can these be swapped over?

scenario is this, I have 7.5" 3.92 open diff with 100mm flanges in my current build, ratio was always a bit off, but I lived with it, its now got a knackered bearing, and seems a good time to pull it out and swap it over

Ive found locally, and its cheap a sierra diff from a 2wd cosworth, its 3.62, a lot closer to what I want, LSD which isnt so good, but will live with it. however I understand that its going to have 108mm output flanges

can you pull the back off the diff, remove a clip and pull them out then swap them over????

Im a bike person, cars are alien to me.

I know its not ideal, but its cheap, its literally on my doorstep. (the seller has offered to pop round to mine with it)

I cant afford to buy new matching shafts to bastardise to go in my build, but cant find/afford the diff I do want ie 3.62 7" non LSD

ok, so a search online, ebay etc, has revealed that the bearings and oil seals seem the same acorss all the diffs, 7" and 7.5" cossie and non cossie

could the splines inside be different?

cant afford to buy this diff and find its of no use to me.

IIRC LSD flanges are longer than non LSD flanges, but that might only apply to 7" diffs?

ok thanks for the input, so do you mean that I might have to shorten my drive shafts?, thats not a problem as the one and only spare part I do have is a pair of bare shafts to suit my lobro joints


why is nothing in life simple, or cheap? LOL

Its not the shaft lenghts, its the actual flanges are different lengths internally. So you 100mm flanges might be too short to suit the LSD, which is expecting longer ones. However I only know this to be the case for 7" diffs, it might be different for the 7.5".

7.5" Open differential output shafts will not fit the 7.5" LSD.

I think there were some 7.5" granada LSDs with 100mm OD Lobro joint output shafts.
These would fit the 7.5" 2WD LSD.

The Sierra Cosworth 2WD 7.5" LSD has 108mm OD output shafts.

Think the ratio of 7.5" LSDs is usually 3.64:1

7" LSD output shafts will not fit the 7.5" due to the internal length of shafts/splines.

You could fit a complete Sierra 4x4 7" LSD 3.62:1 ratio, this has the 100mm OD output shafts.
To keep your existing shafts you would need 1/4" spacers on each coupling.

oh so much to learn

Ive just read on another kitcar forum that I found while googling, that you can swap lobro and push in, about with each other??

Ive seen a few diffs of the right size and ratio, but they had push in shafts, if I can just fit my lobro mounts then that would be very easy, but I doubt its actually that simple

thanks, posted at same time

didnt think it could be that simple

I will continue in my search/quest

I really wanted to get down to 7" diff to save weight and size, and in an ideal world something around 3.6 ratio would be perfect

didnt want LSD anyway LOL

only considered the cosworth diff as the ratio was right, and he would drop it to my house, oh and it was cheap

quote:

---

Originally posted by minitici
I think there were some 7.5" granada LSDs with 100mm OD Lobro joint output shafts.
These would fit the 7.5" 2WD LSD.

---

quote:

---

Originally posted by tony-devon

I really wanted to get down to 7" diff to save weight and size, and in an ideal world something around 3.6 ratio would be perfect

---

quote:

---

Originally posted by tony-devon
didnt want LSD anyway LOL

---

As said, you can't swap out flanges between an LSD and non-LSD. The reason is that in a non LSD the spider gears are right in the middle of the diff, so the internal splined stubs of the flanges are equal length for a non LSD (in other words you could swap the left and right flanges with no issue). In an LSD the viscous coupling takes up some space so the spider gears are pushed over to one side. That means the flanges are different - one is longer and one is shorter.

You could swap the flanges between, say, two 7.5" LSDs, one with 100mm flanges and one with 108mm, but that doesn't help you

You can also remove flanges from a non LSD and make it a push-in diff, but that dont really help you either

I'm really really surprised you can't get a 7" 3.62 non LSD easily for peanuts and a 2WD cossie diff is cheaper 7" 3.62 non-LSD has to be probably the most popular one out there, no? Are they really all drying up? One thing you could consider is snapping up that cheap local cossie diff and flogging it on Ebay with appropriate cossie tax, then you've made a few bob towards that apparently elusive 7" 3.62 non LSD whenever you see one!

[Edited on 6/3/12 by Liam]

I think hes now bought a 3.62 from DH2.. with the flanges I wanted... GRRR lol!

do you just need the flanges??

as Im going to pull apart the diff I had and learn more about them.

then just sell/scrap whats left

mines a 7.5" lobro 3.92 100mm flanges

the diff is being scrapped as its got heaps of play, and the bearing on the left had side has gone, was easier to just change the diff LOL

are my flanges any use to you? how much of a hurry are you in?

make me an offer for them posted

Im after the 100mm 7" flanges, unless you investigations lead you to find that 7.5" flanges are the same?!

If I can get them from you for a reasonable price, hopefuly DH2 might still have his shafts and I can pair them back up!

hmm I was under the impression that the flanges were the same, only differences were twixt LSD and non LSD

but Im far from an expert

I will do my best to get that diff out this weekend and pull the output flanges off, get them measured and photographed

I have to take the back off my 7" as well to modify it for a new breather, ( I run them upside down) so I will see if theres anything obviously different with the flanges, ie overall length etc

FORD 7' REAR DIFF FLANGES INNER SIERRA LOCOST HAYNES KITCAR | eBay

quote:

---

Originally posted by tony-devon
I will do my best to get that diff out this weekend and pull the output flanges off, get them measured and photographed

---