TempesT

hey guys thanks for the flood of help here!
 
Yeh I may have jumped the gun looking at those aeroflows they are only a 351w.... woops.
 
I am thinking the pavteks might be the go! Get their cam package to suite and an air gap dual plane manifold ontop of a freshly rebuilt bottom end should be healthy enough for the F100 without making it unstreetable! 
 
AFD's would be the go if I wanted to chase more HP from this but its more of a weekend / work type street build!

hey guys thanks for the flood of help here!
 
Yeh I may have jumped the gun looking at those aeroflows they are only a 351w.... woops.
 
I am thinking the pavteks might be the go! Get their cam package to suite and an air gap dual plane manifold ontop of a freshly rebuilt bottom end should be healthy enough for the F100 without making it unstreetable! 
 
AFD's would be the go if I wanted to chase more HP from this but its more of a weekend / work type street build!

hey guys thanks for the flood of help here!
 
Yeh I may have jumped the gun looking at those aeroflows they are only a 351w.... woops.
 
I am thinking the pavteks might be the go! Get their cam package to suite and an air gap dual plane manifold ontop of a freshly rebuilt bottom end should be healthy enough for the F100 without making it unstreetable! 
 
AFD's would be the go if I wanted to chase more HP from this but its more of a weekend / work type street build!

Sense of reason lads, thanks!
 
Don't suppose you know what a set of those pavteks would cost?

Top stuff Greg!
Anyone have a source or shims?
This is the only retailer i found, his kit comes with spider gear shims and one to sit under the spring ( 4 pin).
www.mobilediffrepairs.com/store/p25/HOLDEN%2FFORD_LSD_SHIM_REPAIR_KIT_NEW.html

Machining the cones:
Housing end of face, 0.040" off, same for the end lip of the cone. Always do exactly the same for each side.

 
As the gears and cones had some wear marks between them, I decided to clean up the surface where they mate and found some 0.8mm (0.032") shims that were a bit big in the ID, so I skimmed the face deliberately leaving a step in the middle to locate the shim. Took 0.020" off the thrust side, shims measured 0.032". Subtracted, that gave 0.012" of shim up from where it was.
 
 
 
Shim in place

 
Now I know why the standard hemisphere bolts have tiny 5/16" double hex heads. I tried to fit these nice new grade 6 bolts but couldn't fit the socket on where the bolt head area is spot-faced. So in with the old ones.
 

 
 

Sorry i read that again and i wrote it like a dogs breakfast.
Yes the .04" is a hypothetical amount taken from the end of the friction cone to stop it clashing against the housing (lets assume it leaves that gap between the cone and end of housing back within tolerance). I interpreted thom saying he adds about .01 to .015 additional to the shim. So he would add about a .055" spacer between the cone and spider gear?
As for my diff i got today i should have written that i need to test the break away to check the lsd heath (and rotate it to check ratio) I found some numbers in another thread to check break away.

Ok quick question about thoms method of reshimming. So if you took .04" off the end to get your desired cone to hohseing gap youd make your shim .04 + .01 to .015 = .055"?
 
Also any truth to the cones going soft over time and being no good for a reshim? (Sounds bullshit to me could imagine cooking /glazing them or hardening them but soft...)?
Picked up another diff outa an xh xr6 today for $50. Supposed lsd and 3.45 but turning one axle the opposing turn the same direction. Ill presure wash it and pop the rear off tomorrow for a squiz 

anyone have a full exploded diagram of the BW78 or recommend the best service manual for them?
This may be of help for some to follow along with:
 

anyone have a full exploded diagram of the BW78 or recommend the best service manual for them?
This may be of help for some to follow along with:
 

OK disclaimer here: although I'm a mechanic and have the basics covered from the relevant TAFE modules I did 25-odd years ago, I am far from being an expert and will very probably fall short of doing a professional job.

Doing up diffs is a similar trade to auto and manual boxes, in that even within a specific area of a trade, you become further specialised in one or two particular types or brands of diff. So one shop might be good at setting up 9"s whereas another might mostly do GM 10-bolts and BW78s. I have only done up about 4 types of diff: Ford Transit, Falcon BW78, BTR M80 and Mercedes/MAN bus diffs. The Merc ones had drop-out centres, the rest were Salisbury type (ie: integral carrier).

I'm only going to cover the process of doing a driveway rebuild, and share my mistakes in the past along the way. I do have access to a press and a lathe so I'll be using these when possible.

If anyone has any comments, suggestions or corrections, please chime in.... this is a forum after all.

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excellent go full on in depth with this please! While there is alot of info on the web on BW I havnt found an end to end rebuild and set up guide. I have a 3.45 lsd I removed from an el rear diff to go into my XG so Im keen for a saturation of info.
 

excellent go full on in depth with this please! While there is alot of info on the web on BW I havnt found an end to end rebuild and set up guide. I have a 3.45 lsd I removed from an el rear diff to go into my XG so Im keen for a saturation of info.
 

I've scoured our forum looking for a thread on the topic and couldn't find any, so I thought I'd start one.
 
I pulled the hat off the one kindly donated to me by Ando76 and found a bit of a surprise inside. After sitting around my yard for a while plus however long before, it's got some terminal corrosion on the gears. This is quite a setback as the thing seemed to turn OK when I received it. I was only counting on a fresh pinion seal and maybe axle bearings/seals and away I go. It's very sludgy inside, carrier bearings were locked up which made it difficult to remove the axle flange bolts: you can't turn the axles so you can't line up the little window to put a socket through with a rattle gun. All this festiness could just be from sitting collecting moisture in the last year or so.
 
After pulling it down further, I split the centre and found some shims behind the cones, not uncommon but these were quite worn and heat-affected. It could have been setup tight for speedway use so I'll be checking the pre-load and spider mesh on it on assembly. The cones seem OK, bit of corrosion inside the taper where they sit but I think are salvageable. Being a 28-spline unit, the axles and centre are worth hanging on to, but i'm fraid the rest is toast. The calipers, discs, gears, bearings are all too far gone.
 
The brakes seem to be an early disc setup (from say an XC) with vented discs/iron calipers. The axle flanges have a different shape to my current arrangement and are possibly incompatible with my non-vented, alloy caliper type from an XF ute.
 
So my plan is to:
 
* Source some early 2.92 gears
* Strip my housing with the 3.27/open/25 splines
* Use that housing with the 2.92/LSD/28 splines
* Install new bearings and seals throughout.
 
Early gears refers to the size of the ring gear bolts: from what I've read, early one had 3/8" LH thread Vs later 7/16" (possibly XD-onwards?). I have the diff in the coupe with 2.92s so I could strip that out. First I might see what a diff shop charges or an old set, might be easier that way.
 
Some pics so far:
 
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