Moe's 8sp build - [email protected]

[Kotta390]

Completely different because the 4wd driveshaft goes into the transfer case, not directly to the back of the transmission.

You are telling me that both driveshafts come out of the transfer case? I have never seen that. I don't own a 4wd obviously but why would both driveshafts come out of the transfer case?

 

[Kotta390]

Never mind, I looked up the 4wd version of the 8hp70.


Ok goes back to the original question about how come we can't use a solid one oiece driveshaft? Lol

 

[moregrip]

this might help you guys out some, a buddy of mine went through this same issue with his long aluminum driveshaft a few years back, good read if you have minute!

Aftermath of driveshaft mishap: Lessons Learned - PerformanceTrucks.net Forums

 

[Dubstep Shep]

You guys have to understand that just because the crew cabs or a HD or some other truck have a one piece doesn't necessarily mean that it will work on the RCSB.

It's about the specific geometrical relationship between the axle, control arms, transmission, and driveshaft. Moving the transmission further away from the axle (Like in a QC or CC) changes that relationship.

 

[nickpohlaandp]

You guys have to understand that just because the crew cabs or a HD or some other truck have a one piece doesn't necessarily mean that it will work on the RCSB.

It's about the specific geometrical relationship between the axle, control arms, transmission, and driveshaft. Moving the transmission further away from the axle (Like in a QC or CC) changes that relationship.

https://www.youtube.com/watch?v=Idk3BVDVHq4

It's called driveshaft phasing. Watch the video in the link. It doesn't get more plain (and monotone) than that.

 

[moregrip]

what's the good word Matt?

 

[Pull Ya]

I talked to Matt this afternoon and he said they got the pieces and they said they would let him know??????
Jay

 

[Hemi450hp]

what's the good word Matt?

Driveshaft Shop received my stock flanges on Friday and said they would get back to me 1 day this week with options.

I'm taking it a step further and dropping off a complete factory driveshaft with a local driveshaft shop tomorrow. They are going to first see if the stock driveshaft is balanced. Then, they are going to look into building something stronger as well. The local shops looks like they will be a good bit cheaper than DSS, but I wont give up quality for cost.

I plan to buy 1 from each shop and test them both.

 

[moregrip]

Driveshaft Shop received my stock flanges on Friday and said they would get back to me 1 day this week with options.

I'm taking it a step further and dropping off a complete factory driveshaft with a local driveshaft shop tomorrow. They are going to first see if the stock driveshaft is balanced. Then, they are going to look into building something stronger as well. The local shops looks like they will be a good bit cheaper than DSS, but I wont give up quality for cost.

I plan to buy 1 from each shop and test them both.

sounds like a good plan! FWIW, when I had my stock DS balanced in my old chevy truck with the blown LS, it was literally a new truck(read low miles), I also used a local DS shop with an excellent reputation. It didn't hurt that there was a drag strip nearby, well, before it got torn down anyway...........where he was able to earn that reputation. I usually prefer a local dude when doing custom stuff; makes revisions waaaay easier, but no less frustrating. Hopefully there's an easy-ish solution for this! standing by for more!

 

[Kotta390]

I know DSS has great reputation, but I have dealt with a local Driveshaft shop before and their quality was top notch, it just didn't come with the price tag of DSS. Just because it says Nike, doesn't mean its better than New Balance lol!

 

[nickpohlaandp]

...Just because it says Nike, doesn't mean its better than New Balance lol!

Take a look at the senior citizens at the mall. You'll see more New Balance than Nike. Old timers know where it's at!

 

[Dubstep Shep]

It's called driveshaft phasing. Watch the video in the link. It doesn't get more plain (and monotone) than that.

I'm not necessarily talking about the phasing because of the ends on the driveshaft... The two piece in the regular cabs is still a straight driveshaft with only two universal joints. The two pieces simply slide over one another, but are otherwise colinear.

Phasing comes into play when you lower the truck. You have to make sure the pinion angle is correct. That's why I think these failures almost always occur on lowered trucks. I've not seen any from a stock height one, though I think there's a few. They still aren't anywhere near as common as with the lowered ones.

 

[nickpohlaandp]

Phasing comes into play when you lower the truck...

This is partly true, phasing comes into play when you lower your truck, in the form of re-phasing (correcting pinion angle), but it is ALWAYS in play, even in a stock height truck. All I'm trying to point out is that it's a major issue that a lot of people don't even know exists.

I'm a helicopter inspector, so you can imagine the phasing on a tail rotor driveshaft would be pretty damn important. When I get a new A&P and they just slap a driveshaft up there in whatever position, I like to sit them down and show them that little video. I know the video is totally 1980's and monotone as all get out, but it is a great representation of the effect proper and improper phasing can have.

 

[Wild one]

Another couple of good videos to watch.

https://www.youtube.com/watch?v=dt69zYAcXME

https://www.youtube.com/watch?v=f1m-Fh5kiRU

 

[nickpohlaandp]

Another couple of good videos to watch.

https://www.youtube.com/watch?v=dt69zYAcXME

https://www.youtube.com/watch?v=f1m-Fh5kiRU

Nice. Those show more of the math behind it, whereas the video I posted just lets you hear what out-of-phase driveshafts sound like (sound being the vibration).

 

[Hemi450hp]

Local shop said they want nothing to do with this driveshaft. Said the only flanges they can get their hands on are Chinese, and they would not trust putting their name behind the unit.

Still waiting to hear back from DSS, but they did say they would be making the new flanges themselves. Downside is that the cost of the flanges alone is $500.

 

[nickpohlaandp]

Local shop said they want nothing to do with this driveshaft. Said the only flanges they can get their hands on are Chinese, and they would not trust putting their name behind the unit.

Still waiting to hear back from DSS, but they did say they would be making the new flanges themselves. Downside is that the cost of the flanges alone is $500.

Time to invest in one of these and make some flanges!

3-in-1 Machines Swing Over Bed (Inch): 45296092 - MSC

 

[SilverSurfer15]

yea that's way too much money. I'm not going to get into all the problems I have with DSS, but yet again a ridiculous price tag. Good luck!

 

[moregrip]

Matt, check these dudes out, they specialize in long 5" aluminum driveshafts.

Aluminum driveshafts for Trucks

http://www.driveshaftspecialist.com/Truckhtml/Dodge truck.html

 

[Dubstep Shep]

This is partly true, phasing comes into play when you lower your truck, in the form of re-phasing (correcting pinion angle), but it is ALWAYS in play, even in a stock height truck. All I'm trying to point out is that it's a major issue that a lot of people don't even know exists.

Sure, it's in play, but alllllll the engineering was put in for the truck in its stock form.

When is the last time you heard about a 100% stock truck snapping a driveshaft? To my knowledge, it's never happened.

That's because the pinion angle was designed to be correct at the stock ride height and the driveshaft was designed to handle the loads and rpms of the stock truck.

Start changing the angles, loads, or rpms and you've now taken the driveshaft outside the parameters it was designed for, and no one knows what sort of safety factor it had to begin with.