Post Rubithon drivetrain growl

[619TOY]

I have held out on posting about this because I was hoping that somehow my crescent shaped lower control arm was causing somekind of sideways stress on my rear u-joints. No such luck

OK, here are the chain of events that have lead to what sounds like growling u-joints (only on deceleration)

1. Drove 600 miles to Rubithon with no issues whatsoever.
2. Upon hitting the pavement, post Rubithon, noticed what sounds like angry u-joints (growling on deceleration)
3. Decide I should pull my front driveshaft to see if it helps.
4. I'm able to find a sweet spot at about 62 mph with no issues.
5. Set my cruise control at 62 and sail smooth for a few hunderd miles.
6. Stop for gas a little south of Modesto and realize howl has become exponentially worse on deceleration.
7. Decide to pull front shaft in 110 degree temps with A/C water dripping on my head and using Craftsman tools
8. Jump back in rig to noticeable improvement but still some growling (drink whole bottle of gatorade in 15 seconds flat).
9. Get back into San Diego to discover slip yoke siezed on front shaft and have new front driveshaft built (doesn't eliminate problem).
10. Straighten and gusset lower control arms (doesn't fix problem).
11. Will pull rear shaft to see if problem goes away but skeptical as rear shaft has almost no angle on it due to adjustable arms.
12. If pulling rear shaft has shows no improvement, where should I look next?
13. Could I have damaged a bearing? If so, I would assume it to be the output of the transfer or pinion as the front shaft was putting strain on them for ??? miles due to siezed slip yoke.

What do you think?

Update:

1. I pulled the rear shaft and the growl upon decelleration became barely noticable.
2. However the overall angryness/growl became much worse leading me to believe that the added stress to the front output of the transfer is making the situation worse.
3. What should I check or do next? I'm good for a few but some advice would be most appreciated.

Edit: everybody likes pictures, so here are before and after pics of my lower control arms:

 

[Nay]

I think you slightly damaged your rear driveshaft on the 'Con and simply pulling it and having it rebalanced will cure all of your woes.

I could not believe what a difference a $50 rebalance made - like a new rig. These candy canes and dings add up, and one day it finally gets out of tolerance. Don't worry about bearings until you have the rear shaft inspected and balanced.

 

[619TOY]

I'm afraid it won't end up that simple. If the driveshaft were dinged or something wouldn't I have vibration or growling all of the time? This seems more similar to the unpleasentness I experienced with the stock driveshaft on deceleration prior to the DC shaft. Obviously I'll know more once I pull the rear shaft and drive around a little. I will still cross my fingers that it could be something that simple as I have a really good driveshaft shop in town.

 

[Cruiserdrew]

If the front splines were frozen, it can damage the transfer case and growl.

Or, you may have damaged a rear pinion bearing, or simply had the crush sleeve crush a bit more and loosen up the pinion preload. Is there any play at the rear diff flange, or at the rear transfer flange? Any metal on the diff or transfer magnet?

Are the faces of the rear flanges still exactly parallel?

Looking forward to exactly what the problem is.

 

[hj60]

If the driveshaft were dinged or something wouldn't I have vibration or growling all of the time?

Not necessarily. Harmonics will create false negatives at various road speeds.

 

[4WD Toyota Owner Magazine]

If you bent a control arm or something that would throw off your pinion angle, it could cause vibes. On our 80, we finally got rid of a long-time annoying growl with much the same symptoms as yours by slightly rotating the rear diff up.

 

[Nay]

Not necessarily. Harmonics will create false negatives at various road speeds.

80 series driveshafts defy all conventional wisdom. I have gone through every symptom of every type of driveshaft with my old XJ, and I'd have sworn I could diagnose a driveshaft in my sleep.

And yet it took me almost a year to finally realize that vibe I had at 50 mph was the rear driveshaft because it got worse after another trip up an obstacle that always delivers a nice candy cane. I had always figured it was the angles of the front shaft if driveshaft related.

Now that frozen front shaft could be a problem, but if you have symptoms with it removed you have to start with the rear shaft. A bit 'o damage and angles right at the edge of tolerance and a vibe makes perfect sense. Mine was balance and it was only at 45-50 mph - something you'd associate with tire balance, not a driveshaft.

 

[cruiserdan]

Any other impacts?

Sway bar mount(s) ripped up?

Wheel weights?

My wife's truck had weights knocked off/moved around on all 4 wheels......

That fxxxin' granite is not at all forgiving.

 

[Atticus]

Any other impacts?

Sway bar mount(s) ripped up?

Wheel weights?

My wife's truck had weights knocked off/moved around on all 4 wheels......

That fxxxin' granite is not at all forgiving.

The language, the language.

What about u-joints? After my u-joint odyssey on my last 80, that and the drive shaft are the first place I look to diagnose problems.

 

[cruiserdan]

The language, the language.

Thank you Kettle.

 

[Atticus]

Thank you Kettle.

Don't make me PM you about it.

 

[619TOY]

If the front splines were frozen, it can damage the transfer case and growl.

What could get damaged in the transfer case?

Or, you may have damaged a rear pinion bearing, or simply had the crush sleeve crush a bit more and loosen up the pinion preload.

There are no marks at all on the driveshaft or pinion flange leading me to believe there were no impacts and I don't have crush sleeves front or rear

Is there any play at the rear diff flange, or at the rear transfer flange? Any metal on the diff or transfer magnet?.

Haven't got this far yet

Are the faces of the rear flanges still exactly parallel?

Not sure exactly what you're asking or how to measure.

If you bent a control arm or something that would throw off your pinion angle, it could cause vibes. On our 80, we finally got rid of a long-time annoying growl with much the same symptoms as yours by slightly rotating the rear diff up.

Both control arms were bent but they're both straight now with no improvement. Right now the rear pinion flange is exactly 90 degrees to the driveshaft.

Any other impacts?

Sway bar mount(s) ripped up?

Wheel weights?

My wife's truck had weights knocked off/moved around on all 4 wheels......

That fxxxin' granite is not at all forgiving.

Impacts, oh yeah, there were impacts

Don't have swaybars. Wheel weights are all torn up but still there but there really isn't a vibration at any speed. Just the growl/groan upon coasting or deceleration.

I doubt that it could be anything in the front diff as the gears are always on the coast side when the driveshaft is out and I think the growl would be there all of the time if the front diff were to blame. This leaves me with the rear shaft, diff or transfer as possibilities (in my way of thinking anyways)

 

[cpg]

What could get damaged in the transfer case?

Possible front or rear bearings if either the front or rear drive shafts splines are siezed. Just pull each shaft and make sure the slide smoothly on the splines. If they do not you may have transfer case damage. Either front of rear shaft can do it.

 

[Box Rocket]

you said you had the front driveshaft rebuilt. Does it still have single ujoints at both ends? I had nearly identical symptoms to what you described but it didn't go away until I added a DC joint to the front driveshaft.

 

[619TOY]

Yeah, the one that seized up was from Slee and the new one I had made locally are both DC shafts. The rear is as well.

 

[619TOY]

Update: sorry I've allowed my thread to fall into the darkness but I've been waaay to pre-occupied to deal with this. I will update my original post but here is the latest update. Hopefully it sounds familiar to somebody.

I have pulled my rear driveshaft and taken it to a very good local shop. He told me the CV is shot and if I were to continue to run it bad things would probably happen. I called Ben at Slee and he told me to send it back, although I haven't made time to do so yet.

This is the part where the symptoms change. Without the rear shaft in, the growl upon decelleration is pretty much not noticable. What is noticable is that the overall angryness is much worse. I believe that may be due to the additional stress on the front output of the transfer or no load on the rear of the transfer. I have driven alot over the building of my rig on one driveshaft or the other and it is always smoother and quieter than running with both driveshafts. So I guess my question is: what in the transfer would produce these symptoms and what should I do next? I will take it to a local shop with a really good reputation if I have to, but to me, it's like I've failed if I do.

 

[Taz]

I had the same issue come up about 4 years ago. I finally (about a year ago) changed the rear driveshaft to a DC from slee and all my grrsssssss went away. This was after, rebuilding stock rear drive shaft, part time kit, new front driveshaft, adjusting rear pinion angle quite a few times, re gear with all new bearings, longfields and the list goes on. I think the front and rear drive shafts "feed" off each other which can make it extremely hard to diagnose.

 

[Slomo]

Since I went with the 6" Slee I have had a growl in the rear with light throttle only, ie maintaining speed on level ground on the highway. None with no throttle in gear or with 3/4 to full throttle in gear. Mine goes away with the rear shaft removed unlike yours Steve. I have had the shaft re-balanced by a very good shop I have dealt with for 10 years and was told the shaft was fine. I have adjusted my rear pinion about 5 times with the driveshaft removed to be sure of accurate flange angle measurements. I have them identical now and it is the best so far but still annoying. I was told that the angles are just too much despite the fact that they are same it will still vibrate. Sounds like I need a DC rear shaft. On a positive note that would get my rear pinion up out of the rocks a little more.

I am interested to see how yours turns out.