Rear end bottoming out

When going over speed bumps(even at a snails pace) the rear end bottoms out on the bump stops.I've got 300 tdi axles/springs and britpart gaz shocks.It's gas converted with two tanks,a 40l and 50l in place of the original petrol tank.These are heavy even when empty.It seems to sit low too.
I've checked other posts for an answer,but failed.What's the best option?
Do I go for heavy duty standard height (possibly police spec) or maybe 1 inch over standard?
cheers

skunk98 said:

When going over speed bumps(even at a snails pace) the rear end bottoms out on the bump stops.I've got 300 tdi axles/springs and britpart gaz shocks.It's gas converted with two tanks,a 40l and 50l in place of the original petrol tank.These are heavy even when empty.It seems to sit low too.
I've checked other posts for an answer,but failed.What's the best option?
Do I go for heavy duty standard height (possibly police spec) or maybe 1 inch over standard?
cheers

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The Police springs would be my suggestion - I've seen how much a Police Disco/RR carries in the back and your twin tank setup couldn't be heavier !!!

Cheers discool.Saw that thread,but inconclusive at the mo as was hoping to have someones experience of already having fitted some.
I looked at the spring list at http://www.4x4store-exeter.co.uk/catalog/The%204x4%20store%20rr%20ca/RR%20web%20gallery/SPRINGS.HTM as suggested on one of the threads to see the differences in springs.
The thing I'm not sure about is the effect of the spring rate on the ride.Does a lower rate mean a softer ride as the standard are rated at 207 lb/in and the heavy duty are 170 lb/in even though they take a higher load?!

Yes the lower poundage the softer the ride, RRC HD springs have a lower poundage as they are 'progressive' have SLS so can get away with it. It's only in the RRC parts book it mentions "Police Spec" no such thing in the disco book.
Have a look for any colour code on your springs to get an idea of what u have fitted and start from there, depending on what is now fitted a replacement based on the original may restore your disco the original height.

Don't go for any increase in length unless u wilsh to raise the height of your disco.

Iv'e had around 80-100kg in my boot coming back from a booze cruise so a bit of a roll on the roundabouts but the rear is still the same hight and that is on the original 14 year old springs.

Well I've got the same prob with my 1996 Tdi also. Was thinking about these
eBay - The UK's Online Marketplace.
But still a bit confused by the ratings / flex, so gonna wait a while till I'm sure of the best choice.

discool said:

Iv'e had around 80-100kg in my boot coming back from a booze cruise so a bit of a roll on the roundabouts but the rear is still the same hight and that is on the original 14 year old springs.

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When I had the tanks off, i.e. no weight, while I was working on it,it sat very high.At this point I hadn't driven it further than from the back of my mates truck and into the workshop,so didn't know what it was going to be like.
The springs on there now are the original ones from my 300 Tdi which I left on the axle when I fitted it to the V8.I had no probs on the 300 so thought they'd be ok.
I'll check if there's any colour coding on the shocks,but don't remember seeing any when they were off.I'll also measure the free length for reference.
Cheers for help so far.

There are around 3 or 4 change points as far as I can make out by pt. numbers in my book but the diesel rears are the same as the V8 rears for that model year.

fit later 300 springs ,there good for most options ,v8 will need v8 ones at front ,britpart yellow std height hd i used well for years if you want stiffer ride

I've decided to go with heavy duty standard height springs from Rimmer bros,even though their standard height rear is 30mm longer than my existing rear ones. Don't mind though as was thinking of going up an inch anyway.
Also realised the 300 has anti-roll bars which the V8 hasn't got. The springs from the 300 are marked green which are quite soft and the original V8 ones were red/grey. If I'd realised when changing the axles I would have kept the V8 springs on there.

i have police spec rear springs on mine and last summer i drove to a farm to buy 20 x 15kg bags of dog food and stacked them all in the back of the disco and the car just sat level where as when its empty the car sits up buy about 4-5 inches between the tyre and wheel arch.

here are some pics of mine when its empty.

cornish rattler said:

here are some pics of mine when its empty.

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And thats with police spec (sorry to but in but mine are sagging too and i want something along the lines of what yours look like for towing )

dyte said:

And thats with police spec (sorry to but in but mine are sagging too and i want something along the lines of what yours look like for towing )

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yes thats right the only thing you will notice with the police spec springs is that the rear suspension will be slightly stiffer when going over speed bumps, before i got the 98 disco i had a 97 disco with std suspension and that was pretty bad when going over speed bumps and that was a 5 seater where as this one is a 7 seater.

cornish rattler said:

yes thats right the only thing you will notice with the police spec springs is that the rear suspension will be slightly stiffer when going over speed bumps, before i got the 98 disco i had a 97 disco with std suspension and that was pretty bad when going over speed bumps and that was a 5 seater where as this one is a 7 seater.

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Did you do the shocks too r will i get away with standard ones they look quite new

no they where on the car when i bought it but are pretty easy enough to do though if you are ok with spanners its the fronts that are more complicated but i would only do the fronts if you are doing off roading.

there is something ells you could try if you don't want to atempt doing the springs you could try rubber coil spring assisters i have used them on cars in the past and worked very well but never tried them on a disco think they are the biggest ones you can get and they just fit inside the spring and cabled tied in place, you can get them from camping / trailer tent and caravan dealers hope this helps.

Nah doing the springs is a piece o **** just unsure what ones to buy
But think i will give the police ones a go

dyte said:

Nah doing the springs is a piece o **** just unsure what ones to buy
But think i will give the police ones a go

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yeah i would think paddocks sell them if it helps

I went with a full set of standard height heavy duty springs from Rimmer brothers. Fitted the rears so far and hell of a difference already. Gonna fit the fronts this week so should be a big improvement there too.