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80series vs 105series diffs.

Posted: Tue Mar 16, 2010 5:51 pm
by 80's_delirious
I have an 80 series with factory lockers and a 105 series with open centres.

I would like to be able to use my toyota lockers in the 105series diffs. I know there are some diferences in the two diffs, but am not certain to what extent they are different.

Pros of 105s
slightly wider track width??
lower ratio 4.33 vs 4.1. 4.33 would suit my 35"s better
stronger dowels in the hub flanges

I would like to be able to remove and swap the factory locked third member or diff carrier into the 105.

Possible problems and questions I see are:-
I think the axles have different size splines or different spline count?
the factory diff locked diffs have one longer axle with longer splined section on it.
I will probably need custom axles to resolve these things. anyone know a rough cost of custom axles?
are crown wheel and pinion interchange-able?
will the 80 3rd member bolt into the 105 housing (minor mods OK)

Any specs or details on either would be great.

EDIT. sorry Ruff :oops: meant this to go in the Yota section, could a mod move it thx

Posted: Tue Mar 16, 2010 9:07 pm
by crankycruiser
the rears are a different spline count.

u cant swap CW&P as there is more or less bolts? that hold the 105 rear on. found this out as i was gunna sell a mate my old rear 4.8 out of my 80....

its not just stronger dowels in the 105 rear, they have 10mm studs as well..

EDIT: fixed stuff up :?

Posted: Tue Mar 16, 2010 9:30 pm
by 80's_delirious
crankycruiser wrote:the rears are different ratios.

u cant swap CW&P as there is more or less bolts? that hold the 105 rear on. found this out as i was gunna sell a mate my old rear 4.8 out of my 80....

its not just stronger dowels in the 105 rear, they have 10mm studs as well..
bugger. :x
Now I remember reading somewhere they have different number of bolts in the crown wheel. I knew about the studs too.

Posted: Tue Mar 16, 2010 9:37 pm
by crankycruiser
yer dunno how successful ya gunna be on this one :) that shoulda said rears are a differnt spline count too.... my bad :roll:

Posted: Tue Mar 16, 2010 9:57 pm
by 80's_delirious
crankycruiser wrote:yer dunno how successful ya gunna be on this one :) that shoulda said rears are a differnt spline count too.... my bad :roll:
do you know if the third member will bolt in to the housing?

I was thinking I might be able to have custom axles made, the more I think about it the better fitting airlockers sounds :?

Posted: Tue Mar 16, 2010 10:52 pm
by nicbeer
hrmmm selling factory lockers.... :)

Posted: Wed Mar 17, 2010 5:35 pm
by 80's_delirious
nicbeer wrote:hrmmm selling factory lockers.... :)
yeah, could be an option, but freight to WA will cost you a bit :)

Posted: Wed Mar 17, 2010 5:55 pm
by nicbeer
yeh and not wrong,

Ive been doing some searching and looks like i need the housings and not just the 3rd members.

if i am wrong and $$ is reasonable it may be an option.

Dont the 105s have factory lockers? or is more the $$ and already having the older diffs.

Posted: Wed Mar 17, 2010 8:19 pm
by mickdirt
I have a 100 series rear diff in my 80 I have a arb locker with 80 series star gears to fit the 80's axles, yes the 3rd member well fit in I had to do a very small amount of grinding to fit the crown wheel in other then that they pritty much the same. the 100 has bigger axles, hub dia and the bigger studs and dalws. so I think if you used the 80 therd member and axles and hubs they should go in to the 100 housing, just not sure about the brakes. both axles are the same lenght.. hope this helps in some way..

Posted: Wed Mar 17, 2010 9:31 pm
by 80's_delirious
mickdirt wrote:I have a 100 series rear diff in my 80 I have a arb locker with 80 series star gears to fit the 80's axles, yes the 3rd member well fit in I had to do a very small amount of grinding to fit the crown wheel in other then that they pritty much the same. the 100 has bigger axles, hub dia and the bigger studs and dalws. so I think if you used the 80 therd member and axles and hubs they should go in to the 100 housing, just not sure about the brakes. both axles are the same lenght.. hope this helps in some way..
cheers Mickdirt,
can you clarify? you have a 100series third member in an 80series housing?

I did think of swapping the side gears to suit 100 series axles, but axles to suit the factory lockers are longer than standard on one side, and I would have to get side gears for a 100 series diff locked diff so they would have to come from toyota.

are the std 80 series axleas the same length as the 100s? I thought they were slightly different length?

Posted: Thu Mar 18, 2010 8:19 pm
by mickdirt
I measured 80 and 100 axles and they they the same length, both only with lsd centers. I have my 80 series 3rd member with a 100 locker this was done to get the 4.3 diff gears, as 4.56 seam to not exist anymore..