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[lagunatich]

A while back I put a used early TR4(?) all-synchro gearbox in my TR3-A.  Works great except it has a tendency to pop out of 2nd under deceleration.  When the gas is on, 2nd remains engaged.  The problem is more apparent when the car is cold.  A number stamped into the case of the gearbox is CT4506.

Any hints as to the source of the problem would be most appreciated.

Thanks!
Rich
Laguna Beach, CA

[Darrell]

Rich,
Not an expert. However I had a TR250 gearbox that liked to pop out of third gear as you say during deceleration.  I went into the top control unit and tightened up the screw that holds the lever in third gear.  There are some ball bearings and springs in there that can be adjusted with the screw for a tighter hold. That worked for me on the TR250.
Darrell

[spamiam]

I found that the problem is the 2nd gear "top hat" bushing deep insode the transmission.  It usually fails at the edge of the flange (brim of the top hat).

This allows too much motion of the 2nd gear itself, and it pops out. 

Tightening up the retaining parts as listed above is a decent temporizing fix.

-Tony