Just a couple of questions

[twissy]

I've had the car a couple of weeks now. Got it through it's MOT first time Just a couple of advisories on slight play in the trunnions......off to get a grease gun! I'm almost at the stage where I'm confident enough in the car to take it for something longer than a 15 minute drive! It was showing as getting hot but I didn't believe the gauge, so I've fitted something new and an electric fan just in case.
A couple of niggles that I would be grateful for any info on (I've searched but not found much).
I often get a smell of petrol which is due to it coming out the filler cap (Marina based car). Is this common with the roadster and the low down filler? It has a locking cap which I'm going to try to get/fabricate a new rubber seal for.
The other thing, whilst changing the steering rack gaiter I discovered the track rod end in only threaded on by two and half complete turns (offside). As yet I haven't removed the other side but the exposed thread would suggest it is a similar amount. Lock to lock appears pretty even.

I still hope to meet some of you at Donnington, but I may have to park the car near the back.....it's not in the best shape!

[dcunn]

Re: Just a couple of questions

Come as you are to Donington, park with the rest of us, we'll be glad to meet you and see your car

Re petrol smell, years ago someone made up a tube (3-4 inches long) with a leather washer which sat inside the filler cap and stopped the petrol from sloshing all the way up the tube. I had one on a previous Roadster (sorry no pics)and it worked fine, I seem to remember details were in an old Pitstop (Tech Tips)

Re track rod ends, someone with better knowledge than I can advise if two and half turns are sufficiently safe !

Rgds DC

[stevejgreen]

Re: Just a couple of questions

These two pages from the workshop manual show how to centre the rack. Two and a half turns on a tie rod are certainly on the dodgy side. I would be looking at 3/4 of the thread diameter in thread engagement minimum, both sides should be the same. The complete section of the workshop manual is here

57 25 01.jpg57 40 02.jpg

So far as the trunnions go, regular greasing will help, but its worth a stripdown and examination along with a good clean of all the grease passages. You dont want to pump dirty grease that could be 10 years old into the threads.
Once the uprights have corroded trunnion threads, there are two remedies, replace the uprights or fit self cutting Walford trunnions, if you can find some.

On my car I felt the filler was too low and petrol did leak from the flip top cap. I tried new OEM seals but even then with a full tank, fuel still slopped out. I ended up fitting a longer fuel hose and raising the filler much higher. Problem solved, it also saved my back, leaning down to fill the tank.

[b_caswell]

Re: Just a couple of questions

I am not sure which rack the Marlin uses from the Marina/Ital but the spec for these racks show the pre 75 Marina rack at 40.5inch and the later ones as 40.25inch. That quarter of an inch could be important??

[cameronfurnival]

Re: Just a couple of questions

that's a really useful post Steve, many thanks

[stevejgreen]

Re: Just a couple of questions

I am not sure which rack the Marlin uses from the Marina/Ital but the spec for these racks show the pre 75 Marina rack at 40.5inch and the later ones as 40.25inch. That quarter of an inch could be important??

I would love to see that source documented data Ben. Or is it just hearsay?

Due to the length of the rack, it's profile and the fact that both ends are flexible makes an accurate overall length almost impossible to measure in the average workshop.
0.25" over 40" is an error of 0.625% in proportion terms almost insignificant.

I wonder if the Roadster chassis is that accurate, certainly Lee Hunter did some serious cutting and re welding to set one of his roadsters suspension accurately, reporting that there was a difference on each side.

This has been debated before, but nobody has, to my knowledge, ever put the two different racks side by side and done a full comparison. My guess is that the differences were simply a value engineering excercise.

[dogoncrazy]

Re: Just a couple of questions

I always thought that the difference between the MK1/2 Marina racks was to do with the size of the mounting saddle that secures the rack to the chassis . Is that correct?

[twissy]

Re: Just a couple of questions

DC, thanks for the info. I really like the simplicity of the leather washer, ans as a quick fix that may be the way to go.

Steve, Excellent info, I never thought of looking in the Marina manual!! If I can adjust it there is about 3-4mm "space" on the offside to shift the rack along. I'll have to see how many threads there are on the nearside first!

Ben, Not sure how I'd measure it, but you are right, that extra 1/4" may be just enough.

My thoughts are to see if I can find longer track rod ends, or possibly cutting off some of the threads of the rack and making some extenders.

[stevejgreen]

Re: Just a couple of questions

I always thought that the difference between the MK1/2 Marina racks was to do with the size of the mounting saddle that secures the rack to the chassis . Is that correct?

To my knowledge yes, and the fact that the flanges, locating the rack are different. It's all here on the forum so not worth publishing again.
But I have never had both side by side.

There is allegedly a difference in turning circle, lock to lock, but the racks have the same ratio. I think that coincides with the introduction of wider radial tyres over the standard narrow crossply.

[stevejgreen]

Re: Just a couple of questions

Steve, Excellent info, I never thought of looking in the Marina manual!! If I can adjust it there is about 3-4mm "space" on the offside to shift the rack along. I'll have to see how many threads there are on the nearside first!
My thoughts are to see if I can find longer track rod ends, or possibly cutting off some of the threads of the rack and making some extenders.

I would look at centering the rack first it's often overlooked.
Any non standard mods to the tie rods could result in an MOT failure if spotted.

[b_caswell]

Re: Just a couple of questions

[QUOTE=stevejgreen;30202]I would love to see that source documented data Ben. Or is it just hearsay?http://www.steering-racks.co.uk/rack...assenger-cars/ Kiley & Clinton engineering ltd Morris Marina, Ital M -75 KCR250 Length 1030mm. Morris Marina, Ital M 75 -KCR255 Length 1020mm. Listed under Rover Group. I found it somewhere else in imperial before. Also the rubber blocks that mount up the rack are the same as Triumph Herald etc . There is a solid alloy block available to replace the rubber that they say improves the steering feel.

[stevejgreen]

Re: Just a couple of questions

[QUOTE=b.caswell;30210]

I would love to see that source documented data Ben. Or is it just hearsay?http://www.steering-racks.co.uk/rack...assenger-cars/ Kiley & Clinton engineering ltd Morris Marina, Ital M -75 KCR250 Length 1030mm. Morris Marina, Ital M 75 -KCR255 Length 1020mm. Listed under Rover Group. I found it somewhere else in imperial before. Also the rubber blocks that mount up the rack are the same as Triumph Herald etc . There is a solid alloy block available to replace the rubber that they say improves the steering feel.

Interesting, how does that tie into Marina Part Numbers and Vehicle age etc?

As far as I know there are no differences is chassis dimensions, so where does the 10mm (3/8") difference come in?

[b_caswell]

Re: Just a couple of questions

Don't know but the imperial measurement versions are on the Earl Part list, knew I had read it somewhere.

[stevejgreen]

Re: Just a couple of questions

Don't know but the imperial measurement versions are on the Earl Part list, knew I had read it somewhere.

Earlparts also use their own numbering system that does not relate to BL/Marina/Ital part numbers,so we are still none the wiser.

It would be nice to get a definitive answer

[Mike]

Re: Just a couple of questions

Do Marina based Roadsters use a rack extension block like the Triumph based kits used to ?

3 or 4 threads is not sufficient to be safe. The first thread of the track rod joint is usually chamfered, so you are left relying on 2 to 3 real threads.
The rack end should engage at least 15mm into the track rod ends to be safe.

Jason Cundall had an accident on a roundabout in his Sportster. His investigation revealed his steering rack had parted company with the track rod end, and that it had only been engaged by a few threads. Whether this caused the accident no one knows, but it is a cautionary tale of what could happen.

If both ends only engage by a few threads, I would seriously recommend adding an extension bar to your steering rack (like the Triumph set up) - I'm sure Ben will have some details?