Anti-roll bar mount block retention.

[philthehill]

I am just in the process of fitting the new to me Owen Burton/ESM 19mm dia anti-roll bar.
The 6mm retaining cap headed screws used to attach the plastic mount blocks to the mount bracket have very little load bearing surface on the plastic mounting block as they are countersunk into the block.
I have been reading on several Morris Minor web sites that the retention of the plastic mounting block is not all that good. In some cases the block mounting cap headed screws have come loose due the plastic block compressing and the spring washer under the head of the cap headed screw wearing into the bottom of the counter bore.
To overcome any potential problems and to improve the holding of the block to the mount bracket I have used the following plates. https://www.merlinmotorsport.co.uk/p/an ... e-arb-mb-3
Drilling out the plate captive nut threads to 15/64" and inverting the plate so that the two captive nut stubs now fit into the counter bores of the block. The blocks are now held with a load spread over the whole plastic block. You will need slightly longer cap headed screws and larger plain washers to cover what was the underside of the threaded boss and part of the plate. The threaded boss is separate to the flat plate but appears to be welded or fused to the plate.
As regards the mounting bracket - I have used two mounting brackets on each chassis leg to spread the load. The captive nuts of each mount bracket have been drilled through to 15/64" I.D. to allow the 6mm cap headed screws to pass through. The replacement 6mm x 60mm cap headed screws now screw into two high tensile large headed 6mm riv-nuts fitted into the bottom of the chassis leg.
I will be drilling a cross through hole in the chassis leg to accommodate the 8mm dia mount bracket clamping bolt as per the original fitment instructions. Having the two brackets makes for better alignment of the cross hole. That said the bolt may not be used as I am considering fitting two high tensile 8mm riv-nuts. The 8mm hole in the bracket will be enlarged to fit over and around the head of the riv-nut and a cup washer fitted over the head of the riv-nut to clamp the mount bracket to the chassis leg. This should eliminate the need for a spacer inserted into the chassis leg. Having the two mount brackets per chassis leg and having the high tensile riv-nuts and the modified plates should eliminate any problems with the anti-roll bar mounting brackets and plastic blocks.
I will post photos in due course.

[philthehill]

Photo of the twin antiroll bar mounts with the inverted twin boss flat plates fitted.
The horizontal bolt/fitting has yet to be done.
I have changed the M6 x 60mm cap headed screws to M6 x 70mm.

anti roll bar mount 22.JPG (145.18 KiB) Viewed 433 times

Having spent most of the morning trying to get the four plastic mounting blocks fully aligned so as to be without any strain on the chassis legs, mounting blocks and mount brackets etc. I have come to the conclusion that having one mounting block per side is probably best. I will leave the second mount bracket in place and secured to the chassis leg by the two rivnuts as it will give additional support to the cross mounting bolt.

[philthehill]

Both anti-roll bar mount brackets and blocks now fitted.
The mount brackets had to be individually fitted as even though they looked to be the same there were small differences that had to be ironed out. That is why the mount brackets are numbered 1 & 2 plus 3 & 4.
I have a third set of new mount brackets that were so far out with the cross bolt hole that I could not use them paired to the original mount brackets.
When both front mounts and both rear links are fitted then I will paint the areas covered in Fertan.

anti roll bar mount 222.JPG (134.84 KiB) Viewed 382 times