Rising Sun Member Forums

Rising Sun Member Forums (http://www.risingsun4x4club.org/forum2/index.php)
-   General Tech Forum (http://www.risingsun4x4club.org/forum2/forumdisplay.php?f=17)
-   -   Another Plug For Front Range Driveline (http://www.risingsun4x4club.org/forum2/showthread.php?t=8347)

Bikeman 10-08-2008 08:38 PM

Another Plug For Front Range Driveline
 
I had Bill install two supplied factory U-joints (thanks Mike-TCH2FLY) and balance the rear shaft since the old U-joints didn't like the new angles they were operating at. He said the shaft had major run-out. He charged $25 to install the joints which I think is a steal, and $45 to balance it. It even has a new shiny coat of black paint on it, with the PO's undercoating gone. All this with a 2-day turn around. In addition, my front DC shaft (previously a rear Taco shaft) that he re-tubed with heavy-wall tubing is holding up well. He is an extremely nice guy and took the time to answer all my dumb questions.:thumb:

nakman 10-09-2008 06:53 AM

Good to know thanks! :cheers:

So you're running just U-joints in back? No DC... and you have Slee 4" + spacers?

Bikeman 10-09-2008 08:41 AM

Yes on all.

nakman 10-09-2008 08:47 AM

Interesting, thanks. I have been considering adding another inch or so in back, but have been worried the increased height would result in rear driveline vibrations. I've got relatively new U-joints and a retubed/rebalanced shaft already, so maybe I'll go for it! :beer:

Uncle Ben 10-09-2008 08:58 AM

Quote:

Originally Posted by nakman (Post 87930)
Interesting, thanks. I have been considering adding another inch or so in back, but have been worried the increased height would result in rear driveline vibrations. I've got relatively new U-joints and a retubed/rebalanced shaft already, so maybe I'll go for it! :beer:

Nak, The only reason you need a DC shaft is that your pinion flange and your T-case output flange are no longer parallel. As you know, angles cancel out angles so as long as both joints are working the same angle (without binding) they will cancel each other out. I have rotated my pinion up to get my drive shaft above the control arms and out of rock rash mecca. My pinion is now pointed straight at my output flange. By making that angle 0 my joint at the t-case flange is now still at full angle which would create horrible vibrations....thus the need for a CV joint which has two joints splitting the angle thus canceling each other out....comprende? What you will need is adjustable upper control arms so you can rotate the pinion down so you can get your flanges parallel. NOTE: If you do decide to do the CV thang and rotate your pinion up you need to remember that any solution to one problem often creates another. In the case of upward rotated pinion your fill plug will be slightly lower than optimal and your rear sway bar will hang down more.

Tch2fly 10-09-2008 09:00 AM

Quote:

Originally Posted by nakman (Post 87930)
Interesting, thanks. I have been considering adding another inch or so in back, but have been worried the increased height would result in rear driveline vibrations. I've got relatively new U-joints and a retubed/rebalanced shaft already, so maybe I'll go for it! :beer:

You need height or just looking to prevent sag when loaded?

My rear are the 864s and sit about where your 4" do. Even with a full load and my trailer it sits maybe 1/2" under level

nakman 10-09-2008 09:18 AM

UB: so you rotated the angle by lengthening the upper control arms? That seems pretty painless, now that I've got Christo's threaded arms.. but I'm not sure I want/need to do that since I wheel like a :Princess: and pick easy lines... :D so if I keep the upper control arms the same it sounds like I could raise the back up a tad more and not have any issues, agreed?


Mike: yes, just looking to get a little more in back pretty much all the time, with all my tools, jack, heavy Toyos, fridge, etc. it's a little lower than the front, then when I load up for a trip or hook up any trailer it's worse. I'd prefer a tiny bit higher in back, then go camping and it's level.

I am almost positive your 864's have a higher spring rate than the Slee 4's, in fact IIRC the soft to stiff continuum would be FOR's are softest, then OME J's, then OME comp's, then Slee 4's, then 864's, then a wooden 4x4. someone correct me if I'm wrong though

Bikeman 10-09-2008 12:43 PM

IMHO, I played around with rotating the pinion up and down. I don't think rotating it down to get = U-joint angles causes maybe more than a loss of .5" of clearance. It was less than what a lot of mudders were saying.

Nay 10-10-2008 02:43 AM

2 Attachment(s)
Quote:

Originally Posted by nakman (Post 87934)
UB: so you rotated the angle by lengthening the upper control arms? That seems pretty painless, now that I've got Christo's threaded arms.. but I'm not sure I want/need to do that since I wheel like a :Princess: and pick easy lines... :D so if I keep the upper control arms the same it sounds like I could raise the back up a tad more and not have any issues, agreed?


Mike: yes, just looking to get a little more in back pretty much all the time, with all my tools, jack, heavy Toyos, fridge, etc. it's a little lower than the front, then when I load up for a trip or hook up any trailer it's worse. I'd prefer a tiny bit higher in back, then go camping and it's level.

I am almost positive your 864's have a higher spring rate than the Slee 4's, in fact IIRC the soft to stiff continuum would be FOR's are softest, then OME J's, then OME comp's, then Slee 4's, then 864's, then a wooden 4x4. someone correct me if I'm wrong though

It's not about soft, it's about consistency of spring rate throughout the load bearing range.

Pic 1: FOR with nothing onboard except the 3rd row seats.

Pic 2: FOR with 300 lbs of gear and kids in and behind the 3rd row plus a 3,500 lb trailer hooked up.

FOR stated rates are comparable to OME J (227 fr / ~254 rr).

A perfectly level suspension (same hub to flare measurement front to rear) on the 80 has a visual rake. My rig is 23" hub to fender on all four corners unloaded (that means about 150 lbs of gear in the back and spare on the roof). You can see the visual rake in the first pic where all four corners measure equal - it looks level visually 3/4" down in the rear in the second pic with 300 lbs added plus the weight on the hitch (~300 lbs more at a point of max weight leverage).

To the point, adjustable rear uppers will take care of any vibe issues, whether you want a DC shaft or not on ~4" of lift is purely preference. On 6" your u-joint angles will be enough to substantially shorten u-joint life, making a DC an attractive option.

I'm not posting this to suggest that you get FOR springs (if you even can), just to show an illustration that I think the 80 looks right visually at normal load with front and rear perfectly level from a hub to flare measurement as the visual design makes a loaded setup look level. You have to drop the rear >1" to make an 80 look like the rear is sagging.

To get an 80 to look in the first pic below completely loaded means the rear will have to look jacked up unloaded. I say you go level with an excellent load bearing spring unloaded and you'll look level loaded. No additional lift required.

Bikeman 09-17-2010 01:59 PM

Once again, Bill at Front Range Driveline took care of two more drive shafts that needed work and had them bad very quickly, for a very reasonable price. That's now 4 that he has done, 2 which were custom, re-tubed.


All times are GMT -6. The time now is 08:38 AM.

Powered by vBulletin® Version 3.7.1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.