Bum Steer

PostPost by: slowsprinter » Sun Dec 04, 2011 2:11 pm

Fellas

I think I need your help. I have been messing around with the steering rack on my project for some weeks now off and on. The rack I have came with my car. I initially thought the rack would be complete and correct for the car, though on closer inspection I was wrong. I was just going to strip down clean and re-grease everything.

Firstly I found that although there is a passenger side lock limiting spacer there was not one for the drivers side. I managed to purchase one from Brian Buckland that he made up for me, kindly. Then I noticed that both tie rods were different so I assumed the shorter 6ins one to be correct and bought a new one from Paul Matty. When this new one duly arrived I noticed the other one was different too in that although the right length the thread length was different. I decided to purchase another new one from PM too, partly because I knew my project car had been in a crash many years ago so I just wanted to be on the safe side!

Anyway I got my rack back together and with new gaiters got down to re-fitting to my chassis. To cut a long story short I cannot get both wheels to point straight ahead with the rack and pinion in the central position. I have both (new) track rod ends screwed in to the max on the new tie rods at 28 turns each and there is still some slight toe out. Probably 1/4ins on each wheel. Granted there is no weight on the suspension as my chassis is on axle stands. However if anything having weight on would make the situation worse??

As far as I know the rack is assembled correctly. The cup nuts, shims etc seem to give the correct tightness in that the tie rods with the tie rod ends on support their own weight as it says in Brians book and I assembled exactly as Brian says. The rack gives 2 and 1/4 turns of the pinion lock to lock which I think is correct for a Sprint.

So what have I done wrong? Can you fellas help me out? :( Of course I can get it right by grinding 1/4 ins of each of my new tie rods. But I should not have to do that with new tie rods, should I? Another possibility occurs to me as I write this. Perhaps my rack is completely wrong for the car? I have included photos of my latest progress (or lack of) to date so you fellas can see my rack to make sure it looks correct.

As ever I would be most grateful for your help and advice.
Regards
Ian
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PostPost by: miked » Mon Dec 05, 2011 9:01 am

Ian,

Brian's book gives a length of the assembled rack part as I recall. Have you checked yours against that? Also were the cup back nut things (forget their name) set onto the rack at that Dim. As I recall, dont they bottom out to give the correct rack overall length.

Mike
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PostPost by: elanman999 » Mon Dec 05, 2011 12:22 pm

Ian,
It sounds to me as if you've got Spitfire tie rods.
The dimension in the manual for the distance from the centre of the track rod end to the centre of the ball on the tie rod is 7.59in.
Cheers
John
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PostPost by: patrics » Mon Dec 05, 2011 6:51 pm

Hello Ian,

Looking at your photos, are the new and old track rod ends the same length?

Regards
Steve
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PostPost by: elansprint71 » Tue Dec 06, 2011 12:52 am

elanman999 wrote:Ian,
It sounds to me as if you've got Spitfire tie rods.
The dimension in the manual for the distance from the centre of the track rod end to the centre of the ball on the tie rod is 7.59in.
Cheers
John

Sounds right to me;I finished up in the same situation- took it for a drive; rather fiesty in the steering dept. One minute you were weaving down the road, the next you were in the ditch.

I got the hacksaw out and fixed her up real good. :wink:
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PostPost by: Jeff@Jae » Tue Dec 06, 2011 6:55 pm

Check with Brian, he knows where the correct inner tie rods can be had. All you can get from the usual vendors are the Spitwad sourced parts and they're incorrect.
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PostPost by: slowsprinter » Thu Dec 08, 2011 9:17 am

Thanks fellas for all that.
I think you are right. I had assumed Paul Matty new tie rods are correct. They can't be. I think the tie rod ends I got from Sue M are very slightly longer than they should be too.

Rather than keep spending money I think I will simply grind down the 2 tie rods I have slightly. It should be an easy fix.
Stay tuned and thanks.
Ian
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PostPost by: bcmc33 » Thu Dec 08, 2011 6:48 pm

Well, there you go - it seems we've all been buying the wrong track rod ends. :oops:

At the 2010 MOT the tester made comment about one of the track rod ends being a bit sloppy. To address this I bought a new pair - I don't remember from where.
The day before this year's MOT I decided to change them, and found excessive toe-out.
The best adjustment I could achieve was zero toe-out/in.
As I only had to go for the MOT and a return trip to the NEC before the car was off the road for the winter, I left it with that setting.
The pin-point steering I was used to had gone, and was very happy when I was safely home from the NEC.

FWIW, the new ones were about 1/4" longer - not something you would notice, really.
Brian Clarke
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PostPost by: slowsprinter » Fri Dec 09, 2011 9:10 am

Thanks Brian

I did compare the new track rod ends I bought with an old one I found amongst the relics in a box of parts when I bought my project. I agree with you my new ones are 1/4 ins longer.

If I take out this 1/4 ins each side by grinding down my tie rods I reckon that will be about right. Its my Christmas project to get my steering right once and for all!

Thanks for everyone's input.
Ian
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PostPost by: bcmc33 » Fri Dec 09, 2011 10:22 am

[quote="slowsprinter"]Ian,

I found I was out of adjustment by using all the thread on the tie rods.
The only way I could make more adjustment was to thin the lock nut - which I might still do.
Machining 1/4" off the length is probably the best option as I have the facility to do so, but I have to be confident to machine the end face square with the thread. I'm thinking about that.

However, I've ordered new ones from a genuine UK manufacturer using an old one as a pattern - I just hope they make that variant.
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PostPost by: AHM » Fri Dec 09, 2011 12:13 pm

Same problem here!

Slightly confused by what is written above. Are your trackrods too long or are the trackrod ends too long? If you are at the end of the threads then you will have to reduce the length of the trackrod end.

I checked my new trackrod ends and have thrown the old ones away so now I have no idea if the new ones are wrong... maybe the old ones were too!

Simon
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PostPost by: bast0n » Fri Dec 09, 2011 12:30 pm

Suggest you all re-read this before you make any grave errors. D
Image]
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PostPost by: bcmc33 » Fri Dec 09, 2011 12:40 pm

AHM wrote:Are your trackrods too long?[/quote]
No


AHM wrote:I checked my new trackrod ends and have thrown the old ones away so now I have no idea if the new ones are wrong... maybe the old ones were too!
FWIW, My old track rod ends are 2.875" long and the new ones 3.125" long - a difference of 0.25" (1/4") measured from the ball centre to the thread end.
Also the depth of thread in the longer ones is 1/4" deeper than the old ones - so that's where the lack of adjustment disappeared to.
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PostPost by: andyelan » Fri Dec 09, 2011 6:40 pm

Hi There

Just to clarify one point. As you'll see from bast0n post, the lock limiting spacers are not equal on both sides, the one on the driver side is much shorter (and is normally welded to the lock nut). This is necessary because the rack tube is not mounted centrally on the chassis but offset to the drivers side. If you have equal spacers both side of the rack, then the wheels will never point stright ahead with the rack centralised

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PostPost by: patrics » Fri Dec 09, 2011 10:30 pm

Gents,

The spacers are not important in the wheels pointing straight ahead the thing to focus on is the Brian Buckland overall value (centre of track rod end to centre of track rod end), if you can not set it to that then I guess something is wrong.
I have brought new rack, pinion, tie rods and rose joint ends and set it to Brian?s overall value and it looks good but haven?t put my engine in yet.
I am / have made new lock stops - these days there is no point copying the original values unless you have the correct size tyre etc.
Because I intend to go racing this year I will have 185/60 tyres and large roll bar so my lock stops will not be standard length. The lock stops are easy to make and set. Remove the rubber boots turn the wheels on to lock both ways set the clearance you are happy with i.e. between wheel and anti roll bar and measure how much extra you need on top of the standard stops.
Another thing to check if you can not set the track is if the steering arms are bent.
If you have brought your steering arms from Paul Matty I would have thought that they would be good - I can measure my rack to compare if you like.

Regards
Steve
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