The making of a diff jig - PROGRESS

[oldcorollas]

are the axle tubes the same diameter?

if so, should be straightforward to support by the tubes, with fixed fictures () for the mounts, and then just a removable fixture for bolting the pinion flange to (etc)

if they are not same diameter, then interchangeable tops foe the tube supports could work also.

[The Witzl]

i dont think they are the same diameter, and they have differnt methods of bolting the axle backing plate to the housing.

just been doing some searching for traction brackets - there are a fair few nifty products out of the states that have me excited, but i doubt they will suit the RA28.

[Pube]

Ill be using a G series diff, I have 2 here already. I think the axle tubes are about 3", same as the BW and also a ford 9". If someone could measure the diameter of an F series, that would help. Im thinking of making a fixed fixture to hold the diff on the jig and then adjustable (vertical and horizontal) arms that hold the brackets for the trailing arms. If both the F and G series both have the same diameter axle tubes ill just make a horizontal adjustment. The spring perch, panhard rod mount should be the same deal.

[brett_celicacoupe]

ill throw in my idea for a universal diff jig.


have one thick 2" x 4" box that runs parallel with the axle tube to have to square plates at each end (90deg to the box). weld LARGE nuts to this plate and have some bolts go through with BIG alloy cones. these cones will fit into any diff tube as long as its round. you would then centre it by counting threads on each side.

now the jig is located but still can rotate. here you would 'true' the jig by sliding the adjustable plate onto the banjo mounting face.


the rest of the jig is essentially just making sliding brackets that you can lock in place by tightening bolts.

these are the only 2 things that different diffs have in common, they have 2 axle tube holes and a true face where the banjo mounts up.




though you might be fucked if you want to go playing with borg warners

[EVOSTi]

here are the lower control arm brackets im talking about that are currently on my E series diff. as you can see they are just two pieces with 90 degree bends welded together.





its a bit more work but still something to think about. either way ill keep an eye on this thread as im interested somewhat

[Pube]

Brett celicacoupe - good drawing. Thats another way of holding the diff that I havent thought of. The rest though is on the money with my thinking.

EVOSTi - I have seen those lwr brackets you have got there on my search for hints. It would be straight forward to do. www.mcdonaldbrosracing.com.au sell various laser cut brackets. Maybe something could be put togeather to suit.

Also, what have people been quoted by diff shops to transfer mounts? From memory my ringing around last year I was quoted $500-600.

[Big T]

Just one other thing worth researching. The diff shop i use always "straighten the housing" after the mounts have been transferred. I'm not sure what this involves but it'd be best to check it out before making the jig up? And about $500ish is the norm for this kind of work.

Eddie.

[brett_celicacoupe]

probly best to just do short welds and not sink too much heat into it.

when i welded mine, i welded 15mm fillets and then did another 15mm on another mount that was cool. it just takes a long time.

if you had a large industrial oven you could just put it in there and get it considerably hot before welding.

[Pube]

Im aware of getting the diff straightened after welding. From what I have heard is they put some sort of dowle through the diff with the centre removed to check if the axle bearings are running 90 deg to the dowle. To straighten the axle tubes up you it heat then cool the one with a wet rag or something similar and that will pull the axle tube in the direction desired. Getting the mounts welded the time consuming part. You can get it straightened for a small fee by a doff shop.

[The Witzl]

This is all sounding very promising
And i'm hell keen on getting some adjustable traction brackets on there too! If you search for traction brackets in google images, there are a couple of places that sell AE86 ones - i dont know how suitable they are for me though.

["Z" UTE]

There is a mob here in Canberra, that has a jig for MKII Corona diffs, having TA/RA brackets fitted, coutesy of Dylo. He had to pay for the jig build. I have had 3 of these conversions done, at around $350.00 to $400.00 a piece. Might be worth loading up the Stitt Mobile with housings.

cheers Chuck.

[The Witzl]

Yeah but we want Hilux diffs done!

[brett_celicacoupe]

18RGs are powerful enough to break a T series, let alone a G series!

do you care about going around corners at all?

[EVOSTi]

i might be willing to pay $350 for someone to swap ae86 mounts onto an F series. anyones wanna sell me an F series from a mkII?

[Pube]

traction brackets are sounding interesting so I will do some research. Not too sure what it will cost others for me to swap mounts yet, ill see how myne turns out. I will hopefully get started on the jig in about 2 weeks time and ill get some pics up when its done.