Triumph TR3 drawing

  LINKS TO FEATURED PAGES:

TRIUMPH Contents page  > Net Nuggets contents  >  Close ratio Triumph TR6 gear boxes 

 

 

 

Triumph TR3 FAQ page

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

Return to the page top

 

 

  

  

 

© 1997 - 2011 TeriAnn Wakeman. All rights reserved.