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Eoi On 4.375 Ratio Diff Gears For Skylines

Strik3r
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Strik3r Experienced

Strik3r

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So after my hunting around for gts4 diffs to transplant the crown wheel and pinion from into the GTR diffs, I found that these items are becoming harder and harder (AND more expensive) to come by. Particularly seeing as you have to buy the entire GTS4 rear diff and front sump and diff just to get the crown wheel and pinion out of both of them (nobody actually wants the viscous gts4 diff).

I was originally going to Cryotreat my CWP's to make sure they were up to the task, but after talking to a friend who has access to a CNC machine, we discussed the possibility of digitizing the crown wheel and pinion from the front and rear diffs out of a gts4 (4.375 ratio) and having a engineer produce replacement CWP's for people wanting taller diff ratio's. To the best of my knowledge, these diffs would suit 32's, 33's and 34's (rwd cars could just use the rear diff, while GTR's/Stagea's would use the front and rear). Another big advantage would be that the new CWP's would be constructed out of stronger materials, effectively upgrading the strength of the diff.

I'm no expert on any of this, but can possibly relay any questions that people might have. At the moment, i'm just trying to find out if there is enough interest to have this done. We will be able to set it up as a group buy and it should work out very cost effective. I havent done any number crunching, but to defray the cost of the cnc'ing and digitizing over the produced CWP's, i'm guestimating we'll need around 10 people in the group buy to make the process worthwhile. The more people we have, the cheaper it becomes. If i get enough interest in this thread, i'll have a chat to my friend and work out how much each CWP will cost.

bigmikespec Veteran

bigmikespec

Posted
Posted

I would be interested, price dependent of course.

It is not just that they are hard to source, it is also the fact they these gears may be 19 y.o. and done 100,000km or more.

Strik3r Experienced

Strik3r

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Ok so I talked with my contact about the crown wheel and pinions and after some research, he told me that his machine isn't specific enough for the job. We were referred to Albins Off Road gear - www.albinsgear.com.au who do a lot of work for the v8 supercars and rally cars. They basically said that it isn't going to be a cheap exercise unless we are talking about resonably high volume stuff.

The ball park figures we were quoted were $5000 for a 1 off CWP, and around $10000 if we got 5 CWP's. Presumably, it would continue to scale up, but at best guess we would need to be ordering something like 20 or 30 units before the per-unit cost got down to what I would consider reasonable levels (<$1000 per unit). I would have investigated further, but these sort of figures require more responsibility and co-ordination than I am willing to undertake at this point in time. If someone wants to continue to investigate this and organize a large-scale group buy, then I would be interested, but I'm not willing to take it on myself.

Thanks for the interest, and if someone wants to organize it, feel free to contact albins yourself.

bigmikespec Veteran

bigmikespec

Posted
Posted

Probably better off sending it to someone who is more suited to runs of 1-10 sets of parts instead of a company who wants (or needs) at least 30+ to make it at all viable as their machine time is worth a lot more.

Thanks for the effort!

bigmikespec Veteran

bigmikespec

Posted
Posted
$2000 for an end if there's an order of 10, so rear plus front = $4000 each person

Or $5000 for one end on a one off order.

Out of interested what material? Any heat treatment after?

shanef Grand Master

shanef

Posted
Posted
Out of interested what material? Any heat treatment after?

Something flash. Shot peened plus a magnitude of other treatments all included in the price.

Unsure of material, yeah heat treatment included.

The guy i spoke to was a Steve, he said the parts from them would be stronger than the OEM parts for sure

Yeh Steve is the guy i spoke with aswell.

They also do gearsets. Dog arrangement with forks, shafts etc between 8-9k. They list a synchro on their site but i didnt get a price on them.

Axles and shafts they can do aswell, again didnt get price.

33gtst Proficient

33gtst

Posted
Posted
Can I ask why people wan't a shorter ratio? I've got 4.375:1 right now and find it a bit too snappy and violent for an rb25.

same here,well may be not snappy and violent(cause mine is welded) but I have one in my 33 and really really hate it. Instead of using 3rd I now have to rely on 4th more for everyday street driving, and my 4th is a little bit special. Cant wait to get the diff out. LOL

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