Already posted this in the S2000 forum but figured it'd fit better in this forum...


Well since my brother is a CNC machinist and I didn't want to pay over $1000 to have a reinforced differential I decided to put him to work. So I picked up a stock low mileage 4.10 diff to do some "testing" with before I reinforce the 4.77 diff that is currently in my car. This has been a fairly long process and we are finally making some headway.

Anyways, here's some pics of the progress so far...


Stock cap machined down and the steel reinforcement cap. Also in the pic the new, longer tab for the diff bearing "adjusters".





Very tight tolerance between the two caps










And my brothers own personal Makino 3-axis CNC machine



Gonna pick up some bolts tomorrow, go through the diff and put it all back together.

More to come....

 

That's a great DIY.

 

Pretty neat.

Here's a question though. Is it the differential that shreads to **** or does the entire rear assembly tend to break? I'm kinda coming from an LS1 10bolt rear where everything is one assembly though so I'm not really sure if this tends to apply.

 

Sorry I didn't really explain the weak point in my post.

Basically, the stock caps are cast (which obviously isn't the strongest material) and they tend to crack where the hole is for the adj. ring tab bolt (small bolt on top). Once they crack there, ring and pinion tolerances are thrown outta whack and you can imagine where it goes from there.

Being that the adjustment ring (circled in red) is threaded, you can't just make a new cap.

 

good job. Find a solution to a problem instead of paying someone to do it...

Thumbs way up to you and your bro. I hate people that think everything is impossible to make and u have to pay a lot to get anything...

 

In for when it breaks..

Replace it with the R200 from the 240's and never worry about it again?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MidShipCivic &raquo;</TD></TR><TR><TD CLASS="quote">In for when it breaks..

Replace it with the R200 from the 240's and never worry about it again?</TD></TR></TABLE>

Hmmmm always with the negativity. This is the kind of stuff I really like to see in here.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by -RedneckDave- &raquo;</TD></TR><TR><TD CLASS="quote">

Hmmmm always with the negativity. This is the kind of stuff I really like to see in here.</TD></TR></TABLE>




Even the reinforced already out there for 350-400 dollars units they produce have been broken on S2000's .

The R200 is tried and true, which is why there are several kits out there for S2k's to use them and with this capability of making parts it'd be wiser indeed.

On top of that the OP appears to own a 3 liter S13 he should know.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MidShipCivic &raquo;</TD></TR><TR><TD CLASS="quote">
Even the reinforced already out there for 350-400 dollars units they produce have been broken on S2000's .
The R200 is tried and true, which is why there are several kits out there for S2k's to use them and with this capability of making parts it'd be wiser indeed.
On top of that the OP appears to own a 3 liter S13 he should know.
</TD></TR></TABLE>

I am not saying that I like the negativity just so there is no confusion. Why switch the diff if he can produce this for cheap, and try something new especially since he has a 4.77 that he obviously wants to hang on to.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by -RedneckDave- &raquo;</TD></TR><TR><TD CLASS="quote">

I am not saying that I like the negativity just so there is no confusion. Why switch the diff if he can produce this for cheap, and try something new especially since he has a 4.77 that he obviously wants to hang on to.</TD></TR></TABLE>

Whats new exactly though the idea?

Look close.

http://www.scienceofspeed.com/...ntial/

The way I think about it is it can still happen again I say the bore center line protrudes too far from the case's webbing there is some serious twisting action going on there.

Look at the R200 for comparision purposes.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MidShipCivic &raquo;</TD></TR><TR><TD CLASS="quote">

Whats new exactly though the idea?

Look close.

http://www.scienceofspeed.com/...ntial/
</TD></TR></TABLE>
Since you said look close then I am sure you noticed that the piece you linked is nothing like what he made. It is not as well machined nor is it as beefy. The "new" is not in the idea but in the development. It is his part thus it is "new." You should know that nothing in performance parts is truly new. Pretty much everything has been done before and is constantly improved.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
The way I think about it is it can still happen again I say the bore center line protrudes too far from the case's webbing there is some serious twisting action going on there.

Look at the R200 for comparision purposes.

http://www.atlanticz.ca/zclub/...1.jpg
</TD></TR></TABLE>

Sure what he is trying to stop could happen again, but why not try something to lessen the likelyhood of it happening again. Furthermore, with his aftermarket gears I am sure he does not want to switch to the R200 and not be able to use that anymore.
I don't see why you have an issue with this. I mean if someone made their own engine mounts, even though there are mounts available, would you say that they should have just bought some?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by -RedneckDave- &raquo;</TD></TR><TR><TD CLASS="quote">
Since you said look close then I am sure you noticed that the piece you linked is nothing like what he made. It is not as well machined nor is it as beefy. </TD></TR></TABLE>

It's basically a copy of that part. Hell you mean nothing like it?

Have you had both hand in hand to say not as well machined?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
The "new" is not in the idea but in the development. It is his part thus it is "new." You should know that nothing in performance parts is truly new. Pretty much everything has been done before and is constantly improved.
</TD></TR></TABLE>

Wha what?


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
Sure what he is trying to stop could happen again, but why not try something to lessen the likelyhood of it happening again. Furthermore, with his aftermarket gears I am sure he does not want to switch to the R200 and not be able to use that anymore.</TD></TR></TABLE>

Well for one you do some research someone could have walked the path for you...

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CKkit &raquo;</TD></TR><TR><TD CLASS="quote">
As an aside, I'm back to OEM (coming from a broken 4.57 pinion gear in a Comptech housing). I now know the "abuse" limit of that "upgraded" combination (17k miles in my hands). I'm thinking of driving the p!$$ out of the OEM diff and seeing if there's any difference in longevity between the two setups.</TD></TR></TABLE>


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
I don't see why you have an issue with this. I mean if someone made their own engine mounts, even though there are mounts available, would you say that they should have just bought some?</TD></TR></TABLE>

There is a reason why they were swapped out it's inadequate and not a good design for resisting the twisting forces of high torque. Adding a brace to the cap does little because of the specific forces it goes through . Seeing the OP capability and resources there is a good reason for mentioning other options.

 

i saw the same fix done by someone else on s2ki a while ago.

 

Thats awsome, I acutally currently work at Makino Mason as an application engineer. All the horizontal machines now are four axis and you can purchase a fifth axis.

 

Thanks for the CC, good and bad


This car is only going to see around 350-400whp and not launced on sticky tires. There are plenty of people that have went with a setup like this, which sells for $500-$1200, and have had very good luck with it. I just wanted to come up with something on my own (well with the help of my bro) and be able to help out a couple friends with a cheaper alternative when the time comes.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MidShipCivic &raquo;</TD></TR><TR><TD CLASS="quote">
The R200 is tried and true, which is why there are several kits out there </TD></TR></TABLE>

Several? Any that cost less than $2000??


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MidShipCivic &raquo;</TD></TR><TR><TD CLASS="quote">On top of that the OP appears to own a 3 liter S13 he should know.</TD></TR></TABLE>

Used to own, had a VG30dett that I swapped in among other things...

 

I don't understand why this is supposed to fix that particular failure mode. You've still got the same piece of cast material, under the same loads, with the same hole in it at the same geometry.
If it's cracking, it's likely a fracture toughness issue, and adding another part above that bearing cap isn't going to change the loads that the bottom piece sees, so it's still probably going to crack.
Is there something I'm missing?

Edit: forgot to say that I do think the fab work is excellent. It's a really good looking part.


Modified by maskednegator at 4:48 PM 9/30/2008

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MidShipCivic &raquo;</TD></TR><TR><TD CLASS="quote">

It's basically a copy of that part. Hell you mean nothing like it?

Have you had both hand in hand to say not as well machined?

There is a reason why they were swapped out it's inadequate and not a good design for resisting the twisting forces of high torque. Adding a brace to the cap does little because of the specific forces it goes through . Seeing the OP capability and resources there is a good reason for mentioning other options. </TD></TR></TABLE>

Yes I have held that Comptech piece and it is nice, but from looking at his piece I can say the tolerances for his are much higher along with being thicker. When I was refering to machine quality I was refering to how tight his piece fits as opposed to the CT piece.

Adding the Brace obviously works at Hp/Tq levels higher, but not ridiculous, than stock so I don't see why there would be no reason to try this being that he is going for that level of hp/Tq. Since the specific forces exerted on the cap are the ones that need to be addressed, it would seem that a new hardened version of the stock cap would be optimal, but with it being threaded it makes it more difficult.

Honestly MidShip, I am over discussing this. I say Lovely fab and well done to the OP.

 

I like how you machined the original cap for a better fit to your reinforcement.
Good luck. I'm guessing this is part of why autocrossers who run sticky tires and lift rear wheels pop differentials. If you could it might be worthwhile to stress relieve that little portion of the stock cap that didn't get machined smooth.

It's interesting that the haters are typically armchair quarterbacks who don't post their own work for feedback. It's the same in business, then the same people complain when they see those guys that tried something getting ahead.

 

Thanks Dave and Niles for explaining!

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Niles &raquo;</TD></TR><TR><TD CLASS="quote">If you could it might be worthwhile to stress relieve that little portion of the stock cap that didn't get machined smooth.</TD></TR></TABLE>

I was kinda thinking about that but I was assured it wouldn't make much of a difference and that he only wanted to go so far cutting on the stock cap.

So far looks like this is going to clear the rear cover just fine except I might have to mod a little spot on the baffle where the button head screw is on top. But measurements aren't finalized yet...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 29psiHybrid &raquo;</TD></TR><TR><TD CLASS="quote">

Several? Any that cost less than $2000??

</TD></TR></TABLE>

I didn't tell you to get a kit you could just adapt it on your own with the man hours into that cap.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by maskednegator &raquo;</TD></TR><TR><TD CLASS="quote">I don't understand why this is supposed to fix that particular failure mode. You've still got the same piece of cast material, under the same loads, with the same hole in it at the same geometry.
If it's cracking, it's likely a fracture toughness issue, and adding another part above that bearing cap isn't going to change the loads that the bottom piece sees, so it's still probably going to crack.
Is there something I'm missing?

Edit: forgot to say that I do think the fab work is excellent. It's a really good looking part.


Modified by maskednegator at 4:48 PM 9/30/2008</TD></TR></TABLE>


OMG somebody else actually pointing it out thought I'd be the only one here...

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Niles &raquo;</TD></TR><TR><TD CLASS="quote">
It's interesting that the haters are typically armchair quarterbacks who don't post their own work for feedback. It's the same in business, then the same people complain when they see those guys that tried something getting ahead.</TD></TR></TABLE>

Yeah his brothers machining is great.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by -RedneckDave- &raquo;</TD></TR><TR><TD CLASS="quote">


Adding the Brace obviously works at Hp/Tq levels higher, but not ridiculous, than stock so I don't see why there would be no reason to try this being that he is going for that level of hp/Tq. Since the specific forces exerted on the cap are the ones that need to be addressed, it would seem that a new hardened version of the stock cap would be optimal, but with it being threaded it makes it more difficult.

</TD></TR></TABLE>

Obviously works? It was put to abuse already?

 

ford 9"

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MidShipCivic &raquo;</TD></TR><TR><TD CLASS="quote">

I didn't tell you to get a kit you could just adapt it on your own with the man hours into that cap.

</TD></TR></TABLE>


So you think I should make mounts, axles and a driveshaft vs. work on something I can fit in the palm of my hand?

And you said there are several kits out there.... I know only of one. Would like to check out the others if you have a link though!

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by xci_ed6 &raquo;</TD></TR><TR><TD CLASS="quote">http://www.metropartsmarket.co...2.jpg

ford 9"</TD></TR></TABLE>


I wish!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 29psiHybrid &raquo;</TD></TR><TR><TD CLASS="quote">


So you think I should make mounts, axles and a driveshaft vs. work on something I can fit in the palm of my hand? </TD></TR></TABLE>

Where does the size of your part in relation to your hand hold any weight in what you're trying to accomplish?

''make axles and a driveshaft'' ? Cmon now... anyone can have inners and outers altered for CV axles and different ends on driveshafts.


Let's see a few parts involve for that mounting.



and








ooh oh man looks so much more complicated then your complexed contoured part huh?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
And you said there are several kits out there.... I know only of one. Would like to check out the others if you have a link though. </TD></TR></TABLE>

I believe there were 2 different ''kits'' however that's beyond the scope of this section ..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MidShipCivic &raquo;</TD></TR><TR><TD CLASS="quote">Obviously works? It was put to abuse already?</TD></TR></TABLE>

Yes obviously works, because end cap braces that are already produced work and his should function in the same mannner. You missed the whole point of that post, because all you saw is what you wanted. Also the difference in machining that small piece versus a whole mount kit and buying the new diff is substantial. That is why.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by -RedneckDave- &raquo;</TD></TR><TR><TD CLASS="quote">
all you saw is what you wanted. Also the difference in machining that small piece versus a whole mount kit and buying the new diff is substantial. That is why. </TD></TR></TABLE>

Thank you!