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PostPosted: February 21, 2019, 5:33 pm 
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This is a Chevy Colorado CVD that I'd like to use on my BEC, it has all the right splines but needs to be 8+ inches longer.

I had a heck of a time getting the axle out of the outer CVD. I finally made a jack screw press and got it apart, but...

I damaged the splines and "extrude sheared" the clip into 3 pieces, I assume that's not how it's supposed to work.


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PostPosted: February 21, 2019, 9:55 pm 
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Been there, done that, bent the tool I bought. :shock:

From what I can tell, some aftermarket replacements don't have the proper release chamfer cut on the circlip grooves in the CV/tripod joint spiders. You can pop the spider on once, then it locks, and won't ever release. Or the circlip wire is the wrong cross section or OD, and it catches. Or any other number of things that aftermarket "Why repair? Replace!" brands wouldn't be checking for.


I was trying with surtrak(?) brand assemblies, and ended up doing much the same as you did, but with a purpose made CV popper tool from eBay. Bent it unusable. :evil: Ended up cutting the CV cup off, then grinding the inner spider off the shaft.

I eventually decided to abandon sunk cost, focus on other parts of the build, and use the welded shaft method for mockup when that time comes.


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PostPosted: February 22, 2019, 7:11 pm 
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viewtopic.php?f=5&t=10806&p=104440&hilit=board+cv+round#p104440
Some damage around the very tip still occurs and is not the end of the world. Either they come right off or they take a LOT of effort.

Instead of welding, try this to prototype (June 24, 2007 post):
viewtopic.php?f=5&t=2239&hilit=cv+axle+angle+iron

I also have a special tool for separation that works well enough. I'd post a pic but I guess it doesn't really matter now.

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PostPosted: February 23, 2019, 2:30 am 
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I'll have to get a quote on axles, not sure I want to trust my welding on that. Also don't some longer axles need a rubber thing in the middle to damp vibration at high speed? Not sure I want to try to engineer that.

The axle that came out is about 12.18" long and I figure I need about 20.12"

I think I get what you're explaining for you're axle removal technique. You are using a pipe that fits over the axle and is longer than the distance from the center star to the end of the axle. Then when you "bring it down in a stabbing like motion" (Pulp Fiction reference I assume ;)) onto a solid board, the pipe stops and the axles mass pulls itself out of the CVD star.

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PostPosted: February 23, 2019, 7:44 am 
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I expect you will need to mail the axle end(s) along with an instruction sheet to get an accurate quote.
I suggest omitting the grooves for boot retention and necking down from the spline od. Ideally you want gradual necking down to less than the spline root od. The axle twists so welding is bad, increases in shaft od is bad, sudden changes in od(steps) are bad, etc. I’ve found replacement shafts are usually thicker than oem and don’t have a damper for lower cost. I have not noticed any difference from oem in use.

I recall they have their own alloy. I think Colorado front axle dims will be overkill for this build so I would not opt for 4340 thru and induction hardened or 300m. Because the splines will also be overkill, I also would not opt to gradual step machine the od down below the spline root od but I would not cut any boot grooves.

Another option is to weld metric stub flanges (common to vw/Porsche/audi) to the inner and outer cv cups for universal, common, off the shelf axle assemblies (in various lengths) and components with easy replacement and tear down later on. Look at vw buggy axles and flanges.


That is the idea but it doesn’t always work. Here is the tool I have:
https://www.ebay.com/i/163041151726?chn=ps

A more expensive solution (Rockwell inner race driver):
http://motormasterpowersports.com/produ ... 100-12ATV/

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PostPosted: February 23, 2019, 10:01 am 
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Johnsinski wrote:
I'll have to get a quote on axles, not sure I want to trust my welding on that. Also don't some longer axles need a rubber thing in the middle to damp vibration at high speed? Not sure I want to try to engineer that.

The axle that came out is about 12.18" long and I figure I need about 20.12"

I think I get what you're explaining for you're axle removal technique. You are using a pipe that fits over the axle and is longer than the distance from the center star to the end of the axle. Then when you "bring it down in a stabbing like motion" (Pulp Fiction reference I assume ;)) onto a solid board, the pipe stops and the axles mass pulls itself out of the CVD star.


Those must be the shortest axles around if you need to add 8 inches. I had to cut 2 inches from mine.

From what I see of your welding, you would certainly be capable of welding axles, especially for a BEC car. Typically there is very low torque, comparatively. Low torque - less stress. Success is dependent on with the design of the splice and the peak power you are trying to put to the ground.

Not sure that I'd recommend this technique on 2 splices per axle, but I offer it. I ran them over 6K miles on my RX7 powered Locost, another low torque engine. JD did similar splices on his big ole 'muricin V8 Mallock tribute car with sticky slicks and is still running his V2.0 axles on it today.

viewtopic.php?f=35&t=4145&start=37

I remember replacing the outer CV joint on a '81 Mazda GLC. The same problem with the clip. I ended up not damaging the retaining splines on the axle but did cut nice square notches in the retaining clip.

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PostPosted: February 23, 2019, 12:43 pm 
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Yeah, stock they are probably build to hold 2000ft-lbs+, so I suppose even a mediocre extension/welding job would hold. The BEC book makes it sound trivial, but I don't know, I do plan on going over 100 MPH with it. I can see it now, "what's that vibrati.....boom.....skids and screams....flying dirt....hello tree"

We'll see, still a long way out to a roller, much less a runner.

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PostPosted: February 23, 2019, 1:51 pm 
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I don't have BEC book that you reference. DO they recommend splicing?

FWIW, I measured <0.032" TIR on my axles. I figured that was good enough for being <1/2" away from the center of rotation that it would not cause any out of balance vibration. Wheels are acceptable to be at least that or more for lateral and circumferential runout at 7-8" away from the center. As for any weight imbalance added from the welding process, again being that close to the center of rotation, it would not present an issue IMO. Assuming 140MPH and a 24" tire, your axles will only be spinning at slightly lass than 2,000 RPM (not very fast) assuming you have the HP to reach that speed.

YMMV.

I'm not saying that you should use this method. I'm just saying that I did it and it worked for me. And it is working for JD. Having 2 splices per axle is new ground. You have to decide if it is a solution that will work for you. Whatever you choose, you could do this for prototyping and then send the working length axles out to be used as models for new axles to be made. That was my original intention, but it worked out so well for me that I never had 1pc axles made.

Keep up the good work and your posts. :cheers:

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PostPosted: February 23, 2019, 2:53 pm 
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That's the same tool I snagged.

The pins and bolts in the clamp block started bending/shearing. I did have 700+ lb/ft of impact gun on there though... No budge. :shock:


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PostPosted: February 23, 2019, 5:30 pm 
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I'm just saying that I did it and it worked for me. And it is working for JD.
Yep, the axle that got spliced/welded up according to Chuck's methodology is one thing on the Dog A$$ Slotus that I haven't broken. It's got a 331 Stroker Ford V8 on one end of the drivetrain and a 14" wide racing slick on the other with that axle in between. Solid as a rock... :mrgreen:

Good luck with that and the rest of the build-
JDK

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PostPosted: February 23, 2019, 7:36 pm 
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Totally agree that an axle can be made that doesn't twist. It is at the expense of the splines but it will work! As long as the splines last for the use of the car or the length of the race, it doesn't matter. Just means they were stronger/heavier than they needed to be.

I noticed your build is not in the build section of the forum. An admin can move that for you.

You can get the extra length you need without new axles or welding axle shafts by using another pair of inner cv stubs on the diff, trimming the cup length as need, then either welding directly to the inner cv on the shaft or fitting flange plates. The welds would be in the thickest part of the cv with the greatest leverage and weld area. A step should be turned for support and centering if you use flanges, either by boring the flange in a lathe after welding the stub to accept the cv shank (and subsequent trimming of the splined end with a friction disc) or turning the outside corner to inside the stub outside corner before welding. With flanges, you can replace the axles later on by fitting a new flange and cutting off the splines for clearance in the cup.


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PostPosted: February 24, 2019, 5:17 pm 
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rx7, yeah, the BEC book recommends cutting the axle and welding in a new tube/pipe to extend it. I guess if you have a good fit to the axle and inside of the pipe it might end up pretty true. I think I measured the middle of the axle at 1.100", kind of a weird dimension. The extension tube would be at least 10" long, not sure I can fit that in my mini lathe to bore the ends properly.

miata, the pics look like you are sort of making a super long cup, right? Not sure I like that but I kind of like the idea of welding on metric flanges to my stub axles though. The closest thing I could find for stub axles when I was looking were some ridiculously expensive axles for a late model GTO that would probably fit the chevy 27 spline.

I PM'ed dhempy about moving my build thread, if anyone reading this can move it, go ahead, thanks.

After looking at the inside of the CVD star, it looks like there is no chamfer to work that wire clip out, just a straight cut groove. And obviously the axle had a straight wall groove as well.

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PostPosted: April 13, 2019, 3:14 am 
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Second CV dissassembly did not go well. I'm thinking the sure fire way to dissassembly it with minimum damage is to grind up the ball carrier/cage to be able to get the balls out, then replace that cage with a new one.

I may try another one or I am considering VW/930 type CVs. Anybody got a recommendation for size to be adequate for strength?

Found this nice info on them:
http://www.blindchickenracing.com/How_t ... ts_101.htm

I would have to fab stub axles to fit my spines.

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