranny, and
found what looks
>like normal gears. I tried comparing gears with some old TR6
ones I had in a
>box, and one had the same number of teeth and another was
off by one. If
>memory serves me, this is meaningless, as the TR6 changed
in numbers of
>teeth over the range. Does straight cut mean what I think
it does, all the
>gears should look like reverse? Or does it mean something
else? If so, how
>can you tell if it's a C/R gearset?
>TIA
>Keeping the faith in Texas,
>Bob Kramer
>Hill Country Triumph Club
Bob,
The other close ratio gearset used in the TR-6 gearbox was from
the Dolomite Sprint. It had a 2.19:1 first gear. The identifying
factor with this gearset is that it has a smaller diameter input
shaft than the stock TR-6. The input shaft is a 1" x 10 spline.
If it has a 1" input shaft it is a Dolomite close ratio gearset.
Jack Wheeler
I have never heard if a straight cut gearset for this box, and
I have worked on many of them. count the number of revs of the
in shaft vs the prop shaft flange and post it to me & I'll
probably be able to match it to a known set. 1.88 to 1 is the
really trick CR 1st, and all are 1 to 1 in 4th.
Harvy Printice
Jack, Irv and Hardy,
FWIW,
This is an 1.25" input shaft. I'm hoping that it is an original
gearset designed for comp dept. as opposed to the 1" set out of
the Dolomite. I'll check the rev's tonight! Fingers crossed.
Thanks,
Bob Kramer
Bob,
I had about 50 sets of C.R. gears made for the TR6 The following
may be of help to some of you TR6 folks:
|
Teeth counter gear
|
Teeth mainshaft gear
|
Ratio
|
diameters
|
1st.
|
19
|
30
|
1.88
|
2 7/16 x 3 3/4
|
2nd.
|
26
|
31
|
1.42
|
2 13/16 x 3 5/16
|
3rd
|
28
|
29
|
1.24
|
3 1/16 x 3 1/8
|
4th
|
31
|
26
|
1.0
|
|
These are all stock syncro gear sets using the stock replacement
parts and bearings.
Kas Kastner
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