fbekholden.com

Hi all, just got a question about the 3 speed cruncher. I need to change mine over and was wondering is it just a matter of undo the bolts, slide out and in with the new one or is there hidden things i need to watch for? Gearbox looks pretty straight forward. How hard will it be to do on axle stands Cheers Mark.

Gday Mark

It should be straight forward, except the
rear engine mounts are attached to the gearbox.
So you will need to support the motor to remove the mounts.

Cheers Jeff

Hi Mark

The 2 top bolts that hold the gearbox to the motor can be a pain in the bum to undo and do up again.

Disconnect handbrake mech from cross member before undoing cross member bolts etc.

Before you fit the replacement box replace the thrust bearing on the throw out fork with a new one. ( maybe even consider a new clutch and pressure plate if the old one is starting to give you trouble) It will save you pulling the box back out to do it later on..

check the spigot bush for wear .this is the small bush in the centre of the flywheel that the spigot /input shaft of the gearbox locates into.

Put a small smear of grease on the end of the input shaft to help lubricate the spigot bush .. ( starting to sound kinky here folks)

Try and slot the box up and straight in through the clutch centre . if you wrestle around with the box hanging down on an angle when fitting it back in , you can do damage to the clutch centre.

Make sure that you have the car high enough in the air to get the box and bell housing out from under the car once it ( the box) is on the ground

Dont forget to disconnect the speedo cable before removing the box .

Drain the box of oil before attempting to remove it.
If ya dont want to do that.
Use an old front tailshaft yoke to plug the output shaft of the box otherwise you will end up laying in a litre of 90 grade.


Thats about it. why the big list . I have made just about every mistake listed above over the 35 years i have been fiddling with old Holdens.
Mostly due to tare arsing and impatience.

Final bit of advice.. 2 pair of hands are better than one when removing or fitting a gearbox. You can use the other pair of hands to slap you up the head when ya do something wrong

Hope at least some of what i have said is worth considering.
Reddo

Ditto to what Thommo and Reddo have said.

If your mechanical knowledge is slim, the best $50 investment you could spend on your car is buying a Gregorys Number 67 Holden 6 cylinder 1948-1968 workshop manual.Will help with lots of things the home mechanic needs to do it yourself including what you are wanting to do at the moment.Explains everything in step by step sections and has photos as well.
They are available in most auto shops.

I'm told the Ellerys Workshop manuals aren't as good ( although I've never had one ).

To get to the difficult top gearbox-to-engine bolts that Reddo mentioned just peel back the floor mat/carpet or whatever and undo the trans tunnel cover plate/inspection plate and its easier to get to those 2 bolts with a socket.

When I was a mechanic all those years ago,it was considered "best workshop practise" to check and/or replace the clutch assembly with a new one whenever we had a gearbox out for repair/replacement.If you don't want to go to the extra expence/trouble to do that and your old clutch is working OK then thats fine, but definately replace the throwout bearing ( on the clutch fork ) and give the end of the gearbox input shaft a bit of grease to keep the spigot bush happy as Reddo said.Check clutch pressure plate fingers aren't wearing too much where the throwout bearing pushes against the fingers if you decide to use your existing clutch.

Although the boxes are only babies they are all cast iron (except output casing) and do have a fair bit of weight compared to size especially doing it by yourself so an extra pair of hands or two as Reddo suggested can help a lot.

Get the missus under there .I'm sure she'll help .She'll appreciate the return favour when you promise you'll do her ironing for her .

Otherwise its a fairly straight forward in and out job.
Readjust the clutch fork freeplay where the slave cylinder pushrodmeets the clutch fork and make sure there is 1/8th inch ( 3 mm ) freeplay there otherwise the throwout bearing will ride up hard against the clutch pressure plate fingers and very quickly wear out the bearing and/or fingers.

Sorry for lengthy reply, hope it helps,

Cheers,

Terry.

P.S. Just weighed a grey motor box ( no oil ) with the missus scales.

21.5 kilos, not much but feels like a hundred kilos when your on your own under a car with one sitting on your guts and trying to get the bloody thing to go in and it doesn't want to .

Don’t worry about getting the Car up high enough to get the gearbox out so long as you can move the gearbox underneath you can move it under the front to the wheel arch and get it out through there

Also you will need a block of wood to put under your sump to jack the engine up with the sump is fragile and you can put a jack through it!

Having a mate to help you is the best bet he can sit in the car with a rope around the gearbox holding it while you both remove or install it

You can do it with a trolley jack but it’s a fiddly job balancing the gearbox on the jack and getting it in the right spot.

You do have to disconnect the battery and remove the starter motor first!

Thanks for replys all, If you hear of a death in Mount Compass its either me under the car or the neighbour for saying " not that way, do it this way!!!"