Front Drive Shaft grrrrrrrrr findings so far. .

[Cruiserdrew]

You shold go a bit further forward with the grind. Look where the tie rod sits at full lock.

 

[brianinaustin]

The spring package used incorrectly lifted the truck to much. The u-joints in the driveshafts does not like to operate at the new angles, hence the GRRR sounds.

However loading the vehicle with weight causes less lift and the u-joints are happy again

It is a geometry thing. So you have to correct it. How you do it is up to you.

I believe this is the answer many of us have been looking for. I have heavy 850/863 springs, which accommodates an additional 100-250lbs in the front, and 450lbs in the rear. I'm underweight! My ARB might add 50lbs, and I often have no gear and no third row in back.

So no, it's not the spring combo causing the grrrr, but there's not necessarily a problem either. Like Christo said, It's the wrong lift for the circumstances. My truck is prob'ly 4" higher from a 2" lift, because I don't have the constant load prescribed by OME.

As much as I appreciate the grrrrr pioneers boldly going where no others have gone before, I think it's time to put the power tools down and either switch to a 851/860 spring combo or (my favorite) add 600lbs of gear!

 

[fj803fe]

Not to beat this again,

But I am not sure what exactly is going on-I hear things and then hear them again on this thread.

I run J spring lift with spacers f&r-I have no castor adjustments or rear control arm adjustments to speak of. NO grrr-no problems

This spring load seems VERY independant of what is going on here-the rates of the springs will alter lift height but for the most part the same lift height spring in different load ratings will more so alter "rideability"/flex/harshness of ride.

Having the "correct set-up" for different springs is nice-but not necessarily a must. these may be the rare grr cases-but I am guessing, flat out, it is the pinion angle to the output.

Have you taken your castor correction methods off and run it stocker? whether they be plates or bushs?


ALSO for my learning-why turn the pinion angle up for a cardan shaft????? IS the point of the cardan to run at higher angles??? Then turn the pinion down for regular shaft??? Creating more of an angle. I really don't know but it sounds counterintuitive to me.

And if so why was this NOT a problem in my 9" lift 85 4runner with stock cardan shaft and no axle turning?????

 

[concretejungle]

Cruiserdrew, i made sure the area i was grinding was the proper area. I marked it with a paint pen before dropping the arm, then after a little grinding i stuffed it back up in the mounting brackets and turned the wheel to make sure i was in the right area.

 

[sleeoffroad]

But I am not sure what exactly is going on-I hear things and then hear them again on this thread.

I run J spring lift with spacers f&r-I have no castor adjustments or rear control arm adjustments to speak of. NO grrr-no problems

Changing caster in the front changes the pinion. So if you have not corrected the caster, you stand a good chance that you will not have any noises.

ALSO for my learning-why turn the pinion angle up for a cardan shaft????? IS the point of the cardan to run at higher angles??? Then turn the pinion down for regular shaft??? Creating more of an angle. I really don't know but it sounds counterintuitive to me.

Here is sume edjumecation.
http://www.4xshaft.com/techinfo.html

PS, have 1 set of those goofy sliders left.

 

[landtank]

Christo, how much correction in degrees does your caster plates induce. Currently I'm looking to adjust my axle by 5 degrees which is calculated from having the truck put on a rack after the lift. I could go with either 4 or 6 degrees if 5 would be particularly troublesome.

 

[concretejungle]

Rick, i believe the plates are supposed to set your caster at 4 degrees.

I tried this the other day, but someone said it was inacurate. If it were correct, it says i'm running 4.5 degrees.

 

[landtank]

I understand where the target is, but the result of a common plate on different trucks would result in different out comes. I was hoping Christo would share what the amount of compensation was in his plates. I'll have the ability to pick and choose what I want and I'd like some more info so I might avoid this Grrrrrrrr issue if I can.

Are those tools expensive? I know right where my caster is now and could compare it to yours. Even if it wasn't the same reading as my caster we might be able to incorporate some fudge factors and get a reasonable idea.

 

[concretejungle]

Not expensive at all. Picked it up at Sears for $14.00

 

[landtank]

I'll have one tomorrow

 

[Rich]

I tried this the other day, but someone said it was inacurate. If it were correct, it says i'm running 4.5 degrees.

I might clarify that I didn't say that your protracter is inaccurate. I did say that it is not measuring your caster angle.

 

[Bongani]

I have the 105 series with the same grrr problem. Did many things in trying to resolve it with a little success. It had the 850 in the front and the 864 in the back wioth castor correction kit. (No bb, no winch, no rear carrier) Got a 3.2" front lift and 5.2" rear lift. (Stink bug look)

I did the following.
1. Stripped front diff
2. Stripped birfields
3. Replaced output flange bearing on transfer case
4. Balanced props
5. Changed front prop to out of phase (This solved the vibration)
6. Set the preload on the ring gear bearing
7. Set the preload on the pinion
8. Fixed swaybar touching the control arm

I then removed the 850 and fitted 851 and it solved the problem 99%. Now here it gets interesting.
I fitted 15mm of spacers in the front to address the stink bug look and the problem was back.

I then removed only 5mm thus keeping 10mm spacers and viola, problem solved 99% again.

IMHO the lift is the main cuprit and as soon as it gets over 2.5" with the castor correction kit one can get some problems. Not everyone has it though.

 

[landtank]

While everyone is concentrating of lift as it changes driveline angles, I find it odd that people aren't first checking their caster on a rack to ensure it is correct. It would seem that with that info we would know where to go at what lift to avoid this problem.

And I'm thinking it's not going to be a set point for all heights but more of a gradual amount as the truck's height increases, hopefully through the 2* target area.

 

[Tools R Us]

While everyone is concentrating of lift as it changes driveline angles, I find it odd that people aren't first checking their caster on a rack to ensure it is correct. It would seem that with that info we would know where to go at what lift to avoid this problem.

And I'm thinking it's not going to be a set point for all heights but more of a gradual amount as the truck's height increases, hopefully through the 2* target area.

In stock configuration the u-joint angles are about the same, the correct geometry for a broken back design. Because the pinion points up, as the truck is lifted, maintaining the 2* caster, the transfer u-joint angle gets steeper and the axle u-joint angle becomes shallower. At some point about 5-6" of lift or less if the caster is overcorrected the pinion u-joint angle becomes 0* pointing at the transfer, requiring a CV shaft to eliminate vibration.

 

[sleeoffroad]

Rick, the caster plates give about 4 degrees of correction. Rule of thumb (from measuring caster on a lot of trucks) is that you loose about 1 degree for every inch you go up from stock.

In stock form the flange angles are like this \----/ and not like this \----\ They are oposing, but still the same. So when you drop the axle (lift the truck) and you keep the caster constant you will see that eventually the \---/ situation changes to a |---/ situation that is ideal for a cv shaft. That point is between 4" and 6" of lift. If you go beyond 6 inches of lift it changes to \----\

Clear as mud?

 

[sleeoffroad]

Ol----/P

and stock O\----/P?

Where the "O" is TRNSFR output and "P" is pinion side. Which for the first senario, makes perfect sense for use of a CV (Thanks to my edjumication ).

Other way round. O is the diff side and P is the transfercase
D\---/T (stock) vs D|---/T (lifted) where D is diff and T is transfer case and the double cardan is used on the transfer case side.

If castor is a constant (because of correction implementations) then you are showing the output flange as the altering angle as lift increases. But I see this as only being altered by having the "rake" so common to the OME 80 lifts-in effect changing the O\ to Ol.

The diff side changes in relation to the transfercase side as the front axle moves away from the frame. However, you are correct that the rear lift plays a roll as well, although minor.

Does this make sense?

 

[fj803fe]

Other way round. O is the diff side and P is the transfercase
D\---/T (stock) vs D|---/T (lifted) where D is diff and T is transfer case and the double cardan is used on the transfer case side.



The diff side changes in relation to the transfercase side as the front axle moves away from the frame. However, you are correct that the rear lift plays a roll as well, although minor.

Does this make sense?

Yeah, figured that out-hence the delete. I am trying to figure out what type of scenario I am going to end up with w/ Js in front w a 2" spacer and J in rear with a 1.18" spacer w/ castor correction. I'd like to not need a CV shaft-but I guess I figure if I need it-I have plenty of cardan shafts around here I can finangle.

But-every situation is different-I'll just need to wait and see.

Not to hijack the thread or anything-it just prompted my thought.

 

[Tools R Us]

Yeah, figured that out-hence the delete. I am trying to figure out what type of scenario I am going to end up with w/ Js in front w a 2" spacer and J in rear with a 1.18" spacer w/ castor correction. I'd like to not need a CV shaft-but I guess I figure if I need it-I have plenty of cardan shafts around here I can finangle.

But-every situation is different-I'll just need to wait and see.

Not to hijack the thread or anything-it just prompted my thought.

Your going to be in, CV shaft for the front axle and for the rear axle, longer lower and/or shorter upper rear arm, land.

 

[landtank]

Rick, i believe the plates are supposed to set your caster at 4 degrees.

I tried this the other day, but someone said it was inacurate. If it were correct, it says i'm running 4.5 degrees.

Ok, bought this protractor thing and gave it a whirl.

My reading is 13* with no caster correction on a lift that gives 22.5" front hub/fender and 24" rear hub/fender lift. If I was to correct this for a 3.3* caster result it would read 8*. The reading also includes any inclination that you might be parked on. My truck was in the garage which I know has a slight slope to purge water from the floor out the door which would show as an increase to that reading.

One nice possibility with this device might be comparing the angles of the 2 drive flanges to see their relationship to each other.

 

[alia176]

One nice possibility with this device might be comparing the angles of the 2 drive flanges to see their relationship to each other.

I did this couple of months back and if memory serves, the two flanges were within 3* of each other. I tried both an OEM driveshaft and a DC driveshaft. Each DS has fresh UJs. The DC is more favorable in the GRRRR dept, especially when decelerating. This is with a caster of 3*. I wouldn't think that this minor angle require a DC but it does in my case. Once again, 850J/863 sprngs.

Ali