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TR4 gearbox inspection insitu

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Hi all,

I am about to take the plunge during the holiday break to investigate my gearbox oil drips.  I have read threads about not presuming the bell housing is the source of the drips and the various tips on removing the box with long bolts and trolleys.  I am also ready to upgrade the clutch release fork and maybe the gearbox cover.  My questions are:

1.  If I only slide the gearbox back into the space left by removing the propshaft, will there be enough room to inspect the front seals and replace if needed?  Will this also allow access to the clutch plate?

2.  Is there a set position/alignment for the input shaft nose/front cover as I believe that there is an oil catch recess in the moulding

Thank you in anticipation.


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Morning Mark, if you've removed everything to enable the box to be seperated from the engine then I don't see why you wouldn't lift it out & work on the bench? This isn't the kind of work you can really do in situ.

In answer to the second question the - yes there is a set position, you will see a small 'nose' on one side of the front cover that points to the left as you look into the bell housing from the engine end sits over a gap in casing.

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I think the answer to 1 is no and no. If the floor on a TR4 is similar to that on a '3 the box can only come back a couple of inches before the clutch operating arm fouls. You have to twist the box a long way clockwise before you can pull it further backwards and even then you can't see much until you've turned it crosswise in the cabin.  It would be awkward to access the clutch with the box still in the car. 

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+1 fo rthe above Mark,

Plus if you are planning to upgrade your clutch forkand perhaps look at the taper pin

and fit a roll pin, even Houdini would struggle.

That said removing the gearbox is in my opinion not a safe one man operation, you need to consider carefully

whats involved, and ensure help, either a pal or mechanical means.


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Morning Mark,

as the others it’s a no. I have just done mine and found the easiest way for me was to put the car up on ramps at the front and stands at the rear, get the car level. Put a jack under the sump and under the gearbox a small gearbox lift on wheels. Undo all fixing slide back and twist and pull upwards from the rear. When putting back do in reverse and with a bit of luck it will slide back in on the gearbox lift. Mine pushed straight in, do not force it in, good luck.

Mike.  Redrose group 

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Thank you for your thoughts.  I have taken the gearbox out of the car previously by myself with a lot of brute force and that is why I am reluctant to have to do it again just to check the front seals.

I had forgotten about the clutch operating lever and how this snags as soon as one starts to remove the box.  It seems that many of us have removed a gearbox from inside the car before and it can obviously be done, but there is the problem of it not going back so readily and not being able to take it to a garage for help after that point.

Perhaps it is time for a re-think and spend some cash with a TR specialist.


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Be like me and get somebody younger and stronger under the car to do the lifting while you twist it from inside.

I did a major antileak operation a couple of years on my 3A as I got seriously miffed at the cynical remarks by my friendly local (French)  'MOT' inspector about English built cars always pithing oil everywhere.

Once it's out and on the bench don't wipe it down until you have observed (and photographed?) where all the leaks are coming from.

The obvious ones are the front and rear seals - then there are a myriad of others to check. All will have gone brittle over the years, so it's not a bad idea to plan and change the lot and I mean the lot. Don't forget the ones on the top around the gearshift shafts which are often forgotten and even more often ignored as they are a pain to do. The overdrive unit is a bit of a challenge as well.

The operations are well documented if you search the fora here.

I redid all the engine seals as well. The autosatisfaction was considerable when I was able to offer my inspector a leak free car!



Edited by james christie
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Make sure the circlip doesn't block this oil drain hole at the side, the circlip and gearing can turn in the housing, I used a little bit of bearing fit to locate the bearing and stop it turning.

I also use copper washers on all the 6 bolts as they are not blind holes.


IMG_2275_LI (2).jpg

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