Lotus Elan

Steering Rack Travel & # Turns

PostPost by: pharriso » Fri Jan 31, 2020 2:33 pm

As I have perviously posted I am rebuilding a LHD S4/Sprint Steering Rack that was purchased from Europe.

I am just about finished (apart from the pinion spring), but one question remains... I read that the racks were Triumph units mofidied with the addition of 2" & 0.53" spacers to reduce the travel, reducing the number of turns from 3.5 to 2.7.

My unit has the correct spacers installed, but it only rotates about 2 1/3 turns! I have measured everything & the rack itself & housing appear standard vs. dimensions in the workshop manual & Buckland, the pinion is the correct 7 tooth one, so what gives?

If anyone has measurements, the rack moves 4.25"; if the pinion were rotated 2.7 turns the rack would need to translate 4 7/8" - that's 5/8" difference.

Yours Perplexed :roll: :roll: :roll:
Phil Harrison
1972 Elan Sprint 0260K
User avatar
pharriso
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2799
Joined: 15 Sep 2010
Location: Long Island NY, USA

PostPost by: pharriso » Fri Jan 31, 2020 2:50 pm

I may have answered the question myself...

When talking about the number of turns I only see 2.7 mentioned, but on the S4 & Sprint both spacers are 1/4 wider (to reduce the travel further because of wider tyres.)

Just measured the Rack tooth spacing at 1.565" for 6 teeth, so .261" each. 0.5" travel would be 1.915 teeth, based on a 7 tooth pinion that would be 0.275 turns - the difference between 2.7 & what am I seeing!

So why do we only see 2.7 turns mentioned & not 2.4 turns?
Phil Harrison
1972 Elan Sprint 0260K
User avatar
pharriso
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2799
Joined: 15 Sep 2010
Location: Long Island NY, USA

PostPost by: seriouslylotus » Fri Jan 31, 2020 7:44 pm

pharriso wrote:I may have answered the question myself...

When talking about the number of turns I only see 2.7 mentioned, but on the S4 & Sprint both spacers are 1/4 wider (to reduce the travel further because of wider tyres.)

Just measured the Rack tooth spacing at 1.565" for 6 teeth, so .261" each. 0.5" travel would be 1.915 teeth, based on a 7 tooth pinion that would be 0.275 turns - the difference between 2.7 & what am I seeing!

So why do we only see 2.7 turns mentioned & not 2.4 turns?

Earlier cars had shorter spacers so had more turn available lock to lock
seriouslylotus
Second Gear
Second Gear
 
Posts: 84
Joined: 29 Aug 2012
Location: East Yorkshire UK

PostPost by: Quart Meg Miles » Sun Feb 02, 2020 9:49 pm

I guess it just wasn't worth confusing the customers with such a small detail. After a complete turn of the wheel who cares if it only turns another quarter turn rather than a third? The turning circle will be affected but that won't upset most people buying an Elan; do you know the difference?

But technically it is necessary to reduce the lock to avoid rubbing the tyres on full lock (which is illegal) and that is to be documented, as you have described.
Meg

26/4088 1965 S1½ Old and scruffy but in perfect working order; the car too.
________________Put your money where your mouse is, click on "Support LotusElan.net" below.
User avatar
Quart Meg Miles
Fourth Gear
Fourth Gear
 
Posts: 995
Joined: 03 Oct 2012
Location: Barnham, W Sussex, UK

Total Online:

Users browsing this forum: No registered users and 7 guests