Need help diagnosing a clutch/tranny problem

[patrickt]

Originally Posted by dcdoug

I'll have some time to play around with engine tune. After speaking with Mark Williams and Summers Bros, I'm going to send it off to Kirkham. I spoke to Tom and he said he can't recall seeing any broken stub axles.

...

He did ask one question that I'd like opinions on - should I change from a 3:31 rear to a 3.54 rear. I have the TKO600 with the .82 overdrive. He said they install the 3.54 10:1 over the 3.31. Thoughts?

Can't go wrong with Kirkham. But if you have the "soft steel" disease, I would take a long hard look at the stub axles that go through your hub. Those will be the next to go. BTW, I have the 3.54, but I have the .64 fifth gear. Personally, I love it, through all five gears, not just fifth.

[dcdoug]

Originally Posted by patrickt

But if you have the "soft steel" disease, I would take a long hard look at the stub axles that go through your hub. Those will be the next to go.

Maybe a different supplier or I had a bad batch of diff stub axles? Who knows. Easier to replace though and easier to diagnose, although breakage may cause more carnage.

[maurice19]

Doug,
Good choice on the Kirkhams.

I think the 3.54 with the .82 would be a good choice.

Maurice

[patrickt]

Originally Posted by dcdoug

Maybe a different supplier or I had a bad batch of diff stub axles? Who knows. Easier to replace though and easier to diagnose, although breakage may cause more carnage.

I don't know. That pic that I posted looked suspiciously like yours, though. MickMate originally posted it, so he knows more than I. Personally, I can't remember the last time I heard about a half shaft failing. Stub axles, yes, but not the half shafts themselves. Now ERA goes to some extra trouble on their half shaft. They shorten it, neck it down, re-weld it, dip it in the river Styx, and some other stuff. Supposedly to make it "fail safe" -- but who knows. The stub axles have always been the weak point, but when I was there looking over both the plain Jane and ERA rears they assured me they were both good to 600HP, which I don't have, and you don't have. It would be nice if there was an easy way that you could just call somebody up at Shelby and say "hey, were the stub axles in my wheels sourced from the same vendor, and at the same time, as the differential stub axles?" Honestly, though, if it were me, and considering that right now you have the engine, transmission, and rear out of the car , I would go ahead and replace the stub axles in the wheel with stronger ones. Of course, you know you have to phase the universal joints on both sides of the differential so all four of them line up evenly else it will vibrate. (that's a joke, when you think about it, you'll see why....)

[Mdman352]

Originally Posted by dcdoug

i'll have some time to play around with engine tune. After speaking with mark williams and summers bros, i'm going to send it off to kirkham. I spoke to tom and he said he can't recall seeing any broken stub axles. He also told me that mine is 30 spline (apparently i need to get my 6 year old to count next time ), same as theirs, but he did see a csx in a few weeks ago with the same problem and found that the steel used in the axle was too soft.

He did ask one question that i'd like opinions on - should i change from a 3:31 rear to a 3.54 rear. I have the tko600 with the .82 overdrive. He said they install the 3.54 10:1 over the 3.31. Thoughts?

yes................................

[Mdman352]

Originally Posted by patrickt

I don't know. That pic that I posted looked suspiciously like yours, though. MickMate originally posted it, so he knows more than I. Personally, I can't remember the last time I heard about a half shaft failing. Stub axles, yes, but not the half shafts themselves. Now ERA goes to some extra trouble on their half shaft. They shorten it, neck it down, re-weld it, dip it in the river Styx, and some other stuff. Supposedly to make it "fail safe" -- but who knows. The stub axles have always been the weak point, but when I was there looking over both the plain Jane and ERA rears they assured me they were both good to 600HP, which I don't have, and you don't have. It would be nice if there was an easy way that you could just call somebody up at Shelby and say "hey, were the stub axles in my wheels sourced from the same vendor, and at the same time, as the differential stub axles?" Honestly, though, if it were me, and considering that right now you have the engine, transmission, and rear out of the car , I would go ahead and replace the stub axles in the wheel with stronger ones. Of course, you know you have to phase the universal joints on both sides of the differential so all four of them line up evenly else it will vibrate. (that's a joke, when you think about it, you'll see why....)

Never seen a half shaft fail??? This is my 3rd one...... off idle launch did it....

[dcdoug]

Originally Posted by patrickt

Honestly, though, if it were me, and considering that right now you have the engine, transmission, and rear out of the car , I would go ahead and replace the stub axles in the wheel with stronger ones.

Tom tells me that the stub axles going through the wheel hub are a lot larger and not a weak point.

[dcdoug]

Originally Posted by Mdman352

Never seen a half shaft fail??? This is my 3rd one...... off idle launch did it....

Kirkham was talking about his half shafts (which are the same as the CSX). Not sure yours are the same. I believe mine are solid (but not positive).

[patrickt]

Originally Posted by dcdoug

Kirkham was talking about his half shafts (which are the same as the CSX). Not sure yours are the same. I believe mine are solid (but not positive).

Right. There's something wrong with mdman352's half shafts. They look thin skinned and hollow. This is what I think of when I say "half shaft."

Originally Posted by dcdoug

Tom tells me that the stub axles going through the wheel hub are a lot larger and not a weak point.

Count Dogula wants to hear from MickMate on that subject. She says that the Shelby stub axles in the wheel are made of cheap metal from China. And yes, we do dress her up for Halloween.

[RodKnock]

Originally Posted by dcdoug

He did ask one question that I'd like opinions on - should I change from a 3:31 rear to a 3.54 rear. I have the TKO600 with the .82 overdrive. He said they install the 3.54 10:1 over the 3.31. Thoughts?

Doug, I have the 482ci/TKO600/0.82 5th/3.42 combo, but the Kirkhams now install the 3.54 in the rear of their newer cars. If I had the choice now, then I would definitely go to the 3.54's. Definitely. 5th gear is a lug unless I'm exceeding the speed limit by a whole bunch.

[ERA Chas]

Originally Posted by RodKnock

..... unless I'm exceeding the speed limit by a whole bunch.

IN THE GARAGE???

[4pipes]

Rod, we probably have the same setup. I love cruising around 73mph at 1900 rpm in 5th and being able to have a conversation.

[kevins2]

Originally Posted by 4pipes

I love cruising around 73mph at 1900 rpm in 5th and being able to have a conversation.

Sounds right - isn't that what 5th gear is for? ERA described the combination I have coming - a TKO600 w/.82 5th and 3:31 rear as "best of both worlds". This is probably another one of the many topics that will have a variety of opinions.

[mickmate]

I think the 3.54's with the OD is just the ticket. That pic is a South African car, Dougs is HST methinks? I believe the difference is male thread versus a female thread holding the whole mess together. I haven't heard of the half shafts ever failing in a CSX, we're talking 1410 u joints doing nothing but driving, in a Jag rear they also hold it off the ground (or are supposed to right David). Your half shafts have to be splined cos they change length.They have a beefy long spline.

[patrickt]

Originally Posted by mickmate

... in a Jag rear they also hold it off the ground (or are supposed to right David). Your half shafts have to be splined cos they change length.They have a beefy long spline.

Yes, that's the other reason I opted for the ERA outboard braked rear, as opposed to the Jag rear in my car. Thanks... and the Count thanks you, too.

[dcdoug]

Originally Posted by mickmate

I think the 3.54's with the OD is just the ticket. That pic is a South African car, Dougs is HST methinks?

Yep, HST. Depending on who you ask that's either fantastic or awful.

[GT350Mike]

Originally Posted by patrickt

I got news for you, all the splines in the world wouldn't have saved that stubby. You might think about replacing the one on the other side, too. Seriously, if it were me, I'd pull the good one out and send it, along with the broken one, to D-Cel and have him tell me why the broken one sheared and have him test the good one for it's strength. There's a bunch of CSX owners out there that would thank you for that information.

I didn't know about Doug's misfortune until tonight and I was literally holding my breath while I was reading through the thread. I'm relieved Doug's problem was the axle and not the rear end.

[dcdoug]

Originally Posted by GT350Mike

I'm relieved Doug's problem was the axle and not the rear end.

Don't be too relieved. Just getting it out is a serious PITA. And from the last CSX that Kirkham saw, little metal shavings spread throughout the diff and it all needs to be cleaned up, plus the two new axles. But at least they will fix it right.

[RodKnock]

Originally Posted by ERA Chas

IN THE GARAGE???

From when I last remember driving it, which was back in 2011.....or was it 2010.

[csx4017]

Rockwell hardness testers are widely available. We don't know the base material or the processes used during fab. It would be academic. I have seen classic fatigue failure surfaces and I am sure there are people in your area that can put the magnifier on it. The bottom photo shows the surface at the failure and my somewhat trained eye sees what could be fatigue, improper heat treatment, contaminates in the forging/casting...Sorry to see since I most likely have the same part. In aerospace the processes were recorded down to the part or at least the batch. I would suspect that these parts did not get a shot peening process either..........As previously voiced " would be great to call LV and find out the details of these critical parts" or at least their supplier??? No drag racing just the twistys !!!