Please help me identify what these are?

[Mirkz]

Hi guys,

I've just received a fresh recon'd diff (Borg warner 78 series I'm told), with 3.9 ratio.
Just having a quick look at my car. I'm wondering what these bits on my current diff are as the replacement diff doesn't have these at all so I'm a little concerned.

It's basically the little wire going to the diff. There's one on each side, and I've no idea what they're for.

Do they contain oil as in an oil line, or is it something that can be removed ?

Any help appreciated, was hoping to fit my new diff this weekend...


Also, is that the fuel filter in the first pic ?

[woteva]

ABS/ wheel speed sensors.

[Cashman_309]

Yep. Thems your ABS sensors, they read those teeth on the diff

[Mirkz]

Fk... so I'm asuming u can't remove these things?

Here's my current diff


You can just see the flanges on the lid that come out to hold the sensors.

here's the new diff.





Am I fkn screwed or what?

I was told all I had to do was pull the IRS axle stubs off my current one and replace them on the new one and it would basically bolt in fine.

[Cashman_309]

Looks like you've picked up a diff from a non-abs car.
I think people have welded on the mounting brackets successfully.

Wouldnt know about the axle stubs. Talk to a diff shop

[Mirkz]

Would it be possible to just change over the 'lid' onto the new one?

It does look like it's just the brackets that are any different.
The lids look kind of similar apart from that... ?

[Cashman_309]

Oh dude derpp.

Yer I'd say so. If the bolt holes line up then, yes

[Mirkz]

I think asking if it was ABS diff was the only thing I didn't check... fail by me
Didn't even think about the ABS side of things.

I really hope the lids just swap, that'd be fkn brilliant. lol.

[Cashman_309]

Hang on. I keep thinking your going M78 to M80 lol.

Of course the cover will fit its the same diff. Just switch the cover and those axle stubs and your set

[Mirkz]

Fingers crossed!
Thanks for the help guys... I'm still a bit worried about it going smoothly, but hopefully it'll come through fine for me!

I'll probably post up something in my car's thread once it's done giving the outcome! (if not here)

[Cashman_309]

Just remember to drain the oil before you start.
Seen a few make that mistake before hahaha

[Mirkz]

I'll be doing the job with my gf's brother who's a diesel mechanic and apparently done a lot of work with diffs etc in the past. So should be all sweet.
I'm gonna try do most of it myself if possible, but having someone in the business there will be a help!

[Mick1988]

You will have to drop the entire rear suspension to be able to change the diff..... Should do a VX2 adjustable rear end conversion while you're there.

[mummbles]

oil refil plug is in a totally different postion on the new diff too. Why would that be if the diffs are the same?

[Mirkz]

I noticed that, but it may be because it's just IRS they moved it for some reason?
I'm gonna have a look into it anyway and see what happens.

Worst case scenario, my current diff will get an oil change after it gets ripped out to see if the lid is interchangable until I can get the brackets done etc on the new one if it wont fit.


Are the sensors used for speedo as well ? or just strictly ABS?

[Cashman_309]

It will fit. You'll just have 2 fill bolts. If they are both m78 diffs then the covers are interchangeable. m78/m80 are not.

You dont have to drop the entire rear suspension. Ive had the diff out of my vt twice in the last 2 weeks.

Undo cv bolts - 8mm hex i think.
Undo tailshaft - 14mm spanner and socket or gear spanner
Undo abs sensors - 5mm hex
Undo sway bar links - 13mm spanner and socket
Undo diff mount - 14mm i think
Undo sway bar d-mounts and slide sway bar out the way - 13mm
Undo top front bolts 17mm - VERY TIGHT
Support diff with trolley jack (get a mate to stabilise it, if you have a gearbox jack use that instead)
Undo rear top bolts 17mm.

drop diff

do reverse with new diff

3 hours with 2 inexperienced people. 2 hours with 1 experienced (and strong) person

[Cashman_309]

You will have to drop the entire rear suspension to be able to change the diff..... Should do a VX2 adjustable rear end conversion while you're there.

2 guys doing a backyard job will be very hard to change the cradle out. then you have to change brake lines over and bleed them
And no. You absolutely dont have to drop the "entire cradle" what gives you that idea?

[Mirkz]

Awesome info Cashman, thanks!

Should be fairly straight forward. Didn't look to be too difficult last night when I looked at it all.
The only thing that threw me was the sensors.

[Mirkz]

The only other part I'm worried about would be those small lugs that you can see that seem to just 'position' the lid.
But if there's an issue with the lugs not going in due to changing the lid over, I'll just cut em off or something.
I'm sure they're not that important when you have a bunch of bolts holding the thing together.

[Calaber]

Only one poster here has mentioned that you MUST CHANGE THE TWO STUB AXLES. The ABS works off those teeth on your existing stub axle and the axle flanges on your new diff don't have the teeth.

If you're not sure of what to do, it might be a job best left to someone who is. The adjusters on each stub axle pre-load and adjust the bearings and need to be right.

[Mirkz]

That's cool man, already onto the stub axles. The seller pre warned me about those.
Apparently it's a simple job to take em out. Just a matter of levering them off with a flat head or something?

[Mick1988]

2 guys doing a backyard job will be very hard to change the cradle out. then you have to change brake lines over and bleed them
And no. You absolutely dont have to drop the "entire cradle" what gives you that idea?

I always thought you did being as I've never changed a diff before I've just seen the bolts are in the top of the cross member and wouldn't have thought you could get to them

I have removed a cradle, fitted a new control arm and refitted the cradle all by myself in half a day before and I only had 1 trolley jack and 2 scissor jacks to lift it with.

[Mirkz]

Well the job is half done.
It took us quite a few hrs to get the existing diff out as we didn't have all the tools we thought we would (gf's bro wasn't able to get into the workshop to bring his tools home).
The allen key bolts around the stub axle are a fkn prick... and one alone took us an hour or so to get it off.

Had some issues with another one and decided to take the whole arm off with the diff, which worked.
Other than those, it was easy to take the diff out. The lid fits snug, we just took the locating dowels out to allow for this.
Tomorrow is a matter of just putting the diff back into the car, which'll be easy now we know what we're dealing with, and tightening everything up. putting the diff oil and friction modifier and then we should have a winner!

I have taken a few random pics here and there when I was able to, but nothing flash, will upload tomorrow probably.

[scott-95]

1 am Give up time?

i found it quite hard to swap my cradel out, i havent got the diff back in yet, let us know if theres any problems you come accros putting it back in!

[jamesjgts25t]

If you haven't already removed the stub axles...you basically just pull them straight out but they don't come out easily, you have to really force them.