Vibration coming from the drive train.

Whilst pulling up in front of my house the clutch suddenly went. I managed to get it to my Landy Guy who changed the clutch and replaced oil seals and gaskets on the transfer box which had a leak.
Shortly after I noticed a vibration appeared which occurs between 70 KPH to 90 KPH.
I thought the vibration felt as if it was coming from the front somewhere. I disconnected the front propshaft and drove it. ibration still there. I had a spare brand new front prop shaft so I replaced the old one. I
I then disconnected the rear propshaft. Vibration still there.
I then thought it might be a front bearing , so changed all the front bearings.
No change, vibration still there. Replaced all the ball joints.No change.
Took it back to the Landy guy who dropped the transfer box and checked all his work. Clutch and the transfer box. He couldn't find anything.
I jacked up the front wheel and started her up and engaged a gear to spin the wheel. All seemed fine. Did the same to the other side and I could not spin the wheel, it drove off the jack. LAndy guy said there might be the problem. He stripped the front diff which is a Salisbury. He had difficulty in removing the diff mechanism and thought he found the problem and replaced the bearing in the diff. Vibration still there.
I then suggested checking the CV joint. He removed the front right and reported back all seemed OK. He told me before he didn't think that would cause the vibration but running out of things to look at I wanted to check it.
He then suggested it might be a flat spot on a tire or a buckled wheel. we changed the wheels for the ones on his Landy. Vibration still there.
When going down hill I put it in neutral and as it coast down hill the vibration is still there. It feels like a bearing type vibration. I once had an Austin Cambridge where the end of a UJ had come off on the prop shaft. it's that sort of a vibration. I am lost to know where to look next. Any suggestions anyone?

Definitely sounds like front half shaft, CV or bearing. When it drove off the jack, the problem lies with the wheel off the ground.

If the mechanism won't allow one of the front wheels to rotate freely so that the car drives itself off the jack, it sounds to me rather like something in the diff might be binding. Probably not the bearings as they've been done, but in the carrier mechanism maybe. As it's a Salisbury, I'd take the cover off and see what happens when you rotate each front wheel in turn and the propshaft. There's something locking the ring gear motion to one of the halfshafts.

Unless there's a Detroit locker in there that you've not told us about.

Brown said:

If the mechanism won't allow one of the front wheels to rotate freely so that the car drives itself off the jack, it sounds to me rather like something in the diff might be binding. Probably not the bearings as they've been done, but in the carrier mechanism maybe. As it's a Salisbury, I'd take the cover off and see what happens when you rotate each front wheel in turn and the propshaft. There's something locking the ring gear motion to one of the halfshafts.

Unless there's a Detroit locker in there that you've not told us about.

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The diff was stripped and repaired, he had to replace the bearing in the diff as he had trouble getting it out. it's all been put back together again and now I can jack up either side front and drive the wheels round without it going off the jack. So i think that is sorted, except I still have this vibration

Sounds like you have pretty much eliminated the gearbox. If possible, you might disconnect the props and use a set of rollers/rolling road to identify the source.

zeaphod said:

Sounds like you have pretty much eliminated the gearbox. If possible, you might disconnect the props and use a set of rollers/rolling road to identify the source.

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I was waiting for the weather to improve, I was then going to do that but get someone to tow me.

mikescuba said:

When going down hill I put it in neutral and as it coast down hill the vibration is still there.

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could be sommert simple, Steering box bracket loose/cracked
- Panhard rod bushes shot, sounds like a really minor "death wobble" type thing.

My mate had a horrid vibration we thought was coming from the front, turned out to be the rear diff.

mikescuba said:

The diff was stripped and repaired, he had to replace the bearing in the diff as he had trouble getting it out. it's all been put back together again and now I can jack up either side front and drive the wheels round without it going off the jack. So i think that is sorted, except I still have this vibration

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Beg your pardon - I got the impression it was still happening after the bearing was changed.

Lost any wheel balance weights lately?

Brown said:

Beg your pardon - I got the impression it was still happening after the bearing was changed.

Lost any wheel balance weights lately?

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tried switching my four wheels with his. vibration still there.

You could try driving with all the drive flange bolts out and no front prop,nothing would then turn in the axle and if it runs smooth you will know where the problem is. Some oil will escape.