movement of ertalon-bushes?

[bascona]

hello

For my rallycar (Ascona B) i'm planning to use ertalon-bushes in the front suspension.
The ertalon bushes (fixed in arm) will have an inner metal sleeve for the guidance of the bolt.
My question:
Do i make the metal sleeve a little bit longer than the ertalon bush, so the ertalon can move over the (bolted) sleeve.
Or do I make the sleeve a little bit shorter, letting the ertalon move at the sides of the bush.
... or both the same lenght?

greetings
bert

[heimue]

What is ertalon? Never heard of it before!

Dieter

[BQS4]

Dieter;
It may be poly bushings

[sawdust]

This google link might help.

[RallyBob]

Do i make the metal sleeve a little bit longer than the ertalon bush, so the ertalon can move over the (bolted) sleeve.
Or do I make the sleeve a little bit shorter, letting the ertalon move at the sides of the bush.
... or both the same lenght?

Very ironic, but tonight I was assembling an Ascona A front suspension with Delrin AF bushings. I have always made the inner sleeves just a *bit* longer than the bushing material to prevent the bushing from binding. I use the original outer washers as well, but reverse them so they have the concave surface facing away from the bushing...again this prevents binding and wear. You only need to have the metal sleeve a little longer, about .25-.30 mm.

Bob

[wrench459]

I'm not a suspension guy.
I believe if you leave the thru bolts loose until the weight of the car is in the neutral position then tighten them up you'll have a better handling rally car.
Then an alignment is in order.
You might be able to preload or unload the bushings by raising...

[oldopelguy]

I'm not a suspension guy.
I believe if you leave the thru bolts loose until the weight of the car is in the neutral position then tighten them up you'll have a better handling rally car.
Then an alignment is in order.
You might be able to preload or unload the bushings by raising...

For a rubber bushing you are right, for a poly or teflon bushing it doesn't matter as they rotate around the sleeve. Just remember to lube them up with plenty of teflon-based lube and consider adding a grease zerk to lube again later.

[Hiro]

hello

For my rallycar (Ascona B) i'm planning to use ertalon-bushes in the front suspension.
The ertalon bushes (fixed in arm) will have an inner metal sleeve for the guidance of the bolt.
My question:
Do i make the metal sleeve a little bit longer than the ertalon bush, so the ertalon can move over the (bolted) sleeve.
Or do I make the sleeve a little bit shorter, letting the ertalon move at the sides of the bush.
... or both the same lenght?

greetings
bert

I think Ertalon might wear quite fast for race usage,
Delrin as Bob's said is a tougher material,
but I don't know how expensive it is here in Europe?
Hiro

[RallyBob]

I think Ertalon might wear quite fast for race usage,
Delrin as Bob's said is a tougher material,
but I don't know how expensive it is here in Europe?
Hiro

Hiro, I prefer to use 'Delrin AF' instead of regular Delrin. The biggest difference is it has teflon mixed in, and only comes in one color....brown. I have found from experience it lasts about 3 times longer than regular Delrin when used as a suspension bushing. It is also extremely slippery, and can even be used without a lubricant at the inner sleeves (but I still use teflon grease). It is also less brittle than regular Delrin, it does not 'cold-flow' (permanently distort) as much as regular Delrin, and is not hygroscopic either. Regular Delrin will absorb moisture in wet conditions, and it swells up and can bind in the suspension arm. Delrin AF does not do this because of the teflon.

It is more expensive of course, about 3 times the price of normal Delrin. Right now it is about $40 for a 12" length, in 1.5" diameter (about 29€ for 30 cm length, 38.1 mm diameter). This is enough to make six bushings for a Manta A, with a little left over!

I have been using this material for suspension bushings for about 15 years now. In fact one car I installed these bushings into in 1997 I recently re-aquired, and the bushings are still in perfect condition. No looseness, and no binding either.

HTH,
Bob

[opelwasp]

Bob, do you make these bushings for other people? My Manta needs a suspension rebuild and would like to use a superior bushing, not the squishy rubber.

[Hiro]

Hiro, I prefer to use 'Delrin AF' instead of regular Delrin. The biggest difference is it has teflon mixed in, and only comes in one color....brown. I have found from experience it lasts about 3 times longer than regular Delrin when used as a suspension bushing. It is also extremely slippery, and can even be used without a lubricant at the inner sleeves (but I still use teflon grease). It is also less brittle than regular Delrin, it does not 'cold-flow' (permanently distort) as much as regular Delrin, and is not hygroscopic either. Regular Delrin will absorb moisture in wet conditions, and it swells up and can bind in the suspension arm. Delrin AF does not do this because of the teflon.

It is more expensive of course, about 3 times the price of normal Delrin. Right now it is about $40 for a 12" length, in 1.5" diameter (about 29€ for 30 cm length, 38.1 mm diameter). This is enough to make six bushings for a Manta A, with a little left over!

I have been using this material for suspension bushings for about 15 years now. In fact one car I installed these bushings into in 1997 I recently re-aquired, and the bushings are still in perfect condition. No looseness, and no binding either.

HTH,
Bob

Thanks Bob!
Nice to know & very nice price too,
My last attempt with Teflon was expensive & hum... not a good fabrication job,
So I gave up the idea of making my own bushes at the time.
But now I need to try again for another non-Opel project,
So I will (try to) follow your route as usual!
Cheers,
Hiro

[bascona]

@Bob

I asked the shop if they sold Delrin (AF). But as Delrin is a Dupont-brandname, they could only offer me acetal (same material).
Still have to ask if they got acetal mixed with teflon?

So if I understand it right - apart from faster wear/shorter lifespan - regular Delrin could do the job too?
All these different materials with different properties dont make it easy to choose a 'good bushing'...

bert

[RallyBob]

@Bob

I asked the shop if they sold Delrin (AF). But as Delrin is a Dupont-brandname, they could only offer me acetal (same material).
Still have to ask if they got acetal mixed with teflon?

So if I understand it right - apart from faster wear/shorter lifespan - regular Delrin could do the job too?
All these different materials with different properties dont make it easy to choose a 'good bushing'...

bert

Yes, acetal with teflon is what 'Delrin AF' is.

Regular Delrin (acetal) lasts about 1 year of racing I've found. Polyurethane lasts about 4 events (with stiff springs) before they begin to tear. Delrin AF (acetal/teflon), I've gotten 6 years of competition with (about 15 events per year), and this was with extremely stiff springs (715 lbs/inch, or 12.8 kg/mm).

As I said, the regular acetal wears much faster, it is not as 'slippery', it distorts more easily (it will become oval and not stay round), it is more brittle (might crack), and it will expand when it gets wet, which can bind the suspension.

[RallyBob]

Bob, do you make these bushings for other people? My Manta needs a suspension rebuild and would like to use a superior bushing, not the squishy rubber.

I used to have them made and used to sell them through C & R (for GT and Manta). But admittedly it's been years since I've done it, and my own personal stash is from a batch I had made about 5 years ago. So without calling my machinist I have no idea what they'd cost in today's dollars. I still have my blueprints however, and I suspect my machinist still has a copy of them. It's not worth having one set made, I always had 4-5 sets at least. I think I still have the proper ID/OD metric smooth-bore tubing for the inner sleeves as well.

Bob

[bascona]

I also thought that wear would be the major problem with all those 'plastic' bushings. Therefore this thread and question.
But for me its much cheaper (got my own lathe) and less drastical (no grinding and welding) than uniball.
So I defenitely will go for acetal-teflon bushings.

@Bob
thanks for the Delrin-AF tip!

bert