Thread: Polyair Springs

Its nothing much to do with the hitch really. Just that the bar weighs 40KG plus the towball weight, all right out the back.
Polyairs are good for this, but you lose articulation. I took em off, put em on etc , on my old car.
Regards Philip A

This is hard to describe without pictures:

2 issues:

1. The height of the towball above the road should keep the trailer more or less horizontal. Therefore the downturn or upturn on the hitch that goes into the reciever will vary accordingly. When I had a suspension lift (2") I bought a nother hitch with a 2" down turn to suit keeping the trailer balanced over it's axle and level. It's about the load imposed by the trailer and it's contents on the towbar and rear of the vehicle. Those more experienced than I at towing will comment but having the trailer lift the rear can be a problem as well.

2. I installed polyairs to counteract the effect of additional load on the rear from contents in the rear of the Disco and /or load imposed by towing a trailer. This maintains a level stance for the car and without trailer which is generally the case ensure that my departure angle is not compromised. I don't regret installing them. Day to day the Disco is not loaded so my rear coils can be softer and comfortable. When the load is on I can add air to compensate.

I forgot to mention there will be the additional weight also of the long range tank being fitted this week with the r/step and w/carrier

G'day 84RR, are you running standard coils? I've got the same problem with trailer, full load in the back + full tank of fuel equals saggy rear end! But I want to keep the soft comfy stock coils. Mine's an 84 RR too.

Do you[or anyone]find the rear bottoms readily even unladen? Mine does.

I talked to Brian at Land Vehicle Spares[Sydney]and combination of rear Polyairs and 4 X 30mm polyurethane coil spacers seems to be the go. I'll be doing this after July

Let us know how you go, good luck! Cheers Scott. 8)

Hi Scott,
I gave it a 2" lift by fitting new coils and shockers a couple of months ago
When unladen it sits perfectly level (lights pointing down the road)
Towing the camper with a rear end full the headlights look like the southern lights of the Antarctic
Gavin

Rough calculation
I just weighed my rear step and spare +80KG (actually 50KG as spare weighs 30)
Long Range tank +approx 30KG (lifted one today)
Additional fuel =50KG (130-80litres)
Therefore you have potentially 160KG extra before you put the trailer on
Trailer ball weight 70KG???
total extra weight over design 220KG or about or 500Lbs.
Springs at say 180 lb per inch will sag 3 inches!!! and the front will lift quite a bit say 1/2-3/4 inch ( 100 inch wheelbase, weight 20 inches behind back wheel)
I just pulled off my rear step and sold it. Got my Long Range tank on today.
The Dimensions of a Range Rover are working against you. Maybe you need a load equaliser.
I would also begin to worry about my rear axle capacity.
Regard s Philip A

Hi

I had poly-airs in the 76 rangie I had. Thought they were great. Able to drive arround at "normal" ride hight, but pump them up when fully loaded to "maintain" normal ride hight.

Was concidering HD springs at the time, but the polly-airs are quick and easy to adjust, and I wouldn't have fit it under the house with any more lift :!:

Who spotted the deliberate error.
You have to multiply the spring rate by 2. therefore you go down 1 1/2 inches.
All the rest is correct but of course rough estimates.
the more weight further back you have the bigger the problem.
regards Philip A