A single rail gearbox question.

[Richard the old one]

If you look in the Official Triumph Dolomite Range 1976 0nwards Part Catalogue on page 1F 04L Titled Gearbox – Countershaft and Reverse Idler Details -1300cc, 1500cc, 1500HL &1850HL it shows a part number 137532 alongside the lay shaft or to be correct it indicates three should be fitted, and if you look up the part number it is described as a tension spring.


The front of the gearbox casting has three holes surrounding the lay shaft hole and for some time I have wondered, if these tension springs should be fitted in these holes which surround the lay shaft. There is no reference to fitting them in any of the workshop manuals which I have read or any of the magazine articles that cover gearbox rebuilds.

I have never come across these springs being fitted when I have removed a clutch bell housing from a gearbox and they are not shown in the earlier Official Triumph 1500 RWD parts catalogue.

My questions are that what are they for if they are not for what I have described and if fitted would they just increase the wear on the lay shaft thrust washers.

[DOLOMITE 135]

I have come across these a number of times, I have worked on 1850 three rail, Toledo three rail plus Dolomite 1300 /1500 and Spitfire single rail gearboxes. Unfortunately I can't remember which did and did not have them.
They do fit in the three holes in the casing you have identified, when removing the bell housing they are often hidden behind the gasket and as such are easy to miss.
If you have access to the Haynes manual for the 1850/Sprint there is a photo of them in position (in my manual it is bottom of page 111) where they are referred to as 'Layshaft preload springs'.

[Carledo]

The springs were used in the Vitesse/GT6 and (I believe) 3 rail early 1850 gearbox to put a little extra tension on the laygear thrust washers. AFAIK they weren't used in any others though, because they share a common gearbox case, the holes are still there.

Steve