May be getting ahead of yourself. Did you secure rear and test drive prior to removal? If not you should first check with rear properly installed and front removed. While rear off you should replace u-joint unless newish. Shop that said rear was OK didn't see the loose bolt and rebuilt your shaft, top-notch? Who is shade tree?
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Thanks number9. You have a point but I am now sure that the front shaft is not bad.

-D

 

Welcome, sure you're sure. A bit more information of what you found might be helpful for others following or who read your thread.
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Oh, Now I get what you mean...

So I DID tighten up all the bolts, double checked those that were torqued down, and took it for a ride with both front and rear shafts in place. Vibration was there at the same mph and of the same intensity.

To note: this was after I have had the front driveshaft rebuilt, re-balanced, re-painted, re-re all the else, etc, etc. And I did check to see that the front shaft was properly installed.

Then I removed the rear drive shaft, driving her in FWD with the CDL in HI LOCK. I drove her for one week so far, 1 full tank (about 250 miles). As I noted earlier the vibration is still there but it is less intense - yet still annoying enough.

Some side note about driving in FWD. It looks like I have gotten better MPG. I will know today when I fill up at the pump as I keep very religious records of my tank fill. So I will have details tonight.

Yesterday (yes on Valentine's day) I changed the gear oil in the transfer case. I don't know when it was last done as I only have had her since 123k when I got her last April.

I used Mobile 1 synthetic 75/90.

Today was the first 25 miles with the new oil in the transfer case. I will report on the oil change soon too.

I would like some feedback on using a heavier oil in the transfer case too? I do think I will change the oil one more time soon. And I wonder what a heavier oil might achieve?

OH YEA! And bought one of these:
Why I didn't buy something like this earlier! It makes the oil filling SO MUCH EASIER! :-)

More reports to come. Feedback on my post so far, and any questions/comments on the gear oil is much appreciated. :-)

 

Did the oil change reduce vibrations at all?

Recently did a search on using 85W/140 gear oil, found most recommend it all around and particularly for differentials. Some said very pleased using normal weight syn in center case.

Like the fluid pump and would have been a handy time saver when servicing my trans the other day and help with soon to be c/w gear oil changes. Thanks.
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Yes, but I would like to drive it a few more days to have the same conditions. ITs been really hot here (even by June/July standards) as today its 91 outside at 4:30pm!

Sorry I kind of lost you here Number9. Do you mean that when you research using 85/140 you read good things? Or that more people where happy with normal 75/90 weight gear oil?

Yes the pump is worth its weight in GOLD! I filled it with the 75/90 weight oil, pumped it up to 25 PSI - which really didnt take many pumps, maybe 6 or 7- put the filler pipe into the trans box filler hole, opened the value on the pump and sat back. Even at 60 degrees (I was doing this at dusk) it filled up the trans box in about 3 to 4 minutes. Im actually looking FORWARD to my next diff/axle or transfer box oil change!

 

As promised! Here are my MPG numbers both in 4x4 and in FWD:

4x4 MPH (last 4)
1/20/2016 - 261.7 miles driven for 11.88 MPG
1/26/2016 - 231.6 miles driven for 11.63 MPG
2/3/2016 -273.0 miles driven for 12.10 MPG
2/8/2016 - 264.0 miles driven for 12.65 MPG

FWD:
2/15/2016 - 303.1 miles driven for 13.58 MPG

Wonder want the MPG would be in FWD if the weather stayed the same and didn't get so hot?

 

Suggest doing your own web search, read and come to conclusion.

RWD only may differ as well and doubt temps will affect either much? Have considered leaving fwd shaft off while servicing for a tank to see if there's any significant gain.
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OK. Update.

So I have put in the balanced and repaired rear drive shaft.
No change. Still have a vibration.

I borrowed an extra set of rims/tires to remove them from the problem (as if balancing them 100 times didnt help). But no luck. Event with the other tires we have the vibration problem.

I took her to West Coast Rover in Lake Forest, CA. Andrew there treated me real well.

We went for a spin so he knew what the vibration was and what was going on. He suspects the problem is in the front axle somewhere. He had his people look at it but nothing was found. So He looked at it and said he spent over 1 hour under my Disco trying to find anything that might be causing the vibration. He had nothing. His best guess was possibly an issue with CV/Universal joint.

So right now I am stuck. Either I have to spend the $$ for a shop to do exploratory surgery or I have to do the surgery myself, and hope I come across the problem.

Ideas?

 

Don't see in thread where it was removed and vehicle road tested in RWD?
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