mk4 rear end in a mk3?

[Big Rob]

MUCH cheaper than Ian's 9 inch!

From what I have read MK3 CV's bold onto the MKIV stub axles so at the end of the day there is alot of money saved by not having to machine stub axels and bearing blocks. Cost involved would be replacement differential, modification to DS and fabrication to attach MKIV differential to MK3 sub frame.

 

[figgie]

Ford 9!!!

That way, active diff cooling for the long stretches of high way driving at stupid speeds.

 

[JZa80]

ok thanks everyone. would i be bes off buying a used ford 9inch. getting diff gearing. and lsd rear. and jsut piece everything together.
IJ-how much would your set up have cost if you would have just bought a diff from somethign else and change dthe gearing.

-what does everyone think about getting diff gears for the mk3 rear end and getting a machine shop to make better axle shafts. and rock that and beef up the mk3 rear end?

 

[IJ.]

If I had to do it over and was going to stay under 500rwhp I'd drill and tap the G series case for an Oil return between the Pinion bearings and run my Cooler and pump and get some 3.54 gears for a T1 Torsen.

NOTHING for my 9" was off the shelf it's all custom and cost a fortune to do and is firmly in the overkill basket.

 

[fstlane88]

The guys with the Big Daddy performance Orange/Copper 8 Sec. MKIII have a MKIV rear end in it. I couldn't get much info out of the guy the night I saw them at the track, but he said it was custom fit in there, but used Toyota gears, and a MKIV pumpkin. It's behind a powerglide also.

And that car works man, I think they have 4 wins in a row so far this year, someone correct me if I'm wrong.

 

[bmoss85]

I've thought about going with the ford 8.8 irs rear end. You can get about any gear combo you want for it. I've seen some M3 guys using it.

 

[JZa80]

im looking at doing a mild build on a 2j NA-T. looking for aobut 500 whp it will be dirven in summer a lot. its going to be gutted from behind the front seats. would this idea work? get like a oil cooler. drill and tap the casing on the stock mk3 rear end and have the oil cooler ahve gear lube circulating through it? woudl it work. cus i think i would jsut find a local machine shop make me some axle shafts. and kind of do what IJ did and make custom axles to endure it. does anyone know who makes gears for the stock mk3 rear? i know jaws gear does but i cant find anything lowet than 4.10's

 

[figgie]

500rwhp?

Shit stick with the MKIII diff. It works and I have yet to see anyone grenade it. I seen someone grenade the Torsen LSD but not the stock 7m!!

Lower than 4.1?

What are you trying to do? Uproot trees in 1st and 2nd gear???

 

[JZa80]

lol maybe i am looking at getitng into landscapiong haha! but no i was looking at like a 3.73 or 3.90 range. how abd will it bee on the highway? and how nice of a pull will i get?

 

[figgie]

lol maybe i am looking at getitng into landscapiong haha! but no i was looking at like a 3.73 or 3.90 range. how abd will it bee on the highway? and how nice of a pull will i get?

Unfortunatly..

It depends...

 

[JZa80]

ya thanks figgie you have been a big help thanks to everyone. im going to look for a set of gears. does anyone want to chime in on my idea of drilling and tapping the casing and running like a oil cooler or trans cooler but having the diff's gear lube circulating through out it to help the cooling. for when you jsut ahve to beat the fat pig into submission:naughty:

 

[Cz.]

The mk3 rear is an 8 inch diff
The mk4 rear is an 8.5 inch diff for the first years (93.5 - 95 models)...
after 1995 the mk4 had a 8 inch rear diff like the mk3 :biglaugh:
Stock mk3 trans & rear diff can hold up to 600 rwhp with all kinds of abuse
and driving style.And up to 800 rwhp being gentle with 'it' and not doing
1/4 miles on the dragstrip :sarcasm:

So just out of curiousity, are the late model mk4 diffs the same as the mk3? As in we could use those LSDs and ring & pinion in our rear ends?

 

[IJ.]

If I had to do it over and was going to stay under 500rwhp I'd drill and tap the G series case for an Oil return between the Pinion bearings and run my Cooler and pump and get some 3.54 gears for a T1 Torsen.

NOTHING for my 9" was off the shelf it's all custom and cost a fortune to do and is firmly in the overkill basket.

ya thanks figgie you have been a big help thanks to everyone. im going to look for a set of gears. does anyone want to chime in on my idea of drilling and tapping the casing and running like a oil cooler or trans cooler but having the diff's gear lube circulating through out it to help the cooling. for when you jsut ahve to beat the fat pig into submission:naughty:

Your idea? :nono:

 

[SupraClaou]

So just out of curiousity, are the late model mk4 diffs the same as the mk3? As in we could use those LSDs and ring & pinion in our rear ends?

No...unfortunately it isn't :cry:
It is quite different!
But...If anyone did this kind swap please post up!
This for me would be :love:,cause I want to do the 6 speed swap also!

 

[JZa80]

sorry ij i wasn't excatly knowing what you were refering too i thought you were talking about drilling and taping a ford 9inch casing. when you said g i thought you ment out of a gbody chassis. my fail! but would that work? would the gear lube be able to sufficently flow through it? and in teh future ill test the mk4 rear if i ever do go 6spd.

 

[IJ.]

The only failures I've had with both an LSD and a T1 Torsen G series diff were both high speed Pinion bearing failures if you back off and accelerate hard at the top end.

They starve the bearings and they last seconds in this scenario so running a return in between "should" solve it.

In my 9" the Cooler return dumps onto the crownwheel and that flings the oil into the pinion.

 

[Evilempire1.3JZ-GTE]

For the mkiii R154 w58 I would use a 3.7 for free way cruzer 4.3 for weekend around town delivery car.

As far as power goes the more power you have the taller you want your rear gears because you dont want to shift 5 times to go down the track because you spend more time shifting then laying power to the track

The 1JZ in my car had a factory twins & a redline of ~8100 rpms. With a 4.3 it was so fun I was always in boost and always close to peak torque so I was killing mkivs new mustangs EVOs etc. It sucked though cruzing down the freeway 3500rpms ~75

I picked 3.9 after going single should be ideal they say the perfect ratio is about 4.1 but the torsen sucks.

For mkiv 2jz & 6 speed you need a 2.3 then it would be worth while to use a mkiv diff.

As far as custom ford 9" currie enterprise if you decide on streight axle to retrofit for a drag car

IRS go with krugel its the IRS suspension i planned on putting in my opel gt
Heres a picture of their work