53 replies to this topic

[Heath]

I know the 3rd member/housing changes for the different ratios (one for 2.78, 3.08 - one for everything shorter), due to the orientation of the gears.

Does the same thing apply to the carriers or are they all universal? If they are different, can you just shim the crown wheel away from the flange on the carrier or something to go one way?

[76lxhatch]

I always get diff terminology mixed up a bit but:
- no difference in the main housing at all (the biggest part with the axle tubes)
- 2.78:1 and 3.08:1 carriers have a bigger space for the larger pinion gears and use two longer bolts at the bottom
- centres are all the same and interchangeable to any ratio without extra shimming (a Banjo doesn't use shims for the crownwheel lash anyway)

Just check the pinion installed depth if you are changing that, otherwise just bolt everything together with suitable backlash and 3 notches of bearing preload

[Heath]

What you're calling a carrier is what I refer to as a 3rd member. Don't know if that is the best terminology but I think that's what Summit calls it.

Anyway, that is what I wanted to hear, I just read something in two ebay options that had me a bit worried:
http://cgi.ebay.com....e=STRK:MEWAX:IT
AND
http://cgi.ebay.com....e=STRK:MEWAX:IT

[wot179]

I alsways thought "third member " was a term used by journalists and advertising dicks so they sounded smart.

Ive never heard anyone else use the term.

I agree with 76lxhatch.

The housing is the big bit and the carrier holds the gears and little bits.And the axles are the bits the wheels hang off.

Edited by wot179, 19 July 2010 - 05:46 AM.

[76lxhatch]

Anyway, that is what I wanted to hear, I just read something in two ebay options that had me a bit worried

Yep they're wrong, those centres will bolt in with any ratio so you'll be sweet

[Heath]

So we have two distinctly different opinions right now...

Jay builds diffs for a living too I think?

'Third member' is a fairly well known term for the centre housing, as opposed to the main housing which includes the axle tubes etc.
And the 'Carrier' is what contains the differential itself, not the pinion & crownwheel but the actual differential. It 'carries' the planetary gearset around with its pin.

Edited by Heath, 19 July 2010 - 03:43 PM.

[rodomo]

'Third member' is a fairly well known term for the centre housing,

Not really, I've only heard that a couple of times, both times from you.

I've heard it before but no-one uses it. I suppose it depends on who YOU talk to?

[Heath]

http://www.google.co...=og&sa=N&tab=wi

[rodomo]

http://www.google.com.au/images?hl=en&q=diff%20third%20member&um=1&ie=UTF-8&source=og&sa=N&tab=wi

"Pages from Australia" result:
http://www.google.com.au/images?q=third+member+pic&hl=en&rls=com.microsoft:en-au:IE-SearchBox&rlz=1I7ADBS&prmd=ib&cr=countryAU&um=1&ie=UTF-8&source=univ&ei=OFdETMXsCYSAvgOf1sT7DA&sa=X&oi=image_result_group&ct=title&resnum=1&ved=0CDoQsAQwAA

[wot179]

"HI five loses member."

Pucking.Gold.

[76lxhatch]

So we have two distinctly different opinions right now...

Not how I read it, I think we're still just hung up on the terminology but in agreement on the info. I know for a fact that I am right, but whether I can communicate the information successfully is another matter entirely...

The Wikipedia page calls the cast bit a 'casing' and the centre a 'hemisphere' - it doesn't call any of it a carrier despite naming the bearings 'carrier bearings'!

[S pack]

So we have two distinctly different opinions right now...

Not how I read it, I think we're still just hung up on the terminology but in agreement on the info. I know for a fact that I am right, but whether I can communicate the information successfully is another matter entirely...

The Wikipedia page calls the cast bit a 'casing' and the centre a 'hemisphere' - it doesn't call any of it a carrier despite naming the bearings 'carrier bearings'!

Obviously there is varying terminology for the same parts, most of which are prob all correct, depending on which school you went to.
But in 35 years of playing with cars I've never ever heard of any part of a differential being called a third member.
Holden workshop manual refers to the Diff parts as:
The case is the part that the ring gear (crown wheel) bolts to and contains the side gears and the LSD cones etc (if LSD).
The carrier & cap assy is the part that the pinion and the case are assembled into.

[TerrA LX]

Obviously there is varying terminology for the same parts, most of which are prob all correct, depending on which school you went to.

Yeah I spose if you went to a catholic boys school you soon found out what a "third member" was.

[Heath]

Not how I read it, I think we're still just hung up on the terminology but in agreement on the info. I know for a fact that I am right, but whether I can communicate the information successfully is another matter entirely...

No, I mean we have gearex and the eBay sellers saying the carriers are different, and we have most other people saying they are the same, and I was merely assuming they were the same until I started this thread.

The terminology doesn't matter. I will call the Third Member the Casing if that's what people want.

[TerrA LX]

Call it a pumpkin, third member is so gay.

[limo]

I thought there is about 60 th diff between the two at crownwheel mounting surface
eg 308, 278 same
but diff to the 336, 355, 390 group
if you put 1 of each "hemiphere" on flat surface on end (crownwheel mounting surface up) you can see the slight difference in height,
thus one maybe shimmed up to match the other,

[TerrA LX]

hence the term shim and not spacer.

[76lxhatch]

No, I mean we have gearex and the eBay sellers saying the carriers are different

Ah I missed that post, they're wrong

I think the confusion comes from the Salisbury diffs where the tall ratios have different offset centres

[76lxhatch]

Sorry I used Heath's terminology and mixed everything up again, to clarify:

- the carrier or case (bit that the pinion is attached to) is different

- the centre or hemisphere (bit that the crownwheel is bolted to) is not different (Salisbury diffs they are)