Jump to content

What will work as replacement for my internal shocks and springs on my Robin Hood SF Mark 2?


James Agg
 Share

Recommended Posts

Hello all. I’ve been a member of RHOCar for about 7 months now but haven’t yet started any sort of post/thread, so here goes my first, and sorry, it’s a bit of a book filled with questions...

 

In light of the quarantine, I am taking this as an opportunity to do a few bits of overhauling on my Robin Hood SF Mk 2. I am currently working on the front suspension, which if anyone is familiar with the mark 2, the coilovers are inboard rather than external (see my attached pictures). The top eye bushings have very much seen better days and having removed the coilovers today, the bottom eye bushings aren’t far behind, and generally looking at the condition of the rest of both shocks, I’m thinking that I might splash out and treat my RH to a new set of front coilovers, particularly as the shocks that I’ve just removed have no easy damper adjustment facility like all the modern shocks seem to have.
 

I found these build your own Protech shock absorbers. I have used protech before when I was building a MEV a few years back that I never completed (long story for another time!) and loved the general quality/design/weight/adjustability https://www.protechshocks.co.uk/build-a-shock/

 

I’m generally armed and ready with my measurements for the shocks. My one concern is the open height. Protech request that you take the open height measurement from the centre of the top eye hole to the centre of the bottom eye hole. As you will see in my photos, my bushings are absolutely clapped out and the best I could do for a measurement was to take it from where I thought centre was originally at each end and the closest measurement I could deduce that is available for ordering was 13”. However, there is a 12.5” option available which does seem too short, but I notice that the bushing tear pattern on the old shocks suggests that the shocks installed originally might be too long for the design of the mark 2. Would this make sense? And  would it be prudent therefore to go for 12.5” open length? The only time the shocks would ordinarily be in full open length would be when all four wheels are off the ground, which I endeavour to keep as only being the case when I jack the car up!! Thoughts on whether I should go for a shorter reach would be much appreciated.

 

I’m also thinking that I would like to reduce the poundage of my springs from what’s on there currently as the current setup is a bit rigid (perhaps spring length and poundage may be a factor in the wearing of the top and bottom eye bushings??) and I do find that the handling is a bit lifeless until you really give it some welly at which point I get the wrong kind of life; all I ever seem to get is bump steer and understeer, which I’m guessing is a bi-product of the bump steer. I’ve read that a recommended mod to the front suspension on the Mk2 is to do away with the Sierra anti-roll bar and do a tie bar conversion. This is something I mean to do along with the grease nipple mod on the wishbone once I have access to more of my workshop equipment (annoyingly not with me where I’m at in isolation). I’ve also seen that reducing the poundage of the springs goes a long way to making the handling and ride generally better on these old Mk 2s. Does anyone know if it drives ok with reduced poundage whilst still running the sierra anti-roll bar for the time being or should I hold out on changing to lighter poundage until the tie bar conversion is done? I’m looking to order a new set of springs with the shocks and so I need to be clear on what poundage to go for in any case (I don’t even know what the existing poundage on there is and I guess it’s not especially easy to find out without the right equipment).


And final question (I promise)... Does anyone happen to know if it’s the standard (obviously non power steering) sierra rack and tie rod ends that the RH Mk 2 uses? I need to change the rubber boots and tie rod ends on mine and I’m also thinking of possibly getting a quick rack to reduce the amount of loping about I have to do when parking!!!

 

Thanks in advance everyone. I hope you’re all keeping well in these unusual circumstances!

 

 

98EBE3A0-CA7E-4871-BE75-4B81E8BB61B0.jpeg

CD8C87E9-05CF-4D4C-983B-99533230CFE5.jpeg

6001BFF6-7B32-4F6E-A97A-9F5731ECE37F.jpeg

Edited by James Agg
Link to comment
Share on other sites

Hi. Welcome to the club. I have just completed all the work on the front suspension you talk about so hope I can help a bit. Firstly the common opinion regarding coilovers seems to be to contact Dave at Dampertec. Lots of posts will mention him. He will know exactly what you need regarding lengths. I didn't! I'm a cheapskate and went for some hardly used ones for less money. Fully adjustable. I'm pretty sure the open length was 13". Springs...I went for 120lb. Original ones are 180 I believe. Far too stiff. I did the tie bar conversation first and just that made a huge difference. Lighter more positive steering. You won't feel the benefit of new coilovers until you do it. Its a different car with all that done. However I'm a cruiser not a racer so I don't explore the limits. Its just easier to driver and less bone shaking.

I haven't changed the steering rack so cant help with that but did change boots and tie rods a few years ago. I seem to remember they were standard Sierra.

I'm sure others will be along to add or correct anything. Hope this helps a bit.

Also some good info here.

http://www.dvandrews.co.uk

Edited by dandan62
Add info
Link to comment
Share on other sites

Thank you both. What you say corresponds with my findings about measurements. I will give Dave at dampertech a shout. Dandan62, did you create a thread on your tie bar conversion? And do you have links to the required parts? It would be great to do this while I’m at it if I can! 

Link to comment
Share on other sites

Hi. I had to pay a lical metal worshop to drill and thread the old antiroll bar. The brackets I fashioned from box section and used rose bearings to join. Make sure you use some angle iron inside the panel to strengthen where the brackets are attached. There are some drawings in the Dave Andrews link if you look for the link to front suspension info towards the bottom of the page. Here is a pic of what i ended up with. I'm no great mechanic. All done with an angle grinder!

IMG_20200407_115251_compress42.jpg

  • Thanks 1
Link to comment
Share on other sites

Ah! Brilliant. This is what I need. Thanks! The current setup of the original anti roll bar is horrendous; this is bound to be an improvement! I like the fact that you were able to salvage the original bar for the tie bar conversion.

Link to comment
Share on other sites

Much easier than starting from scratch. It seems to be quite a common method. 

You may find depending on the position of your engine mounts that they are just where you need to drill through for the brackets. I just got away with mine and in fact used the mounts to sandwich the inner angle iron which gives further support. All depends where your mounts are. There will be a way round it.

Link to comment
Share on other sites

All good to know! You don’t happen to remember what size of box section you used to fabricate that do you? Also, do you remember the bolt sizes for the rose joint eye? And what bolt sizes did you use to mount the box section to the chassis? Angle iron is easy enough size up as it presumably only needs to be big enough to receive the bolts and bolt down to whatever is on the other side (I need to have a look at what’s going on internally), and of course it needs to have enough depth to be of sufficient Reinforcement. I like this tie bar conversion as it effectively converts the track control arm into a lower wishbone. 

Link to comment
Share on other sites

These will all be great improvements to the car. The softer springs are the way to go. I don't consider myself to be a great authority on chassis set up but as soon as I first drove my car I realised that the front springs were too hard. The softer springs will make a great deal of difference,  mine seems to turn in much better with less effort at the wheel and the anti roll bar conversion improves things even more.  I used poly bushes when I had mine apart and yes I let Dave at dampertech select the right bits for me.

Dampertech 01709 703992

Link to comment
Share on other sites

  • 1 month later...

It was made from 2"x1" box section steel. All done with an angle grinder. The only tool in my tool box😂 Some people use U section but i thought leaving the outer edge closed would add some strength. It seems to be holding up well so far. I'm sure there are neater solutions out there but it does the job.

Link to comment
Share on other sites

5 minutes ago, dandan62 said:

It was made from 2"x1" box section steel. All done with an angle grinder. The only tool in my tool box😂 Some people use U section but i thought leaving the outer edge closed would add some strength. It seems to be holding up well so far. I'm sure there are neater solutions out there but it does the job.

Oh I see now, that's pretty slick. Thanks!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...