gearbox double roller..
Turbo Mini Forums

hmmm ,well rod ,reading between the lines ,a thing i have to do often ,as a therapist , im getting the feeling ,correct me if this is too ''out there'' , that you think there should be no overhang ? .


so some more pictures ..

these are a bit jumbled , but they are the primary bush ,and the diff interface ..see what you think ..

Edited by robert on 9th Sep, 2010.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

the diff definatly looks too far over to the right to me,

I'll have a look in my gearboxes tomorrow to see where mine sit,

bush is a bit dry and cooked, but the do that sometimes, crank looks ok where it runs though.

Considering the diff only, those photos suggest the crownwheel is running at the outer side of the pinion....

So how can it be less than 1mm away from the bearing outer race which is at the inner side of the pinion ???

EDIT - talking nonsense, the shadows on one photo were confusing me - one photo (3rd from bottom) shows it very clearly further to the right than I remember or would expect.

Edited by Rod S on 10th Sep, 2010.

Schrödinger's cat - so which one am I ???

Of the three minispared cross pin diffs I have had the pleasure of working with, they all needed at least 1mm of shims, and on mine, with the hardy spicer outputs, that i had to place the shims equally either side, rather than all on one side, but that was due to the output flange bursting the seal lip as it put pressure on the lip itself.

so if the diff has been shimmed correctly, there is a possability of pushing the dif to one side by 0.5mm at least, in the direction we are concerned with.

How many mm worth of shims were fitted?

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Colin reminds me..... I too had to use a lot more shims than normal with the X-pin diff (the quaiffe I bought is for the second gearbox) and I'm pretty certain I also spread them equally on both sides as there were so many needed.

Schrödinger's cat - so which one am I ???

looks like a common situation rod , so iv swapped .7 over ,and we'll see how that goes !

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

going to debur the edge of the crown wheel?

no just throw it in joe , lets face it ,the rest of the engine is just thrown together !

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

hmm ,now ...do i just plonk it on with no box to block gasket ?????

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Schrödinger's cat - so which one am I ???

A/BZ1 BC DAM5626.original diff ,all off a turbo metro f reg .

no rod i was going to use the ''sprocket ring'' but maybe ,just use silicone on the join .

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

The thing with just silcone on the box/block join is the same issue as using aftermarket gaskets which are the wrong thickness (usually far too thick)... it alters the engagement clearance on the drop gears.

Same as the diff housing - if it's one that is meant to have gaskets, use them (but make sure they are the genuine ones the right thickness), and if it's the later one, use RTV.

Another issue I had with shimming the diff side clearances was the outer cover gaskets either side..... the non-genuine are way too thick.

I didn't have enough shims to do the job with them.

Even once I had the genuine Rover gaskets, I still needed a lot of shims with the MiniSpares X-pin (hence the earlier comment the same as Colin) but I have found, like with the gasket behind the timing chain plate, using the proper gaskets is really important. :)

Schrödinger's cat - so which one am I ???

yes i agree rod , this q of using the gasket from block to box is an ongoing discussion on here .colin uses no gasket ,but , has had a line bore , trhers somewone else who doesnt use one too .i think ill plop it on and see what my finger thinks of the play in my idler !

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

FFS! Enough already



Robert, to give you an idea of mesh clearance, put the block on the box, assemble the gears, and check for binding. If you don't feel any binding, put some plastigauge on the mesh of the idler teeth at 3 and 9 o'clock positions, assemble the transfer caseand nip it up, turn the primary gear 180 degrees and then remove the transfer case and measure the plastigauge. compare the idler to input gear clearance (pretty much a fixed dimension) with the primary to idler clearance. this will give you a better picture of what is going on, rather than just hoping for the best.

As for diff side covers, I dont use any gaskets, just RTV, and still have to use loads of shims.

Double check any diff bearing housings for roundness to see if it needs gaskets or not, but rule of thumb is that if its retained with all bolts, it doesnt have gaskets, but if it has studs, it has gaskets. I measure any gearbox with a bore gauge to check the roundness of these holes, as you never know if some one has replaced the studs with bolts of bolts with studs, unless you know for sure that the gearbox has never been touched from the factory. I have rebuilt two gearboxes originaly built by reputable people and both used gaskets when they shouldn't!

thanks colin ,thats pretty much what i thought you'd done .
this case and diff carrier are all original turbo metro , i was the first to take it apart .
no gasket is used on the diff carrier to case ,the side plate gaskets i assess on an individual basis ,and aim for 1 thou pre load .using the older non thrust races .

it wasnt my intent to hope for the best ill assess it as usual ,maybe my ironic self deprecation isnt getting over

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM