Dobinsons IMS Struts and Shocks - Adjustable Height Monotubes - 2nd/3rd Gen Tacomas

The cat got out of the bag recently about the new Dobinsons IMS shocks, so I'm starting this thread to give the details about these new struts from Dobinsons that are arriving in March 2020, and rear shocks arriving later in 2020.

IMS
Internal reservoir
Monotube
Shocks

I guess IRMS sounded silly, and considering the already existing MRR (Monotube Remote Resi), a non-resi version didn't sound right either, this is the wording Dobinsons are going with.

In a nutshell, the IMS struts and shocks are almost the same as the MRR/MRA but with an IFP (Internal Floating Piston) inside the shock body with a small gas reservoir, and no external hose or reservoir. Same monotube body size, piston diameter, shaft thickness, and also the struts are height adjustable thanks to the fully threaded body. Super easy installation.
These do not have any valving adjustment.

From the manufacturer:
Dobinsons IMS Monotube Shock Absorbers are designed for next level performance over Twin Tube Shocks in those hot, harsh, demanding conditions. By utilising the Monotube design, Dobinsons IMS Shock Absorbers are able to resist fade far longer on corrugated roads, long or hard working 4WD trips, towing or racing conditions.

The larger 50 and 60mm high flow pistons reduce internal pressures, reduce the heat generated, transfer heat to the body for faster cooling and offer improved damping performance and vehicle control at higher shaft speeds on rough terrain and during big impacts. Threaded bodies on struts allow for fine tuning of height and offer further improvements in cooling.
The micro-polished, hard chromed and heat treated shock shaft, CNC aluminium high flow race inspired piston, and DOM seamless tubing body provides the ultimate in performance and off-road durability.

Composite piston wear bands and a race style 3-stage sealing system offer the lowest levels of friction whilst maintaining durability and longevity. Dobinsons team of engineers spend hundreds of hours of testing and tuning
the shim stacks and damping characteristics in each IMS Shock to ensure a balance of comfort, handling, vehicle control and offroad performance - Enjoy the ride

Features

• Fully re-buildable and re-valvable
• Zero shock fade in all terrains with full load
• Direct, bolt-on replacement for easy fitment
• Uses existing full range of coil springs and top mounts
• Highest quality rubber bushings top and bottom for maximum NVH dampening
• Corrosion resistant (EDP Surface Protection)
• Heavy duty single piece lower leg
• Enormous oil capacity
• Heavy Duty 3 Stage FKM HNBR Sealing System for the ultimate in reliability
• Race inspired hi-flow CNC 6061 Billet alloy piston – for the ultimate in offroad handling
• 56mm/2.2” Bodied Series - 50mm hi-flow CNC 6061 Billet alloy piston - 50mm bore
• 66mm/2.6” Bodied Series - 60mm hi-flow CNC 6061 Billet alloy piston - 60mm bore

The body size is 56mm with a 50mm piston for these vehicles:
4th/5th Gen 4Runner
2nd/3rd Gen Tacoma
Lexus GX470 and GX460

The body size is 66mm with a 60mm piston for these vehicles:
Land Cruiser 80, 100, and 200 series

Part numbers for 2nd and 3rd Gen Tacoma 2005+ IMS struts and shocks. Click on part number to see pricing and further details of each item. **SOLD IN PAIRS**
IMS59-50220 - IMS Front Struts - suits 0-3.5" lift - stock arrived 3/19/20
IMS Rear Options - ETA mid-October 2020

At this time, a new IMS rear shock is in development for the Tacoma, but no part number or specs are available. Dobinsons will have the MRA59-A940 before the IMS version is out.

Initial pricing is $500/pr front struts

Instructions on how to set the coil seat height and how to adjust them: https://exitoffroad.com/wp-content/uploads/2020/03/ExitOffroad.com-IMS_MRA-adjustment.pdf

https://www.youtube.com/embed/Npfx40VD3kM

 

subd

 

Added a write up and instructions on how to set and adjust the height on these.

https://exitoffroad.com/wp-content/uploads/2020/03/ExitOffroad.com-IMS_MRA-adjustment.pdf

 

Front adjustable height IMS struts arrived today. Any pending orders will ship out today or tomorrow!!

 

Great deal going for May, save $180!!!

https://exitoffroad.com/product-category/maypromo

 

I see in the setup guide it says
"2005-2020 Toyota Tacoma - Stock height is 213mm"

So am I understanding right that if I want it to sit 2" higher, I set the distance to be 2" + 213mm (which is 10.38") ?

 

I'm thinking I've got that wrong and the struts should be set to that height for every installation. And the spring is what is giving the lift... And the adjustability of the strut is just for minor fixes, like fixing a lean. That right?

 

You are close-ish. Haha.

The stock coil seat height is 213mm. So if you put stock coils on there then, you'll have no lift. Normally you'd put lifted coils on at that height and get the lift out of the coils instead of raising the seat height, but it depends what coils you're using.

It's a 2:1 ratio of lift at the strut to the wheel, so for a 2" lift with a stock coil, you'd add 1" to the 213mm measurement to end up 2" taller at the wheel.

And yes, most would adjust the collars to compensate for a lean if there is one.

For the IMS59-50220 though, we're using it for all lift heights from 0-3.5", so normal setting is 213mm, but for those that want 2.5" to 3.5", we use 226mm seat height to add 1" of lift to the 1.5" to 2.5" coil range to get 2.5-3.5" of lift.

 

Thank you for the reply.

I was installing IMS struts with 2"springs. I set my passenger to 213mm and the drivers to 213mm + 1/4". Both front corner heights were within 1/16" of my before measurements. Before suspension was stock with 2"spacers.

Took it for a 5 mile test drive tonight. It rides SIGNIFICANTLY nicer. Can't wait to get some more miles on it

Tomorrow the Dobinson's medium rear springs go in, along with Firestone air bags.

 

That's good to hear bud, keep putting updates on here when you can, and add some photos too!!

 

Today the rear medium-strength springs went in. I didn't realize that Dobinson's ships them without bushings, so I had to scramble for some. Found a pair of poly bushings in my stash and then pressed the factory bushing out of the stock springs for the 2nd pair.

The medium spring gave me 3.25" of lift, measured at the fender flare. I'm hoping the shell I have on order brings that number down a bit.

I drove it about 70 miles of city streets & freeway and 30 mi on tight, curvy, mountain roads. Very very happy with how the new suspension is performing.

The truck feels much more firmly planted. Pot holes that would have previously unsettled the truck were sucked up by the IMS struts and the truck kept it's composure.

Handling during braking is wonderful. That was a huge complaint of mine before... Especially the huge nose dive the truck used to do under only moderate braking. No more nose dive!

[Edit] paragraph deleted due to incorrect assumption... New info is in post #16 [end edit]

Speaking of airbags, they're not finished yet bc they wouldn't fit with the 3"of lift I got from the springs. I will make spacers to get them set at the right height and finish the install.

Won't have time to work on it this week, so photos & finishing the air bags will have to wait.

 

Here's how it sits. IMS struts with 2" springs in the front. Dobinson's Medium strength replacement springs in the rear. Sitting on 285/70R17 Nitto Terra Grapplers.

The tires and wheels in the bed weighed 360 lbs

 

Looks awesome! I'm fixing to install the same setup. What did you set your seat height at? I'm looking to target around 2.75" of lift.

 

Thanks! I should have read back a few posts...

 

So... I need to correct something I said in a prior post. I initially said the medium Dobinson's springs were too stiff, but I've since figured out that was because I was still using stock shocks in the rear. I had forgotten to order rear shocks in my initial order, so I had to keep using the stock rear shocks that first week.

The taller ride height was causing the factory rear shocks to be nearly fully extended when at ride height. It didn't take much for the shock to fully extend, and I was mistaking that harshness as being caused by a very stiff spring.

Tonight I installed the Dobinson's rear shocks, which are an appropriate length for the higher ride height. The springs ride really nice with the Dobinson's shocks!

They're noticably less harsh than stock springs going over big bumps, like speed bumps. The stock springs take very little compression to contact the overload leaf, which makes them miserable going over stuff like speed bumps. With the Dobinson's you have more suspension travel before you're on the overload leafs and it results in a better ride.

I also finished my airbag install tonight. Instead of creating a custom spacer to make the air bag work with this 3"of lift in the rear, I went with Daystar cradles. With the cradles your air bags hang from the upper mount and land in the cradle when your suspension is compressed.

This let's you have more usable wheel travel. If the tiny air bags were fixed top and bottom, and you like to 4 wheel, the bags would be limiting your wheel travel and you'd eventually tear a bag.

I was nervous they'd be loud and annoying when the bottom of the bag contacted the cradle, but that wasn't the case. With the windows up I couldn't even hear the airbags landing in the cradles. With the windows down I could hear it, but it wasn't a harsh noise. I'm easily irritated by extra noises in my vehicles, but I'll easily tolerate this.

Next week I'll make some time to setup the weight distribution hitch for my car trailer and see how well my Tacoma tows my 4Runner around.

 

I was quoted 6 weeks for my new shell to arrive. I finally got it at 13.5 weeks! Thanks covid19! But they did throw in the frameless windows and a hook system on the ceiling for free because of the delay.

The weight of the shell didn't have a significant impact on handling or ride height. I don't know the weight of the shell, but you can see from the photos it compresses the springs less than the 360# wheels/tires.

I've got no regrets going with the Dobinson's medium springs. Ride quality is much better than stock and they (along with the air bags) handle the 4000k# travel trailer I bought really well.

 

That shell looks really slick, especially color matched with those better side windows!!

Glad to hear the suspension is handling it all well too!!

 

Any updates on the IMS rears being released?

 

They're just about done and shipping over. Should be in the US around mid-October.