TR3a Front Suspension

[Ian Vincent]

As the topic description says this post is about which way round should the upper fulcrum pin go on my TR3a?

 

Roger Wiliams excellent book on how to restore a TR3a goes into the subject in some detail on page 126 where he explains that for a 3a the apex of the central bar's curve should face the centerline of car. That's fine because that was how my vehicle was before I dismantled it.

 

The problem comes in the next para when he says that for TR4a to TR6 cars it should be the other way round.

 

I am about to fit TR4a upper wishbones so that I can introduce some castor action into the steering so my question is - which way round should the fulcrum pin go - facing centreline as for a TR3a or facing out as for a TR4a?

 

By the way, I have found that one of my vertical links is damaged so I am intending to fit new ones with negative camber - will this make a difference to the way the upper fulcrum pin is fitted?

 

As this is a fairly common mod, I assume someone must have come across this before?

 

Suggestions please?

 

Ian Vincent

[RAHTR4]

Ian,

 

I was under the impression that on TR2 to TR4a the top fulcrum pin goes the way yours came off.

 

Even the diagram in the TR4 / 4A Autobook shows this.

 

However not sure about TR5 onwards.

 

In Bill Piggot's book Original TR4/4A/5/6 is a picture of a TR6 chassis - page 92 - this has the fulcrum pin the opposite way round.

 

Will be interested in what others have to say on the subject.

 

Regards, Richard

 

P.S. your parts went off on Saturday

 

 

As the topic description says this post is about which way round should the upper fulcrum pin go on my TR3a?

 

Roger Wiliams excellent book on how to restore a TR3a goes into the subject in some detail on page 126 where he explains that for a 3a the apex of the central bar's curve should face the centerline of car. That's fine because that was how my vehicle was before I dismantled it.

 

The problem comes in the next para when he says that for TR4a to TR6 cars it should be the other way round.

 

I am about to fit TR4a upper wishbones so that I can introduce some castor action into the steering so my question is - which way round should the fulcrum pin go - facing centreline as for a TR3a or facing out as for a TR4a?

 

By the way, I have found that one of my vertical links is damaged so I am intending to fit new ones with negative camber - will this make a difference to the way the upper fulcrum pin is fitted?

 

As this is a fairly common mod, I assume someone must have come across this before?

 

Suggestions please?

 

Ian Vincent