A-Frame

[analog_me]

As i am working on making my caterham a better car by fixing leaks, aligning suspension parts, an minimizing clonking noises etc, etc, a new one come up which i cannot tell if was there before.
If I use the handbrake and rock the car back and forward there is a clonking noise which i believe is coming from the bolt of the A-frame to the dedion.
There is definitely a small play there which you can see as exaggerated motion at the end of the rear antiroll ball (where connected to he hub).
May be a mm of play at the join between A-frame and dedion translates into a few mm of motion of the antirollbar.
I did not tighten up the bolt as per the manual at 82nm yet since i am missing the second 19mm socket needed to do the job but will do so shortly.
The manual refers to 2 x "racing washers" (as called) on either side of the Dedion and A-frame articulation but my car doesnt seem to have them,
Should this be the cause of the "play" and noise?
Should i just install 2 washers and tighten to 82nm?
Thanks

[Eric Mc]

There should be a bush where the A frame connects to the chassis. If the bush is missing or worn, you will hear a "clunk".

[analog_me]

Eric Mc said:

There should be a bush where the A frame connects to the chassis. If the bush is missing or worn, you will hear a "clunk".

Thank you Eric, so i might need to order a new one and replace the existing. But do you need a hydraulic press to remove the existing and install the new one or would just gentil hammering be sufficient?

[Equus]

It used to be said that the definition of a Frazer Nash expert was one who could change the chain drive at the side of the road without spoiling his dinner jacket.

Caterham A-frame bushes are much the same... they fail with alarming regularity (they typically only last about 6,000 miles), but are fairly straightforward to change. No hydraulic press required, though they're a tight fit so the bush housing will need to be clean and uncorroded, and washing-up liquid or rubber grease as a lubricant helps.

Edited by Equus on Monday 29th March 20:02

[BertBert]

Aren't we taking about the a-frame connecting to the DD, not the chassis? I don't recall there being a bush in the a-frame there. But it's been a while. There's a bush in the dd there.

[HustleRussell]

BertBert said:

Aren't we taking about the a-frame connecting to the DD, not the chassis? I don't recall there being a bush in the a-frame there. But it's been a while. There's a bush in the dd there.

Yep it’s only live axle cars which have the top hat bushes in the ‘A’-frame where it connects to the axle. De-Dion cars use longer lasting metalastic bushes (unlikely to be the source of the play IMO)

[analog_me]

Hi all,

All this might be a false alert, i got the socket i was missing in the first place and tighten the assemble to 82nm as per the manual's instructions.
By using the handbrake then rocking the car back and forwards the seems to be no more clunking noise comming out from it and the assembly looks rigid.
Cant drive it to test it out because another issue came up with a broken engine mount... Agggrrr!!

[Equus]

HustleRussell said:

Yep it’s only live axle cars which have the top hat bushes in the ‘A’-frame where it connects to the axle. De-Dion cars use longer lasting metalastic bushes (unlikely to be the source of the play IMO)

Depends on the age of the car. There have been several designs of A-frame, even on the de Dion; some use metalastic bushes, some use a pair of Y16 top hat bushes.