Dobinsons 5th Gen T4R Suspension options - from Exit Offroad

[Crikeymike]

Hey Mike (and others) I could use some expert advice on my 4th gen rear end with all the Dobsons spring options. I'm leaning towards the dual rate springs, but possibly a single rate if necessary. I installed a 4X4 labs rear bumper and a custom drawer system, now the OME springs (260lb) I have installed don't cut it anymore (dropped about 1 1/4" and bottoming out on bumps way too easy. Currently running Bilstein 5100s and not interested in changing those out if I don't need to.

See below for the added weight items on the rear, unfortunately I don't know the weights. Aside from ride quality suffering due to too stiff of springs, I'm concerned about lift height. Maybe I'm overthinking the problem, but I'm not running extended brake lines and would prefer not to go over the 2.5" lift or increasing the drop on full extension from what I had before the bumper change. Obviously the weights will be much higher loaded with supplies for overlanding. What are your Dobinsons recommendations?

4X4 Labs rear bumper, swing-outs W/33" spare, Hi-lift, & custom Water/firewood holder.
RSG sliders.
Sherpa roof rack.
Custom drawers, 80-100 Lb estimate.
ICECO VL45 ProS fridge with slider.
ARB CKMA12 compressor.
Renogy 100W LiFePO4 battery & Giandel 1000W inverter.

*Future ~10 gallon custom aluminum fuel tank in OEM spare location, only filled for off road.

A 260lb spring is the correct rate, or close to it, for that weight you have. If you weren't happy with the ride quality, then it's your shocks. See the spring rates of the Dobinsons coils in the first post. Since you don't want to go over 2.5", C59-329 would be the closest option offered.

What's your current hub to fender measurement on the rear?

 

[08ShadowRunner]

Thanks for the quick reply Mike. With about 3/4 tank, center hub to fender measurement is 22 1/8" on the Right and 21 5/8" left. Interestingly the spacer I had on the LH rear is MIA. Guess it wasn't MOAB trail rated... I also have the spare, jack, fridge and second battery on the right side.

I'm happy with the ride and on the street everything is smooth so I'm okay with the shocks. It's on the trail on the bumps and ruts that I have issues. The springs just aren't cutting it. I just don't want to go too heavy on the spring capacity and sacrifice ride quality which is why the dual rated springs caught my attention. What's your thoughts on the C59-677V? I'm thinking that will do okay with the stock rear control arms. I'm trying to avoid going with a long travel system and aftermarket control arms which is why I was wanted about 2 1/2 inch lift. I mis-communicated that part.

 

[Crikeymike]

Thanks for the quick reply Mike. With about 3/4 tank, center hub to fender measurement is 22 1/8" on the Right and 21 5/8" left. Interestingly the spacer I had on the LH rear is MIA. Guess it wasn't MOAB trail rated... I also have the spare, jack, fridge and second battery on the right side.

I'm happy with the ride and on the street everything is smooth so I'm okay with the shocks. It's on the trail on the bumps and ruts that I have issues. The springs just aren't cutting it. I just don't want to go too heavy on the spring capacity and sacrifice ride quality which is why the dual rated springs caught my attention. What's your thoughts on the C59-677V? I'm thinking that will do okay with the stock rear control arms. I'm trying to avoid going with a long travel system and aftermarket control arms which is why I was wanted about 2 1/2 inch lift. I mis-communicated that part.

What part number are the current springs?

You're about 1/2" taller than stock height right now, which really shows how much weight you have in the back if they're 260lb springs. Going to 677V would be a reduction in spring rate, and could be the same or lower than you're at now.

 

[08ShadowRunner]

I've got OME springs P/N OME-895 or 2895. That is probably just enough to cover the bumper comfortably. With the drawers battery, jack, fridge and larger spare I'm probably twice their optimal rating now.

 

[Crikeymike]

I've got OME springs P/N OME-895 or 2895. That is probably just enough to cover the bumper comfortably. With the drawers battery, jack, fridge and larger spare I'm probably twice their optimal rating now.

OK.

I still recommend C59-329 based on the weight you have and the height you want.

C59-677V probably wouldn't give any lift over what you've got due to that extra weight and the lighter spring rate

 

[Killerpopcorn]

Do you need spacers for the radiator brackets or does the Sway bar relocation kit address that? I didn't know if those might rub.

 

[08ShadowRunner]

OK.

I still recommend C59-329 based on the weight you have and the height you want.

C59-677V probably wouldn't give any lift over what you've got due to that extra weight and the lighter spring rate

Gotcha, thanks for the info.

 

[Crikeymike]

Do you need spacers for the radiator brackets or does the Sway bar relocation kit address that? I didn't know if those might rub.

The Dobinsons sway bar relocation bracket kit comes with the radiator brackets

 

[Ventura_Hondo]

Hey guys, my name is Mike Tomczyk (aka Crikeymike), owner at ExitOffroad.com. I've been in the 4x4 industry since 1998 and have always preferred to focus on suspension for 4x4's, since it's something you'll feel every single time you move your vehicle, whether driving to work or home, or offroad for the weekend. Everyone has their own build plans for their vehicle, so no same combo of parts is necessarily right for everyone, which is why we offer such a variety - to get you exactly what you're looking for!!









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Hey Mike

I’ve been running the C59-677V on the rear and wanted to switch to either the C59-327 or C59-329. My setup currently is

Kings 2.5 Extended
RSG Full Steel Skids and Sliders
RTT 120lbs
Frontrunner Roof Rack
Frontrunner Drawers
ICECO VL45 Pro Fridge
80-100lbs in tools and gear
Rig’d Ultra Swing Tire Carrier 4gallon water

What do you recommend for the rear spring. Thanks and I’ll order this tomorrow.

 

[Crikeymike]

Hey Mike

I’ve been running the C59-677V on the rear and wanted to switch to either the C59-327 or C59-329. My setup currently is

Kings 2.5 Extended
RSG Full Steel Skids and Sliders
RTT 120lbs
Frontrunner Roof Rack
Frontrunner Drawers
ICECO VL45 Pro Fridge
80-100lbs in tools and gear
Rig’d Ultra Swing Tire Carrier 4gallon water

What do you recommend for the rear spring. Thanks and I’ll order this tomorrow.

C59-327 are a similar equivalent to the 677V, but 1" shorter.
C59-329 are stronger, and are similar to 701V.

It depends what you're trying to achieve and why you're changing from what you've already got.

 

[Ventura_Hondo]

Hey Mike

I’ve been running the C59-677V on the rear and wanted to switch to either the C59-327 or C59-329. My setup currently is

Kings 2.5 Extended
RSG Full Steel Skids and Sliders
RTT 120lbs
Frontrunner Roof Rack
Frontrunner Drawers
ICECO VL45 Pro Fridge
80-100lbs in tools and gear
Rig’d Ultra Swing Tire Carrier 4gallon water

What do you recommend for the rear spring. Thanks and I’ll order this tomorrow.

C59-327 are a similar equivalent to the 677V, but 1" shorter.
C59-329 are stronger, and are similar to 701V.

It depends what you're trying to achieve and why you're changing from what you've already got.

I’m changing them out cause the 677V’s are to long for my shocks. I don’t mind going a little lower on rears also. If I went with the 329’s I would still go down an inch from the 677V’s? It’s kinda hard to calculate the weight cause do I only attribute the weight in the rear or all around? Either way I appreciate your feedback.

 

[Crikeymike]

I’m changing them out cause the 677V’s are to long for my shocks. I don’t mind going a little lower on rears also. If I went with the 329’s I would still go down an inch from the 677V’s? It’s kinda hard to calculate the weight cause do I only attribute the weight in the rear or all around? Either way I appreciate your feedback.

What's your current hub to fender measurement in the rear? You're probably at 24.5-25" (25" being a 3" lift).

C59-327 usually sit at 24" and 329's at 24.5"

So the shocks you have must be made for a low lift height. Do they say how much?

 

[Ventura_Hondo]

What's your current hub to fender measurement in the rear? You're probably at 24.5-25" (25" being a 3" lift).

C59-327 usually sit at 24" and 329's at 24.5"

So the shocks you have must be made for a low lift height. Do they say how much?

Yah I’m currently sitting at around 24.5 on the rears. I have King Ext Travel shocks w/adjusters.

 

[Crikeymike]

If anyone ever has a problem adjusting or turning the purple or black adjuster knobs on their Dobinsons MRA shocks or struts, here's a guide to clear that up.

https://exitoffroad.com/wp-content/...ns-MRR-MRA-Adjuster-Stuck-or-Hard-to-Turn.pdf

 

[Crikeymike]

Black Friday deals start tomorrow. Check out the post here for any and all deals we will be offering. We'll update it if any other brands add a deal.

2023 Black Friday Deals & Discounts - Exit Offroad

 

[baldrik78]

Black Friday deals start tomorrow. Check out the post here for any and all deals we will be offering. We'll update it if any other brands add a deal.

2023 Black Friday Deals & Discounts - Exit Offroad

I was hoping this sale would happen again this year. Just ordered a set of IMS to replace my 100k mile Bilsteins!

 

[Crikeymike]

I was hoping this sale would happen again this year. Just ordered a set of IMS to replace my 100k mile Bilsteins!

Thanks man. It's been so busy since midnight. LOL

 

[Stebrock]

Does anyone run IMS with C59-300 springs up front (~1.75” lift) and C59-323 springs in the rear (“stock” height)? On a stock weight truck, do you still have a little bit of rake or is this set-up completely level?

For context, I’m debating between C59-323 or C59-599 springs for the rear and I’m at a loss about which direction to go. I’m looking for just a little bit of rake (less than an inch).

 

[ag12s]

Does anyone run IMS with C59-300 springs up front (~1.75” lift) and C59-323 springs in the rear (“stock” height)? On a stock weight truck, do you still have a little bit of rake or is this set-up completely level?

For context, I’m debating between C59-323 or C59-599 springs for the rear and I’m at a loss about which direction to go. I’m looking for just a little bit of rake (less than an inch).

I'm running the MRA's, but have the spring setup of C59-300 in the front and C59-323 in the rear. It gave me a true a 1.75"-2" up front (which is adjustable of course with MRA's or IMS) and 1" in the back. I've included some photos, this is running stock size tires as well. One photo has my old Toyo AT3's, the other has Wildpeaks. With this I have just a small amount of rake built in there.

 

[Secretarynotsure]

Does having the adjustable shocks make the MRR able to be progressive, digressive, and linear? Or just different levels of progressive because it uses a progressive valve?