Author Topic: TC radius arm washers  (Read 1591 times)

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Offline vito84

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TC radius arm washers
« on: Friday,June 03, 2016, 10:36:56 AM »
Hi guys,
i'm putting together radius arm and chassis and i'v a lot of doubt about the correct location of varius washers and shims . Does anyone help me (better with a drawing  ;D ;D ;D)?

Thank you, ciao!
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Lotus Europa TC
Lotus Elan S2
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Offline jbcollier

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Re: TC radius arm washers
« Reply #1 on: Friday,June 03, 2016, 03:54:02 PM »

Offline EuropaTC

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Re: TC radius arm washers
« Reply #2 on: Friday,June 03, 2016, 11:13:30 PM »
If the manual drawing isn't close enough, then this is from underneath my car. Conventionally you have....

1. Rubber mounting on chassis with thick rubber section pointing inwards.

2. On my car I had two large diameter washers per mounting, one is inside the chassis and the other was outside, in direct contact with the rubber mounting. This is in case the steel insert in the rubber bush disbonds, the large washer stops the radius arm separating from the chassis or letting the arm toe-out too badly. Stops catastrophic failure in other words.

3. Originally I had smaller diameter adjustment shim washers between the radius arm and the outer large washer, pushing the leading edge of the radius arm away from the chassis. The procedure is to assemble everything, measure and then slide out the bolt to insert shim washers.
The manual shows the bolt going in the opposite direction to my photo. The reason mine's the other way is because the space between the body & chassis is tight with the number of spacers (& hence bolt length) that I needed.  It is also simpler to slide the bolt inwards towards the chassis spine than it is to pull the arm & bolt the other way when inserting shims.

The photo shows my current arrangement which uses shims between the rubber mounting flange and the chassis. This is similar to the Esprit and personally I find it's easier to adjust the rear toe with this type of shim because you only have to slacken off the mounting bolts and slide in the shims. Once you've got the adjustment in spec I took out the shims, measured and made a single one out of Al plate.

Brian

Offline fulmine

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Re: TC radius arm washers
« Reply #3 on: Saturday,June 04, 2016, 04:58:15 AM »
Se vuoi dare un'occhiata alla mia ci possiamo vedere o passi dalle mie parti.
Lotus Europa Twin Cam 1972

Offline BDA

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Re: TC radius arm washers
« Reply #4 on: Saturday,June 04, 2016, 07:04:55 AM »
Nyloc nut and cotter pin - belt and suspenders!

Offline EuropaTC

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Re: TC radius arm washers
« Reply #5 on: Saturday,June 04, 2016, 09:40:30 AM »
Nyloc nut and cotter pin - belt and suspenders!

Yeah, I know, paranoid.....   :-[

It's just me I'm afraid. Just after I'd bought the car a dealer friend decided to tell me about an Esprit he'd had in with "half the back end hanging off".  Basically a nut had come loose and the owner (a none mechanical guy) was complaining about the handling being a bit off.  Just one of those little things that stayed with me, even 30-odd years later I think about it when I'm bolting up the suspension.

Offline BDA

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Re: TC radius arm washers
« Reply #6 on: Saturday,June 04, 2016, 09:49:17 AM »
Better to be safe than sorry!

Offline vito84

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Re: TC radius arm washers
« Reply #7 on: Sunday,June 05, 2016, 03:34:03 AM »
Thank you for suggestion and pics, i will put shims between chassis and resilient mount such as int EuropaTC picture.
Fulmine, appena รจ pronta dobbiamo organizzare un raduno!
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Lotus Europa TC
Lotus Elan S2
Lotus Elan +2
Lotus Elise S1
Lotus Esprit S1

Offline fulmine

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Re: TC radius arm washers
« Reply #8 on: Sunday,June 05, 2016, 04:57:06 AM »
 :I-agree:  :beerchug:
Lotus Europa Twin Cam 1972

Offline jbcollier

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Re: TC radius arm washers
« Reply #9 on: Sunday,June 05, 2016, 02:11:45 PM »
It is possible that if you install the mount on the "outside" of the frame as shown in the photo above, you may end up with toe out and no way to adjust it. 

Offline EuropaTC

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Re: TC radius arm washers
« Reply #10 on: Monday,June 06, 2016, 12:09:33 AM »
Agreed John, and it's something to bear in mind when you're doing the geometry measurements. 

The manual for the S2 shows it outside the chassis but in the production notes there's a comment about re-locating it from outside to inside the chassis from #2414 onwards to achieve correct toe-in. This also moves the reinforcement plate to the outside of the chassis.

Drifting off topic, that change comment always puzzled me. Did that mean that the first 2414 Europas were sent out with rear toe-out or were they "exact" with no adjustment needed ? Or did Lotus alter component dimensions accidentally somewhere along the line and then have to make the change when they started getting complaints about poor handling ?   Strange, but then again, this is Lotus.....   ;)

 

Offline jbcollier

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Re: TC radius arm washers
« Reply #11 on: Monday,June 06, 2016, 06:05:52 AM »
I installed the mounts "inside" the frame on my S1 and the toe was spot on with no adjustment required.