19 replies to this topic

[Entaran]

Attn people who know more than me

Is the Centre diff from a w5m33 box in a GVR4, the same as the one in a E1-3? Or are there differences and thus not interchangeable?

[Evo-00x]

Edit - Not sure about the VR4 centre diff mate as I think they have a different tooth helix and if so, would only mate with VR4 intermediate shafts.
However, the GSR and EVO I-III all have the same centre diffs and internals of the centre diff are interchangeable. They also have the same intermediate shaft. Reason is because 3rd gear intermediate meshes with the centre diff teeth.
The only difference Ive noticed is in the spider gears of VR4/GSR as they came with a little groove on the back face of the spider gears when the Evo's didnt. The groove to me looks like an oil groove for the brass shims on the cross-shaft, but... and its a big BUT and Im only insinuating here, the groove could also be a weakspot in the spider gear. Not that there has been any evidence to confirm otherwise as VR4/GSR and EVO W5M33 boxes break centre diff spider gears when you like to launch the car hard with a bit of power under the bonnet.
All the rest as far as housing, upper and lower pinions, crosshaft and brass lower shim (cock-ring) are the same. The cross-shaft and lower brass ring may have slight thickness differences to suit that particular housing 's tolerances. You should get a slight click with a centre diff when moving the upper pinion in and out, it shouldnt rattle.

Edited by EVO-00X, 01 November 2012 - 12:00 PM.

[blackvr]

Actually, I reckon there is a difference... Evo 3 centre diffs certainly WONT fit into VR4 and E2 gear clusters. The gears are cut slightly different. The same goes with E3 selector shafts. One of the shafts ( reverse from memory) has the roll pin holes drilled approx 5 degrees offset from earlier versions. Speak to Albins and Pfitzner gear box manufacturers... they are certainly very aware of the differences !!

[brisvr4]

Yep, e3 centre diff has the main gear teeth cut on a slighly different pitch. I've tried it myself and it binds.

[BMGTZ]

cusco only list one for all 123 models....

[Entaran]

Thanks guys

[Evo-00x]

Ive worked on VR4, RVR, GSR, EVO I, EVO II and EVO III gearboxes over the last couple of years and found no difference between the tooth helix of the centre diffs between RVR, GSR, EVO I, II and III's.
The EVO III gearboxes I worked on were EVO III GSR with viscous LSD, and EVO III GSR without LSD. I have not worked on an EVO III RS gearbox yet.

I can tell you that there is definitely no difference between GSR and Evo I-III centre diff tooth helix.
Even Mitsu parts database lists the centre diff part numbers for the GSR and EVO I-III as MD741919 = one part number for all of them.

Now part numbers aside, think of another physical and logical way of proving that the GSR, EVO I-III all have the same centre diff housings or more importantly, tooth helix.
The centre diff lives inside the gearbox and its teeth mesh onto the intermediate shaft.
As far as the actual intermediate and input shafts go, the intermediate shaft from the GSR, EVO I-III are all the same.... its only the input shaft that differs between GSR, EVO I and EVO II/III boxes.
Therefore if the intermediate shaft is the same between GSR and EVO I-III, then why would the tooth helix on the centre diff of the EVO III be any different when they are all mating to the same intermediate shaft.

I dont know what experiences Blackvr and Brisvr4 were having with their gearbox builds, but it shouldnt have been the case unless there was a difference in your early VR4 gearboxes that doesnt mate to GSR/EVO I-III internals.

Im concerned that Blackvr said about the EVO III centre diff didnt fit onto the EVO II gear clusters because EVO II-III gear clusters are the same.
The differences between EVO II and EVO III gearboxes are that the EVO III front diff crownwheel has 63 teeth and the EVO II has 64 teeth. EVO III also has the angle of the roll pin on the reverse/5th gear shift fork on a slightly different angle, thus requiring an EVO III specific 5th/reverse shift fork.
But there is another difference also... early EVO III boxes were identical to EVO II boxes apart from the crownwheel of course. This means that early EVO III boxes possessed solid cast steel selector forks for 1/2, 3/4 and 5th/R same as the EVO II boxes, but the EVO III still required its own specific 5th/R fork due to the different roll pin angle as mentioned above.
Then sometime during production Mitsubishi commenced producing the EVO III gearbox with the updated selector forks with nylon pads. Probably from lessons learned from the EVO II and early III competition cars as the solid forks may have been producing excessive heat > friction on the hub sliders and wore out prematurely under extreme operating temps

[brisvr4]

Easy way to solve this. I have several VR4 boxes at Troys house (jetgsr) and we have to pull his Evo 3 box apart to replace a couple of bits so I will see if the centre diff meshes with the VR4 shaft or not.
Easy peasy!

[Evo-00x]

Awesome Tim . Im thinking if there is a difference it'll be with the VR4 box or a certain run of VR4 boxes.
If you do find a tooth helix difference between the EVO centre diff and the VR4 intermediate shaft, can you please note the VR4 gearbox code/s for me?
cheers mate.

[brisvr4]

No worries Rob,
I current have a W5m33, C50p, and a VR4 RS box there in bits so I can try them all out!

[blackvr]

I can tell you that there is definitely no difference between GSR and Evo I-III centre diff tooth helix.

Well, I have three centre diffs here that have a different helix to all my other " hundreds" of VR4/GSR/Evo gearboxs. They all come out of Evo 3 boxes... As BrisVR4 has also found out, where theres smoke theres fire ! I'd certainly be interested to find out what the go is .. There is absolutely no way they mesh with a VR4 gearset.

[Evo-00x]

It will be good to find out what you guys are actually trying to mate up to eachother.

I have a PDF file that compares EVO III GSR (CE9A SNGF) vs EVO III RS (CE9A SNDF) gearbox part numbers - http://www.mediafire...c5terr3xx4cog98 . Have a look on page 3, 5th item down for Centre Diff case part numbers = MD741919. It also shows the same part number as GSR and EVO I-III's as well.

Actually I just went into the garage and have about 2 x EVO III centre diffs, 1 x EVO II, 1 x EVO I, and 3 x GSR. All boxes I pulled down and labelled with a piece of wire and gasket paper ready for rebuilds. All of the centre diffs have 1 notch in the teeth, all in the same place on the teeth. See attached pic.

Are you guys in a position to count the number of notches (and position of the notch/s) in the teeth of the centre diffs you are having trouble mating to? See pic...

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[VR-4Squid]

It will be good to find out what you guys are actually trying to mate up to eachother.

I have a PDF file that compares EVO III GSR (CE9A SNGF) vs EVO III RS (CE9A SNDF) gearbox part numbers - http://www.mediafire...c5terr3xx4cog98 . Have a look on page 3, 5th item down for Centre Diff case part numbers = MD741919. It also shows the same part number as GSR and EVO I-III's as well.

Actually I just went into the garage and have about 2 x EVO III centre diffs, 1 x EVO II, 1 x EVO I, and 3 x GSR. All boxes I pulled down and labelled with a piece of wire and gasket paper ready for rebuilds. All of the centre diffs have 1 notch in the teeth, all in the same place on the teeth. See attached pic.

Are you guys in a position to count the number of notches (and position of the notch/s) in the teeth of the centre diffs you are having trouble mating to? See pic...

What have the notches got to do with anything? All the centre diff's I've seen have had them in the same place.

Early vr4 boxes are KM255's (3.545 only) whilst later ones are W5M33's (3.545 and 3.909), perhaps someone could check if the part numbers for centre diff's are different between the km and w5 vr4 boxes?

JDM E39A - 0010362 is a km255 box
JDM E39A - 0020096 is a w5m33 box

both 3.545 ratio.

[brisvr4]

The part numbers between VR4 boxes are the same. The discussion is about trying to mate VR4 and Evo gear.

[VR-4Squid]

The part numbers between VR4 boxes are the same. The discussion is about trying to mate VR4 and Evo gear.

I'm aware what the discussion is about.

I posted the information in response to this post:

Awesome Tim . Im thinking if there is a difference it'll be with the VR4 box or a certain run of VR4 boxes.
If you do find a tooth helix difference between the EVO centre diff and the VR4 intermediate shaft, can you please note the VR4 gearbox code/s for me?
cheers mate.

So we have ascertained that:
* All 3 variations of vr4 gearbox (km255, w5m33 3.545 and w5m33 3.909) use the same centre diff.
* gsr (w5m33 3.545) and evo 1,2,3 (w5m33 3.909) use the same centre diff (MD741919)

What is the part number for the vr4 centre diff? (for each of the 3 boxes).

Either there are several people who have centre diffs/gearboxes which are not what they believe them to be.

Or one of the above statements is incorrect (or possibly both).

[Evo-00x]

VR4 Squid: "What have the notches got to do with anything? All the centre diff's I've seen have had them in the same place"

Notches on the teeth actually already have a lot to do with identifying gears, front diff crownwheels and output pinions between models. Even if some parts have the same tooth count and physically look the same, a different number of notches, different thickness of the notches (thin or wide), or if they are cut in a different location on the teeth can identify different parts/different tooth helix. Ive come across it myself and it helps drill down on what parts mate together and what doesnt.

I asked the question as it 'may' possibly be the same case with the VR4 centre diffs which would be an easy way to immediately identify it as non GSR/EVO at first glance.
Thats why if one of the boys with a genuine VR4 centre diff can take a photo of it and post it up (too see if there is a physical difference in the tooth notches), it could save some hassle in future if people try to mix and match VR4 to GSR/EVO internals (it would also mean the VR4 intermediate shaft would be different).

[blackvr]

I will dig the items out and take some photos... just be a bit patient as I am under the pump with work. Damned customers get in the way of a leisurely life LOL !

[Evo-00x]

lol.. back onto this subject we can finally put it to rest. I know Brian & I spoke about this recently on the phone.

Anyhow, I dont normally have GVR4 gearboxes at hand but I purchased an Auspec GVR4 gearset and have finally made some comparisons (Im off work on sick leave at the moment and need to keep myself amused lol).
The GVR4 gearset was compared against 2 x EVO I boxes, 1 x EVO II box, 3 x EVO III boxes, 1 x RVR box and several GSR gearbox internals, to see how they meshed against the GSR/EVO parts.
Thanks also to VR4_Evopwr for sending me pics of his Japspec GVR4 gearset to check it against the Auspec etc.

I have made the following comparisons:

Centre Diff
Nil Notches in Centre diff teeth = GVR4 (both Auspec and Japspec)
1 small notch in Centre diff teeth = GSR & EVO I-III

Intermediate Shaft
Nil notches in 3rd gear intermediate teeth = GVR4 Auspec
1 large wide notch in 3rd gear intermediate teeth = GVR4 Japspec
1 to 3 small narrow notches in the 3rd gear intermediate teeth = GSR and EVO I-III

Therefore I can confirm the following:
Auspec GVR4 CENTRE DIFF IS DIFFERENT/ DOES NOT MESH PROPERLY WITH GSR / EVO I-III INTERMEDIATE SHAFTS
Auspec GVR4 INTERMEDIATE SHAFT IS DIFFERENT/ DOES NOT MESH PROPERLY WITH GSR / EVO I-III CENTRE DIFFS
As the Japspec GVR4 centre diff has no notches in the teeth, I make the assumption that its the same centre diff as used in the Auspec GVR4 - but cannot confirm 100% unless I try it.

GSR & EVO I-III
GSR and EVO I-III centre diffs and intermediate shafts are interchangeable.
If you have one to three small notches in your intermediate shaft, it will suit the centre diff with the small notch in it.

See pics.

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Edited by EVO-00X, 02 November 2012 - 06:50 AM.

[Rockabilly]

Looking at Rob's pics, the VR4 teeth tips & roots are thicker & stronger than GSR & Evo.
Both are geared 1.275 37/29 but were cut with different cutters. So you can't run one of each.
Cheers !

[Evo-00x]

Just updated above because I was bored and needed to know lol