Springs and Shackles Information
13 May 2013 06:05 - 13 May 2013 13:35 #4
by dandjcr
David and Janet Ribbans - Oka 148
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dandjcr replied the topic: Springs and Shackles Information
OiA, I agree with Russ, sliding front springs in the hangers at the front is the most likely cause for clonks when turning. Other possible causes are worn tie rod ends or loose U bolts. I've also had a hole in the steering arm which was worn oval and clonked, even though the tie rod end was tight. I fixed that with some shims in the hole.
Shim/thrust washers can be used to reduce the sliding spring problem. In an emergency (ie away from home), I used some tent pegs bent in a U shape and inserted either side of the spring and wired in, or a thick washer with a slot cut out to do the same thing. Bush mechanics they maybe, but they worked and there's no need to remove the suspension pin.
I should add that I've subsequently replaced all suspension pins with 20mm pins with urethane bushes and no-gap thrust washers, fitted all new springs and airbag suspension all round. Suspension problems have now largely retreated expensively into history.
Shim/thrust washers can be used to reduce the sliding spring problem. In an emergency (ie away from home), I used some tent pegs bent in a U shape and inserted either side of the spring and wired in, or a thick washer with a slot cut out to do the same thing. Bush mechanics they maybe, but they worked and there's no need to remove the suspension pin.
I should add that I've subsequently replaced all suspension pins with 20mm pins with urethane bushes and no-gap thrust washers, fitted all new springs and airbag suspension all round. Suspension problems have now largely retreated expensively into history.
David and Janet Ribbans - Oka 148
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13 May 2013 16:05 - 13 May 2013 16:13 #7
by dandjcr
David and Janet Ribbans - Oka 148
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dandjcr replied the topic: Springs and Shackles Information
OiA, in my case it was a combination of wear on all the the metal components of the original Oka spring fixing: the insides of the hanger (worn by the hardened thrust washers), the 2 piece metal bush, the 16mm pin, the steel cylinders in the spring eye (which were crushed), and hole in the hangers wearing oval. Even with greaseable pins, as soon as there is some wear, grease will follow the line of least resistance and not go to the points of metal to metal contact where it's needed most. This accelerates wear.
Also the leaves of the springs can slide laterally over each other since only the top eye leaf controls the lateral load, if the clamps are not a tight fit or the leaves are weak.
Clonking only happened (to me) on the front of the front springs and it was unnerving, but it's unlikely anything is broken, just wearing, and packing things only puts off the inevitable. The only complete cure is to replace the entire shackle system and I think 20mm pins (or the new 25mm(??) NT suspension pins) with urethane bushes would be the way to go, especially if the hanger holes are oval. Both need a fair degree of drilling and welding work on the hangers but it does make a tighter, stronger system which is more resistant to wear.
There are a lot of parts in the original Oka spring system, this is the rear of the front spring.
Also the leaves of the springs can slide laterally over each other since only the top eye leaf controls the lateral load, if the clamps are not a tight fit or the leaves are weak.
Clonking only happened (to me) on the front of the front springs and it was unnerving, but it's unlikely anything is broken, just wearing, and packing things only puts off the inevitable. The only complete cure is to replace the entire shackle system and I think 20mm pins (or the new 25mm(??) NT suspension pins) with urethane bushes would be the way to go, especially if the hanger holes are oval. Both need a fair degree of drilling and welding work on the hangers but it does make a tighter, stronger system which is more resistant to wear.
There are a lot of parts in the original Oka spring system, this is the rear of the front spring.
David and Janet Ribbans - Oka 148
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15 May 2013 12:54 #10
by OKABloke
For Sale:
XT and LT Parts and Service Manuals Available on CD or Download. $150.00 Set
OKA 4x4 Facebook Page
www.facebook.com/groups/1597409843913222/
David
OKABloke replied the topic: Springs and Shackles Information
These are worth looking at
David
David
For Sale:
XT and LT Parts and Service Manuals Available on CD or Download. $150.00 Set
OKA 4x4 Facebook Page
www.facebook.com/groups/1597409843913222/
David
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15 May 2013 17:24 - 15 May 2013 17:33 #11
by Peter_n_Margaret
Cheers, Peter.
OKA196 tinyurl.com/OKA196xtMotorhome
Mob.0428171214
Peter_n_Margaret replied the topic: Springs and Shackles Information
Shameless advertisement 
I developed the above kit primarily for my own use after breaking a pin in a remote spot in the Kimberley.
They seem to last very well. No one, including me, has worn out a part yet since 2009.
The pins are made from standard "off the shelf" M20 HT bolts, so can be purchased almost anywhere if required.
The urethane bushes are likewise as simple as possible and could be made by anyone from a variety of materials in an emergency. All thrust components are hardened steel.
Trying to maintain the original OKA philosophy of simplicity and availability.
Shims are laser cut from spring steel shim followed by hardening. Hex head locators are also laser cut (from 6mm mild steel).
Complete conversion kits are $900 (as shown above) plus post (just under 10kg) and David has them in stock, so contact him if you need one.
I developed the above kit primarily for my own use after breaking a pin in a remote spot in the Kimberley.
They seem to last very well. No one, including me, has worn out a part yet since 2009.
The pins are made from standard "off the shelf" M20 HT bolts, so can be purchased almost anywhere if required.
The urethane bushes are likewise as simple as possible and could be made by anyone from a variety of materials in an emergency. All thrust components are hardened steel.
Trying to maintain the original OKA philosophy of simplicity and availability.
Shims are laser cut from spring steel shim followed by hardening. Hex head locators are also laser cut (from 6mm mild steel).
Complete conversion kits are $900 (as shown above) plus post (just under 10kg) and David has them in stock, so contact him if you need one.
Cheers, Peter.
OKA196 tinyurl.com/OKA196xtMotorhome
Mob.0428171214
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01 Jun 2013 07:26 #16
by dandjcr
David and Janet Ribbans - Oka 148
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dandjcr replied the topic: Springs and Shackles Information
OiA, yes the big thrust washers carry the lateral load directly from the spring eye to the hangers.
I wouldn't recommend nylon washers, they will get crushed and torn by the combined pressure and rotation of the spring eye. I did use stepped bushes once and this was the result.
The thrust washers should preferably be hardened steel but I've cut washers from various thickness of mild steel plate quite successfully, depending on the gap you need to fill (springs/hangers can vary in width). They don't have to be round of course (except the hole), rectangular washers are easier to make.
I wouldn't recommend nylon washers, they will get crushed and torn by the combined pressure and rotation of the spring eye. I did use stepped bushes once and this was the result.
The thrust washers should preferably be hardened steel but I've cut washers from various thickness of mild steel plate quite successfully, depending on the gap you need to fill (springs/hangers can vary in width). They don't have to be round of course (except the hole), rectangular washers are easier to make.
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01 Jun 2013 08:29 - 01 Jun 2013 08:32 #17
by dandjcr
OiA your bushing set probably looks like this (plus a steel cylinder liner inside the spring eye):
It's all metal on metal, so grease won't easily reach the contact points, and the bolts are too short and can/did break where the threads end.
I don't think the spring bushes are a Dana part, the Oka p/n is 006330 which looks like an Oka special.
You'd be lucky to find them locally and I would suggest changing the metal bushes to fairly hard urethane bushes which should be available locally (even if you have to shorten them or remove the lip on a bench grinder) and fit longer greaseable bolts (standard bolts can be drilled). While the bolts are out, check the hanger holes for oval wear. They can be welded up and re-drilled and/or thick plates welded over the holes and drilled.
Either way, don't over-tighten the nyloc nuts, they are only there to hold everything together and some movement is necessary.
David and Janet Ribbans - Oka 148
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dandjcr replied the topic: Springs and Shackles Information
OKA in Africa wrote: Tho you know what I have to look/ask for at the shops? Is the original bushing set just made for the OKA? Is it a Dana bushing set?
OiA your bushing set probably looks like this (plus a steel cylinder liner inside the spring eye):
It's all metal on metal, so grease won't easily reach the contact points, and the bolts are too short and can/did break where the threads end.
I don't think the spring bushes are a Dana part, the Oka p/n is 006330 which looks like an Oka special.
You'd be lucky to find them locally and I would suggest changing the metal bushes to fairly hard urethane bushes which should be available locally (even if you have to shorten them or remove the lip on a bench grinder) and fit longer greaseable bolts (standard bolts can be drilled). While the bolts are out, check the hanger holes for oval wear. They can be welded up and re-drilled and/or thick plates welded over the holes and drilled.
Either way, don't over-tighten the nyloc nuts, they are only there to hold everything together and some movement is necessary.
David and Janet Ribbans - Oka 148
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02 Nov 2016 15:40 - 04 Nov 2016 07:05 #18
by dandjcr
David and Janet Ribbans - Oka 148
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dandjcr replied the topic: Springs and Shackles Information
I upgraded 10 of our 12 spring bolts to Peter's 20mm pin system in 2009 and had no more problems with those.
For years earlier I'd had a continuous woes with springs and suspension pins breaking, and/or the shackle holes wearing ragged, mostly on the front pins of the rear springs, which do most of the work. For those 2 locations I'd had some bespoke plates and screw-in bushes fitted for 16mm pins a year earlier.
Those 2 remaining 16mm pins still only lasted a few more years so belatedly I also upgraded them to 20mm. This one had obviously been broken for some time and was protruding 50mm (hidden behind a gas bottle) but surprisingly both halves were still in place.
However, the screw-in bush hole was 21mm diameter so I couldn't drill them out for 20mm pins. So instead I drilled them out to 25mm and fabricated some bushes to fit from the original Oka steel shackle bushes (of which I now had dozens). This would be a useful mod for any ragged shackle pin holes and I've also used them to replace the flimsy pin arrangement on our rear spare wheel gate which now has 16mm hinge pins.
These (top right) have an OD of 25mm and ID of 16mm which can easily be drilled out to 20mm and cut to the required length. Some were worn and/or damaged so I made several and selected the best fitting ones.
The end result is 20mm pins but with the load spread over a much larger surface area, and with replaceable bushes.
I used socket head bolts because they were the only types I could get at the time which were long enough (with the extra width of plates fitted), and of the strength I wanted (Grade 12.9). Hex heads would have been better. I've subsequently fitted anti-rotation devices fabricated from a section of large Allen key welded to a bracket and bolted to the spring mount).
Since doing this mod, we've done 2 more outback trips (25,000km total, including the GSD crossing), with no more suspension pin problems.
There are a few more details on our our blog entry here .
David
For years earlier I'd had a continuous woes with springs and suspension pins breaking, and/or the shackle holes wearing ragged, mostly on the front pins of the rear springs, which do most of the work. For those 2 locations I'd had some bespoke plates and screw-in bushes fitted for 16mm pins a year earlier.
Those 2 remaining 16mm pins still only lasted a few more years so belatedly I also upgraded them to 20mm. This one had obviously been broken for some time and was protruding 50mm (hidden behind a gas bottle) but surprisingly both halves were still in place.
However, the screw-in bush hole was 21mm diameter so I couldn't drill them out for 20mm pins. So instead I drilled them out to 25mm and fabricated some bushes to fit from the original Oka steel shackle bushes (of which I now had dozens). This would be a useful mod for any ragged shackle pin holes and I've also used them to replace the flimsy pin arrangement on our rear spare wheel gate which now has 16mm hinge pins.
These (top right) have an OD of 25mm and ID of 16mm which can easily be drilled out to 20mm and cut to the required length. Some were worn and/or damaged so I made several and selected the best fitting ones.
The end result is 20mm pins but with the load spread over a much larger surface area, and with replaceable bushes.
I used socket head bolts because they were the only types I could get at the time which were long enough (with the extra width of plates fitted), and of the strength I wanted (Grade 12.9). Hex heads would have been better. I've subsequently fitted anti-rotation devices fabricated from a section of large Allen key welded to a bracket and bolted to the spring mount).
Since doing this mod, we've done 2 more outback trips (25,000km total, including the GSD crossing), with no more suspension pin problems.
There are a few more details on our our blog entry here .
David
David and Janet Ribbans - Oka 148
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