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  Topic Review (Newest First)
05-07-2021 08:25 PM
80cj Looking at the original pic. That's too much angle. Even DC joints have limitations. Ujoint and centering ball life will be short if anything else.
05-07-2021 07:55 PM
pipeburn
Quote:
Originally Posted by bruinjeeper View Post
So.

In continuance of my postings in the WDYDTY YJ thread...

I am now running a UCF ultra high clearance skid, which hangs down from the frame rails a LITTLE less than an inch.

At the same time, I installed a SS SYE... moving the rear output snout approximately 3" shorter than the standard SYE I removed.

I had my shaft lengthened to accommodate ...4"... yes... I probably should have gone 4.5-4.75" longer. Either way it works.

What looks no bueno now is the angle at my double cardan joint. I do have a MML of 1".
@fishadventure to retort to your post in the WDYDTY YJ thread, an independent crossmember would exacerbate the issue here. I am wondering why this joint is so tight. While I have you in particular on this thread, I believe you are using an XJ cut down shaft like me which makes your perspective on this situation particularly important.

I believe you are completely flat skid, independent cross member, SS Sye (?) And XJ shaft. If anything, your angle should be worse than mine in THEORY at the double cardan joint.... I'm trying to figure out why it's so steep on my setup.

Also if anyone is running a poly transmission mount, do you know if they are lower profile than stock?

I am not in a position to mod my own OEM mount right now (cut, re-weld). Though I am aware this would alleviate my issue.

Hence, curious on the Poly mounts, if they are in fact lower profile... this would solve this issue albeit leaving me working with a poly mount instead of rubber.

I'm just not understanding why this occurred. I gained MORE in snout shortening than I did drive train lift (3" vs 2.75"). At least that's how I remember the numbers. Why does this angle end up looking so steep?
ok so i measured yoke to yoke ,from transfer case to rear using the flats or face i get 17 inches, i am running a sye kit regular not the ss sye and a prothane poly mount bothe my front and rear are adams double cardin no xj ,4inches of lift, i ended up with 25 degrees on the rear shaft and 24 on the rear of axle [flats] paralell to driveshaft and it all looks good, hope this helps you!.
05-04-2021 04:13 PM
shaggyjim
Quote:
Originally Posted by pipeburn View Post
i will get you some numbers tonight, but the best way is from the yoke flat to flat , my actual rear shaft angle was 26 degress , on the back off the axle
there are flats making it paralell to the drive shaft and in line with pinion was 25 degrees, now i dont the tub on yet so i left it as is and when i put tub on if need be ill readjust. the way i was taught years ago was the better you square up your axles and upper arm bolts should slide in and out on both sides the better you will be when its time to do the pinion angle, its seem to work for more on this build and my old bronco, i have never seen what you have going on and im suprised some off the old timers have not chimed in, they usually have a good reason why!.
Well its not quite the same with the leaf springs that he's running, no matter how hard he tries he's not going to get his upper arms bolted up squarely.
Good idea to use the case spreading flange for a good read on pinion angle.
05-04-2021 04:08 PM
Boojo35
Quote:
Originally Posted by pipeburn View Post
im suprised some off the old timers have not chimed in, they usually have a good reason why!.
I am pretty old. I think Fish is also.

What would be their good reason for why you think other old timers have not chimed in? I am curious. You kinda dropped a bomb maybe and did not explain it.
05-04-2021 03:48 PM
pipeburn
numbers

Quote:
Originally Posted by Waternut View Post
I may have to look into one of those. I've been using my phone for years and although it works, it's not something I can just stick on what I want and leave it. I have to hold it and try to keep everything consistent.

@bruinjeeper Any chance you can get measurements of your driveline? I'm trying to figure out how you've gotten here. I know the AW4 is slightly longer but not that it would cause this with a super short SYE.

1. Actual driveshaft angle - Clinometer is a free app on most phones if you don't have an angle finder
2. Height of center of u-joint at axle
4. Height of center of u-joint at t-case
4. Length between fwd most u-joint at the t-case to the u-joint on the axle side
i will get you some numbers tonight, but the best way is from the yoke flat to flat , my actual rear shaft angle was 26 degress , on the back off the axle
there are flats making it paralell to the drive shaft and in line with pinion was 25 degrees, now i dont the tub on yet so i left it as is and when i put tub on if need be ill readjust. the way i was taught years ago was the better you square up your axles and upper arm bolts should slide in and out on both sides the better you will be when its time to do the pinion angle, its seem to work for more on this build and my old bronco, i have never seen what you have going on and im suprised some off the old timers have not chimed in, they usually have a good reason why!.
05-02-2021 06:15 PM
bruinjeeper
Quote:
Originally Posted by shaggyjim View Post
So it looks like Both Spicer and Saginaw make high angle wobble joints and center H sections. Maybe you could just change out a few parts on your driveshaft and get the clearance you need?
I'm well aware of the options out there but thanks for pushing. There really is no point. Looking at it again it really isn't that bad, though not ideal. It should be fine for light trails and street for this year. I didnt really have big wheeling plans until I was finalized. If I am going through the process of new shafts and springs in a year. I spent the $40 on lengthening both driveshafts and I was spent as far as this goes. I really really want to make SOA happen in a year... been talking about it for 2 years now, I can get all of that sorted then. This should work for now. Maybe a (free) tweak here or there will assist. But I am certainly not putting more money into this driveshaft when I plan on dropping a load on better/proper stuff in a year.

I really gotta look into a parking spot on the 1st level of parking - I can certainly fit it up there SOA (my jeep). But I need the one spot with electrical outlets to get to that point for now lol

If it looks like I REALLY need to do something...doubtful after my measurements and a closer look today, your earlier suggestion of spacing down the belly up (I know I know) might be the easiest solution as counterintuitive it may be
05-02-2021 04:50 PM
shaggyjim So it looks like Both Spicer and Saginaw make high angle wobble joints and center H sections. Maybe you could just change out a few parts on your driveshaft and get the clearance you need?
05-02-2021 04:23 PM
bruinjeeper Hm.

Also food for thought. You might be right... I have never read about what is inside the rubber... anytime I played with it, it just seemed like bell shaped rubber.

Lol. Only ONE way to find out *zip zip*

I kid, I kid.

I'll try and research what you're throwing down here... and if that IS the case. I am going to leave it as is and run it for the year. I really am hoping to reconfigure everything over next winter when I re-upped the jeep account

Edit: well that was quick. You're right @shaggyjim .

So, looks like I'm running it!
05-02-2021 03:44 PM
shaggyjim Ok I like the independent cross member like fish shows and I have a needlessly complex trans crossmember of my own and its great for removing the skid to work on stuff but if its not in the cards its not in the cards.
I guess what I don't understand is the trans mount you're working with. When I had a stock rubber automatic trans mount blow out I replace it and cut to old one open to see what it was like inside and it had interlocking J shaped metal pieces vulcanized into the rubber to hold everything together. I don't think it could have been cut and shortened and still functioned as intended. Am I not thinking of the same thing as you guys are talking about? It wouldn't be the first time I wasn't on the same page as everyone else.
05-02-2021 03:36 PM
bruinjeeper It is certainly a thought.

Unsure if I need to go that drastic of an approach however.

It is food for thought though. Good idea.
05-02-2021 03:11 PM
Waternut I know you said you didn't want to make a new mount but what about just scrapping the mount? I know my situation is vastly different but that small black piece at the bottom is just a 1/4" piece of an old tire. I cut two holes in it, slide it into place, and bolt the trans mount directly to the skid plate. I don't notice any engine vibrations.

Sent from my SM-G981U1 using Tapatalk
05-02-2021 02:29 PM
bruinjeeper Fish is right.

The bolts are seized through the rubber. You trim the rubber... so the transmission mounts lower in suspension on its mounting placement. If you hack off 1/2" of rubber... the transmission sits 1/2" lower... allowing better angling at the tcase output = more tolerable angling at the double cardan joint. Not that the transmission SITS 1/2" lower... it just allows the MML to do more what it's intended to do... it slopes the transmission and hence transfer case and hence output yoke

I'm not gonna go through the trouble of an independent crossmember at this junction. It's not in the cards at all currently.
05-02-2021 01:54 PM
fishadventure
Quote:
Originally Posted by shaggyjim View Post
How about a cheap one inch TC drop spacers until you get around to the spring over?
I guess I don’t see how you can cut a transmission mount and make it shorter.
Hack the rubber off of it

I still think a winged plate and crossmember would heal some of it and have many other benefits. You would ‘gain’ the thickness of the trans mount less the bolt heads and 3/8” plate.
05-02-2021 01:34 PM
shaggyjim How about a cheap one inch TC drop spacers until you get around to the spring over?
I guess I don’t see how you can cut a transmission mount and make it shorter.
05-02-2021 01:26 PM
bruinjeeper The beauty of retiring a project vehicle from DD duties?

It's no rush 🙂
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