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Discussion Starter · #1 · (Edited)
OK guys, put on the new shocks today that came with the lift that I didn't put on two weeks ago due to a batch of bad bushings...

While I was under there and working on the Jeep, took some pics of the driveshafts. I have been worried about pinion angle since I did the lift. PhilD has been extremely helpful as I have been communicating with him repeatedly via email. However, he has a business to run, and I do not want to take advantage of him unduly. I have been thinking about going with the Reel 1310 O.E. driveshafts for my JK since I did the lift. However, when I first did it, I would say I got closer to three inches, maybe a bit more, now, I have between 2" and 2.5" since it has settled. I am not even sure I need shafts now. The boots and shafts look great. I have pics. Problem is, I do not really know what I am looking at. Phil wanted me to check the pinion to see if it were less than 5 or 6 degrees so I would not have to purchase control arms, cause I can't afford that at all, but it was actually less than that. Here are the pics:

Front pinion angle of driveshaft-











and here is the rear shaft and pictures of angles and what not....











The readings I got using the level and diagram suggested by PhilD are as follows: and they vary depending on where I put the level on the driveshaft

Front-3.9-4.6 degrees, with 2.6 closest to the transfer case

Rear-3.9-4.7 degrees

Those pinion angles are lower than I expected for some reason, even though its a 2" lift. Its also a two-door. I think Phil and I have determined that the 1310 OE will be fine for me if I replace shafts, but I am wondering if I even need to, or if I can get away with running these things.

I do plan on putting 33s on there when I can afford them, rather than the 32s that are on there now.

So what do you guys think, and Phil feel free to chime in, I just didn't want to be wearing out your email at work?

Thanks.
 

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Does not look too bad but it is hard to really tell from pictures.

Are you getting any vibes at highway speeds? I would guess that you are not.


I also have a two door and have stock shafts/arms as well. I am sitting right about 4"


The rear should be fine. I was going to get a rear drive shaft but am low on the cash flow so I will just be picking up a spare stocker to carry in case the rear gives up the ghost.


My rear looks a little worse angle then yours and everything is still all good


In the front, I am surprised your middle boot on the slip joint there did not rip yet. Mine did right away. That one really, I would not worry about so much. Not good, but I personally do not think it is so bad if it rips.

The biggest problem in your situation is going to be the boot going into the rzeepa joint. That is the small boot going into the joint at the TC end of the DS. Mine ripped a few thousand miles ago.

I forgot we had CV driveshafts on these jeeps, the angle going into that joint is what will most likely to cause a failer although I have yet to see it happen. Once you get grit and water in there it is really going to speed up the process. Mine has be slinging grease out of it this whole time



BTW, I have put about 10k on these stock shafts with this lift



So, on a budget, I am going to carry a spare reaer oem DS with hopes of one day upgrading it. For the front, I will be upgrading to a double cardon DS and getting some adjustable front LCA's. I do not belive the angle will just happen to be ok with the double cardon DS so I want to be able to adjust it
 

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good question...you bring up a good point for any of us planning on lifting our 2dr jeeps. I am looking at getting the 2.5" teraflex spring and shock kit eventually. Supposedly the 2DRs are made by Jeep to handle a 3" lift or smaller. Everything I found out is that as long as you are under a 3" lift you dont have to replace the drive shafts as it wouldnt put it over the angle degree that could cause drive component problems.

Anyone have any comments or concerns?
I would say that from what I have seen 3" on the 2 door is the max for those joints. I think the rear could go to 3.5-4" though that would be really maxing it out.
 

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Discussion Starter · #4 ·
Are you getting any vibes at highway speeds? I would guess that you are not.


I also have a two door and have stock shafts/arms as well. I am sitting right about 4"

In the front, I am surprised your middle boot on the slip joint there did not rip yet. Mine did right away. That one really, I would not worry about so much. Not good, but I personally do not think it is so bad if it rips.

The biggest problem in your situation is going to be the boot going into the rzeepa joint. That is the small boot going into the joint at the TC end of the DS. Mine ripped a few thousand miles ago.
So far, I am not getting any vibes anywhere. I was clearly closer or over 3" when I did the lift two weeks ago. Now, I am almost certain it is between 2" and 2.5". The middle boot on the front, isn't that ripping on a skid plate for most people? I have an aftermarket plate, and maybe that is why mine hasn't ripped yet. Although I only have about 600 miles on the lift at this point. I will keep an eye on the boot by the transfer case.


good question...you bring up a good point for any of us planning on lifting our 2dr jeeps. I am looking at getting the 2.5" teraflex spring and shock kit eventually. Supposedly the 2DRs are made by Jeep to handle a 3" lift or smaller. Everything I found out is that as long as you are under a 3" lift you dont have to replace the drive shafts as it wouldnt put it over the angle degree that could cause drive component problems.

Anyone have any comments or concerns?
Well, first of all, let me say that I am totally anal about stuff like this and I worry too much. When I decided to do the lift, one of the reasons that I chose the lift I did, besides price, was that it would stay under 3" which I had been told what the gold standard for driveshafts on two-door Jeeps by multiple people. However, after I got my lift on, it had not settled yet, and was clearly over 3" but now its between 2 and 2.5" since it has settled. I am taking a trip in March out to Big Bend and its really remote out there. You can go all day on the trail and see no one. I didn't want to have drive shaft failure while there and the bigger length of my lift, at least initially is what got me worried about stuff. If you are sure you can keep it 2.5 or under, personally, I think you should be fine as long as nothing rips. Problem is, I didn't measure before I put the lift on:pissed:, so I am not sure how much I am lifted, but I am sure it was more than advertised to begin with, and I worry too much, so I am soliciting multiple opinions here...

Shafts are on my list for one day, but I simply am going to have to allow the credit card to pay for them if I do it now and with this economy and the tenuous nature of job security these days, I don't want to have to do this, but at the same time, I don't want to hike in the burning desert of a border region...:grinpimp:
 

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you are fine. i wouldn't change them, at least until you go up in tire size, and still maybe not then unless you are doing some tough wheeling.

you do need to be worried about the driveshaft hitting that skid plate, when you flex the suspension, though.

my only recommendation, if you want to keep it simple, would be to consider some upper adjustable control arms, to gain back some of the caster you lost with the lift.
 

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Discussion Starter · #6 ·
you are fine. i wouldn't change them, at least until you go up in tire size, and still maybe not then unless you are doing some tough wheeling.

you do need to be worried about the driveshaft hitting that skid plate, when you flex the suspension, though.

my only recommendation, if you want to keep it simple, would be to consider some upper adjustable control arms, to gain back some of the caster you lost with the lift.
I do not rock hop per se. I did get into some mud over at Barnwell Mountain Recreation Area, but it was not that thick industrial slop at any rate, and I do not go looking for mud, as it were. To be honest, when I went to Barnwell that was probably some of the toughest wheeling I have done. Even then, I did not go on anything above a three diamond. Most of what I do if go to the Mountains in Colorado and out in Big Bend. There is some articulating for sure, but more often then not its a few boulders in the way here and there, maybe climbing over some smaller ones that lesser 4x4s would not have any problem with either. Although I did scrape quite a bit last year and scraped the tow hitch along the ground several times while departing ravines and stuff... I haven't done anything like you see at Katemecy Rocks or out on the Rubicon. I do get into some off-camber situations and I ford streams quite a bit in Colorado, which is the main reason I wanted the lift. When my buddy and I went over to Barnwell, he disconnected his sway bar on his TJ (2" of lift with quick disconnects and 32s), I did not, as I do not have quick disconnects and I run an X...I went everywhere he did, sometimes with less trouble. That was pre-lift. I thought it was a good idea to tell everyone how I usually use my Jeep. Most of the time, I drive back and forth to work in it. If this changes anyone's opinions, let me know. And thanks again everyone...:beer:
 

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The middle boot on the front, isn't that ripping on a skid plate for most people?
It will rip on the auto trans pan when you flex off-road.

Those angles sound fine. You are not that interested with the angle at the t-case end as aftermarket shafts have a double cardan there. It is the axle end that matters more with a single UJ. This can be problematic at the front with a lot of lift, as you have to lose caster to maintain a healthy pinion angle. However with the amount of lift you have, it should not be a problem.
 

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Discussion Starter · #8 · (Edited)
It will rip on the auto trans pan when you flex off-road.

Those angles sound fine. You are not that interested with the angle at the t-case end as aftermarket shafts have a double cardan there. It is the axle end that matters more with a single UJ. This can be problematic at the front with a lot of lift, as you have to lose caster to maintain a healthy pinion angle. However with the amount of lift you have, it should not be a problem.
Awesome Phil, thank you for all of your help!:beer:

I have decided to hold off on the shafts until I need them, if I need them...I appreciate everyone's input...I am going to get them most likely at some point, but when I can afford them, or when I HAVE to have them...
 

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i've lifted my 2 door JK about 3" and have a 11 degree pinion angle on the DS so I bought a single u-jt drive shaft and currie Upper & lower control arms to align the pinion with the DS. Do you think that will be okay or you think I need to back off my 11-degree pinion angle and put my lower u-jt at a slight angle?
 

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so I bought a single u-jt drive shaft
What do you mean by single UJ? Does it have the usual double cardan at the t-case end?

Do you think that will be okay or you think I need to back off my 11-degree pinion angle and put my lower u-jt at a slight angle?
How are you measuring the pinion angle? The pinion angle should be the difference between the the angle of the pinion and the angle of the drive shaft. 11° is way too high for a UJ.

http://trailduty.com/temp/pinion_angle.pdf
 

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I believe cduggan is saying that the pinion itself is 11 degrees and in line with the drive shaft(also 11 degrees). What is the maximum angle he can adjust to before it starts causing problems. I've been told 2 degrees, but I'll let the official answer come from someone that's smarter than me.

cduggan- If you're doing this to get some of the bow out of your rear springs, you may want to look into getting some wedges for the spring perches.

PhilD - Thanks for the pdf link. That helped clear up some of the terminology confusion on my part.
 

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Thanks Denny for helping relay the info I was trying to say, here is what I meant to say.

I adjusted my upper and lower control arms so my pinion shaft would point higher were it attaches to the drive shaft and bring both in direct line with each other (pinion shaft & DS) which turned out to be 11 degrees up from level using a digital level/protractor. When checking the angle of the rear axle I put the protractor in every place that I thought would give me a good reading. locations were the 2 flat spots by my diff cover on the axle housing (back), flange outside the diff housing by my pinion shaft (appears to be in direct line with the Pinion-shaft) and the u-joints lower bearing flat area. The jk has coil springs and that is why I used the upper and lower control arms to adjust the angle. I was concerned about the oil not reaching the upper pinion bearing causing it to go bad and possible doing damage to my axle housing? The cost was bad enough the first time and I was concerned about doing it again because I did something wrong. I guess the why the link you sent me I have a -.5 degree pinion angle with a 11 degree up from level. Sorry for the lack of information on my part. Any advice you can give me would be very appreciated anyone.
 

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When I replied "U-jt", I was trying to say I removed my stock rear drive shaft and replaced it with a Tom Wood drive shaft with 1ea U-joint on the transfer case side and 1ea U-joint on the rear axle side. I guess I should have bought a double U-joint or I guess a double CV joint at the transfer case side? sorry if my terminological is incorrect. You think I need to get the double @ the transfer case?
 

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Tire size, gears, lift height, etc all have an impact on the max pinion angle, but I've generally found that anything over 5° on a double cardan to single UJ shaft causes vibration and may result in premature wear or worse.

However, shafts with a single UJ at each end are a little different and should be in phase, ie: the angle at the t-case should be the same as the angle at the pinion. The actual angle isn't important, but they both need to be the same. You can even do it by measuring from top of flange to top of flange, then bottom of flange to bottom of flange, both measurements should be the same.

However, if the angle is too high, the shaft will vibrate and fail. Hence the reason most go with a double cardan at the t-case end and a single UJ at the pinion end. You can't adjust t-case angle, but you can adjust pinion angle.

I know you are talking about a rear shaft, but I'll mention this for reference anyway. At the front the better the pinion angle the worse the caster will be, so you usually have to trade off and get the best caster angle you can without any drive line vibration.

Hope that makes sense.
 

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is the double cardan DS good for highway use? I drive back and forth to work in my JK everyday (30 miles one way). Also the rear transfer case is getting to hot to touch with normal fluid levels. Is the hot diff cover normal or do you think this may be a result of the 11 deg angle and pinion bearing starving for oil?
 

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is the double cardan DS good for highway use?
Yes, I've put 103k on double cardan shafts on my JK.

Also the rear transfer case is getting to hot to touch with normal fluid levels. Is the hot diff cover normal or do you think this may be a result of the 11 deg angle and pinion bearing starving for oil?
Hot is normal, the higher numerical gear ratio, the hotter it will get. If you have stock diff covers you most probably aren't even getting the factory amount of fluid in there, you'll have to add it through the vent tube. If you have aftermarket covers then it's usually not an issue as the fill plug is higher to account for the raised angle of the pinion. Adding more fluid is a good idea to ensure the pinion is well lubed.
 

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Thanks for all the info to help me trouble shoot this thing! I have a ARB cover and increased the fluid until it come out of the vent tube and still getting hotter than I thought it should. You think I can have my Tom Wood drive shaft sent back and have the double cardan joint installed @ the TC or you think I just need to buy another one?
 

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Front Drive Shaft Angle

I have a 09 JK Unlimited Rubicon. It has a 3.5in RockKrawler Mid Arm Lift.
I want to adjust the front oem driveshaft angle. I have adjustable lower control arms, can adjusting those arms be sufficient to adjust the driveshaft angle??
 

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I'm not positive re: RK's arms, but with any I've seen, yes, you can get the pinion angle in the ballpark. The problem then becomes getting adequate caster angle for stability. Some guys say they can live with 2 - 3 degrees and their rigs are ok, with a decent, if not perfect pinion angle. On mine, TF 4" lift & Tom Woods shafts, there was no happy medium, I never got rid of excessive front driveline vibration and the handling at anything less than about 3.5 degrees was unacceptable. I bit the bullet and went with Spyntech manual hubs. No more DL vibes, caster not an issue.
 

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You think I can have my Tom Wood drive shaft sent back and have the double cardan joint installed @ the TC or you think I just need to buy another one?
Can't see any reason why they couldn't just convert it to a double cardan at one end, the tubes will be long enough. However, it may cost quite a bit. Give them a call and get a price, a new shaft is $435 shipped.
 
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