Compbrake Top Mounts, Rebuild/repair?

[Ruffiano]

I wanted to replace the spherical bearings in my top mounts, does anyone know the size of them? I'm in the USA so i'm trying to source them over here if possible.

THanks in advance!

[ralleyquattro]

I have some brand new on the shelf, if no one chimes in I can measure it for you on Wednesday.

[dubmanted]

Can i ask (if a little unhelpfully ) how long have the topmounts lasted you?

Thanks

[Ruffiano]

I have some brand new on the shelf, if no one chimes in I can measure it for you on Wednesday.

Thanks Martin!


And Dubmanted, I do not know, they were pulled from a random parts car i stumbled upon. I'd been wanting a set so i was excited to find them. Before I use them, i'd like to have them back to new condition. I'm also interested/tempted to add a layer of rubber or Derlin to the top of it to avoid any potential noise.

[ralleyquattro]

. I'm also interested/tempted to add a layer of rubber or Derlin to the top of it to avoid any potential noise.

No need.. have them on three cars and no noise or unwanted harshness transferred.
In fact I was surprised how comfortable they felt on my '84 Ur-q with Eibachs and Billie HDs on long trips.

[LHD_Kid]

I'm looking for better quality bearings for these - normal ones seem to last me around 4 - 5,000 miles
I agree they are not harsh and worth the effort, if only I could find motorsport bearings...

[ralleyquattro]

I'm looking for better quality bearings for these - normal ones seem to last me around 4 - 5,000 miles
I agree they are not harsh and worth the effort, if only I could find motorsport bearings...

I've put a lot more than 5000 miles on mine and no issues so far.
As I mentioned I had them on 3 of my cars, this summer the '85 Urq will be getting them as well.

I did notice that the first set I ever got had bearings that were not as "tight" as I am used to.. even then they have lasted over 12k.
The last two sets of mounts I got have very "tight" bearings.

[Rusty]

The top mount bearings I have used cost £35 each, so it's not surprising that the comp brake ones fail, given that's about the cost if the entire mount and that includes profit margin.

[LHD_Kid]

I've put a lot more than 5000 miles on mine and no issues so far.
As I mentioned I had them on 3 of my cars, this summer the '85 Urq will be getting them as well.

I did notice that the first set I ever got had bearings that were not as "tight" as I am used to.. even then they have lasted over 12k.
The last two sets of mounts I got have very "tight" bearings.

I guess it really depends on the quality of the road surface. I'm on my 5th or 6th pair of front bearings. Rear ones last longer.

European roads are all tosh...

[quattrostyle]

I don't agree, Dutch roads are pretty good. We pay for it though so they should be.

[LHD_Kid]

I don't agree, Dutch roads are pretty good. We pay for it though so they should be.

We pay in Belgium too, sadly they must only spend the money on beaurocracy. ..

[quattrostyle]

Agreed Belgium roads are definately not the best in Europe.

[andy10v]

I'm also interested/tempted to add a layer of rubber or Derlin to the top of it to avoid any potential noise.

You might be able to add a thin layer.

I cut a bit off a standard top mount, but that was too thick



Only got 2.5 turns of engagement



Bearing just pops out the bottom when you remove the circlip



I also drilled and tapped the lockring, pop a little nylon ball in the hole, then a grub screw and the lockring wont loosen. I double nutted the strut nut as it kept coming loose.

If I can find my other set tomorrow I will measure them, they are lost in the garage somewhere.

I was planning to get some better PTFE aurora bearings or similar when needed.

[andy10v]

Inner diameter 17mm
Outer diameter 35mm

Outer race height 12mm
Bal height 20mm

[andy10v]

From compbrakes site

High angular (22000lb) Loading Goldman precision 20mm race bearing .

featuring a 17mm race bearing