What is a typical life for suspension bushes?

[Carrotland AR]

Just wondered how many years/miles before suspension bushes need replacing on a road car? 1996 K-Series Roadsport.

Ta.

[Geoff Brown]

Your chassis is more compliant than the latest 'Westbury' chassis so some of the forces imposed on the suspension are likely to be partly absorbed by the chassis.

I owned a 2000 1.6K Supersport for 11 years & 48,000 enthusiastically driven miles & never had a bush fail or wear.

Fast forward the clock to my 2013 R400D & it eats front roll bar balls & bushes/ rear anti roll bar drop link ends like they are going out of fashion. ...well two lots of front end replacements & one set of drop link ends now that I dismantle & lubricate annually. This wear I believe is due to the fact that they work harder given the increased stiffness of the chassis & I do drive it like I stole it!

 

[Carrotland AR]

Thanks Geoff, sounds like you have fun in yours 

I just wondered, they have never been changed since new in 1996.

Having discovered how the engine mounts had deteriorated this year, I wondered about the rubber in the suspension bushes. It doesn't seem easy to check.

[Geoff Brown]

The suspension bushes can only be inspected completely by strip down

I can only comment from my experience as above & from one other when I assisted a now ex member in overhauling his complete car down to 'basket case' condition to re build to 'as new'.

The car was a 1.8K upgraded original Superlight with mileage reflecting its age.

Part of the overhaul was to upgrade to Powerflex bushes after re powder coating all the suspension components, so the first job was to remove all the old bushes.

On inspection before extraction all the bushes were found in good condition except for some fine radial 'cracking' on the ends of the bushes. Interior condition was good except for one where the steel sleeve had corroded solid to the mounting bolt! The shock absorber bushes were also ok except again for the fine radial cracks.

On in depth inspection the fine radial cracks appear just at the outer ends of the bushes & did not extend into the bush.

I had them on my Ksrs & to some extent on the R400D so there is no need to be worried about this.

As with any maintenance on a Seven one should always check the suspension & bushes for play at least annually. A good wiggle & the assistance of a lever can help.

The only suspension bush that can be susceptible to accelerated wear in all cars is the spherical bush situated in the front lower wishbone where it mounts to the upright. I got through three in eleven years with my K. Some owners seem to go for years without trouble & others change them on a regular basis. Could be something to do with suspension set up.

As to engine mount rubbers, again my K was OK. Obviously the condition depends on the quality of the rubber& if lubricants etc have been spilt on them.

The main failure area is the rubber separating from the bolt sleeve not unusual in any car. Duratec mounts need careful supervision as they are under a lot of stress as the engine is mounted with loose mount bolts to block. Then when the chassis mount bolts are in & secure the block bolts are tightened up which draws everything in putting stress on the rubber.

Hope this all helps? 

 

 

 

 

[Tazio]

Like most lives I expect, full of ups and downs....

[Carrotland AR]

Thanks Geoff, for the detailed analysis. I'll certainly check the spherical bush and check for play in the others. Great stuff!

Tazio, thanks for raising a smile