F my life. - SOLUTION FOUND!

[FuzzyDunlop]

I finally received a new axle yesterday! Awesome! I took no hesitance in getting it put on and going for a romp. What a blast! Almost forgot how fun this car was.

So tonight, same story, I went out for a quick blat around the neighborhood and decided to give it a good launch.

*SNAP*

The axle on the OTHER side snapped now... WTF! $%^ %^& ^*()@#

It snapped on the inner CV.

The guy I buy these axles from is not going to be impressed.


But seriously, what the hell. I would think that the weak link in my set up would be my clutch or tires. There are guys running 700+hp/500+tq cars on these axles.

I dont get it.

F my life.
/blog

 

[lavaheadache]

bad engine mount perhaps?

 

[Fenixgoon]

bad engine mount perhaps?

how would a bad engine mount cause an axle to break? honest question, i just have no idea.

no clue how much hp/tq the OP is running, but would a wonky diff or suspension geometry/flex cause one of the joints to get overloaded and fail?

you know if you're not going to do anything with the broken axle but throw it away, it might make for a fun display piece for me (part of my job is failure analysis). Any idea how much it would be to ship? I'd take a look at it in my spare time for ya just for fun

 

[phucheneh]

Define 'snapped the inner CV'? Did the inner part of the plunge joint come apart?

What were you doing when it broke? Maybe back off of them drag launches... ;P

 

[lavaheadache]

how would a bad engine mount cause an axle to break? honest question, i just have no idea.

no clue how much hp/tq the OP is running, but would a wonky diff or suspension geometry/flex cause one of the joints to get overloaded and fail?

you know if you're not going to do anything with the broken axle but throw it away, it might make for a fun display piece for me (part of my job is failure analysis). Any idea how much it would be to ship? I'd take a look at it in my spare time for ya just for fun

I've broken quite a few in high power front wheel drive cars. What happens is that a weak mount will cause the engine to lift on hard acceleration or sudden launches which can put an irregular force on the axle causing it to snap or sometimes rip the yoke out of the cv joint. I've done em both =(


Not sure how it applies to mr2's

 

[jlee]

Ohh that sucks! Do you have any wheel hop on launch?

 

[Black2na]

he has to have some wheelhop. have to be shock loading the axle some how

 

[exdeath]

First world problems...

 

[lavaheadache]

First world problems...

huh?

edit---

After further thinking about it. I think you are saying that cause the title is *F* my life, and I agree with you. My wife say's it all the time about trivial things. Not so much about her car blowing axles but nevertheless about things that make me look at her funny. It's as if her life quality is some how diminished when she burned her croissant in the toaster cause she was too busy on facebook.

 

[_Rick_]

Oh snap!

 

[exdeath]

huh?

edit---

After further thinking about it. I think you are saying that cause the title is *F* my life, and I agree with you. My wife say's it all the time about trivial things. Not so much about her car blowing axles but nevertheless about things that make me look at her funny. It's as if her life quality is some how diminished when she burned her croissant in the toaster cause she was too busy on facebook.

Boo hoo I have too much power and keep breaking things :awe:

Hence first world problems.

 

[monkeydelmagico]

I would think that the weak link in my set up would be my clutch or tires. There are guys running 700+hp/500+tq cars on these axles.

I dont get it.

Your tires may be part of the problem. I'm fairly certain you are aware but I figured I'd throw it out there anyways. You may want to go with a less sticky tire.

Seen guys go to dragstrip, bolt on a set of slicks, and POP goes the diff, axle, trans, etc.

 

[FuzzyDunlop]

First world problems...

haha, this was runner up in thread title options. I'm not really whining, crying, stamping my feet and throwing things. More just annoyed because this is not supposed to be happening.

Ohh that sucks! Do you have any wheel hop on launch?

This snap happened before any wheel hop. It seemed like it was instantly after I let the clutch out. Is it possible that there is wheel hop that I am not noticing... I don't see how. Every other launch the wheels will just spin or I can smell my clutch. This time I just an instant crack and whirrrrrrrrr.

I don't know exactly where the cv broke. I haven't taken it apart yet. just parked the car in my garage and went inside to pout.

 

[sm625]

I had a car (not even gonna mention the model, lets just say it was bad). And this same thing happened. Replaced one CV and the other one went 2 weeks later. After that it ran fine until it died (death unrelated).

 

[FuzzyDunlop]

Your tires may be part of the problem. I'm fairly certain you are aware but I figured I'd throw it out there anyways. You may want to go with a less sticky tire.

Seen guys go to dragstrip, bolt on a set of slicks, and POP goes the diff, axle, trans, etc.

The axles shouldn't be taking the brunt of the force though. They are ridiculously over built. My clutch should be my weak link.
I'll have to take some time and look over the car this winter... Try and figure out why this is happening... But it seems strange that I've been driving it for two years and just now this problem arises and it happened to both sides at nearly the exact time....like within 3 hours of driving time.

 

[jlee]

MR2s can pull the front end off the ground. There's no need to go with less sticky tires.

If it was wheel hop, you should notice - it'd be like BAMBAMBAMBAMBAM coming from the back end. I've never experienced it in my MR2, but it's worth asking about anyway.

 

[FuzzyDunlop]

MR2s can pull the front end off the ground. There's no need to go with less sticky tires.

If it was wheel hop, you should notice - it'd be like BAMBAMBAMBAMBAM coming from the back end. I've never experienced it in my MR2, but it's worth asking about anyway.

I used to get a bit of it with the stock suspension, but havent noticed it since I put in the ground control kit.

 

[JCH13]

Weird axle angles are a big culprit in exploded axles AFAIK. Can you measure the axle angle? Usually too much angle = exploded bits.

 

[Vdubchaos]

Launching a car HARD = extreme stress

Unless needed, don't do it. ESPECIALLY if one has a FWD car and if you are doing it while turning etc.

If you play, you have to pay!!!

 

[FuzzyDunlop]

Weird axle angles are a big culprit in exploded axles AFAIK. Can you measure the axle angle? Usually too much angle = exploded bits.

It is difficult to make the engine fit without some funny axle angles. This could very well be the case. As far as I know I am not too far off from where other guys have placed their engines.

The engine mounts I bought were from a guy that makes them in bulk and sells them. Normally he sends out a Jig that makes sure the mounts are welded exactly where they needed to be. But when I built my car he wouldnt send the jig to me because Canadain Customs was holding it at the border for too long every time he sent it. I had measurements and put the mounts as close as i could to where he said to put them, but it is not unlikely that I am off by 1/4".

Launching a car HARD = extreme stress

Unless needed, don't do it. ESPECIALLY if one has a FWD car and if you are doing it while turning etc.

If you play, you have a pay!!!

Thanks! ill keep that in mind.

 

[jlee]

It is a lot of stress, but if it's built with quality parts, it should handle it. The next weak link in my drivetrain (aside from tires - 245/40-17 Star Specs) is likely either the splined end of the axle into the hub, or the differential. Neither should be a problem under 600-700rwhp.

I'm wondering if you got bum axles or if the angle is funny. I can send some pics of mine if you like.

 

[exdeath]

Your tires may be part of the problem. I'm fairly certain you are aware but I figured I'd throw it out there anyways. You may want to go with a less sticky tire.

Seen guys go to dragstrip, bolt on a set of slicks, and POP goes the diff, axle, trans, etc.

Not necessarily.

If wheel hop is a problem, stickier tires can fix the problem.

As said numerous times, this likely isn't a axle capacity problem.

Its normally shock oscillation and angle.

Being transverse mounted and inner CV, I'd look to flexing motor and failing LSD.

 

[JCH13]

If you could measure your axle angles, and JLee measures his, we should be able to see if yours are measurably more aggressive than his (stock).

You can keep replacing axles every time one of them explodes, but replacing two in such short succession screams that there is some underlying cause that needs to be addressed. Until that's figured out you'll just be rolling around on two time bombs.

Any pictures of the failure would be great too, it might tell us something useful.

 

[FuzzyDunlop]

ya.
I may get a chance to work on it over the weekend here.
Im going to take a few measurements and photos to get an idea of whats happening.

Most likely case is that I effed up when I welded in my motor mounts and the engine is crooked just enough to make a difference.

Just seems strange that they happened within such a short time frame. And I would have thought the problem would have arisen well before now. Ill really give the car a going over.

I had a car (not even gonna mention the model, lets just say it was bad). And this same thing happened. Replaced one CV and the other one went 2 weeks later. After that it ran fine until it died (death unrelated).

I hope this happens.

Edit: minus the whole death part. Dont need that.

 

[boomerang]

Here's a theory for you. You broke one side and vendor replaced it. Now the other side broke.

What if the problem was improper heat treating or even improper machining? In other words, there could have been a bad batch. New heat treating company, new vendor for machining. You don't know but guy you bought them from might. If he knows and is willing to share the information, it could save you a lot of wasted time.