Thread: D4 Suspension Problem

Originally Posted by imaz

Huge price differences for aftermarket vs genuine.

When working on, in or around the Discovery I always ask myself "is this a job I want to do twice?". The answer generally covers the cost difference.

Originally Posted by BradC

When working on, in or around the Discovery I always ask myself "is this a job I want to do twice?". The answer generally covers the cost difference.

I take it doing the job twice is genuine part where quality is not considered

After lots of research i generally choose OEM- it's the same item but just not in a LR box.

Depends on the item too. Re your question, I bought the Delphi units from Advanced Factors

quote...2cm is a big difference and not so much affecting suspension height but would play havoc with the speed sensors and abs/DSC

this quite concerns me , that having a different , though supposedly same size tyre fitted , can totally change the driving dynamics of the vehicle.

it concerns me to the point where my plans of re-entering the Land Rover fold may be completely shelved

there are many more options available in the motoring market without that sort of headache......I go bush a fair bit and see no joy in that happening if I have to put a different tyre on.

Originally Posted by ramblingboy42

quote...2cm is a big difference and not so much affecting suspension height but would play havoc with the speed sensors and abs/DSC

this quite concerns me , that having a different , though supposedly same size tyre fitted , can totally change the driving dynamics of the vehicle.

it concerns me to the point where my plans of re-entering the Land Rover fold may be completely shelved

there are many more options available in the motoring market without that sort of headache......I go bush a fair bit and see no joy in that happening if I have to put a different tyre on.

On no vehicle is it acceptable to have a tyre that is 20mm different to the rest,it defies logic.

Originally Posted by imaz

Replace the failed or in pairs.

After 200 000km on the original struts and airbags, I replaced all four with Delphi / BWI units. Ordered the two fronts and 2 rears under separate orders, keeping the value below 1k each order.

Originally Posted by imaz

So what are you all replacing the airbags with? Are you going genuine or aftermarket replacement? Replace the failed or in pairs.

Huge price differences for aftermarket vs genuine.

Always do in pairs, unless in an emergency situation.

And in the case of struts, OEM from a trusted supplier like Advanced Factors or LRDirect is what you want. In this case it is BWI/Delphi.

Originally Posted by ramblingboy42

it concerns me to the point where my plans of re-entering the Land Rover fold may be completely shelved

Let's take a worked example.

A 265/50/20 has a diameter of 773mm (275/45-R20 vs 265/50-R20 Tire Comparison - Tire Size Calculator | Tacoma World). That's a circumference of 2.427M. The tyre in question being some ~2cm shorter (753mm) has a circumference of 2.365M. The main 3 tyres on the vehicle are 4.3% larger. That's 443 Rotations/km vs 412 Rotations/km.

Let's take a limited slip diff for example, you are rotating those clutch plates 30 times per kilometer, or once every 33.3M. At 100kph that's just under once a second. That's enough to cook the fluid in a Haldex (as found on most AWD passenger vehicles from the late 80s til current). Even if the clutch isn't engaged, the shear force on the oil is enough to generate enough heat to cook it. Now think about what that does to the clutches in the transfer case of a D3/4.

Any vehicle more complicated than my 2WD 1988 Volvo with an open diff is going to sustain damage if you persistently drive like that. Nothing to do with the D4 being fragile and complex, but everything to do with doing something really dumb.