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Z31 axle swap problems

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So in an effort to fix my rear end vibration I decided to upgrade to 300zx axles. Looking back now, I should have just put new u joints in the stock axles, but I liked the idea of CVs. Anyways, Not only do they *barely* squeeze in to the car with the adapters welded to the outer flanges, but apparently the inner boots also rub on the control arms. They both split open, and there is now grease all over the underside of my car (that I just cleaned while doing the axle swap in the first place). I am using CJ Cave weld on adapters and rock auto axles (that I believe are tripod style). What is the cheapest solution here? Should I just buy new boots, swap those out, and take an angle grinder to the control arms where they hit? Should I buy some T3 rear control arms that I believe have more axle clearance? Is there a such thing as a low profile CV boot? I'm sure everyone reading this knows that I just want to drive the car, and that I am looking for the fastest way back on the road. I was thinking about the T3 arms already in order to space the rear track width half an inch on each side, hopefully giving the axles more wiggle room. Now with my ripped boots, I have another reason to go T3. I guess I am just looking for suggestions, input, and maybe someone else who has been through the same thing to chime in. Below are some pictures of my "super fun" situation.....thanks for looking all. 

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I'm not sure about the boots breaking open. For the length, modern motorsport sells shorter half shafts that give the correct length for Z31 axels but they are pretty expensive. It is possible that fixing the length would prevent damage to the boots because the suspension can bottom out, which stresses all the parts and might be tearing the boots, if the axels are too long. Alternatively, you can try flipping the bearing cages on the axels to make them shorter (just youtube for how to do it). Apparently this works for some people but not for others. Also, as a disclaimer, I have not done this swap yet but I have done a lot of research on this topic because I plan on switching to CV axels soon. Hopefully this is helpful.

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The rock auto axles are tripod instead of birchfield (sp?), so no cages to be flipped.

 

300zx axles are on the long side to start with. The Cave adapters apparently don't really do anything to address that. There is a guy on facebook that makes some really thin ones to at least give some clearance, but shorter axles or longer track width would be required most likely to run these axles. 

 

Spreading out the track width would help, but that would force a bit more camber out of the rear. If you had top hats cambering out the bottoms and cambering out the tops would get you good clearance without forcing too much camber. T3 arms are ok, but I think AE (Apex Engineering) has a much better design, although they haven't been around as long as T3 so I can't comment on the quality.

 

It looks like it isn't the boot diameter, but one of the bellows that caught and ripped. You can undo the clamp inboard side and pull it closer to stretch out the boot a bit more. They do make boots that don't bellow out on the first ring like that, more designed conically. You would have to go to the parts store with some part numbers to figure that out, I'm not sure what housings they used though so not sure what you can go in and ask for, best to take the housing or measure the shaft and the housing diameter.

 

You could clearance the arm, but you would really want to weld in support depending on what you are taking out

 

 

 

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Thanks for the input Brian. I'm thinking I'll do new boots, and I will try and get my hands on a few at the parts store to see if I can get a slim one. I'm also thinking the aftermarket arms will give me clearance. I have camber plates with some play left, so I can add half an inch at the bottom and keep my camber fine. I also have the tire clearance. I feel the same way about T3 vs Apex, I think they both have the same adjustability, and price, and clearance, but as for track record Apex doesn't really have one yet. 

 

I guess my final question is do you think those shorter axles work with the tripod ends? I wasn't sure if they were meant for OEM style axles. Its basically the same price for control arms or the axles for the same fix. 

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Had the exact same thing happen on my car with stock suspension ,Z31t axles, and Modern Motorsports adapters. Stretching out the boot might help but it relies on friction to hold it in place so it may just slide back after some period of time.  But, it's worth a shot.  I had decided that the differential was flexing too much so I installed TTT mustache bar (previously stock 280z) and ground the corner off the LCA where it comes close to the boot. The car is still on jack stands so I don't know if that combination worked.  Installing aftermarket LCAs hadn't crossed my mind until now....

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rossman, I ordered Apex Engineering A Arms, I will let you know if they provide the needed clearance. I am also going to go to the auto parts store and see what options they have, the slimmest boot is what I will buy.

 

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Posted (edited)

 I had the exactsame thing happen to me. Im not sure if the mms axles will fit, i wasnt even going to chance it since the tripod design is weaker. The Autozone ones are made by the same company so they won't work either. I ended up buying a OEM set used off Facebook marketplace. It took like 4 hours of me dragging a bubble around the U.S. to completely search for them, but I got them. I ended up buying them from Marcos autoworks located in Walkertown, NC (336-577-7128) for 175 shipped.

 

I then shortened my axles per someone else's idea (see below). He however only shortened one end, I shortened both ends and flipped the cages... I have about 3/4 of an inch with it fully dropped and just over 1/3 an inch with the jack under the control arm.

 

Hope everything works out.

 

Edited by walkerbk

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