Front DC drive shaft vibration: (2 Viewers)

[ShottsUZJ100]

ToolsRUs brought up a good question...."Your first D/C shaft was bad...they sent you a second new one...and the truck drives just the same? There should of been some improvement in having a good vs bad front driveshaft." There wasn't. ??? Hmmm, do we have another bad CV shaft?

 

[T Y L E R]

Chopped?

I'm teasin ya. The rear tires, and lighting almost make it look like you made that shot up in photoshop.


Cool area, by the looks of things ..

Hopefully your vibes won't bother you as much now. Just turn up some kick ass music, and crank the sub!





TY

 

[ShottsUZJ100]

I'm teasin ya. The rear tires, and lighting almost make it look like you made that shot up in photoshop.


Cool area, by the looks of things ..

Hopefully your vibes won't bother you as much now. Just turn up some kick ass music, and crank the sub!





TY

Ahhh...OK, gotcha.

The funny thing is that I can "live" with the vibes...for now. As long as they don't HURT the truck I can use it while we improve it. That's my issue.

 

[landtank]

Do you know if these experts also checked the angles on both sides of the CV joint to be sure they were the same?

 

[ShottsUZJ100]

Do you know if these experts also checked the angles on both sides of the CV joint to be sure they were the same?

I measured and they measured. My driveshaft slope is right-on 90* front the front diff flange. That pinion points right at that CV.

Spike's 6-inch lift has the pinion actually down a degree or two from ideal though it's smoooooth.

A THIRD BAD SHAFT? I can tell you my truck stinks from all the grease that's flipped off of the new driveshaft and landed onto hot parts. P U

 

[landtank]

I measured and they measured. My driveshaft slope is right-on 90* front the front diff flange. That pinion points right at that CV.

Spike's 6-inch lift has the pinion actually down a degree or two from ideal though it's smoooooth.

A THIRD BAD SHAFT? I can tell you my truck stinks from all the grease that's flipped off of the new driveshaft and landed onto hot parts. P U

That's not what I asked. Talk with those experts they should know what I'm talking about.

 

[T Y L E R]

A never ending vortex of middlemanedness

 

[Nay]

A never ending vortex of middlemanedness

We have a winner.

 

[desertdude]

AZ is quite known for the vortex phenomenon.

 

[-Spike-]

My LX was looked over pretty good today by some experts. They measured my front pinion/shaft angle and it's perfect.

Everything else felt tight. I was told to drive it and not worry about it and the bad part might begin to show itself. We also decided I should rebuild my front axle ASAP to see what change that makes.

I did do about an hour of wheeling today and yes that front axle is popping on the driver's side. The longer we were out the more often it popped. It popped as we'd change directions and hit the brakes or holes when flexing. My old 80 did that too intil we rebuilt the axle.

So, I'll resume to this thread after the axle rebuild.

Meanwhile MartT...if you find something please post up. THANKS!

That's about the funniest thing I've seen this week. The Copper State Cruisers went wheeling there today (Shotts actually escorted us to the trailhead- these shots are from a play area at the end of the trail) and I was told how this particular ledge was Shotts' Holy Grail, that he regularly posed on and posted about this particular spot. Lo and behold, he drives to the play area and posts up about it. Too funny. Hopefully, one of the guys in our group that was taking pics can post a couple of our attempts at this spot.

I was one of the 'experts' who looked at Shotts' truck. My qualifications are: I've worked on my own vehicles since before I could drive, and I've owned (and modded, and maintained) an 80 for several months. The other 'expert' might actually deserve this designation; he took the measurements and such, and has much more experience with suspension in general and 80's in particular. I mostly wanted to have a look, drive the vehicle, and give a different perspective to Shotts. My determination was:
The front pinion angle looks technically better (and measures better) than mine. My pinion is pointed to a spot slightly behind the t-case, and there's a noticeable angle at the pinion side u-joint. My truck (wiith the Slee 6" complete lift kit) does indeed drive, sound, and ride perfectly.
The front axle is due for a repack per mileage. This should have been done before all the other monkeying around, IMHO. I made the caveat in my earlier posts that I had done all the maintenance to my axles when I did the lift, and I had no issues. My personal belief is that you get everything as close to perfect as possible before modding it, and certainly before, or as part of the process of trying to troubleshoot a problem.
The vibrations are not as pronounced as I understood them to be. They definitely exist, but I wouldn't consider them as anything near 'shaking'. You have to pay attention while driving to notice them.
The rear driveshaft has an issue, or at least that's the way it feels and sounds. There's a definite vibration and noise coming from the area of the rear axle at certain speeds, most noticeably ~25 MPH indicated. After thinking about this all day on the trail I would not be suprised, when this is over, to find that all the problem was at the rear axle. From what I can gather, and I may have misheard, the mechanic set the adjustable upper arms at a length Christo suggested as a starting point and then drove the vehicle, adjusting the length until the best result was obtained. Shotts himself pointed out that there was still some work to be done to get the adjustment right. When I installed my adjustable upper control arms, I simply measured the angle at the T-case output flange and matched it with the axle pinion. No issues.
I realize the truck feels 'smooth' to Shotts without the front driveshaft installed, but that doesn't prove anything. The rear driveshaft has double the torque applied to it when the front is removed, and that changes things, like loading the u-joints more and loading the suspension differently.
My 'expert' recommendation is to rebuild the front axle, which needs to be done regardless, and to address the issue of the rear axle driveline noise. I think it's very possible this will fix everything. Also, something I didn't ask but think I know the answer to, is when was the rear axle last serviced? If it's due, do it. It has the same spindle configuration as the front axle minus the steering components, and requires attention too. It's not likely to be the cause of the problem, but it wouldn't hurt to eliminate it.

-Spike

 

[landtank]

Thanks Spike for the info.

The reason for my question has to do with the angles at the CV joint itself and not at the other end at the pinion. As you probably know there is a centering ball of sorts in that joint which is there to keep the angles between the 2 u-joints the same. When spec-ing out a DC Shaft for a particular application it's important to get the correct size so that those 2 angles will be the same.

While talking with Christo I had a comcern that because the caster plate rotates the axle on the rear bolt, which moves the axle rearward, the axle might be crowding the T-case. By that I mean the slope of the drive shaft would be slightly steeper and produce an anglarity difference across the CV joint.

Because you have his arms, which actually moves the axle away from the T-Case, you might actually be in a better spot.

There was a link in a post a while ago that explains this sort of thing. It went on to say that if there was some angularity at the joint you would then induce some error at the diff end to compensate for it. So if there was a 2* difference across the CV joint you would then put a 2* angle at the diff to cancel that out.

Getting the pinion angle at the diff correct was the first step in diagnosing his vib problem as it should have corrected it and you can't get a good reading on the CV joint till that's done. Since it didn't fix it he needs to dig deeper.

 

[ShottsUZJ100]

That's about the funniest thing I've seen this week. The Copper State Cruisers went wheeling there today (Shotts actually escorted us to the trailhead- these shots are from a play area at the end of the trail) and I was told how this particular ledge was Shotts' Holy Grail, that he regularly posed on and posted about this particular spot. Lo and behold, he drives to the play area and posts up about it. Too funny. Hopefully, one of the guys in our group that was taking pics can post a couple of our attempts at this spot.

What are you worried about? Your truck's built for this spot too. You can take the steepest lines up and down because you don't have all the typical front and rear bumper crud! I'm sure you had a blast! I luv having a shortened 80 and I know you do too! Sure missed the run but like I said, we had to pick up kids in Catalina at 12:45.

Yes, I know since we added the 2nd front shaft we need to re-tweak the rear again. From the first go-around though the same vibes I have now existed with the rear shaft out even. That's why I wanted somebody else to look at it before I make any decisions. You and Kev did that for me.

Front axle's ASAP. After that 1.5 hours it was popping over all the bumps!

THANKS AGAIN!

 

[ShottsUZJ100]

I measured and they measured. My driveshaft slope is right-on 90* front the front diff flange. That pinion points right at that CV.

Spike's 6-inch lift has the pinion actually down a degree or two from ideal though it's smoooooth.

A THIRD BAD SHAFT? I can tell you my truck stinks from all the grease that's flipped off of the new driveshaft and landed onto hot parts. P U

Check this info out from another buddy who just slapped on a D/C shaft for his 4" kit:

"You might - my DC shaft showed up with one U-joint cup half way out and the clip off hanging in the grease - ( can you say quality control?) I put it back together but I don't fell 100% about it - I am calling to talk with........"

I might just take my D/C shaft to a local shop to have it checked.

 

[Waggoner5]

Quality control has nothing to do with a cap being off. Shipping can easily do this. There is no driveshaft shop in the country that would send out a shaft with a cap half way off.

Before doing anything, why not swap shafts with Spike to verify you even have a front shaft problem? Then if his shaft still has a vib, then rebuild the axle and put yours back on.

 

[ShottsUZJ100]

Before doing anything, why not swap shafts with Spike to verify you even have a front shaft problem? Then if his shaft still has a vib, then rebuild the axle and put yours back on.

We thought of that. He's 2 hours away though. We'll see what's up after the axle job.

 

[sleeoffroad]

Ok, I think it is time I also step in here Just back from a 1800 mile round trip to wheel with the Texans. Had fun.

First, in my discussions when I spoke to John I recommended bringing the truck up here, or swapping arms with someone local. I can not diagnose anything more over the phone since I can not see anything wrong with the angles. It is really difficult to diagnose, not having the truck here. As Spike's post illustrates, what might be huge vibrations to someone, if not the same to another.

Also, with the mileage on the truck, the front needs to be serviced. Not saying the problem is there, but this is a process of elimination. The shop that did John's gears & lockers did not even know what is needed for a 80 diff in terms of bearings etc. So I would like to make sure the front end it put together correctly. We could be chasing our tails.

As for a 2nd bad shafts, I doubt it. Because of all the issues, we all checked that shaft before it left. As for the post RE: someone else's problem. No comment, haven't got that phone call yet.

I am also speaking to the driveline shop. They know how important quality control to us is. The problem that we dealing with is that there is only 1 company in the US the supplies that style cv head assembly. The only other option to get a Koyo part would be to buy the appropriate Toyota shaft, and mate it with the front of the 80 shaft. The problem with this is that it would be a $1000 shaft when said and done.

Believe me that we want to provide the best possible quality control on the shafts we can.

However in John's case I am just not sure we are not chasing something else.

 

[ShottsUZJ100]

The shop that did John's gears & lockers did not even know what is needed for a 80 diff in terms of bearings etc. So I would like to make sure the front end it put together correctly. We could be chasing our tails.

We tried several things BEFORE the shop did the lockers/gears. The vibes hit the day of the lift.

When the lockers/gears finally went in there was a tiny bit of improvement from what others say is reduced driveline whatever due to the 4.88 ratio.

OK, how many birf's did you break in Texas?

 

[desertdude]

I should let this die and stay out of here but... I want to set something straight

My apologies to Christo and Ben at Slee offroad - I have received only the best service - better than the best service - My parts always arrive earlier than the tracking says -and the quality of fit and install instructions perfect - Because of Slee offroad my 80 is now everything I hoped it could be everything in this world should be this fun and rewarding - Thanks!

I should know better than to post in Johns other threads I was trying to suggest to John in a "quiet way" to look over his DC shaft carefully - nothing at all to do with Slee offroad quality or service - (only the DS folks)- lesson learned


John shame on you - when you use my post for ammo please include the complete text:

Quote:
Hmmm, do we have another bad CV shaft?

You might - my DC shaft showed up with one U-joint cup half way out and the clip off hanging in the grease - ( can you say quality control?) I put it back together but I don't fell 100% about it - I am calling to talk with Ben at Slee tomorrow if they are back from Texas.


::

 

[Tools R Us]

However in John's case I am just not sure we are not chasing something else.

Agreed, our "expert analysis" consisted of looking at for a few minutes in a Circle K parking lot and a quick test drive. One observation is that his front transfer output has slightly more play than Spike's or mine.

A couple of "chops" of Spike's and my junk playing on that ledge, mine is hobbled by the huge a$$ POS ARB, little 295 tires and draging the hitch, but it's still fun to play. At one point Spike had it stood up at 44+ degrees!:hillbilly

 

[sleeoffroad]

We tried several things BEFORE the shop did the lockers/gears. The vibes hit the day of the lift.

When the lockers/gears finally went in there was a tiny bit of improvement from what others say is reduced driveline whatever due to the 4.88 ratio.

OK, how many birf's did you break in Texas?

Yes, but we have also corrected a lot of things and changed a lot of things. The problem is not being the one that has driven the truck after each change and being able to pinpoint if the mods changed the vibrations and noises. I can not believe that after all we went through the truck still drives and vibrates like the first day. Hence the suggestion to bring it up here, unless you can find someone locally to do it.

No birfields, only 2 x Aisin hubs, took lots of paint off and removed a badly twisted rear Moser shaft.