Nolathane or Rubber for DRB ?

[peter de]

Hi all

I would appreciate your thoughts/advice on whether to use nolathane or rubber suspension bushes.

Running RTS sunbird suspension, front subframe solid mounted to chassis, solid mounted steering rack and planning on 17in wheels.

I anticipate 90% road use 10% track, I am leaning towards rubber at pivot points to reduce transmission of vibration, and nolathane for antiroll bars for crisp control of weight transfer.

Anybody with a DRB please tell me what you have used ,and if you are happy with your choice. (or not!?)

thanks,

Peter

[REPTYL]

I used rubber suspension bushes on my Torana frontend and nolathane everywhere else.

I'm Happy

[cameron02]

Mine is not on the raod yet. I used rubber bushes on advice from several mechanics who said that vibration would be pretty bad for road use.

[NASSTY]

I'm using rubber bushes on my RCM (uses Jag front & rear) except for the steering rack. Haven't decided what to use on sway bars yet. A mate used nolathane on the front of his XJ6 and changed it back to rubber two months later b/c of the harsh ride/vibration/noise, but left it on the steering rake for improved feel & sharper response. I've driven his XJ & the steering feel/response is great, much better than with rubber.

[PCC]

I agree with Al.

The rubber bushes are fine on my Jag suspension. However, will switch over to nolathine on the steering as does seem a little vague.

Still playing around with my ride height - front is up - back now has to rise.

Back to the old link of back high front low. I'll be happy with somewhere level, but out of the grass!

[Ant]

I am using nolathane/urethane on my inner suspension arm bushings!

On the T/Bird uprights I am also using urethane, my first car had this firmer material and heim joints throughout, and as far I am concerned rubber is has to much compliance. Nolathane is widely used now even on farm vehicles but doesn't like the grit and grime which reduces life of bushings.

Its the old story they used to solid bush everything years ago with bronze etc and parts cracked, gave a jarring effect, because rubber has to much movement, urethane is in my opinion better.

Mounting motors I have gone to rubber mounts with bolts through, but they are not tight just a bit of clearance, on the gearbox (when I get it) I will use the same a rubber mount, or urethane, but I dont believe in mix and matching mediums.

Having said all that I am probably talking through a hole in my head, and welcome any advice!

[Aussie Mike]

Pete,

Where are the rubber bushes on the Jag steering? I'd probably put the vagueness down to wheel alignment. You might need a bit more positive casto or toe in to keep it tracking straignt.

One of the things with front suspensions where the steering rack is behind the A arms, as the suspension bushes wear and distort over time it adds toe out to your steering.

The factory Jag XJ6 front suspension bushes are actually pretty good. The inner lowers are a metalised rubber and are fairly rigid. The inner uppers are more a bearing than a rubber bush. They don't twist like a rubber bush they have greased inner and outer race that slide over each other. Most of the time you can get away with just repacking them. I wish my later model Jag had them.

I'm using some quite rigid eurethane bushes in the Jag front on my Cobra and I'll be interested to see how they perform.

One downside to eurethane that Ant has mentioned is the grit and grime. Eurethane isn't designed to be mounted rigid and twist like rubber bushes. It needs to slip as the suspension moves. This means it's got to be greased properly when assembled. unfortunately the grease dries out and dust and dirt adheres and you end up with squeaky suspension. It's probably a good idea to strip your eurethan bushes every few years and re grease them to keep them working well.

Cheers

[NASSTY]

Mike,

The Jag steering rack is held in place by three sets of bushes mounted vertically. As they wear out the rack will start to move sideways in its mounts before it starts turning the wheels, leading to vague steering response.

Your right about the factory bushes, well made & they don't turn in situ.

Cheers

[Aussie Mike]

Thanks Al, That's interesting to know.

My front end uses Jag arms and spindles but I have a Commodore manual rack that's solid mounted to the chassis.

It looks like they changed that on the later model jags too. I changed the rack in my XJ40 a few weeks back and I think the mounts were solid on that too.

Would it be worth while making up some aluminium bushes to solid mount your Jag rack rather than relying on the rubber bushes. I imagine the rubber bushes are there to isolate vibration from the steering wheel in the plush riding jaguar. Who cares about a bit of vibration in a Cobra? It's a road registered race car after all.

Cheers

[NASSTY]

Good point re aluminium bushes. I'll look into that. Rubber bushes certainly do isolate any vibrations through the steering wheel. I've got a good contract at the Vic Jag club. I'll get him to ask around to see if anyone has done it, especially the race boys of the club. Someone there has probably done it There is quite a strong racing group with their stripped out XJ's and Mach 2's etc

Cheers

[peter de]

Thanks for the replies

I am going to use rubber at pivot points.With the sunbird front subframe being solid mounted, rather than mounted on rubber insulators and the steering rack also being solid mounted(no rubber bushes at all), I feel that nolathane would transmit to much vibration through the pivot points into the steering wheel and car for road use.I will use nolathane for the sway bars however, because these will be isolated from road related vibration through the rubber at pivot points, but the firmer bushes will help the swaybars to react more 'instantly' in cornering situations.

As far as the rear suspension goes, I have plans to make some modifications which will/should be the subject of another thread.

Peter