ezzzzzzz Posted November 15, 2007 Share Posted November 15, 2007 To date, no one offers a new set of S30 rear stub axles. I am speaking with a major axle manufacturer about reproducing the S30 280Z 27 spline stub axles. These can be machined to match the stock stub axle or positive offset to match the Z31 front hubs. They can be drilled either 4 or 5 hole. The flange face will be round not squared off. The splines are broached into the axle not rolled as original. That means the splines will be cut slightly into the bearing seat. This is not a issue of strength and should actually be stronger. The axles will be made from a higher quality alloy steel than originals. The threading will need to be done at another machine shop. I've run custom axles from this company in my Land Rover for years. There has never been a failure despite putting the 4x4 through hellish offroad conditions. Cost for a pair of axles will be in the $500 range. I'm having a set made for me regardless. My question to you is there any real interest in these? If so, let me know. Maybe we can get the price down a little if the numbers are right. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted November 15, 2007 Share Posted November 15, 2007 How will these be different from the modern motorsport stubs? http://www.modern-motorsports.com/catalog/product_info.php?manufacturers_id=&products_id=62 $500 beats $695, but other than that? I knows a large number of people were asking for a set with a larger than stock spline count. If you made sets with matching companion flanges, then you would have something unique. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted November 15, 2007 Author Share Posted November 15, 2007 Differences are the option of offset. As noted, the positive offset will match the Z31 front hubs so matching wheels can be run to allow for tire rotation, if desired. Higher spline counts are doable. I'll see if they can provide a matching flange to allow for this to make if viable. Actually, I was over at MM and looking for these axles but never saw them. That is why I persued this option. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted November 15, 2007 Share Posted November 15, 2007 I'm listening. Still not sure yet. I like the idea of stronger materials, and wonder if the splined end could be cut (larger diameter) so that it the OEM bearings could still slip over the splines and onto the the races and have a matching companion flange using the existing OEM bolt pattern. Quote Link to comment Share on other sites More sharing options...
fastzcars Posted November 16, 2007 Share Posted November 16, 2007 I would be interested in a 40 spline stuby. I have MM stubs and a friend of mine said he would be interested in purchasing them from me if I decided to change them! Quote Link to comment Share on other sites More sharing options...
JustinOlson Posted November 16, 2007 Share Posted November 16, 2007 I would be interested in a 40 spline stuby. I have MM stubs and a friend of mine said he would be interested in purchasing them from me if I decided to change them! I would as well be interested in purchasing a 40 spline stub axle. I wouldn't be interested in purchasing a stub axle the factory spline count. If your going to make something, you might as well provide a part that isn't currently available as far as strength is concerned. Justin Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted November 16, 2007 Author Share Posted November 16, 2007 I'm hearing you. My first interest was in the 3/4" offset to match my Z31 hubs. I prefer to run a matching set of tires/wheels. I'm sending a stub axle off today for review. The issue of producing the mating flange is the bigger issue. Regarding the 40 spline. Are you looking for a larger girth as well or simply a 40 spline count on the existing stub diameter? I'll need to investigate oil seals to find a thinner piece allowing the use of a stock S30 strut housing. I looked at the flange this morning as I packed it up. I don't think the original flange is not thick enough to support a larger shaft diameter. I'll get into the seal cross reference book shortly. Quote Link to comment Share on other sites More sharing options...
JustinOlson Posted November 16, 2007 Share Posted November 16, 2007 The far left stub axel is what I'm looking for. It doesn't neck down.. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted November 16, 2007 Author Share Posted November 16, 2007 I'm sending off several drawings including the far left stub axle. I think necking down the area between bearing seats would not affect strength but ease outer bearing installation. I'm also looking a a finer spline count on the stock diameter as well as somewhere inbetween. The manufacturer will be able to provide valuable input on the subject of size vs strength. If the flange can be produced it's then an issue of different bolt patterns to acommodate the axle shaft joint or CV used. We'll see how things progress. Quote Link to comment Share on other sites More sharing options...
getZ Posted November 16, 2007 Share Posted November 16, 2007 Part of the problem getting a larger spline count and larger diameter axles is the bearing size. The bearing diameter gets to large to fit in the stock strut tower. You will also have to find a smaller bearings (ball size) with the same outer diameter and larger inner diameter. Another point to think about after looking at some of the pictures of a broken stub axles including the MM stub axle is the weak part seems to be more at where it tapers to threads. I thought about getting larger thread diameter, but if it has to break. Where would you rather have it break? On the inside the wheel will probably stay on the car. If the axle breaks internaly who knows what the wheel will do....just my 2 cents. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted November 16, 2007 Share Posted November 16, 2007 If the axle breaks internaly who knows what the wheel will do....just my 2 cents. That is why you ditch the drums and put on a set of disk brakes. Quote Link to comment Share on other sites More sharing options...
fastzcars Posted November 16, 2007 Share Posted November 16, 2007 getZ Part of the problem getting a larger spline count and larger diameter axles is the bearing size. The bearing diameter gets to large to fit in the stock strut tower. The issue Is not so much as the diameter of the shaft but the taper down to the spline's. If we keep the same diameter of the shaft but NOT introduce the taper but do a straight cut of the splines. Even reduce the depth of the splines would help the strength of that area. Quote Link to comment Share on other sites More sharing options...
Zfan1 Posted November 17, 2007 Share Posted November 17, 2007 I would be interested in a 40 spline design. I am tired of snapping the 27 spline axles every couple of months, longer if I stay away from the dragstrip. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted November 19, 2007 Author Share Posted November 19, 2007 I'm investigating it. The stub axle and flange went out Friday. I included drawings of a straight shaft. There's plenty of room. The oil seal will need to be replaced with a larger ID because the mating flange will need to big bigger too. These flanges may have to be machined at one shop and sent out for internal splining. I'm guess that a round flange could be used then drilled to the required CV or U-joint flange bolt pattern. As with anything the price will go steadily upwards. I'll have to wait for the manufacturer to call me with specifications. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted November 20, 2007 Author Share Posted November 20, 2007 I spoke at length with one of the engineers this morning. He pointed out the higher spline count does nothing for strength. More finer splines help reduce splines being sheared off. That is not the problem folks here are experiencing. It is girth of the shaft that is the culprit. I'm investigating to see if there is a bearing with a larger ID to allow for a larger shaft diameter and still provide adequate load properties. In the meantime, a slightly larger spline diameter can be made (1.20" vs 1.095"). This is a big jump (.105") in diameter and should greatly reduce shearing. The Ford 8.8 uses a pinion companion flange with a 1.20" ID and a 30 spline count from what I read. The flange could be welded/drilled the accommodate any pattern. They're making a set of axles for me to test. I will likely need a test volunteer as I haven't the power to break them or the desire to tax my 240Z like that. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted November 27, 2007 Author Share Posted November 27, 2007 I'm looking at two reasonable options at this time. One is a possible bearing with a larger ID but retaining the original OD. The only one available has a width nestled between the narrower inner bearing and wider outer bearing. I'm waiting to get static and dynamic load ratings for this bearing compared to the stock RW116 and RW117. If it works, it allows for a axle shaft in the 1.4" diameter range. The second option is using an existing Spicer 28 involuted spline with a 1.20" ID. That would allow for more meat where the stock axles are breaking. The third option is a custom companion flange with a 1.250" to match the stock axle diameter. The cost of turning and broaching that flange would be up there with the axle though. A matched set of custom axles and flanges could possibly run in the range of $1000. My manufacturer is waiting for me to supply definate dimensions before producing the first axles. I will need someone to torture test these as my 240Z doesn't produce to HP/TQ to trash an axle. Any takers in Virginia when that time comes? One more bit of interest, it was explained to me that a billet axle has controlled grain structure but does not necessarily make for a stronger part. If the stresses go across that grain pattern then it may be no stronger than a forged part. That could explain, in part, why Ross' axle snapped. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted December 5, 2007 Author Share Posted December 5, 2007 The preliminary set of S30 5 x 4.5" stub axles are on their way to me. They are positive offset 19mm to match the Z31 front hubs. The stock 1.25" bearing ID is retained and the spline diameter is now 1.245" and is now a 29 spline count. That's a .150 jump in diameter! This beefs up the axle where they traditionally break but eliminates the cost of machining the strut housings for larger OD bearings (the only way to get a larger bearing ID and larger axle diameter over stock). The threads for the lock nut will need to be threaded a my local machine shop. I've ordered the 4.5" round stock to fab the companion flanges. Once these are machined they'll be sent out for broaching at a specialized shop. They will resemble the full diameter axle shown in post #8 but are necked down .005" between the bearing seats to ease bearing installation. By the way, the flange shown in the background of that picture appears to be a Chrysler or AMC pinion flange. I'll post pictures soon. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted December 5, 2007 Share Posted December 5, 2007 What is your percieved design for the companion flange. OEM 4 bolt pattern (Yes!), or another configuration? The reason I ask, and you know exactly what I mean because you've done the same thing, is my set-up uses the OEM configuration. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted December 5, 2007 Author Share Posted December 5, 2007 The initial flange will be 4.5" in diameter with a small lip to accept my 930 CV joints. This flange will be thinner overall than the stock flange/adapter I'm using presently. This will provide for a slightly longer axle shaft and help boot clearance from the E-brake bracket too. Once I'm satisfied with that then other diameter flanges can be produced and drilled to accept the stock 4 bolt, 6 bolt tulip, or later 6 bolt CV flanges. One thing I failed to mention is a larger oil seal will be needed at the inner bearing. Also, since the wheel flange is offset 19mm, the stock dust shield will not work. I'm looking to use a large seal on the outside of the outer bearing or have a new dust shield fabbed at yet another local metal shop as a replacement. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted December 5, 2007 Share Posted December 5, 2007 If I understand this correctly then, this would eliminate the need for your outboard 930 adapters, and the CF would be drilled to the 930 six-bolt pattern? Lastly, the offset on the wheel flange; I'm not visualizing the flange, so would it simply be set further outboard 3/4", and thus the axle is extended in length 3/4" past the outboard bearing by that amount? This would be no different than higher offset wheels, or using spacers, as seen by the bearing, but how will the axle shaft itself respond to this extension? Does it pose any risk being "out there" with no support, even if it is only 3/4"? If this is a concern, does the desire (not a need as I see it) for the additional offset outweigh that concern? Last point for me personally being I'm still using four lug wheels. Would this flange be round and easily drilled for the four-bold pattern? Quote Link to comment Share on other sites More sharing options...
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