Ltaboso

Is the supra jza80 diff similar and will bolt on to our F? Will the isf prop shaft also bolt on to the supra diff?


TIA

Justind27

iTrader: (6)

Can send me dimensions of one and I can check I have a isf diff on the shelf

Justind27

iTrader: (6)

There is a lot of variations of the mk4 diff, they are similar it's just that they use flanged axles and whether or not you get a "big" or "small" diff which both are not directly interchangeable on a mk4 without a little work. Being that you can put atleast one of the variations in a sc makes me think that the sc would fall into the mix as well, I'll keep my eyes open for one local and try to grab one to compare.

Ltaboso

Im thinking about taking the ring gear and pinion to transfer to the isf diff...im just not sure if the correct size is 200mm or 220mm for the isf ring gear size....im still searching around here

Justind27

iTrader: (6)

There is another thread on that idea, I can get you the dimension though my gear is out of my f diff currently (still waiting to get the f giken, Rollin a 350 diff/ giken currently it's crazy)

Just found this though:

Justind27

iTrader: (6)

Got it figured out: 98-00 sc400 diff (200mm r&p)+ mk4 auto shafts+ auto LSD unit and you'll have a 3.26 gear ratio and LSD options that are well within budgets! And not break the bank the way the is350 diff swap is doing to me (mpg/tires)

Biggu

iTrader: (12)

yes it will bolt in but the axles will not work. ive looked into it just never did anything about it.

Justind27

iTrader: (6)

The F axles and supras are the same length and according to the second site I listed the outers both work with the hubs it's just the supra uses a external abs ring that the f axle needed to be machines to have the ring pressed on the outer. I'll be getting a diff and axles tomorow and I will take lots of measurements of everything vs the isf diff since it is still out of my car.

PDP180180

iTrader: (3)

Nice project.

Following this with interest. Be great if there is a more cost effective way of getting a proper LSD in the early F's.

Keep us posted on your progress mate.

Cheers.


Pete

pharnhyte

iTrader: (1)

Funny you guys mention this, we have about 10 mkiv supra's at our shop, and the other day we had my IS-F on the lift, and we happened to notice that the diffs looked just about identical. I didn't really think to pursue the idea but we have everything here multiple times over.....



Keep in mind that the 97-98 auto tt supra's had a LSD as an option, while the 93-96 models had them standard.




Steve
DEFIV POWER


FYI, Cusco makes 9 different variations of differentials for our cars, all of which are cheaper than OS Giken: http://www.cuscousainc.com/vehicle-r...&modelname=422

Justind27

iTrader: (6)

Have you checked the cost of the diffs though? Mk4 diffs on eBay are spendy with factory LSD even! I brought all this to attention cause there is a cheaper way to go about it and have a better than oem setup for just doing a bit of research and work in the local wrecker yards. The setup I am shooting for should only cost $2k rebuilt (as long as r&p are within specs) to have a little better acceleration, LSD and easier maintenance vs $2700+ for just LSD on factory setup.

lobuxracer

iTrader: (2)

The setup I have didn't cost much more because I bought the Giken spool on the group buy. No junkyard searches or Frankenstein setups the next buyer will freak about.

I still want to know what R&P sets will fit in the IS F case on the OEM or aftermarket LSD spool. It does not appear any of the B options will fit because the F has an A spool, not a B spool.

Justind27

iTrader: (6)

The 350 ring bolts in its just the thickness of the ring mounting area is thinner than the f's this is also why the spool has a more offset mounting flange. I'll let you know when I take the sc400 case apart which is a "a" case if there is similar differences like the 350 case/spool

lobuxracer

iTrader: (2)

So the flange on the spool where the ring gear mounts is thinner on the 350 spool than the IS F spool?

I did a global search for the IS F spool part number and crossed it to all Lexus models globally. Here are the gears available to fit the exact same spool as the IS F has:

41201-59165 - 2.474:1 (super overdrive...)

41201-59235 - 2.937:1 (stock for all IS F)

41201-59245 - 3.133:1

41201-80445 - 3.266:1

Nothing else is used with that spool or the Torsen spool. I suspect they get entire train loads of 2.937 gears as they are by far and away the most common final drive ratio Lexus uses.

Justind27

iTrader: (6)

The flange on he spool is offset to one side more than the f, I put the f ring on the 350 giken and tried dropping it I the f case and it was about .5" difference atleast. This was just out curiosity then I put the 350 diff in and the f diff was going to get a giken but if this other setup works then it will be sold or just collecting dust.

Well if it does use the same spool as the sc then we should be able to put in the corresponding aftermarket LSD into the f case and keep everything the way it is. I'll be getting the case today and start pullin it apart to test it