My point about the steel ends is that the wouldn't have been destroyed like the aluminum.
Let's be clear on the price thing. What comes with that CF shaft for $950?
The strange 3-1/2" CM one is $415 including solid u-joints but no CM yoke.
3 1/2" Chrome-moly driveshaft with Strange forged 1350 weld-ends & heavy duty u-joints. - Tubular Driveshafts - Driveshafts & Components - Drag Race
Make up your mind, is the CM shaft $415 or $600-$800? lol
The CF DS for $900-950 included everything, spicer trans yoke, u-joints front and rear, 7075 aluminum driveshaft yokes, and ford pinion yoke, shipped from FL to NJ.
Here's the pics of the u-joint I was talking about, just look at the amount of material on the right hand side that is worn away....that did NOT happen in the fraction of a second when things broke....that's years and miles of wear eating away, and causing a LOT of slop inside that joint cup
I'm assuming either a non-ideal pinion angle, or a tiny piece of dirt in the bearings caused it to eat away over time, slowly destroying the needle bearings, then slowly eating away at the joint, causing lots of slop inside that cup, eventually cracking the cup, losing the grease, heating up, getting brittle, getting stressed, and finally shattered the cap, breaking loose, breaking the ear and dropping the driveshaft, and snapping the tube once it hit the muffler (rather than stay in tact like a steel or aluminum one would have done and destroy the ever living snot out of everything under my truck lol)
The pics dont show it very well, but you can clearly see signs of heating in the metal around the wear area, which would be from high friction on long durations of use (street truck problems [smilie=om LOL). I work with a lot of mechanical and materials engineers and took it to a few of them who aren't car guys, had no idea what the part was at first, other than they look at failed parts all day long, and they all said basically the same thing as what I suspected. Then I showed them the driveshaft tube and their jaws dropped when they realized it was out of my truck lol.
So once again, with the u-joint being the culprit that failed first, that driveshaft was coming out no matter what material it was made out of. I'll use your very own analogy again, "tune it right and you won't have to worry about melting a piston or lifting a head gasket", well set your pinion angle right and you won't have to worry about failing a u-joint taking out your driveshaft, therefore the tube material has nothing to do with the failure, and CF has advantages all across the board other than a couple hundred dollar price difference.
[QUOTE="oilwell1415, post: 2083002, member: 22767"]A quick google search has CF driveshafts still in the $900 range. That's a $500 difference. If for whatever reason the DS is loose under the vehicle it is going to do $500 in damage if it is steel. Depending on how it fails, it could take the rearend or trans with it and then you are really spending money. None of us like it when stuff breaks, but if I have to put a fuse to put in the driveline a CF DS works really well for that.[/QUOTE]
I can't keep up on what a steel driveshaft goes for. First it was $300, then it was $800, now it's $400 lol. Whatever it is, $500 is a drop in the bucket on what we spend on these trucks, and to shed 40-60 lbs over a steel one on rotational mass is a HUGE chunk, and the added safety factor with it having 3 times the strength, it's a small price difference to pay. Like you said I've seen guys break steel and aluminum ones and it trash the exhaust, dent the floor, dent the fuel tank, and even crack the transmission case. The CF in that scenario is just shattering itself, and maybe leaving a black mark or two on whatever it hits as it shatters.
That was like a biography I just read lol. I changed my u joints 2 years ago or so just bc they were old. Looked fine when I removed them. Spicer solid u joints. Did raising the back of your truck up help it hook? My truck is way low and works awesome.
lol yeah I type fast haha.
I'm not sure what brand my u-joints were that are in there (anybody recogonize the markings?) but Mark @ PST did say we'd use spicer solid u-joints, spicer yokes, and a thicker tube with the power my truck is making, compared to how this one was spec'ed out to 9 years ago when I was making half the power.
Raising my truck up definitely helped, but I made a lot of changes at the same time, so can't say exactly what changed what. I used to have a 5" rear drop with hotchkis leafs and 4" shackles. I swapped that to fiberglass leafs and 1" shackles bringing it up to a 3" rear drop. The shackles made the biggest difference on pinion angle bringing it back from being really negative, but I never dialed it in beyond whatever it landed at from the new leafs and shackles. With pulling several 1.34 sixty foots in a 19' long lightning limo, I wasn't about to touch the suspension after getting my 60' down like that lol.
Anyway, I snagged a great deal on an aluminum driveshaft from screwonbudnik20s. It's from a 4R70W 139" wheelbase supercrew so I'm dropping it off today to get it shortened for the 4R100 139" wheelbase length. (from 76" to 69" u-joint centerline to u-joint centerline for anyone's future reference). Then I can check the trans out, make sure all is well internally, and decide my path forward from there on the trans and rear mod plans (no time like the present to upgrade if I'm ever going to do it!), and if the trans is okay I'll be able to cruise for the rest of the spring and summer, and I'll order a new CF DS for the fall :rockon_ford
