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#1 Balance Link Springs
Posted: Mon Feb 03, 2020 4:49 pm
by Philk
I've just taken delivery of four replacement bonnet balance link springs (BD19972) from SNG to save myself the challenge of stripping, priming and repainting my 3.8 S1 originals (which, annoyingly, had been repainted silver in the past). To my surprise, the springs are of a different design in terms of the location of the "eye hooks"... the dimensions (and number of coils) in the spring are identical but the "eye hook" at each end of the new spring are on opposite sides of the spring whereas my original spring has them centred (see image below). In addition, it looks like the new springs have been painted in their compressed position which means each coil is joined to each other with a paint "bridge" which will crack open when the spring is stretched when the bonnet is in its closed position.
I've raised these points with SNG who are looking into things. In the meantime, is anyone aware of whether the spring design was changed at any point from centre "eye hooks" to offset?
Many thanks!
#2 Re: Balance Link Springs
Posted: Mon Feb 03, 2020 5:33 pm
by mgcjag
Hi Phil.....what am i missing they look almost identical in the photo...Steve
#3 Re: Balance Link Springs
Posted: Mon Feb 03, 2020 5:51 pm
by Philk
mgcjag wrote: ↑Mon Feb 03, 2020 5:33 pm
Hi Phil.....what am i missing they look almost identical in the photo...Steve
Hi Steve
Hopefully clearer on the photo below (where I've added some centre lines). On my old (silver) spring, the hooks are in the centre at both ends. On the new springs, they are on opposite sides of the centre lines. As such, when fitted to the car, they'll be aligned differently to my existing springs. In other respects (dimensions / no. of coils the springs are identical)
Having trawled through some of the Forum pages, I'm wondering whether the spring designs were altered when some of the different bonnet link arms were introduced (which had different angles present within them).
Best Regards
Phil

#4 Re: Balance Link Springs
Posted: Mon Feb 03, 2020 8:27 pm
by abowie
Just reuse your old ones.
#5 Re: Balance Link Springs
Posted: Mon Feb 03, 2020 11:17 pm
by 265bhp
I spent ages cleaning my old ones...and to avoid the problem of painting in the unstretched position, I stretched them whilst painting.....

#6 Re: Balance Link Springs
Posted: Tue Feb 04, 2020 8:49 pm
by Philk
265bhp wrote: ↑Mon Feb 03, 2020 11:17 pm
I spent ages cleaning my old ones...and to avoid the problem of painting in the unstretched position, I stretched them whilst painting.....
I may go down that route. Out of interest, what brand of gloss black paint did you use on them? Did you prime them first?
#7 Re: Balance Link Springs
Posted: Tue Feb 04, 2020 10:14 pm
by 265bhp
Hi Phil
A quick etch prime and then gloss top coat...all in 2K paint, no particular brand
Best
Jonathan
#8 Re: Balance Link Springs
Posted: Tue Mar 24, 2020 8:18 am
by Philk
265bhp wrote: ↑Tue Feb 04, 2020 10:14 pm
Hi Phil
A quick etch prime and then gloss top coat...all in 2K paint, no particular brand
Best
Jonathan
The lockdown is providing the ideal opportunity to do this. Heavy duty frame constructed, springs bead blasted (offsite at an earlier stage), wire brushed (with coils stretched open), etch primed and gloss painted. Time consuming but very satisfying in terms of the end result. The only thing I have to do is tidy up the ends of the hooks where the wires went to pull the springs open.
Frame constructed prior to springs being stretched out
Springs etch primed - Note how far the eye-hook has moved - with the number of coils in each spring, just opening to a 1-1.5mm gap between each coil adds considerably to their length. [This was the second pair of springs - I forgot to photograph the etch prime stage on the first pair - these are bagged up post-painting in the background of the picture]
Springs top-coated. Eye-hook released by a small amount just to reduce overall tension but with gaps still present between the coils for the paint to cure. I left them 3 days prior to releasing completely.
#9 Re: Balance Link Springs
Posted: Tue Mar 24, 2020 9:20 pm
by 265bhp
Good job Phil
Well worth it
#10 Re: Balance Link Springs
Posted: Tue Mar 24, 2020 9:38 pm
by PeterCrespin
Perfectly beveled jig corners - weep! Mine aren’t that nice when I’m framing a picture.
I suppose you’re good looking and excel at sports as well?
#11 Re: Balance Link Springs
Posted: Wed Mar 25, 2020 12:15 pm
by Philk
PeterCrespin wrote: ↑Tue Mar 24, 2020 9:38 pm
Perfectly beveled jig corners - weep! Mine aren’t that nice when I’m framing a picture.
I suppose you’re good looking and excel at sports as well?
You can take comfort in neither of the above being true! Years ago, I purchased a mitre saw to deal with a DIY project I had underway in the house and I've been surprised at how much I've used it over the years. Whilst the corner joints were glued on the "spring frame", I also put a substantial screw into each corner. It's quite amazing the amount of force required to pull the two springs open by an inch or so each.
#12 Re: Balance Link Springs
Posted: Fri Mar 27, 2020 7:04 pm
by Philk
And.... today, the finished product fitted. A very enjoyable task (aside from cleaning up the brass washers!).

#13 Re: Balance Link Springs
Posted: Fri Mar 27, 2020 9:06 pm
by Jeremy
Lovely work Phil!
#14 Re: Balance Link Springs
Posted: Fri Mar 27, 2020 9:55 pm
by 288gto
Very nice!

#15 Re: Balance Link Springs
Posted: Wed May 27, 2020 3:41 pm
by ETTony
Just had a light bulb moment, maybe that is where my front rattle is coming from, if my springs are on the loose side of not quite tight enough

#16 Re: Balance Link Springs
Posted: Wed May 27, 2020 3:54 pm
by Philk
ETTony wrote: ↑Wed May 27, 2020 3:41 pm
Just had a light bulb moment, maybe that is where my front rattle is coming from, if my springs are on the loose side of not quite tight enough
When the bonnet is locked down, the springs are under heavy tension and therefore will be tightly secured at each end on their retaining pegs. IMHO that is unlikely to cause a rattle.
#17 Re: Balance Link Springs
Posted: Fri Jun 05, 2020 11:52 am
by ETTony
Philk wrote: ↑Wed May 27, 2020 3:54 pm
ETTony wrote: ↑Wed May 27, 2020 3:41 pm
Just had a light bulb moment, maybe that is where my front rattle is coming from, if my springs are on the loose side of not quite tight enough
When the bonnet is locked down, the springs are under heavy tension and therefore will be tightly secured at each end on their retaining pegs. IMHO that is unlikely to cause a rattle.
You are so right, they are tight.
A few years ago on the RBCD up in Scotland, we all realised we all had rattles.
Still searching for rattle sources, as we all are
