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steering rack outrigger dimensions

PostPosted: Thu Jul 04, 2013 2:09 am
by robertverhey
Hello all

As per my resto thread, I'm having some trouble getting the steering rack to fit.

I can't imagine that Spyder would make a mistake with the mounting holes, but to discount this as a variable, could I ask someone to confirm the dimension below? Can be from Spyder or original chassis.

Image

Many thanks

Robert

Re: steering rack outrigger dimensions

PostPosted: Thu Jul 04, 2013 8:38 am
by oldelanman
Hi Robert,
I have a Spyder remanufactured chassis, it's difficult to measure accurately with it all assembled but I get 275mm between each pair of mounting holes. Measuring from the centre line the LH holes are at 120mm and 160mm and the RH holes are at 115mm and 155mm - although the difference left to right may just be down to my measuring.
Your outriggers look different to mine - yours appear to be different widths and the RHS looks too narrow - mine are the same width. Looking at the pic you posted in your resto thread your pinion housing appears to be overhanging the RH platform and not supported. My RH mount sits pretty much in the centre of the platform and the flat at the bottom of the pinion housing is also sitting on the platform.

Steering Rack Mount 005.jpg and
Steering Rack Mount 006.jpg and
engine 011.jpg and

Re: steering rack outrigger dimensions

PostPosted: Thu Jul 04, 2013 10:39 am
by robertverhey
Many thanks for prompt reply Roger
The dimensions all tally, ie distances between holes on mine are the same as yours, as are distances from centre

Which just leaves that strange overhang.....you're quite right, my O/S outrigger is more narrow than yours and no part of the pinion housing sits on it. Different to yours....and different to the chassis I scrapped (as shown below)

Image

Can any other Spyder chassis owners shed any further light? I will need to give Spyder a call (they don't do email), but it would be good to know what I'm dealing with here!

Robert

Re: steering rack outrigger dimensions

PostPosted: Thu Jul 04, 2013 7:53 pm
by RichardHawkins
Robert,
I don't have a Spyder chassis, but the photograph in Brian Bucklands book looks like the one you show.

My chassis is a Lotus Replacement. The holes for rack mounting on my chassis are 12 & 1/8 inches apart for the outer pair and 9 & 3/16 apart for the inner pair. I use imperial dimensions as due to the age of our cars they were almost certainly designed to imperial sizes.

I hope this helps.

Richard Hawkins

Re: steering rack outrigger dimensions

PostPosted: Fri Jul 05, 2013 2:34 am
by robertverhey
Thanks for replies. Interesting.....Richard if you've measured centre to centre, my outrigger holes are definitely 1/8" wider apart. Doesn't sound like much but it's enough to put a fair bit of strain on the mounts and rubbers. When you say my pic accords with the spyder pick in Brian buckland's book, do you mean his pic shows an overhang as well?

Sorry for banging on about this but I know how crucial it is to get the steering geometry exactly right.

Any further advice from spyder chassis owners welcomed before I make the call.

Re: steering rack outrigger dimensions

PostPosted: Fri Jul 05, 2013 6:56 am
by andyelan
Hi Robert

I measured the mounting holes spacing on my original Plus 2 chassis as 269mm or 10.6" which ties in pretty well with the measurement Richard gave of 10.66". From this I would suggest the actual distance should be 10 5/8" or 269.88mm

Regards
Andy

Re: steering rack outrigger dimensions

PostPosted: Fri Jul 05, 2013 11:11 am
by mart2elan
Hi Robert,
I think I have some good pictures made during the restoration of my S4. It hase the same Spyder chassis but I'm using solid alu mountings. I think these mountings are Spyder also. May be these pictures give you some infomation. When I'm home this evening I will post them.
Marten

Re: steering rack outrigger dimensions

PostPosted: Fri Jul 05, 2013 5:54 pm
by mart2elan
hi Robert, the pictures. The distance between the inner holes is 273 mm and 350 mm between the outer holes.

Re: steering rack outrigger dimensions

PostPosted: Fri Jul 05, 2013 6:17 pm
by oldelanman
mart2elan wrote:The distance between the inner holes is 273 mm and 350 mm between the outer holes.


Are you sure ?

Re: steering rack outrigger dimensions

PostPosted: Fri Jul 05, 2013 6:20 pm
by billwill
mart2elan wrote:hi Robert, the pictures. The distance between the inner holes is 273 mm and 350 mm between the outer holes.


That doesn't actually answer the desired question, because the holes are apparently for a LHD steering rack or for a RHD steering rack, so the 'pairs' are not Inner and Outer but left hand pair and right hand pair.

However from your figures, assuming the inner pair are symmetrically placed in the outer pair, the distance between a rack's mounting holes as per the diagram in the original posris 273 + 0.5(350-273) which is 311.5mm

Re: steering rack outrigger dimensions

PostPosted: Fri Jul 05, 2013 6:41 pm
by oldelanman
billwill wrote:
mart2elan wrote:hi Robert, the pictures. The distance between the inner holes is 273 mm and 350 mm between the outer holes.


That doesn't actually answer the desired question, because the holes are apparently for a LHD steering rack or for a RHD steering rack, so the 'pairs' are not Inner and Outer but left hand pair and right hand pair.

However from your figures, assuming the inner pair are symmetrically placed in the outer pair, the distance between a rack's mounting holes as per the diagram in the original posris 273 + 0.5(350-273) which is 311.5mm


Hence my question above - the rack itself is only 320mm long between the flanges so those figures don't look right. I think the dimensions given are each about 40mm too large which just happens to be the offset of the inner and outer pairs of holes.

Re: steering rack outrigger dimensions

PostPosted: Fri Jul 05, 2013 10:15 pm
by mart2elan
Hi Roger and BillWill. In the picture you can see the pair off holes witch are used. BillWill,s calculation is correct for my Spyder steering rack placement (312 +/- 1mm)

Re: steering rack outrigger dimensions

PostPosted: Fri Jul 05, 2013 10:35 pm
by robertverhey
Thanks all for replies. I spoke to very helpful Sean at spyder last night (morning UK time) and he said that spyder space the paired holes slightly further apart than standard, to reduce the tendency for lateral movement when original mounts are used. It has the effect of pushing the rubber bushes harder against the flanges. If solid mounts are used, their solid nature prevents this movement no matter where they're clamped. The spyder instructions say to position the rack flanges equidistant from the aluminium mounting blocks.

On the issue of the narrow O/S outrigger, Sean advised that this is one of the more recent chassis (about 6 years old going by the serial number) they designed to take their replacement steering rack, which must need more room I guess. He said the overhang is not an issue when a triumph rack is used. I have however sent him a photo of my setup. I want to be absolutely sure about this!

Robert

Re: steering rack outrigger dimensions

PostPosted: Sat Jul 06, 2013 9:21 am
by RichardHawkins
Robert,
The picture in Brian Bucklands book Page 424 is similar to the photograph you show in your post Thursday July 4 2:09am in that it shows a chassis without a rack.

I have re-checked the dimensions I sent earlier, and I get the same results.

Bill Williams is correct that the holes are not really inner and outer, but left and right hand drive. The pitch of the holes that I have measures 10 & 21/32 inches.

I have checked the distance between the rack flanges at 12 & 5/8 inches (320mm).

Looking more closely at your photograph, the extreme right hand holes (drivers side) seem too close to the right hand side of the rack platform. Judging from the photograph in Brian Buckland the holes should be about as far from the edge of the rack platform as the inner and outer holes are apart from one another.

My rack platform measures 15 & 3/8 inches across, giving 1 & 5/8 inches from the centre of the outer hole to the edge of the rack platform.

I have heard that Spyder offer an alternative rack for Elans. I am not sure if this is correct, or just gossip, but it might account for the apparent discrepancy in your chassis.

Regards,

Richard Hawkins

Re: steering rack outrigger dimensions

PostPosted: Fri Jul 12, 2013 12:24 am
by robertverhey
Hi just to close this one off and in case anyone else faces the same issue in future, I decided to make a small bracket which has the effect of making the O/S outrigger as wide as the N/S, at least where it sits under the pinion housing. Might be psychological, but it gives me some comfort that the pinion housing is properly supported.