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jthom5147

Companion flange 27 spline idea

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I want to start off by saying:

1) I'm not an engineer

2) Im not a mechanic by trade

3) if this idea is absurd, which it most likely is, then great.... but I'm trying to start the discussion to understand then WHY it's absurd.

 

I had been working on my axle setup for a while, not being able to stomach the $ for quality companion flanges, so I did some google searching and found a commercially available 27 spline pinion flange(available from multiple manufacturers and sources). I bought one because research and the spline shape and diameter match the 280z stub axles that I have lying around.

 

It's not a direct fit with the OE 4-bolt u-joint companion flange though. The OD where the grease seal is a few mm smaller than the OE unit. Don't have exact measurements in front of me. If i am looking at the z rear bearing assembly correctly, the companion flange isn't a bearing surface, so the reduced diameter wouldn't change anything mechanically? Just require different seals.

 

And the throat for the splines is longer. This could be overcome through modifications?

 

At $40-60ish each, I can muck up 10 before I've gone through a pair of good quality ones.

 

Here is one example

http://www.coreswest.com/blank-toyota-flange-fits-27-spline-pinion-and-transfer-case-trail-gear/

 

So, in short, using a pinion flange as a axle companion flange.Thoughts?

Edited by jthom5147

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I want to start off by saying:

1) I'm not an engineer

2) Im not a mechanic by trade

3) if this idea is absurd, which it most likely is, then great.... but I'm trying to start the discussion to understand then WHY it's absurd.

 

I had been working on my axle setup for a while, not being able to stomach the $ for quality companion flanges, so I did some google searching and found a commercially available 27 spline pinion flange(available from multiple manufacturers and sources). I bought one because research and the spline shape and diameter match the 280z stub axles that I have lying around.

 

It's not a direct fit with the OE 4-bolt u-joint companion flange though. The OD where the grease seal is a few mm smaller than the OE unit. Don't have exact measurements in front of me. If i am looking at the z rear bearing assembly correctly, the companion flange isn't a bearing surface, so the reduced diameter wouldn't change anything mechanically? Just require different seals.

 

And the throat for the splines is longer. This could be overcome through modifications?

 

At $40-60ish each, I can muck up 10 before I've gone through a pair of good quality ones.

 

Here is one example

http://www.coreswest.com/blank-toyota-flange-fits-27-spline-pinion-and-transfer-case-trail-gear/

 

So, in short, using a pinion flange as a axle companion flange.Thoughts?

 

Aside from concerns over actually finding a proper seal, and machining the part for proper fitment, etc., my main concern would be that the pinion generally sees less torque than the halfshafts do, by a factor of whatever your differential's gear ratio is (x3 - x4).  So, it may not be designed for the torque loading that it will likely see in service as a companion flange.  Is there any way to find out a general idea of it's maximum design torque?  Not flywheel torque, but the actual torque at the Flange?

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I had a hunch that the differential gearing would mess things up. Seems logical though that the input and output of the differential gear would see completely different forces.

 

I'll call a couple manufacturers and ask about design requirements, alloy/construction, and tempering.

 

Only way I can think of to test it would be to set it up and then break it in as controlled a manner as possible... adding incremental weights to a lever arm to apply increasing torque until failure? Drop weights onto a level arm to simulate shock, increase till failure?

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But a differential also splits the power to two sides, where as the front pinion will be seeing all of the torque coming from the transmission.

 

I would love for someone to try this out and see how much modification is required to make them work.

For an open diff this is true, so in this case 1.5x - 2x the torque at the pinion.  For a limited slip I would assume it could send everything to one side for design purposes...

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That's a good find.  Seems worth a look.  The axle, at a stress riser, is where failure usually occurs at the hub.  Their ad copy says "forged 5140"  which seems to have some high stress uses, according to the internet.  Cranks, for example.  Not clear if they are cutting blanks from forged steel or forging the shape and machining though.  Proper grammar would say "blanks forged from 5140...).  Anyway.

 

"Our Blank Output Flange is made from forged 5140 chromoly steel. "

 

Number and diameter of splines and shaft won't tell you if it's a good fit for the axle though.  You won't know until you try it.  Spline shapes differ.  You'll need to do some machining also, either a new distance spacer, or the flange, to fit the hub.

 

Still interesting though.  I'd spend $30-40 just to mess around with it.

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This is the one I bought:

http://www.4wheelparts.com/Drivetrain-Differential/Toyota-FJ-27-Spline-Pinion-Flange-Yoke.aspx?t_c=12&t_s=515&t_pt=7940&t_pn=G%2F290-2058M

 

Been sitting in my shop for more than a year untouched.

 

I'll get my calipers out and take measurements.

 

Timken offers a grease seal that looks like a replacement for the OE grease seal, but with a narrower inner race diameter.

 

I gave my set of 280z stub axles to my dad, so RE-measuring the necessary "throat" removal for spline engagement and the stub axle nut threads won't be as simple, but If I remember right it was to cut off about 1/2 inch. I don't have machining equipment, so I was goofing with a grinder and a mock-lathe.

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It's the shape of the teeth and the grooves that will get you.  I picked up a J30 diff because it has a 28 spline axle (just to mess around with, I know that the VLSD has la longer axle) and found that the stock Z axles were sloppy in the J30 and the stock J30 axles were very tight in their original home.  Can't remember if I tried the J30 axle in the Z R200 or not.  That's why I  bring it up though,.  It's more than number and diameter.

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Well I ordered a blank flange yesterday. I am in the process of putting on some ground control coil overs, so I can pull my stub axles and take some measurements. I am a machinist, so I should be able to modify the flange as long as the spline portions mate pretty well.

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I did stick an axle through it. Snug fit. That's where the grease on the tip of the flange in the photos came from.

If you decide to try the machining to make it work, you might look in to another heat treatment to get the desired physical properties, if you can't determine what you have now.  Although I think heat treatment can change your dimensions.

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Here's the update. I received my blank flange today and got to measuring it. Before I did that though I test fitted it on my stub axle and I am happy to say its a direct fit in terms of spline count and diameter! There are a few things that will need to be modified to make the flange work though. As jthom said the splined portion is too long, long so it will need to be shortened about 10.4mm. The outside diameter is also 4mm smaller, so either a new oil seal will be needed or a 2mm thick sleeve will need to be put on the new flange. I drew up both flanges since I had them, and I will attach the 3D files for them. There are fairly quick measurements done with a cheap caliper, so please dont rush off to a machinist with the model and complain when they made something that doesn't fit. The splines are pretty accurate, but please treat them as just a visual representation as well.

 

If anyone is interested in looking at the models and doesn't have any program to open them with, I would suggest downloading Fusion 360 from Autodesk. It's what I modeled them in and its free to pretty much anyone unless you're a company that makes $100k+ a year.  

 

 

EDIT: I am unable to attach the .STEP files. Does anyone know how to attach them?

 

post-3840-0-85459800-1481135349_thumb.jpg

post-3840-0-42822000-1481135362_thumb.jpg

Edited by ArizonaZ

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I was doing some measuring on your parts. Correct me if I'm wrong here.

 

So to make this work, we need to remove 10mm of the blank material on the Toyota flange, then attach a sleeve that goes around the splined portion 2mm thick.

 

I draw up a sleeve that would just slide over Toyota part and hard stop against the back of the upper lip of the cone portion of the flange.

post-12254-0-66095600-1481148293_thumb.jpg

post-12254-0-42094500-1481148287_thumb.jpg

 

Any reason why this wouldn't work?

 

Not sure where to weld it to the flange...someone with more fabrication experience than I should probably chime in on that one.

Edited by Neverdone

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Yep, that would work. I was thinking about how to attach that sleeve, and my first thought was to use loctite that is meant for cylindrical parts. I also looked into new oil seals and you can find 72mmx38mmx10mm ones pretty easily for ~$4 as well.

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I'm super excited that you've been able to validate the suspicion on the spline compatibility.

 

Follow-up questions then:

1)Given an idea of the modifications required to make it interchangeable with the OE unit, would anticipated machining costs make this option cost-neutral or cost-prohibitive to other options that have been available to the community for years such as Chequered Flag Joe / Modern Motorsport?

 

2)Would the reduction in material around the splines (both from design and further rework) weaken the component to the point of inferiority to the OE unit?

 

3)Is the flange large enough to be practical for use with common CV options? 930, z31t, etc.

 

I'm sure these are all questions to be figured out as the research continues.

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1) 2 of these flanges will cost around 60 dollars. The ones Chequered Flag offers cost 440 dollars. If you can get the machining (cutting 10mm off the collar, making a sleve/ordering a larger oil seal, and drilling new holes in a concentric pattern to the axis) done for under 380 dollars, then yes.

 

2) It will be weaker. There's less material. Without running destructive testing or at least running finite element analysis on both, we won't know. 

 

3) The outer diameter of the flange is 111mm. I think the hole pattern of a 930 CV goes along a 94mm circle.

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I plan on using these flanges with 930 joints, but I think a small spacer will need to go between the joint and the flange accommodate the plunging of the axle. I'm thinking a 5/8" spacer should be plenty. The outer diameter of a 930 joint is 108mm, so there is plenty of room for them.

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