[TR] TR4 Slave Cylinder Stay Rod

Randall tr3driver at ca.rr.com
Wed Jun 17 17:19:55 MDT 2009


> If you measure the thickness of the bell housing flange
> that
> bolts to the engine, it is about 3/8 of an inch thick on the early
> transmissions
> but close to 1/2 inch or more on the later transmissions! Much stronger! I
> don't
> know when this change occurred, but my guess is it changed when the gear
> box
> went to a synchro 1st gear.

I believe it changed more than once.  The TR2-3 version was only perhaps
1/4".  I don't recall it getting thicker when the 4-synchro box was
introduced with the TR4 (and some TR3B), but perhaps it did.  Then it got
thicker when the 6-cylinder TR5/250 was introduced; and again at least once
sometime during TR6 production.  I believe one of those changes was when
they tried to rationalize transmission parts between the TR6 and Stag.  The
castings were the same, but the Stag casting is machined differently (to
accommodate the roller thrust bearings on the countershaft).

I hadn't realized that the 6-cylinder TRs didn't have the brace.  I wonder
if this is yet another piece of the puzzle why they have so many more clutch
woes than the other cars do.  The mounting plate definitely flexes somewhat
without the brace.

-- Randall 


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