TR4A gearbox installation

After installing the new clutch that I purchased from Moss Motors it was time to slide the gearbox back in.  While trying to line up the nose of the gearbox to go into the clutch it became apparent that the rear of the gearbox would not drop down due to the front of the drive shaft.  After un bolting the rear of the drive shaft and allowing the drive shaft to drop down the rear of the gearbox could then be lowered allowing it to be lined up and thus I could push it home.  Then I simply re-connected the drive shaft.  None of the installation procedures in the manuals mention this simple but important fact.

By Gary Meckes

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'TR4A gearbox installation' have 5 comments

  1. December 10, 2014 @ 9:47 pm wes gray

    It is always this way…manuals actually are good at instructions: “remove the radiator”… example.. for a given car, could be simple to remove entire engine and gearbox,
    for others, “remove radiator” might mean “40 nuts and bolts, now you can remove radiator” where same instruction could mean you have removed engine gearbox
    from an MGA…Your point is a very good one… what is not obvious becomes obvious in houndsight…
    I think a lot of instructs on British “sport cars” are very accurate, assuming you have removed the body from the chassis first… then: working on powertrain is child’s play.

    I am “preserving” a TR6, which involved pulling engine/gearbox… which begins with removing the interior of the car (!)… and it is true, you could remove gearbox and work on clutch
    that way… but in end seemed easier just to remove powertrain entirely (in my case necessary, since it had not run for 22 years, but stored in closed garage at least…)
    everything about the car had gone to pieces, engine, fuel system, all hydraulics… I simply took to long to confront the broken clutch fork to shaft locating pin…
    oh well… but all is looking up now… sorry to go on… that is to say, there is more to what you say than what you say, yours was a big job… congrats.
    is a cinch.


  2. February 16, 2017 @ 12:43 pm Kevin Kelly

    Gary got the job done on his TR but it could be that the sliding splines on the driveshaft were stuck. Next time that driveshaft is out, separate and lubricate the parts being certain to reassemble in exactly the same alignment (mark the pieces first).


  3. March 27, 2017 @ 1:14 pm John Nichols

    If you are installing an engine and transmission in a Bugeye Sprite, don’t even think of not putting the driveshaft in before sliding in the works, otherwise you can look forward to an extra hour,(or 2) trying to “snake” the shaft through the under body tube resulting in a mixture of dirt, oil,blood, and excess frustration. These jobs are hard enough to do when everything goes perfectly, no point in “challenging” yourself with a hard extra step.


  4. May 24, 2018 @ 11:03 am Ton Schalken

    I want to Separate my Gearbox from the motor!
    I have a Triumph TR4A from 1967.
    I have All the fittings and bolts seperated !
    My Ask is :
    1) How I Seprate the Gearbox from the motor if ALL The bollts has seperated ???
    The box seems glueted to the motor !!!
    2) There is a “Bridge” at the end of the Gearbox (Note : TR4A) It is mounted on the chassis. Thre is NO Posibility to Remove these bridge, because there is a “inkeeping” .
    How can I remove the Gearbox backwards and Free them from the Motor, if I can Not remove this bridge ????
    A Little Desperate TR 4A owner !!
    Please, HELP !!!


  5. May 9, 2020 @ 4:56 am Jackson E Boyd

    You were dealing with a combination of two things related to inexperience/lack of knowledge. The one gent mentioned the sliding splines on the front yoke. The other issue is that you didn’t have the engine supported properly such that you could slide the trans back in to mate properly. When the engine is lifted sufficiently, the tail of the gearbox sits up high enough that the driveshaft flange doesn’t interfere. It’s developed technique.


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