29 replies to this topic

[Steam]

You will soon know if the shock is bottoming out as it will let you know with a loud clunk and a jolt that will remove fillings, as you go over bumps.

[maystro]

Just wandering if these rear shocks would be all right for a Moke?
Apparently they are a longer van type.

Thanks
Brad

https://automotivesu...m.au/kyb-342006

 

Oh yeah Chris,  you were right again.  Lucky I'm not a guy sick of eating humble pie    

The KYB Gas a adjust mini rear shocks don't work in a Moke.   If I go over a pot hole, I can hear a distinctive shock ring ding sound  and feel a thump.  I'm guessing this is the shock bottoming out and probably bending my new radius pins I just installed?  

 

Anyway I ordered a couple of these KYB 342006's which were made for a mini van and I will let you know how they go?

 

Thanks 
Brad

Edited by maystro, 27 March 2023 - 09:26 AM.

[Spider]

Just wandering if these rear shocks would be all right for a Moke?
Apparently they are a longer van type.

Thanks
Brad

https://automotivesu...m.au/kyb-342006

 

Oh yeah Chris,  you were right again.  Lucky I'm not a guy sick of eating humble pie    

The KYB Gas a adjust mini rear shocks don't work in a Moke.   If I go over a pot hole, I can hear a distinctive shock ring ding sound  and feel a thump.  I'm guessing this is the shock bottoming out and probably bending my new radius pins I just installed?  

 

Anyway I ordered a couple of these KYB 342006's which were made for a mini van and I will let you know how they go?

 

Thanks 
Brad

 

They are said to be for a Mini Van, however, I can't find any specs on them, and I've seen loads of rear shockers over the years that say they are for a Van but are in fact too short.

The KYB 343374 looks promising, though the body diameter (at 43 mm) needs to be checked that these will fit.

[maystro]

Thanks Chris,
 

I went on the KYB web site and found this info using their search by size function.

 

KYB Excel-G Shock Rears

 

KYB 342006 (van)      Extended length      = 401mm,
KYB 342006 (van)      Compressed length = 241mm,

 

KYB 342002 (sedan)  Extended length      = 371mm,

KYB 342002 (sedan)  Compressed length = 226mm,

 

So ignoring the actual measurements because like you said all manufactures use a different system for measuring shock travel but using the fact that both these measurements were calculated by the same manufacturer on the same range of shocks, it shows their 342006 (van) range are 30mm longer on the Extended length and 15mm longer on the Compressed length over their standard sedan range.  

Also if you factor in how Leyland derived their original measurements as you have said they measure "at the upper end from the midpoint between the 2 top rubbers with the nut done up to the centre of the eye on the lower end"  that differs to how KYB have taken their top measurement from the top of the cylinder, which doesn't factor in any rubber bushes.    So you could easily add another 10 mm to the 342006 figures which brings them pretty close to Van, Estate/ Moke spec?? 

Looks promising to me?

Brad

Edited by maystro, 28 March 2023 - 10:11 AM.

[TimDaly]

Ok, I'll admit it.  I'm still confused.

 

If the concern is that the shock will bottom out and then transfer the load directly to the radius arm pin, wouldn't a shock with a shorter compressed length be better?  In other words, the wheel would be able to travel up farther before being forced to stop by the shock absorber.  The downfall here is that the radius arm would not be able to travel down as far due to the shorter extended length.  Have I got this all muddled up?

 

I've already modified the rear frame to remove the internal bump stop to eliminate that 'stopping' issue.  I'm leaning toward the SPAX C-STR308 http://www.minispare...~absorbers.aspx but their compressed length still isn't as short as the desired 255mm (although I have no clue which points they actually measure from).

 

Any further clarification would be appreciated.  I must be in a fog of some sort these days.

 

Tim.

[Spider]

I went on the KYB web site and found this info using their search by size function.

 

KYB Excel-G Shock Rears

 

KYB 342006 (van)      Compressed length = 241mm,

 

KYB 342002 (sedan)  Compressed length = 226mm,

 

Hey Brad,

 

Based on these figures, yes, they do appear OK

 

You did well !  I put in the 342006 in to KYB and nothing came up in the specs sheet, but it did come up listed as for an Austin Mini Van.

 

 

Ok, I'll admit it.  I'm still confused.

 

If the concern is that the shock will bottom out and then transfer the load directly to the radius arm pin, wouldn't a shock with a shorter compressed length be better?  In other words, the wheel would be able to travel up farther before being forced to stop by the shock absorber.  The downfall here is that the radius arm would not be able to travel down as far due to the shorter extended length.  Have I got this all muddled up?

 

I've already modified the rear frame to remove the internal bump stop to eliminate that 'stopping' issue.  I'm leaning toward the SPAX C-STR308 http://www.minispare...~absorbers.aspx but their compressed length still isn't as short as the desired 255mm (although I have no clue which points they actually measure from).

 

Any further clarification would be appreciated.  I must be in a fog of some sort these days.

 

Tim.

 

 

 

I'm thinking if I am keeping it low I mightn't need the longer shocks on the back.

 

The Rear Suspension in Mokes (and Minis) doesn't have a conventional Bump Stop, like you have on the Front. The Bump Stop that's built in to the system is actually when the Rubber Cone bottoms out on the Subframe, but that's also what breaks the Trailing Arm Pins. With the Standard Length Moke Shocks there's a shared arrangement between the Shock bottoming out and the rubber Cone, though more is taken on the Shock. Fitting shorter shocks in there on a Moke that's already riding low will break these pins with regular monotony.

 

The Moke I pulled this one from had done less than 1000 km since it's last pin broke

 

 

and yes, it was fitted with standard Mini Shocks on the back.

I have noticed and get annoyed that as the proper length Moke Shocks are thin on the ground, they advertise Mini Shocks as being suitable, when they certainly are not.

 

Keep in mind here that the Rear Arms have a Leverage Ratio of 5:1 on to the Cone and also on to the Trailing Arm Pins. So what ever you might have in the back (even when empty), 5 times that is on the Pins. Put another way, say 2 x 20 kg bags of cement isn't terribly heavy, yeah ? They put 200 kg 'pressure' (it's not the correct engineering term, but for the sake of discussion) on to these Pins. That's static. When you start driving and going over those Potholes and bumps in the road that Anastasia has left for you   this goes up to 2 - 3 times that and that's what guillotines the ends of the Pins off. Shorter than standard Moke shocks aren't wise.

 

I get that you'd like it low and I think you get that it does need to be raise some to get some movement back in the suspension, just keep in mind here that pretty much a lower ride does come at the expense of comfort.If you fit Hilos, as you are planning, it does give you an option if going on a trip to Raise it up some more to 'dial in' more comfort.

 

In short Tim, you want it to bottom out on the shock not on the factory coff coff bump stop, that's what causes damage !

Longer shocks, not shorter

[TimDaly]

Ah!  That makes sense.  Bottoming out on the shock creates a vertical stop, rather than the horizontal stop (from the 'bump stop') which creates a shearing force on the radius arm pin.

 

I've already got the GAZ Adjustable Standard height shocks (C-STN233) .  As mentioned earlier, they have a compressed length that is slightly larger than the SPAX Van/Estate equivalent.  (GAZ = 280mm compressed, SPAX = 271.25mm compressed).  By your logic above, these GAZ ones should fit the bill.  I'm willing to buy the SPAX if necessary and transfer the GAZ to my Mini, but no need to buy another set if not needed.  Would you think the GAZ would be ok then?

 

Great discussion, very much appreciated.

Tim.

[maystro]

Hey Tim,  

 

I love your analogy about the vertical and  horizontal forces, that is spot on.  

 

On paper it looks like your Gaz shocks should work but like Spider said where are these measurements taken from and I don't think even Arnie could do an accurate compressed value?

 

Brad 

[TimDaly]

Hey Tim,  

 

I love your analogy about the vertical and  horizontal forces, that is spot on.  

 

On paper it looks like your Gaz shocks should work but like Spider said where are these measurements taken from and I don't think even Arnie could do an accurate compressed value?

 

Brad 

 

Right, where do these measurements come from?  I figure, if the SPAX Van/Estate ones are known to work, and these GAZ ones are only 9ish mm longer in length (based on MiniSpares measurements for each), they should do the trick.  Seeing as I already have the GAZ ones, I'll just have to put them on, load up the Moke, and take it off-roading to test the theory.  If there's massive destruction of the radius arm pins, then they obviously weren't the right shocks. 

 

The shocks are easy to change in the future if I find they are causing problems.  I'll take it easy for the first bit once the Moke is on the road and see what happens.

 

Tim. 

[Spider]

Right, where do these measurements come from?

 

This any help ?

 

 

10.36" (263 mm) compressed length from the factory drawing. The previous number I was quoting came from the workshop manual. This drawing also shows where these measurements were taken from. As you already have your chosen shock to hand, I'd measure them directly.

Inside this cone, you can see where it's been thumping the coff coff Bump Stop

 

 

 

 

[TimDaly]

Very helpful. I thought that’s what you meant but wasn’t sure if GAZ was using the same points. Here is what I found…

 A797B42F-2F96-432B-9207-F02170874342.jpeg   37.83K   2 downloads
 1B970E01-0096-4767-BF2C-2CA2F318E158.jpeg   49.12K   1 downloads

Roughy 277-278mm closed, this is without the bushings tightened down. A little bit longer, but I think they’ll do the trick. Time will tell.

Tim.

Edited by TimDaly, 31 March 2023 - 04:44 AM.

[Spider]

I'd say they'll do the trick there Tim.

[maystro]

They look the goods for sure.

Those Gaz shocks look like they have a lock nut or spacer nut on the top pin stud and some extra thick bushes which would all add to why they have a long 278 mm compressed length over the required 263 mm as supplied by Spider's extensive knowledge.   

You may have just found the other elusive Moke shock we can use for big wheelers?  
 

I look forward to your road trials.

 

Cheers Brad

[maystro]

Guys these shocks look like a good Moke match.

 

These 342006 KYB Excel G Shocks measure up bang on as the same compressed length and open length as the original Moke Shockers.

 

From my measurements they  have a compressed length of 263mm and a open length of 420mm.

I'll let you know how they perform and I'm especially interested to compare the compressed length of the Gaz A Just which I have now which are bottoming out  to these new 342006 shocks?  

 

 

 

 

Attached Files

•  shock1.jpg   470.14K   2 downloads
•  shock2.jpg   466.07K   3 downloads

[maystro]

OK, I  just replaced the KYB GAZ A-Just rear shocks because they were bottoming out with the KYB 342006 shocks and the new ones measure about 40mm longer in the open position. Sorry I never got a closed picture for comparison.

Attached Files

•  IMG_20230407_203323.jpg   18.53K   0 downloads

Edited by maystro, 09 April 2023 - 10:00 AM.