Suspension sagging at the rear. What can I do?

[Tezzzhead]

Hi everyone

I'm looking for advice on upgrading my suspension, I've converted a T28 2017 and the rear end is lower than the front.
What do people do to their conversions? Do I upgrade the suspension so its harder? Or lower the front to bring it inline with the rear? Any information or advice would be excellent
Cheers

 

[r8ger]

Speak to @CRS Performance. I think he’s sorted plenty of converted vans out with similar issues.

 

[CAB]

Hi everyone

I'm looking for advice on upgrading my suspension, I've converted a T28 2017 and the rear end is lower than the front.
What do people do to their conversions? Do I upgrade the suspension so its harder? Or lower the front to bring it inline with the rear? Any information or advice would be excellent
Cheers

@BognorMotors would be your first call based on location, nice drive back across the Downs and the Weald!

 

[BognorMotors]

@BognorMotors would be your first call based on location, nice drive back across the Downs and the Weald!

Already booked in

But thanks for the recommendation as always.

 

[dj_]

Suspension spacers worked a treat. Decided to splurge on some wheels / tyres while I was at it.
First pic unloaded, 2nd pic fully loaded vs the way it used to be. I'm delighted, thanks Steve @CRS Performance.

View attachment 108836

View attachment 108837

View attachment 108838

Looks brilliant! What size spacer did you end up with?

 

[Gmajor]

I’ve had problems with my underslung water tank hitting speed humps. Looking at the suspension, it is about 15mm lower at the rear. I though it should have some rake and be higher at back than front. My conversion company assured me it should be lower at the rear. Here’s a picture. It’s got a full camper conversion, and 20inch wheels. Does this look correct?

 

[Ads_Essex]

I’ve had problems with my underslung water tank hitting speed humps. Looking at the suspension, it is about 15mm lower at the rear. I though it should have some rake and be higher at back than front. My conversion company assured me it should be lower at the rear. Here’s a picture. It’s got a full camper conversion, and 20inch wheels. Does this look correct?

View attachment 130612

I’d say you’re right, they are wrong.
Is your steering light?
What’s the ride like, particularly the rear?
What does the rear look like when you’re loaded up with family etc?

If a van is leveled out - IE the gap on both wheels is the same - the chassis will have a 40 mm forward rake. This needs to be measured on the sill (the sill line to the floor). Behind the front wheel to in-front of the rear wheel.
if a van has a camper conversion the rear sags 30 mm approx. this makes the rake 10 mm and it isn’t enough.
Weight transfers from the front axle to the rear axle and the result is light steering.

 

[Dellmassive]

Not sure about lower at the rear bring normal?

It's all about the weight in the van.

An empty van will be higher at the rear ready for a load.

A full van will be lower at the rear when full up.

If you have a fixed weight in the rear .... IE a camper conversion . . . Then you need to set your suspension for that.

Either level across from to back....

Or slightly higher at the rear, giving you capacity for more weight to be added in the back.

Most people with adjustable suspension can adjust the heights as needed.

People with fixed suspension will normally upgrade the rear springs to T32 springs to handle the extra weight and stop the sag.

So.

What van spec have you got?

What T rating?

What suspension have you got?

 

[T6ARF]

Hi @Gmajor I’m sure an expert @CRS Performance @The Van Cave will be along shortly to give you a definitive answer, but I remember Steve at CRS telling me there should be a 40mm rake to the front, so I’d say your conversion company is wrong.

https://www.t6forum.com/attachments/transporter-measurments-jpg.79249/

Use the measuring points above?

 

[Gmajor]

Thanks everyone. Just measured from wheel centre to arch - 38cm at rear, and 40cm at front. The steering feels a bit light when fully loaded. I’ve also got a tow bar fitted for a storage crate too. I think it was set up this way for looks.

 

[Pauly]

What model of van is it ?
What suspension setup do you have, is it all still standard or anything been changed ?

 

[T6ARF]

Thanks everyone. Just measured from wheel centre to arch - 38cm at rear, and 40cm at front. The steering feels a bit light when fully loaded. I’ve also got a tow bar fitted for a storage crate too. I think it was set up this way for looks.

The wheel centre to arch measurement should be the same (front and rear)…. the front sill to ground measurement should be 40mm lower than the rear.

 

[Gmajor]

Thanks. I know it’s not the standard set up and was lowered. I don’t know the spec of the new set up. It really crashes at the back if it hits a pot hole.

 

[Dellmassive]

Can you get down and take some pics of the F/R suspension?

That may help.

 

[DXX]

it is about 15mm lower at the rear.

I have a SWB camper with stock T32 running gear and an underslung water tank. The drain cap is without a doubt the lowest point.
I haven’t bottomed out yet but if on rough ground there have been the points where I’ve jumped out to take a look.
IMO underslung tanks and van lowering don’t go together well.

 

[The Van Cave]

Thanks everyone. Just measured from wheel centre to arch - 38cm at rear, and 40cm at front. The steering feels a bit light when fully loaded. I’ve also got a tow bar fitted for a storage crate too. I think it was set up this way for looks.

For the ideal combination of looks and correct steering feel/handling, you want the measurements you've given us to be the same, so the rear needs to be lifted a bit. Standard ride height on these vans is approx 465mm from wheel centre to arch +/- about 5mm, so you're something in the region of 85mm lower than standard at the rear and 65mm at the front.

If you're on coilover suspension, it can possibly be adjusted at the rear to raise the ride height a bit, if not, a spacer or heavier weight spring can be installed at the rear to give it a lift.

Thanks. I know it’s not the standard set up and was lowered. I don’t know the spec of the new set up. It really crashes at the back if it hits a pot hole.

As @Dellmassive has said, some photos of what is under there would help us determine the setup you have and how best to achieve the required results. I suspect if it's quite crashy at the rear it might be a standard shock with lowering springs.

 

[Gmajor]

I’ve taken some photos from underneath if these help with a diagnosis?







That’s the rear.

 

[Dellmassive]

Not much travel left in that spring.....

Who knows what they are? (Defo not OEM)

Can you get a few pics of the shock absorber too?

And fronts.

 

[The Van Cave]

They look like cobra springs so I’m guessing the shocks are still OEM. They are so compressed that they are almost completely coil bound so no surprise that the ride is crashy.

 

[DXX]

When is a spring not a spring!