Will ARB move towards CAK tank when lowering T6.1?

Jamesno376

New Member
Hi, I am new to Transporters, all of my questions have been answered here without me having to create any post, thread on T32 20" wheels/tyres was very informative. Now I'm looking to lower my 6.1 T32 Kombi 30mm, looks like I need the Eibach 6.1 comfort 30mm springs though I am concerned about how much the ARB will roll towards the CAK tank I have installed, there isn't a lot of room between the two now and when I installed it it was a real effort to get the space I have.
Am I worrying about nothing or does the ARB roll as it looks like it would by the pivot points?
998A3978-E1A6-43D0-A87E-6ACA3B829100_1_201_a.jpeg
Red arrow is ARB, blue is front of CAK tank/bracket.
 

Stay Frosty

Electrician
T6 Guru
I've got an identical setup and the H&R anti roll bar touches the tank but given that both ARB and water tank are bolted to the floor and any movement of the bar is virtually non existent there hasn't been an issue in the 2yrs since I had the bars fitted.
If you think of the bar as a torsion bar spring then most of any movement would be at the right angle bend point with the twisting movement being through the length of the bar rather than say the up down movement of a suspended tube axle.
 

The Bear78

112,000 miles and just broken in!
VIP Member
T6 Guru
The bar is indeed in torsion when unequal loads/road levels are felt across the axle. However, the centre section is cranked away from the mounting points such that it will rotate backwards when the suspension on both sides is subjected to compression.
A rudimentary calculation for the amount of deflection would be:
Maximum suspension travel ÷ distance from ARB pivot/Bush centreline from shock absorber mounting point. Multiply this figure by the distance from the ARB bush centreline to the centreline cranked section of ARB nearest the tank. This will give you the movement of the bar nearest the tank.
Obviously if this is checked while jacked (and the wheels are unsupported) then both the tank clearance and static suspension positions will not be representative.16154007280822450149242734396824.jpg
From your picture above it looks quite close and @Stay Frosty , are you sure your tank isn't under and load?
 

Stay Frosty

Electrician
T6 Guru
From the point of view that the bar hasn't worn through the tank yet we're looking ok still although the bar does touch the tank.

IMG20210311125247[1].jpgIMG20210311125247[1].jpg
 

Stay Frosty

Electrician
T6 Guru
Yep, same picture twice:unsure:

Perhaps should add that I have B14 suspension at a mid height setting with 18" wheels running 255 45 18 tyres and the tank rides just about 3" above the road surface which has been more of a worry than the limited amount of movement of the anti roll bar which is a bit of a fat thing which along with the reduced suspension travel probably helps reduce the amount of impingement on the water tank?
 
Last edited:

Jamesno376

New Member
Yep, same picture twice:unsure:

Perhaps should add that I have B14 suspension at a mid height setting with 18" wheels running 255 45 18 tyres and the tank rides just about 3" above the road surface which has been more of a worry than the limited amount of movement of the anti roll bar which is a bit of a fat thing which along with the reduced suspension travel probably helps reduce the amount of impingement on the water tank?
Thank you for pictures & reply, I see your tank is mounted slightly differently to mine, I'll have metal against metal when mine touches (mounting bracket again ARB) which I don't like the idea of so much, I think I'll see if its possible for tank manufacturer to alter the tank before I order the springs then if I do it and it's rubbing a lot I can get tank altered.

The bar is indeed in torsion when unequal loads/road levels are felt across the axle. However, the centre section is cranked away from the mounting points such that it will rotate backwards when the suspension on both sides is subjected to compression.
A rudimentary calculation for the amount of deflection would be:
Maximum suspension travel ÷ distance from ARB pivot/Bush centreline from shock absorber mounting point. Multiply this figure by the distance from the ARB bush centreline to the centreline cranked section of ARB nearest the tank. This will give you the movement of the bar nearest the tank.
Obviously if this is checked while jacked (and the wheels are unsupported) then both the tank clearance and static suspension positions will not be representative.View attachment 107679
From your picture above it looks quite close and @Stay Frosty , are you sure your tank isn't under and load?
Thanks, I'll see if I can get some correct figures into that equation!
 

CRS Performance

Suspension Specialist
Trade Member
T6 Guru
I've got an identical setup and the H&R anti roll bar touches the tank but given that both ARB and water tank are bolted to the floor and any movement of the bar is virtually non existent there hasn't been an issue in the 2yrs since I had the bars fitted.
If you think of the bar as a torsion bar spring then most of any movement would be at the right angle bend point with the twisting movement being through the length of the bar rather than say the up down movement of a suspended tube axle.
I see from your pictures that the H and R roll bars have the bracket problem , If you look closely. The bolt ( cap screw) Is not sitting square on the bracket , we experienced a set coming lose as the bolt bent. The issue has been sorted now and H and R have revised the bracket. , We. Took a grinder to the bracket to get the bolt flat on the bracket. ( then repainted them )
might be nothing to worry about but it was a problem. H and R were aware of it ,
 

Stay Frosty

Electrician
T6 Guru
I'll have a squint under there tomorrow Steve but they've been on for two years so far so probably rusted together by now.
 

CRS Performance

Suspension Specialist
Trade Member
T6 Guru
Yeah we fitted. Tons of them. No issues. Sadly. We aren’t sure how many had the bad brackets. It’s just one case where the cap screws. Worked lose. After. A few months and fell out. , maybe. Just check they are tight to be sure
 
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