I have been sold on royal purple synthetic for quite some time and it already contains the LS additive. I know it's spendy but worth the cost in my opinion.

I know wheel bearings are costly to replace for a rule out. Maybe there is a way to test them with a load? I think I'm remembering you had some trouble getting the one out that you did replace. If that a sign of the history of the axle, maybe replacing it is not that much of a long shot. Maybe there is just a couple of bad spots in the bearing that are hard to detect and show up at high speed and torque

 

Yes I had a hard time getting the other side out.

The passenger side, the one that is old. Just kindve fell out. It was easy. And it looked new. It wasn't very rusted. And still shiny in places.

I went for the cheap standard gear oil this time. It's what was at the part store and I needed to get it done. I am not opposed to a more costly oil. I might spring For it next time.

 

This just means you're not suited to drive that fast.

Perhaps also check tightness of bolts on tcase to tranny. Also what is condition of the tranny mount bushing, bolts, etc.?

 

I'll add that to the list WN.

I haven't checked specifically but none of my bushings seem terrible just from being under there and looking around.

Dangit, I forgot to check the snap ring today!

 

well, see if you can squish the bushing by hand by pulling the tcase down onto it. You can't always see cracked rubber crap.

 

I can squish it a little bit. Definetly some play in the t case. I can grab drive shaft and move it around a little.

But how could that cause my issue?

 

Alright fellas here's an update.

Took passenger side wheel off to see if I could inspect the wheel bearing closer. Didn't find anything with that. But I did find a loose brake caliper bracket. The big bolts. Not the guide pins.

Tightened those up and thought I had finally found my problem.

Went up a hill and accelerated all the way to 70 and held it steady. It was as smooth as babies bottom.

Turned around and came back down the hill and the symptoms developed again at 65ish to 70. At first it seemed a lot milder. But then it all came back nice and angry.

Got back home and checked bolts again. Still tight. Other side was good too.

Suggestions? Maybe my rotor is shot from driving around with it flopping around? Warped? So will still cause an issue?

I dont really think it could be an issue. But could it be pinion nut?

Just trying to rule out as much as possible before replacing wheel beearing for the hell of it. I just don't see why it would cause such an issue in a straight line. If i haven't fixed it by next wednesday I will just replace it.

Thanks guys

 

If the rotor was warped, when you stepped on the brakes, you would certainly notice. Pedal would bounce around under your foot. (and the steering wheel would shake too.)

How are your shocks? Have you rotated your tires? Does the brake caliper release properly? Your rotors are sandwiched between the wheel, and the hub, aren't they?

 

No the rotors are free floating on the hub. Just held by the calipers.

SOMETIMES it does do the old bounce thing. Mildly.

Shocks are two years old. Brakes work. Calipers float on the guide pins well.

I'm thinking I will change out that u joint at the rear drive shaft at the t case. It did pop a cap off a while ago.

I'm thinking that under torque the u joint is pressed to the same side all the time. But when coasting down the hill it could bounce around.

Just an idea. The u joint is tight so that's why I ruled it out but at this point it's becoming questionable again.

Also the rear end breaks loose a lot easier now. Probabbky a combination of the new rear diff with limited skip additive and removing the drag from that rotor.

I have not rotated tires yet.

 

There's a crapton of things that can cause issue.

All rotating mass contributes.

I took a video of me shaking the heck out of my front driveshaft and not a bit of play whatsoever. Your response implies you have play, therefore, it will contribute to the vibe. However, it might not be the source. Just as HeyYou is walking you step by step to rule things out, the easy stuff, before tossing any money and time.



I'd consider focusing on that rear ujoint as you mentioned as that did change the system, especially if you didn't reinstall in the same clock position it was before. In another thread, I mentioned it's always practice to reinstall stock DS in same way as removal. Those things wear together over many miles. Understandably....you put swapped in the front and rear axles, which changes things.

Is there any other speed you detect a vibe or even hint of? Like in the 40 to 60 range?