Diff shim and torque settings for a gearbox split

[El_Freddo]

G'day all.

I'm about to split some gearboxes to swap the internals. What I need to know is:

How do I re-shim the diff? Are there any methods better than others?

What are the torque settings on the different bolts?

My haynes manual is crap and doesn't show anything on the gearbox but I know there is one version out there that has all the info - If someone could scan and post or PM me the relevant pages that would be much appreciated.

I'm putting the EA PT4wd into an EJ casing. Why? I'm avoiding an adaptor plate as I'd need an engineer's report - I'm planning on doing this later...

Cheers

Bennie

[Suby Wan Kenobi]

You dont shim the diff to place, there are adjustable cups on the sides of the gearbox you wind in and out to get it to the correct toe. Its a long process as you need to assemble the case and blue the teeth then adjust it side to side and keep checking the toe. You can look in on the drain bung to get an idea of whats going on but you need to keep splitting it to add blue or smear over blueing.

I hope that makes sense?

[El_Freddo]

You dont shim the diff to place, there are adjustable cups on the sides of the gearbox you wind in and out to get it to the correct toe. Its a long process as you need to assemble the case and blue the teeth then adjust it side to side and keep checking the toe. You can look in on the drain bung to get an idea of whats going on but you need to keep splitting it to add blue or smear over blueing.

I hope that makes sense?

Thanks subi wan - I realise its not shimming but I didn't know any other term to use for it

So what's this blue/smear over blue stuff? Sounds like its a bit of a time consuming exercise. I'm guessing I'm aiming for the pinion gear to just meet with the centre of the ring gears "trough" between the teeth?

Do you use a sealant like the high temp silicone on the gearbox joints? And what sort of torque settings have you used? This is all new to me so I want to make sure I get it right the first time round on the build. I don't want any leaks...

Thanks for your quick reply!

Cheers

Bennie

[Suby Wan Kenobi]

The blue stuff is bearing blue so you get the correct wear pattern on the crown and pinion. I use a grey silicon gasket maker for joining the gearbox back together, the stuff i use stays sticky for a couple of days but hardens up nicely after a few days. Ill get the name tomorrow as im putting a gearbox together then. Torque settings are in the FSM but once again theyre in the cold shed so its tomorrow again for them.

Yeah shimming is in the ball park correct term but backlash adjustment. I should have used it myself but hey i knew what you where on about so its all good.

When adjusting the backlash you have to keep tapping (sometimes hitting hard) the pinion shaft as it is held in there with the mid section housing and if you dont have the pinion driven forward (towards the crown wheel) the backlash will be way way out and when final assembly is done the box will sieze and if way out crack the gearbox casing.

[El_Freddo]

When adjusting the backlash you have to keep tapping (sometimes hitting hard) the pinion shaft as it is held in there with the mid section housing and if you dont have the pinion driven forward (towards the crown wheel) the backlash will be way way out and when final assembly is done the box will sieze and if way out crack the gearbox casing.

That's good to know! Steptoe has posted me the pages from a manual on the gearbox, hopefully the process will be in there for reference.

I was thinking of using some of the red high temp silicone, otherwise I've got some of the black silicone that is coolant, fuel and oil resistant - its holding up well on my inlet manifold (yeah I know I should be using gaskets but its just my temporary engine...).

Anything else I should know?

Cheers

Bennie

[Suby Wan Kenobi]

You dont use a gasket between the gearbox halves they only have gaskets on the extension housing. I use RTV Grey Gasket maker, about $20 a cartridge i think. Just make sure you clean the old silicon and then wax and grease the mating surfaces prior to sealing and bolting back together. There is no black art to gear box rebuilding but just take your time and check everything as you go and also keep the internals clean.

[Phizinza]

I've done a couple of gearbox swapsies. Both times just done it by feel (had another box to compare too and general knowledge on how diffs are set). Haven't had an issue with diffs yet, touch wood

seriously though, a mate of mine had one side cap loose for 2 years or so on his L series, only found out when we needed to change the box due to synchros going bad. No noises, wobbles, etc. And I've pulled that box down, diff looked fine no wear visible.


Blue RTV works fine

[AlpineRaven]

You dont use a gasket between the gearbox halves they only have gaskets on the extension housing. I use RTV Grey Gasket maker, about $20 a cartridge i think. Just make sure you clean the old silicon and then wax and grease the mating surfaces prior to sealing and bolting back together. There is no black art to gear box rebuilding but just take your time and check everything as you go and also keep the internals clean.

When I did the gearbox myself, I refused to pay somewhat $36 or something for gasket, and thought myself as there would be less than hairline seals that needs to be filled up, so used high temp oil resistance silicone - that blue staff that I used, since its in my liberty now it hasnt leaked at all. But once you apply silicone make sure its free of grease/dirt etc. I used prepsol to clean up before i applied.
Cheers
AP