Dialling in the bell housing

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jonnyt

Active Member
Posts
213
I'm quite a long way off this job as I've still to port the heads and build the engine up but I've been wondering for a while since I stripped it all down so thought I would ask!

I've got a new short engine so not the block originally mated to the bell housing I've got. I accept its all standard and will probably be ok but want to check there is no run out when old bell housing is bolted to the new block.

I think I understand dialling in as a process - dial guage, varying measurements at 12, 3, 6 and 9 o'clock etc, and that is easy when the bell housing has a round hole in it. Trouble is the Landy bell housing has a square hole in it on the output end which I don't see how you dial in. Do you have to make up and adaptor plate to fit the gearbox with accurate alignment of the input shaft?

Thnaks,

Jon
 
not sure what you mean if the original engine was a v8 and the new engine is a v8 then it should all fit no problem.
now if it is a auto you need to make sure you have installed the torque convertor properly if not it will destroy the box when you install it
 
Yup - I agree it should all fit together but I would like to check the alignment of the bell housing which is why I would like to check that it is dialled in correctly. The tolerances of the blocks, dowels and bell housing might well mean that the new block mated to the old bell housing might not be in tolerance.

There must be a way of checking this but I'm guessing there is some sort of insert that goes in the end of the bell housing to create a round hole that will allow me to determine whether I'm within the +/- 0.005" tolerance.

Thanks,

Jon
 
the gearbox bell housing will be square to input shaft of box and unless flywheel or crank boss have been machined so will engine to flywheel housing,but this can be checked by clamping dti on housing face and setting dti on drive plate or flywheel turning engine over and measuring runnout
 
I can see the point in checking the plane of the flywheel but won't that only tell me if the flywheel is rotating in a plane parallel to the rear face of the bell housing?

It won't tell me though (will it?) whether the bell housing is centralised to the centre line of the crank / input shaft of the gearbox
 
what are you building that requires more accuracy than lr have already done gear boxes are inlined bored to ensure shafts are aligned
 
Not building anything special - just overly cautious given the problems that this can cause. To be fair I'm more concerned that something may have happened to the new block i've got that would mean that the bell housing is out of alignment. The bell housing and gearbox will still be in original alignment as they are both original items.
 
I've been playing with RV8 for 35 years including transplants and mating with other gearboxes and transaxles.

I have never come across this 'issue' before:confused:
 
I assume Fanatic that means you are of a similar view to some of the others that have posted on here in thinking that its not necessary...

Thanks for the help!
 
Putting into context the fact land rover had a issue with casting the internals the externals very rarely suffered mounting issues to the transmission!
Never known of the issue with the flywheel but if you have the crank and flywheel balanced as a matched set it would not cause issues from experience
 
Thanks for the info.

The only time I can find when it is suggested is if the crank bearings have been line bored (if you use an ARP kit or something). This might put the alignment out a little. However, I'm pretty sure mine hasn't been as it still uses the same bolts and the torque on those isn't generally enough to deform the journals.

Thanks for all the advice,

Jon
 
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