Defender 110 Td5 Vibration Under Acceleration

Dear All,
My first post on this forum!
I am looking for advice on a vibration that I now experience under acceleration on my Td5 2001my Defender 110.
The vibration goes when I reach a steady speed in which ever gear I’m in. There is no vibration when coasting or decelerating.
The only thing that I have changed are all 4 springs plus an isolator on each front spring. I would have fitted isolators to the rear springs but I can’t find any of those on the market (110 rear springs are wider in diameter than 90 rear springs).
Prior to the change I had no such vibration although it wallowed badly around corners which was one of the reasons to change the springs. The front was also lifted by about 2 inches with the new springs as the old ones were so saggy.

Any thoughts on where the vibes may be coming from? Could I have mis fitted the springs or could this be due to the isolators (even though it should be an improvement)?

All serious advice gratefully received!

That sort of vibration is often the sign of a UJ starting to seize. Did you renew dampers/shocks as well as springs?
The increased height of the springs and isolator would mean a UJ on the front prop would be working at greater angles and could be the reason for the problem.

Yes, I think universal joints too. When I replaced my springs the vehicle sat a good deal higher than it had before, so much so that I got the packaging out of the bin to see whether they'd sent me lift kit springs by accident - no, apparently they were standard. So the universal joints will be doing a lot more work. If by 'isolator' you mean those rubber pads that you sometimes find between the spring and the spring seat, I've not found they make a difference to the ride. But if you're desperate to fit some, you might try just cutting some circles out of rubber matting or similar. We made some for my mother's Morris Oxford out of a piece of discarded conveyor belting, for example. I don't suppose that'll stop your vibration though. It sounds like something running slightly out of true under load.

tottot said:

That sort of vibration is often the sign of a UJ starting to seize. Did you renew dampers/shocks as well as springs?
The increased height of the springs and isolator would mean a UJ on the front prop would be working at greater angles and could be the reason for the problem.

Click to expand...

I am not convinced that it is the UJ as I replaced them 6 months ago. However your point has reminded me that the spline on the prop shaft was seized when the UJ was changed and it may have seized again which may well be a cause of the vibration.

It will have to wait until the weekend but I will take the prop off and try without as well as assessing it off the vehicle.

Great tips! Thanks guys.

Yes, a stiff spline can give the same symptoms. And so can a badly worn spline.

Sometimes the universal joints can have disappointingly short lives, even if you grease them. It's easier to feel for slack when they're on the vehicle in my experience, because the ends are being held steady. With the handbrake off in the case of the rear one, so it's not under load. Preferably on a flat surface too, so you don't accidentally run yourself over.

RMackie said:

I am not convinced that it is the UJ as I replaced them 6 months ago. However your point has reminded me that the spline on the prop shaft was seized when the UJ was changed and it may have seized again which may well be a cause of the vibration.

It will have to wait until the weekend but I will take the prop off and try without as well as assessing it off the vehicle.

Great tips! Thanks guys.

Click to expand...

If the splined section of the shaft has seized, you will need a new propshaft.