Thud!! in rear

[wimp]

when roadin' I get a fairly loud thud in the rear suspension when coming off even the smallest obstacles.

My setup:

99 disco II
Rear SLS w/ RTE 2" spacer (noise was present even before the spacer was installed)
ACE
Bilstein HD shocks (fairly new)
Front OME springs 2" lift (brand new, but problem waqs present before the springs were installed)
16" alloys w/ 245/75 R16 Goodyear MT/R's

At first, I thought this was a trait of the airbag suspension, but then I started thinking that range rovers with 4 wheel SLS is supposed to be the smoothest, most posh ride.
Problem seems to happen on the right and left sides equally.
Otherwise the vehicle is super tight and drives great!

any help is appreciated.

M

[KevinNY]

Start simple, check for loose shocks.

[Disco Mike]

I have a very similiar set up in my 99 with SLS and the spacers. Mine started sometime after installing the RTE space and lift adjusters. I just recently replaced my air bags cause of a slight leak and believe the noise is gone but haven't tested it off road yet, too much snow.
Send me your tele number and a good time for me to call you, I would like to compare noises.
Mike

[Knut]

I had the same issue with my 2001 DII with SLS, with HD OME lift and RTE spacers in the rear. It disappeared when I converted to coils in the rear, after a few blown air springs when off roading.

I think the air springs work good when compressed, i.e. going up on an obstacle, but when coming off the obstacle the air springs expands (rapidly) and makes the loud thud.

[wimp]

Correct me if I'm wrong, but isn't the shock absorber supposed to conteract spring or airbag extension. When you climb an obstacle, the spring or airbag compresses....When you fall off of it suddenly, the spring or airbag wants to extend rapidly (it has stored energy). When it releases that energy, the shock absorber slows it down. The harder the spring pushes, the more dampening the shock absorber provides. I thought that is how it worked.

So, why does it matter weather you have springs or airbags.

Also, I thought the supposed more luxurious Range rovers have airbags on all four corners because it is smoother, more luxurious, and height sensing for staying level with various amounts of passengers. There is no way in hell the airbags would thud in a luxury car meant to be quiet and capable.

[Knut]

I don't think you're wrong. The shock absorber is supposed to dampen shock. That is why this "thud" problem had me puzzled. I changed to coils in the rear due to being tired of limping home on the rear bump stops after several occasions with a blown rear air spring.

[Disco Mike]

Originally Posted by wimp

Correct me if I'm wrong, but isn't the shock absorber supposed to conteract spring or airbag extension. When you climb an obstacle, the spring or airbag compresses....When you fall off of it suddenly, the spring or airbag wants to extend rapidly (it has stored energy). When it releases that energy, the shock absorber slows it down. The harder the spring pushes, the more dampening the shock absorber provides. I thought that is how it worked.

So, why does it matter weather you have springs or airbags.

Also, I thought the supposed more luxurious Range rovers have airbags on all four corners because it is smoother, more luxurious, and height sensing for staying level with various amounts of passengers. There is no way in hell the airbags would thud in a luxury car meant to be quiet and capable.

Try resetting the height adjuster and bring the rear end down about 1/2 inch see what happens or if it changes it. Also have you had a chance to check the part number on your shocks?
Mike

[Dan Erickson]

I have raised the rear of my DII about 1.5" (maybe closer to 2"). Just the CB method for now until I can get the time/money to do it right.

Since my shocks are original and with the extra height, I hear/feel my shocks toping out (fully extending until they are out of stroke) all the time. In my truck the noise is pretty much a "thud" when going over large bumps or comming down off a ledge.

It also did this when I was completely stock, but had it in off road mode (air suspension raised).

Seems to me this is what you could be hearing.

I figured that when I get longer travel shocks, it won't do it as often (if at all).

Peace,

Dan

[wimp]

I went off roading again, just lived with the thud for now

There is still a thud, but it is now mixed with a "something is loose or broken sound in the driver rear corner!

I think I was extending the shocks to full capacity! Even before the lift!! maybe the SLS suspension should be used with Bilsteins dispite their being listed and catalogued for that application.

I am sending them back, all 4! I'll put on OME. supposedly made for the 2" lift
thanks for all your help on this
I'll let you know if the new shocks fix the problem