Dobinsons Monotube Remote Reservoir Shock Absorbers

[Whitey Shockie Maker of the Month Award Find all posts View Profile Close Whitey]

Repost from the Bilstein and Kings spring thread. Was dragging it off topic.



Straight up and down bounce at the front. Takes 3-4 cycles to settle down. Rear behaves, no sign of leaks (713 with airbags).

Springs are ridepro medium. Prado has front and rear bars, dual spare wheels, no winch. Will probably swap them out, maybe Dobinson 314/327.

The measurements I have say the A713 has 580mm extension vs standard 575.

Standard Dobinson 120 MRR's are F: 427-560, R: 362-583 so 44mm extra wheel travel at front and 8mm at rear over standard.

MRR Rear shock options MRR LC80 is 603 (+28mm), MRR 60701 is 615mm (+40mm)

MRR's are revalveable back at the Dobinsons dealer, but not by the owner. A set of MRR shocks are around $1300, way less than on vehicle adjustables.

Hey,

Yep your 712's are flogged and not damping. No surprise, mine did the same thing.

Using a 314 Dobinson coil on the front will give you too much height, with a 327 in the rear, you will have a front end higher than rear. You need to keep the front end around 2" lift, any higher and you start to loose droop because of the leverage ratio. I would be using a 300 or maybe a 302 coil. You'll find the 327 doesn't give enough lift in the rear, I run a 487 coil that is 20mm taller, and I'm much happier with how the rear sits now.

The 427-560mm MRR is ok, still another 10mm of shaft travel to be had out to open length of 570mm max for the 120, which translates to another 22mm at the wheel. 560mm is better than the 712 though!

Best

Mark

[Whitey Shockie Maker of the Month Award Find all posts View Profile Close Whitey]

In terms of wheel travel, is it a fair assumption that if the front is extended by 44mm, the rear should be in the same league?

That would mean going for the 60701's (+40mm) on the rear. The 120 would handle that without dragging on sway bar links or brake lines?

Cheers,

Hey,

I would definitely be going for the MRR 60701. Keep in mind the swaybar binds at 615mm open length on the 120, so you'll need to lengthen your links a bit. That's an easy fix, you can run up to 30mm longer links which pushes the swaybar bind out to 645mm. That way you top out on the 60701 at 615mm open instead of the swaybar. Topping out on the swaybar is when you can snap it, so if you're planning to keep the swaybar in and run a rear shock longer than 615mm, then use longer swaybar links.

You should also check what the 60701 closed length is relative to axle-bumpstop bind at 405mm on the 120.

You'll have considerably better articulation with 560mm/615mm open lengths, and I would consider a 300/487 coil setup as a possible starting point, or maybe 302/487.

Best

Mark

[Whitey Shockie Maker of the Month Award Find all posts View Profile Close Whitey]

Hey again photoprado,

I also forgot to mention that the oem brake lines on the 120 tend to be at full stretch in the 610-615mm range, so I would put longer stainless brake lines in. I run a 618mm open length rear shock, and have put in longer stainless brake lines.

So 560mm/615mm MRR with 300/487 and 30mm longer links and longer stainless brake lines.

Best

Mark

[photoprado Avid PP Poster! Find all posts View Profile Close photoprado]

Thanks a bunch for your help Whitey!

Best I can tell, I have the intermediate ridepros:

F: Ridepro ZC7302 395 617*
R: Ridepro ZC7327 410 (40.6)232*

Dobinsons Front:
Dobinsons C59-300 385 (102.7)586*
Dobinsons C59-302 395 (102.7)586*
Dobinsons C59-314 405 (102.7)586*

Dobinsons Rear:
Dobinsons C59-327 410 (47.5)271*
Dobinsons C59-487 430 (49)280

All from the pradopoint suspension database.

So the Dobinsons front 302 is same free length as the ridepro but a bit softer. I wonder if they can test the ridepro fronts, maybe keep them if they are in spec, not much in it though.

The rear 487 is higher and stiffer than the ridepro. Probably a good idea with the rear bar. If I go for those, should I keep the airbags. Are longer swaybar links available?

The 327's are only a bit stiffer than the ridepro, there are a few negative comments about them about that's enough to sway me away from them.

The front MRR's are adjustable for spring seat height, so the front wouldn't have to be higher unless there wasn't enough adjustment.

[Whitey Shockie Maker of the Month Award Find all posts View Profile Close Whitey]

Thanks a bunch for your help Whitey!

Best I can tell, I have the intermediate ridepros:


All from the pradopoint suspension database.

So the Dobinsons front 302 is same free length as the ridepro but a bit softer. I wonder if they can test the ridepro fronts, maybe keep them if they are in spec, not much in it though.

The rear 487 is higher and stiffer than the ridepro. Probably a good idea with the rear bar. If I go for those, should I keep the airbags. Are longer swaybar links available?

The 327's are only a bit stiffer than the ridepro, there are a few negative comments about them about that's enough to sway me away from them.

The front MRR's are adjustable for spring seat height, so the front wouldn't have to be higher unless there wasn't enough adjustment.

Hey again,

All of the spring rates for Ridepro in the database are incorrect. Ridepro and Dobinsons are the same rates, made from the same place, one is powder coated black, the other green. At least that is how it used to be, I think Ridepro have outsourced there gear now.

The Dobinsons all used to read 612lb/in for the front coils, but then I discovered through Ben Dobinson they are actually 586lb/in. All the Ridepro coils need to have their spring rates corrected in the database. Your 302 Ridepro is exactly the same as a Dobinsons 302.

Definitely a good idea to go for the 487 in the rear with your rear bar. Keep the airbags, they'll prolly fit the 487 at working height.

You can get adjustable threaded swaybar links for the 120 from Roadsafe or Superior Engineering. The Roadsafe are cheaper, but the same as the Superior ones. They both utilise heim joints with a greasable zerk. I've been running the Roadsafe links for a long time now, I greased them when I put them in, haven't heard a peep out of them since.

See here for Roadsafe links on ebay;

http://www.ebay.com.au/itm/TOYOTA-PR...IAAOSwD0lUbCeY

Regarding the 327 coils, I've seen the complaints that they are too stiff etc. They are 271lb/in. I used to run 327 coils in the rear and found them soft as mush. In my opinion they aren't tall or stiff enough for the rear of the Prado. In a loaded vehicle with my airbags inflated to 30psi, I could never get the rear end level with 327's.

The 487 is 20mm taller at 430mm free height, and a touch over 280lb/in. With this coil, my Prado finally sits level in the rear where it should sit relative to the front. With 300's in the front and 487's in the rear, I have 10mm of rake. I think the car drives a ton better now as well.

One thing you are going to struggle with is vehicle pitch. This is because of the extra weight from your rear bar. To keep the front:rear suspension frequency near or better than 1:1 (which minimises pitch) you need the front:rear coil spring rates in the ratio 586/280. If you add the extra weight of the bar to the equation, then the ratio goes under 1:1, ie., you'll never construct a linear or multi-rate rear coil that has high enough spring rate to combat vehicle pitch.

Your airbags may combat it slightly, but they won't combat it completely. That's just life with a rear bar, expect "some" vehicle pitch in undulating conditions where obstacles are wheelbase apart in width.

As the front MRR is fully height adjustable, I would rather use a 300 than a 302 coil. Perhaps your 302 Ridepro has sagged a few mm, so it might be ok. If the height doesn't settle around 2", then I would look at changing to a 300.

Your Prado is about to undergo quite a transformation, I think you'll be very happy with that setup after your pogo 712/713 combo.

Keep us posted with your install!

Best

Mark

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I have C59-302 on the front with Sovereign bullbar + winch cradle (no winch or aux batt). The circlip is on the 2nd groove from the bottom and the suspension height is 790-800mm.

Currently have 270lb/in in the rear and it feels good. Looking to adjust that to 290lb/in.

[Whitey Shockie Maker of the Month Award Find all posts View Profile Close Whitey]

I have C59-302 on the front with Sovereign bullbar + winch cradle (no winch or aux batt). The circlip is on the 2nd groove from the bottom and the suspension height is 790-800mm.

Currently have 270lb/in in the rear and it feels good. Looking to adjust that to 290lb/in.

Hey amts,

Good to know the 302 isn't too tall to keep the ride height around 790-800mm!

Is that the 2nd circlip position on your 5100's? Are those grooves cut at the same height positions as the 712 etc.?

Which 290lb/in coil are you putting in the rear, free height/manufacturer?

...btw, I've been hunting hard trying to find rebound and compression forces for the 5100's, I found 3040N:880N, but this was just numbers from a forum thread. I'll hopefully have accurate figures soon from Bilstein.

Best

Mark

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Is that the 2nd circlip position on your 5100's?

Yes

Are those grooves cut at the same height positions as the 712 etc.?

Not sure but I'm assuming that they are

Which 290lb/in coil are you putting in the rear, free height/manufacturer?

Top secret.

[Whitey Shockie Maker of the Month Award Find all posts View Profile Close Whitey]

Yes


Not sure but I'm assuming that they are


Top secret.

Hahaha!

Well I know the Dobinson 487 linear coil is pretty much at its design limits at 430mm free height with 280lb/in, so at 290lb/in I'm guessing you have slightly less free height??

...unless you've discovered a new superalloy that has a better torsional modulus?

Best

Mark

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The spring doesn't exist yet

[photoprado Avid PP Poster! Find all posts View Profile Close photoprado]

Hey again photoprado,

I also forgot to mention that the oem brake lines on the 120 tend to be at full stretch in the 610-615mm range, so I would put longer stainless brake lines in. I run a 618mm open length rear shock, and have put in longer stainless brake lines.

So 560mm/615mm MRR with 300/487 and 30mm longer links and longer stainless brake lines.

Best

Mark

I wondered about that, can't seem to find any longer rear brake lines advertised for the 120. Any links?

Do HiLux brake lines fit, and what length overall do I need? Is this something that can be done on site by a mobile hydraulic line mob like ENZED?

BTW: Ordered the Roadsafe sway bar links, already shipped!

Thanks for your help!

Edit: Found some at Superior Engineering for a 2 inch lift. $110 ea
https://www.superiorengineering.com....filter=240,355

Would they be suitable?

[Whitey Shockie Maker of the Month Award Find all posts View Profile Close Whitey]

I wondered about that, can't seem to find any longer rear brake lines advertised for the 120. Any links?

Do HiLux brake lines fit, and what length overall do I need? Is this something that can be done on site by a mobile hydraulic line mob like ENZED?

BTW: Ordered the Roadsafe sway bar links, already shipped!

Thanks for your help!

Edit: Found some at Superior Engineering for a 2 inch lift. $110 ea
https://www.superiorengineering.com....filter=240,355

Would they be suitable?

Hey,

Those extended lines from Superior will do the job...they are pricey though. If you shop around, eg., a brakes specialist workshop, you can get extended stainless lines made up for half that price. The savings will pay for your links!

I would get at least 3 inch longer lines than factory, in case you decide to run even longer rear shocks later.

When are you installing your MRR's?

Best

Mark

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Have a look around, you can get lines made up locally.

[photoprado Avid PP Poster! Find all posts View Profile Close photoprado]

Thanks Whitey and Piggy,

Will check locally, sounds like the best plan.

Waiting on confirmation on the MRR 60701 minimum length, delivery of the Roadsafe links, and then I'm good to go.

Easter might get in the way but we should be sorted in a few weeks.

[photoprado Avid PP Poster! Find all posts View Profile Close photoprado]

See here for Roadsafe links on ebay;

http://www.ebay.com.au/itm/TOYOTA-PR...IAAOSwD0lUbCeY

These have arrived.



Pretty solid. They also fit GQ/GU Patrol, and Prado 120/150.