Made some good progress this weekend on exhaust and misc. other things. Then took my wife for a quick ride. Chirped the tires going from 1st to 2nd, then clunk, clunk, clunk...
2011-03-20Brokenleftaxlehalfshaft2.jpg
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Rob, Man, If that is the way those axles were built, I would take them both off and redo them. The "pin" should be 3/4" tool steel and both sides of the axle chamfered 45* and the gap built up with weld. I prefer one piece axles and am planning on using a VW Vanagon axle cut in half and resplined. Makes two 1 3/8" super strong one piece axles about 11" long and then VW Type 2(Transporter/Vanagon) CV's with Microstub and Dodge Intrepid hub(33 spline 5X4.5 Ford bolt pattern). The axle pictured is 14" for Datsun 510.
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Looks like Todd needs to do some redesign in that area. I'm sure he'll come up with something that will hold up better. No self respecting V8 MGB owner should be restricted to not chirping the tires now and then. ;-) Maybe something like the way Jim Blackwood spliced the axles on the Roadmaster rear end. Those have taken some abuse already in the parking lot at Indy and no problems so far.
Hi Rob,
I went through the same thing with my CV axle. The CV blew out with just spining tire acceration. I had to do it to make sure they would hold up to some power, and not wanting to be stranded somewhere. When this blew out, the car wouldn't move under its own power.
I was lucky that Richard Good stood behind his products, and sent me some new axles that were better made.
Good luck!
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Bill, The stub ends inside a tube welded on each end like the Roadmaster would be an excellent fix.
Anyone know what page of the roadmaster project this was dealt with?
In the interest of time I might have to order new ones but I'd like to fix the ones I have if I can. Seems like where the current welds are, a sleeve would need to extend through the hub side boot so I'd need to find:
- the right size tube for the sleeve -- what material/wall thickness?
- a replacment boot with the same big side & bigger diameter on the shaft side -- where would I go about that?
Once welded, does the 1/2 shaft need to be heat treated or otherwise treated? Anything special in the welding process? I don't think I want to attempt the weld, but there is a great welder nearby who I could probably enlist to do the welding.
Rob, there isn't much detail on the forum in the Roadmaster section. On page 19 Jim described it like this:
" Good enough for the uprights, at least for now, we next turned our attention to the half shafts. First we rough turned the shafts to 1.020" and then set up for finish turning and polishing, cutting both shafts to 11-7/8" x .997", which gave us.0005 to .001" of clearance with the tube.We precisely cut the tubes to length, squared and chamfered the ends, and cut the shafts to exactly fit the length of the tubes. On assembly the fit was dead on, so close in fact that the parts slid together easily but snugly, trapping the air inside and bouncing before being shoved home. They snugged up just right as they seated, but still could be rotated. I don't think we could have gotten a more perfect fit for this application. Once welded the internal shaft will provide full support for the tube to help resist wrinkling under torque, and the slip fit will allow the torque to be absorbed by the full length of the tube rather than a short section between the ends. Given the weight of the car I think they will hold up well. "
I found some thick wall DOM tubing that was close to the required size of the original half shaft and Jim cut the half shaft into, narrowed it and then chucked it in the lathe and turned it down to a very close slip fit in the DOM. He then welded it in place on both ends. So far so good as we chirped the tires repeatedly at Indy. Granted those were old hard as rocks tires that came on the wheels that Flying Circus donated, but they're wide and still have a bit of traction left in them.
Custom axles are looking like about $425 each side -- and early estimate is anywhere from 3 weeks to 90 day turn around.
If I've got the roadmaster approach right it is basically to turn down the sections to be joined; snug fit DOM pipe over that; & welded at each end of the DOM sleeve. That sounds like it's not much different than what I had snap already --- the weld is only as thick as the DOM tube; maybe a little more. I must be misunderstanding something? What will keep that weld from breaking the same way -- or the DOM tube from twisting?
Hey Rob,
Do you have an end shot of the broken pieces.
From the pictures that I've seen the break looks odd.
Jim's method for shortening the 1/2 shafts should work just fine. If it's a concern you can drill and plugweld the DOM tube in several spots to lock it in better.
Another option is a friction or spin weld. Basically the same build up but instead of welding. The shaft is spun inside the DOM tube on a large lathe. The tight fit causes the shaft to sieze inside the tube creating a very strong joint.
CV boots are very pliable and will accomodate the larger shaft size without a problem.
When you have the outer CV joints out, do not put the cars weight on the wheels. The wheel bearings are held together by the CV joints and they will be destroyed if they are not clamped together.
Any way, hang in there.
Stuff like this happens and it gives us good stories to tell down the road.
Cheers
Fred
The difficulty here is the shafts are of two different diameters. The GM shaft has a 1.250" shaft and the Nissan shaft is closer to 1.75". These shafts were made using a method that has worked well in other units be it a lower HP but just as much torqe. The shafts are center drilled, tapped, machined down with a 45deg angle to a minimum of 1/2" the thickness of the shaft. The dowel is a tool steel grade bolt that is threaded about 1" into each end of the shaft. This is a method that was tought to me by an Army machinest that repaierd broken hummer axles this way.for years.
I have moved away from this method. Hawk also has had many failures with this same issue. Rob's build was uniqe in that we needed a 5 bolt hub that would work with the wheels that he purchased. The S-10 Hubs had the right peices parts
. There is a fix that I have to solve Rob's imediate needs. I will machine down a stock shaft to fit into the stock Nissan yolk and weld the yolk to the shaft. The Nissan yolk is rebuildable by replacing the 3 smaller cylindrical bearings that slide in the hub. This allows a treamnedious amount of weld to be put on the yolk and not effect its operation. The shaft will be macined infront of the yolk to allow for maximum penitration into the shaft. It then will be sent for cryo treatment to make sure the shaft will not break or twist at the weld.
Any new IRS units are built with porsche CVs that have adapters for almost every hub and differential configuation imaginable.
Hey Todd,
I knew you'd be in there taking care of things.
It's as heartbreaking for you as it is for Rob.
If I can be of any service PM me and we'll see what we can do.
Cheers
Fred
I dont want to hurt anyones feelings, but the way it was set up was fairly weak and I dont see much penetration of weld into the joint, If you pick up some DOM tubing and turn the stubs to fit inside snugly and trued, staggered rosette welds and a final weld around the joint will get it strong to last long, using the components you have will save alot of coin and get you running again.
Rob, the secret to the DOM success is size. Just like a drive shaft the larger the diameter of the tubing the greater the torque capability is even with a thinner wall. On the Roadmaster the DOM ID was almost as large as the original half shaft diameter. Just small enough to clear the coil over shock. Then the half shaft was turned down it wasn't much to slip fit inside the DOM. Jim Nichols posted a photo on page 10 of the Roadmaster threads that shows a stock Jag half shaft, one that is spliced with small DOM tubing and one that is spliced with a larger diameter DOM tubing, the later is the way Jim B went. According to Jim N the use of the larger tubing made the part 4 times stronger than the smaller tube shaft.
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Ok Jim, Fred, & others with experience with this stuff -- I think I may be in better shape than I thought but not sure it really changes the decision points... For a while I was thinking I had tripod type CV's but now that I've taken them apart, they appear to be regular Rzeppa 6-ball type (see the pic below). When I thought they were tripod style I was concerned I'd be throwing good money after bad if I put money into the the axles (I got some input that the 280Z crowd seems to find that to be the weak link when they do Ford or Chevy V8 swaps & some quick internet research seems to support that).
Assuming the CV's are regular Rzeppa 6-ball, then I should be ok strength wise right? So I'm back to 3 options --
a) Least expensive answer is sleeving & welding them. Note, DOM would only extend about 1" over the existing axle on the hub side. Any more than that & it would limit the CV angles by the yoke (if thats the right term). On the other side it could cover the smaller diameter portion of the 1/2 shaft to the point where it gets bigger. Anyone care to give odds on them breaking again if I go this route? Cost for this is pretty minimal. Todd will fix the broken one but wants me to pay to do the same to the other side since it's not broken -- ~$150.
b) Next most expensive is replacing just the axle shafts. Two downsides on this are 1) turn around is longest -- 4 weeks to 90 days depending on which supplier and 2) I'm not sure I can disassemble/reassemble. Most of it looks pretty easy but there's a retaining clip of some sort holding the CV inner collar to the shaft on the hub side. I don't know how to remove or replace that or if special tools are needed? Or if the collars need to be pressed off/on. If I have to have a CV rebuilding shop do that stuff, the cost of this option & the next start to get pretty close. 1/2 shafts alone are about $550 from The Drive Shaft Shop in NC.
c) Complete replacement axle assemblies. The Drive Shaft Shop in NC offered this solution:
our axles would use a billet plate to bolt to the inner flange (6 bolt)
to convert it over to a porsche 930 CV joint and the outer would be a
Chromoly one we use for the kit car market. i would need dimensions
from the flat of the inner flange to the back of the inner race of thw wheel bearing
(where the CV touches the inner race)
Turn around for this option is 1 week which is good. Of course, cost is the highest @ $750 (& I'd have to verify that it's the same to do a 5 bolt flange instead of 6 bolt).
I'm leaning toward option C since that should be a do it once & be done answer & the turn around is as good or better than the other options. But if option A really has very low odds of breaking again I'd be throwing away a lot of money.
What do ya'll think?
Rob
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I drove ( flogged) the heck out of my B until a rear wheel suddenly had a different vibe to it and wobbled to boot, come to find out the axles(9"ford) were welded and not even in the correct place, I went ahead and got new axles from Mark Wms.
DOM done the right way and well thought out would be plenty strong, I see the problem with the dual 6 ball type, there would be minimal or no slip action causing binding at extreme travel, like putting a solid shaft in a 4x4 with no slip yoke, unless the geometry is dead on its gonna break.
If you have the coin and more things to finalize on the B during the down time, go for opt. C for the piece of mind
Rob is the diameter on the unbroken side the same as the broken stub? If so I would cut it off about the same,clean it up, use 1/4" thick DOM tube full length to replace the fat center part. Tig weld and plug weld twice on both ends. This pic is for a u-joint shaft but you get the idea.
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John is right, you have to have plunge on the CV's at least on one end as the suspension moves up and down. The VW/Porsche type slide on splines on both ends. Can you compress the end with the bell?
Here is a picture of the Driveshaft Shop setup. The adapters look just like mine except mine are for VW Type 2 Transporter/Vanagon. Porsche CV is 108MM/28 spline. VW Type 2 is 100MM/33 spline. Both, If done right should be good to 600HP.
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Hey Rob,
To start with only your outer joint is a Rzeppa joint.
The inner is a plunging disc joint that allows the 1/2 shaft to change length with suspension movement.
So no real worries with what you already have.
They should be easily able to handle your toque ( oops.. Canadian slip) torque needs.
Your present axles modified with some DOM tubing will hold up just fine as well.
Turning the inner axle to the same dimension as the outer stub and joining them per Jim's description will work well.
Be carefull with the VW/Porsche CV joints. They come in two flavours. A true fixed Rzeppa joint and a double offset style.
They aren't intended to slide on the splines.
If however, your pockets are deep enough.
Option C would be prefered and would be the most reliable fix
Not to mention they probably look the coolest.
It's your call.
Cheers
Fred
Thanks guys. The concern I have with the DOM approach is that the shaft is not the same diameter for the full length. Unless I'm thinking about this wrong, the DOM would only go from about the 10 1/4" mark to the about the 11 1/2" mark in the pic I included above -- at least unless the entire length of the longer piece were turned down to make it uniform size? Is that what you're thinking?
No, Rob, You would have matching stubs on both ends and go full length with the DOM tube. Look at the red lines in the drawing. It would replace the entire center of the axle. Believe it or not the hollow tubing is probably stronger than the solid shaft.
My new CV axles only have one moving CV joint on the inner CV joint. My old CV axles had a floating axle that both CV joints moved.
There is an adapter from 5 bolt to 6 bolt at the diff R200 like yours Rob. I don,t know if your diff are 5 or 6 bolt flanges. Richard Good has those adapters from 5 to 6 bolt already made up if that helps.
QuoteThe concern I have with the DOM approach is that the shaft is not the same diameter for the full length. Unless I'm thinking about this wrong, the DOM would only go from about the 10 1/4" mark to the about the 11 1/2" mark in the pic I included above -- at least unless the entire length of the longer piece were turned down to make it uniform size? Is that what you're thinking?
What I was going to suggest last night is to go from the 2 inch mark to the 11 1/2 inch mark having equal stubs as Jim pointed out, snugly fit and rosette welded and then welded around the end of tube to stub.
Tube is stronger torsionally than solid.
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Even if you were to have the stubs turned down to 5/8 od to fit into 5/8" id x 1" od DOM tube it would be strong!
edit, you could go deeper this way and closer to the flange, also bevel the end of the tube and step in the stub for best weld penetration.
Sorry for the crude drawing ;o)
Yep,
As long as it's in the lathe I would make the DOM tube go the full length.
Just like the rest of the guys are saying.
Much stronger and better appearing.
Cheers
Fred
One last question, then it's decision time... is there any value to the existing axles/CV's that I might recoup on ebay or the like? E.g., if new axles are on the order of $775 to upwards of $1k, are there folks out there who'd see these as a bargain - either for parts or to make to the size they need by cutting/turning & using DOM like above? If there's a market for them, any idea what I'd likely be able to get back?
Rob, I can;'t see that they would have any value to anyone else as they are built for your particuilar applicatiion and IRS. I don't know what Todd has to say, but if it were my car I'd use the existing axles and some DOM and try it, really don't have much to lose for now and the cost would be small even if they didn't hold up. You'd have plenty of time to try them out before taking off for Townsend. I'd use some DOM that was just small enough OD to clear the shocks and other suspension bits with an ID just smaller than the OD of the smaller of the two stub axles you're working with. If you need a source for a small length of DOM at a reasonable price let me know, we have a good store here in KC that sells stock by the inch. That's where we got the stock for the Roadmaster rear axles. I can get it and ship it to you. Check out their website to get an idea of the sizes available and the cost. http://www.metalbythefoot.com/ Same goes for anyone else that can't find stock locally as long as the quantity is small enough to ship by UPS or parcel post.
Yeah, I checked ebay & nothing but parts for OEM cars - nothing that looks like they're catering to the hot rod crowd.
Looks like I'm going to have to remove the passenger side & measure before I finalize dimensions because I'm confused. I put the car back on the ground & measured from the diff flange (where the axle bolts up) out to the bearing where the outer CV meets -- it's 17". I then put the axle back together & measured it from the same places & it's only 16" -- even with the inboard plunge part fully extended to the very end of the plung housing. I measured twice & got the same result. It's almost like there was a 1" piece welded in the middle that broke loose & got lost when the axle broke -- honestly, I can't imagine that could be the case but I haven't been able to think of another explanation. Before I can close on either machining or the drive shaft shop I need to sort out what the right measurement is.
Rob the weight of the car compresses or plunges the axle slightly. Maybe the axle was slightly too long and bottomed out is why it broke. You would think at normal road height it wouldn't be compressed very much. Tape it up and have somebody push down on the fender and see if it bottoms. A lot of times the axles are different lengths to center the pinion. If the control arms are the same length both sides, the axles are probably the same. Also on my R230 the output flanges are different length from the diff.
Actually what I'm seeing is just the opposite Jim. The [broken] axle is measuring 16" from diff flange to hub bearing mating surface -- that's with the axle plunged "out" to where the CV balls would be at the very outboard edge of the collar -- any more out & the axle would fall out of the collar. That's why I was saying it's like a piece is missing.
I get it after rereading. Long day at work. The wheel is just moved out with the axle out. Jack up that side and I bet you can push the wheel in and bolt up the taped axle. Put the car back down on the ground. Then try pushing the fender down and see if it bottoms. Then you can measure both axles and see if they are the same.
Quote,,,,,,,, The wheel is just moved out with the axle out. Jack up that side and I bet you can push the wheel in and bolt up the taped axle. Put the car back down on the ground. Then try pushing the fender down and see if it bottoms. Then you can measure both axles and see if they are the same.
Take a measurement with the car jacked up then with the suspension compressed and make sure the travel is correct with the travel in the cv joints.
If need be wind the spanners on the coilovers back to get a few extra compressed inches of travel for any unforseen circumcisions.
Rob, I was just reading through the Roadmaster build posts and found where I posted the size of the DOM tubing we used. It was 1.5" OD with a .250" wall thickness.
If your axle did indeed reach the end of the travel in the CV joints that would explain some extra stress placed on the welded area. Add the torque plus some linerar stress could easily result in a stress failure.
In the Jag rear the half shaft acts also as the upper control arm so it has to be able to handle both rotational and linerar forces. So far there are a lot of Cobra kit cars and hot rods running around with axles narrowed using DOM that seem to be doing quite well.
Todd, hope you know we're not trying to out engineer you, just offering ideas to both you and Rob on how to fix his problem and get him on the road towards Townsend without worry.
These links are very informational on axle length: http://www.rorty-design.com/content/axles.htm#Determining%20Custom%20Axle%20Lengths http://www.swayaway.net/joomla/images/InstallInstructions/AxleLengthMeasurementInstructions.pdf
Good info -- I'd read portions of it before... what's the deal with unwinding? The pic @ that link sort of looks like the break in mine. Do I need to worry about being sure the axles are spinning the right way if they're being cut, turned & DOM sleeved? If so is there any way to determine if they're on the right or wrong side already?
Rob,
I have never heard of "un winding".
Possibly this is an old wives tale resulting from the twist that some forged axles seem to have.
This twist appearance is caused when the axle is run through a rolling forge to strengthen it.
If this was an issue you would think that the axles would have a direction printed on them.
I've been wrong before but all the witnesses have disappeared.
Cheers
Fred
Basically the axle has to be shortest when level(straight across) and longest at full droop without bottoming either way to determine length. I wonder if you were a little short and when you adjusted your coilovers for ride height extended the distance even more.
Rob, I don't know about the unwinding thing, but it shouldn't be difficlut to just do one axle at a time and keep track of what side they each came from and reinstall them on the same side. Most of the problems associated with changing axles from side to side relates to the splined area where the axle fits into the side gear in the differential. I suppose that could also be the same for splines on CV joints as well, so just keep them seperate side for side.
ordered new axles from "The Drive Shaft Shop" in NC. By the time I added up cost of machining, DOM, welding, etc. I was at about 1/2 or more compared to DSS price for complete new axles
And probably some peace of mind.
There is an element of peace of mind, but I really wanted to do the DOM route. What really put me over the edge was the combination of two things:
1. since I can't turn & weld them myself, I'm dependant on shops. Local shops were quoting about 3 to 3.5 hrs per axle for machining & welding time; that plus the DOM puts the price not all that much less than the DSS answer.
2. turn around time -- DSS is 1 week. The two shops I'm comfortable with here were talking approx 3 weeks which puts me very close to Townsend -- not much time left to shake out the car before the meet.
Rob
Rob, Sounds like you are almost there. This article on CV's talk a little about using used axles and "unwinding". Made me rethink about using one axle and cutting it in half. I will get 2 Vanagon axles and mark them L and R the way they came off. If you think about it, it makes sense.The axles always twist the same way,so when you reverse them they want to twist the opposite. Your break does look like that,plus your 1" short axle might have even stressed it more. The modifications for travel angle are for buggys. Most car u joints only have 7-8 max angle where the VW Type 2 has 17. He likes the BMW CV's. Same as type 2 but allow 21 degree angle(not neccessary for street). GT40 and Cobra kit cars use the Porsche 930 like the ones you are getting,should be heavy duty. http://www.rorty-design.com/content/CV_joints.htm
Rob,
Releived to hear you went with the DSS solution. Im sure your wallet isnt but in this case DSS will serve you well. I have had several sets of axles and drive shafts made up by them and trully am impressed with the quality. The other peice of this is down the road if you ever have a CV failure the parts are MUCH easier to get and install.
If there is anything else you need in this please let me know!
Guess what came on the UPS truck today...
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Hey Looky there, Someone must have been home to sign the DIAD I'll bet you're ecstatic!!!!!
Nice!
Get those bad boy's installed now :-)
Jim or anyone who's messed with the R200S differential -- should there be any end play on the diff stub axles? On mine the driver side is solid -- if i tug on the flange there's no movement. On the passenger side there's 3/32 to 1/8" of end play. I did a little google surfing & found some folks saying that's normal & some saying not normal??
Rob, Take a rubber hammer and tap on it a little. It's held in with a snap ring. If that is the side that broke, it might have pulled out a bit. I can't wiggle either on my R230.
it isn't the side that the axle broke on. Driver side axle broke: this is on the passenger side. Is the snap ring something you can get at by taking the rear cover off or would I have to disassemble the whole thing?
Rob, You don't need to take the cover off or disassemble. The output stub shafts just pop in. It is a simple round wire snap ring in a groove. I've pried the output stub shafts out with two pry bars and used a slide hammer puller also. Just use a rubber hammer or hammer a block of wood to put it back in. I would just try tapping it in first. Keep us posted.