TR4A Wishbones and Vertical Links fitted to my TR4

[graham505]

Hi Folks

Having stripped out the front suspension from my TR4 chassis, I've discovered that the lower wishbones and vertical links on both sides are the TR4A type and not TR4.  The vertical links are left and right hand threaded as they are on the 4A and not the 4.  The wishbones are the type that take the bushes and pivot bolt rather than sleeved to take the trunnion with the pin.

My first question is whether or not this is an acceptable set up from a suspension and steering geometry viewpoint.  I understand the top wishbones are common to both the 4 and 4A as are the upper fulcrum pins.  However, I'm not sure about any differences in the lower fulcrum pin positioning in the chassis of the 4 and 4A.

My chassis number is CT37539.

Thanks in advance for any help.

Graham

 

 

[stuart]

That’s a common upgrade, I’ve done that conversion on sidescreen cars before now, you should have the later type top wishbones too which then give you the 3degree setup as the later cars 

Stuart.

Edited June 7 by stuart

[graham505]

Thanks Stuart.  Thats good to hear.  I do have the later top wishbones.   My spring pans are original TR4 (part no. 200193),  but as far as I can tell, the shock and spring mountings on these and the later 4A type (part no. 140951) are identical.

[Chilliman]

9 hours ago, graham505 said:

My spring pans are original TR4 (part no. 200193),  but as far as I can tell, the shock and spring mountings on these and the later 4A type (part no. 140951) are identical.

No, they are different pressings Graham. the studs for the lower shock mountings are not the same & not interchangeable. . I did post some more precise details on this back along.

[graham505]

Thanks John

I'll try and find your previous posts on this.

On further inspection, the nearside on mine is the TR4A type, but the offside is TR4 so there has been some interesting 'upgrades' done in the past ;-0.

Cheers

Graham

[Richmac]

Hope you don't mind if I hijack this thread Graham and ask where best to obtain the wishbone bushes for TR4 please. I looked at old posts but the links had expired.

Thanks Richard 

[stuart]

53 minutes ago, Richmac said:

Hope you don't mind if I hijack this thread Graham and ask where best to obtain the wishbone bushes for TR4 please. I looked at old posts but the links had expired.

Thanks Richard 

TR Shop will supply what you need.

Stuart.

[BlueTR3A-5EKT]

14 hours ago, graham505 said:

Thanks Stuart.  Thats good to hear.  I do have the later top wishbones.   My spring pans are original TR4 (part no. 200193),  but as far as I can tell, the shock and spring mountings on these and the later 4A type (part no. 140951) are identical.

How did you identify the spring pan as 200193 ?

[graham505]

Hi Peter

200193 is the part number given in the Rimmer Bros catalogue for the TR2 to 4 lower spring pan.

Cheers

Graham