CV joint tolerances

[theexbrit]

Hi all, just wondering if anyone knows how high can you go with a lift before you exceed Nissan specs for the CV joints?

Edited April 5, 2012 by theexbrit

[XPLORx4]

I have heard of someone on this forum who installed 1" strut spacers (between the top of the strut and the body) who blew out his CV joints at least twice while off-roading. This occurs when one or both front wheels are completely unloaded, and the suspension is at full droop. Due to the "topping out" issue, you really don't want to put coil springs in the strut which lift beyond about 2".

 

Due to this, the 4" subframe drop lift is a better solution for lifting more than 2".

[theexbrit]

Thanks. I was kind of figuring that but just wanted to confirm. I guess next year it's an SFD for me then!

[dynomax]

I have heard of someone on this forum who installed 1" strut spacers (between the top of the strut and the body) who blew out his CV joints at least twice while off-roading. This occurs when one or both front wheels are completely unloaded, and the suspension is at full droop. Due to the "topping out" issue, you really don't want to put coil springs in the strut which lift beyond about 2".

 

Due to this, the 4" subframe drop lift is a better solution for lifting more than 2".

 

How would the 1" strut spacer be any harder on the CV than the 2" lift coil?

[devonianwalk]

I run around just fine with the AC 2" lift and the 1" spacer.

[XPLORx4]

I run around just fine with the AC 2" lift and the 1" spacer.

 

Hmmm. Next time you've got both your front wheels in the air (such as during some kind of maintenance), lock your hubs (don't shift to 4WD), crank the steering wheel full left or right, and spin a tire by hand. I would be interested to see how smoothly the CV joints operate at that angle. Post a video of this on youtube.

[theexbrit]

How would the 1" strut spacer be any harder on the CV than the 2" lift coil?

 

I think XPLORx4 means that because the R50 has engine mounts that are on the body, when you add another inch to the body lift you're adding more angle to the drive shaft/CV joint relationship. The CV joint stays where it is but the engine goes up with the body lift & therefore increases the angle that the axle has to take to reach the CV joint. You can only go so far with drive shaft angle before you WILL wreck the CV joint. Don't forget, if the wheel drops into say a deep hole, the angle on the axle in relation to the CV joint will be even more severe the higher the engine is moved up away from the CV joint. Also the camber will go to @!*% as well the higher you raise the body, although this can be fixed. as XPLOx4 said, this is why people usually do a sub frame drop for anything higher than a 2" lift on the R50.

 

@devonianwalk, just out of interest why did you remove the spacer?

Edited April 5, 2012 by theexbrit

[Phantom01Pathfinder]

I think XPLORx4 means that because the R50 has engine mounts that are on the body, when you add another inch to the body lift you're adding more angle to the drive shaft/CV joint relationship. The CV joint stays where it is but the engine goes up with the body lift & therefore increases the angle that the axle has to take to reach the CV joint. You can only go so far with drive shaft angle before you WILL wreck the CV joint. Don't forget, if the wheel drops into say a deep hole, the angle on the axle in relation to the CV joint will be even more severe the higher the engine is moved up away from the CV joint. Also the camber will go to @!*% as well the higher you raise the body, although this can be fixed. as XPLOx4 said, this is why people usually do a sub frame drop for anything higher than a 2" lift on the R50.

 

@devonianwalk, just out of interest why did you remove the spacer?

Its not actually a body lift since the R50 is a unibody... (i think you understand how it works, just didnt explain it correctly) the spacer just increasing the angle on the CV, in turn giving more lift

Edited April 6, 2012 by Phantom01Pathfinder

[PaMountianbiker]

Buy My SFD lift !!!!

[theexbrit]

Its not actually a body lift since the R50 is a unibody... (i think you understand how it works, just didnt explain it correctly) the spacer just increasing the angle on the CV, in turn giving more lift

 

True, my mistake I should have just said lift as there's no separation between the chassis & "body" such as with say a WD21, which is a truck chassis with the body mounted on it

[devonianwalk]

Hmmm. Next time you've got both your front wheels in the air (such as during some kind of maintenance), lock your hubs (don't shift to 4WD), crank the steering wheel full left or right, and spin a tire by hand. I would be interested to see how smoothly the CV joints operate at that angle. Post a video of this on youtube.

 

Interesting point. I'll try to remember to do this the next time she's on a lift.

 

@devonianwalk, just out of interest why did you remove the spacer?

 

The spacer is still in place. I was trying to convey that I have yet to experience any issues with my CV's due to running both, the AC springs and the NX4 spacer simultaneously.

[XPLORx4]

Here's one way to think about how the 2 ways a strut-based IFS lift can be achieved (other than completely dropping ALL of the front suspension components with a subframe drop):

 

1. Replace the stock coil spring with a stiffer coil spring that is harder to compress

 

Let's say the strut has an 8" range of travel from fully extended to fully compressed, and on level ground, you lift the vehicle (using a jack or hydraulic lift) until the tires are off the ground. At this point, the strut is fully extended, having 8" of compression available, but 0" of extension. Now, let's also assume that before you started jacking up the vehicle, you measured the distance between the tire and fender, and came up with 5". And after the tires were in the air, you measured and came up with 9". (9-5=4) This means that, if your strut has a range of 8", the stock springs provide for 4" of extension and 4" of compression, on level ground.

 

Next, you remove the struts and replace the stock springs with ones that are harder to compress. After you put the strut back on the vehicle, you measure the distance between the tire and fender, and find that it's still 9"! Well, that's because you only changed the spring, you didn't change how far the strut extends. However, when you remove the vehicle from the hydraulic lift, you now discover that the tire is now 7" from the fender (instead of 5"). There's your 2" of lift! (9-7=2)

 

This means that your 8" long strut can now compress 6" but only extend 2" on level ground. One of the problems with having only 2" of available extension is that there's not enough range to allow the strut to compensate for most paved road surfaces, and it "tops out" (reaches maximum extension) more frequently.

 

2. Insert a spacer between the top of the strut and the body.

 

With this approach, you still haven't changed the travel range of the strut, and you haven't changed the spring rate, either. So, you still have 4" of compression and 4" of extension. However, since you have relocated the top mount of the strut, you've pushed the tire further from the body. Instead of the 9" of distance between the tire and fender (when the tires are off the ground), you add to this measurement the thickness of the spacer.

 

The problem with doing this is that the suspension is allowed to drop potentially too far for other components (tie rods, brake lines, ABS wires, axles, etc.) to safely handle. For example, if you wanted a 6" lift, why not just insert a 6" spacer above the strut? Well, the answer should be obvious. Your CV axles would be making near right-angles at both the inner and outer joints. CV joints aren't designed to operate well at very extreme angles. Fortunately, the brake lines, tie rods, and other stuff attached to the knuckle aren't as sensitive to dropping the suspension as the CV joints are.

 

So, the question is: What is the thickest spacer I could insert between the top of the strut and body, and still not exceed the safest operating angle of the CV axle? I personally do not know. As I mentioned earlier, some people haven't had any problems with a 1" spacer, but others have. I do know that about 10 years ago, when lifting an R50 was an alien concept, one R50 owner made his own 2" spacers and grenaded both CV axles on his first off-road trip with them.

[linkinpark]

I have the AC 2" inch lift coils front and back with the strut spacers up front to try and level it out. My back still sits an inch higher than the front but I have been in the mountains with one front wheel in the air at full lock left and right and nothing bad has happened yet.

[theexbrit]

Interesting point. I'll try to remember to do this the next time she's on a lift.

 

 

 

The spacer is still in place. I was trying to convey that I have yet to experience any issues with my CV's due to running both, the AC springs and the NX4 spacer simultaneously.

 

I was curious because the first time I saw your sig you had the spacer mentioned there & now you don't, so I figured you'd removed it

 

I need to run my Pathy for a while, let it settle & then see how it looks & feels before I decide on a spacer or not. I kind of like the "rakish" angle it's got at the moment. I'll have to see if I keep slipping out of the seat because of the angle though :D

[devonianwalk]

I was curious because the first time I saw your sig you had the spacer mentioned there & now you don't, so I figured you'd removed it

 

Unless someone hacked my account, I have not made any changes to my sig other than brag about winning the ToTM.

 

 

I'll have to see if I keep slipping out of the seat because of the angle though :D

 

[theexbrit]

I'm going crazy, your sig does mention your NX4 spacers. Must be old age setting in

[devonianwalk]

It's all good. As soon as I read your claim I scrolled up immediately to re-read my sig.

[Splish]

According to the guy at National 4WD in Burlington, Ontario. The max angle is 30°. I have put my Truck on the hoist and let the front suspension sag as low as it will go. I have the AC 2" Lift Kit on there, but the total strut extension is still the same as OEM. Fully extended, my CV axles were at 28°. This means, by applying the 1" strut spacers, you will at some point exceed the rating. Now the guys at Burlington 4WD say I could do it, and it will only exceed for a short while whenever my front wheels leave the ground, but they warned me, I will be burning through CV axles every few months. Especially if you take the front sway bar off!

[devonianwalk]

I would think that you would be going through the CV's if they are always engaged. I leave my manual hubs unlocked all the time with the exception of off roading. Even then, how long is a trail? 8, 10, 20 miles? I'll post here when/if my CV's fail.

 

*knocks on wood*

[pathfounder]

If the CV joints are rotating, and they bind, they will break. Sending drive through them while they bind will make them break more.

[theexbrit]

I would think that you would be going through the CV's if they are always engaged. I leave my manual hubs unlocked all the time with the exception of off roading. Even then, how long is a trail? 8, 10, 20 miles? I'll post here when/if my CV's fail.

 

*knocks on wood*

 

I think I'll let the springs settle for a few months then maybe try a 1" spacer. I have the manual hubs & don't really do any rock climbing or get "air" any other way so my front wheels hardly ever leave the ground. I kinda like the rake but I'd like to see it with a spacer to see if I prefer a more level look.

[devonianwalk]

I kinda like the rake but I'd like to see it with a spacer to see if I prefer a more level look.

 

I let my springs settle for six to seven months before buying my strut spacers from PAmountainbiker. I felt the "nose up" difference more than the visual stance. In other words, no one will notice but you!

[Splish]

According to the Mechanics at National 4x4 in Burlington who specialize in building 4x4 vehicles, the maximum angle you can go on any CV axle is 30°.

The way to check this is to lift your vehicle off the ground using a hoist until the front wheels are hanging as low as they can. Hold a floating protractor to your CV axle, and the needle will point to the angle you have. Now, when you are on the ground the CV axle won't be at that angle, but every time you flex the front end ,you will exceed the 30° angle. The mechanics there tell me that anything more than a 30° angle on your CV axles will tear them apart and will need replacing every 2 to 3 months depending on how often you drive and how often you flex it out.

[Iceman2989]

I dont really know very much about CVs... and I'm curious- What happens when one goes out/breaks? Is your vehicle then completely undrivable?

[rwd5021]

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