Dobinsons IMS fj60 lift (2 Viewers)

[wngrog]

When installing the Dobinsons springs, is it pretty standard practice to install shims of around 4* to correct caster, extended sway bar links (and possibly sway bar bushings), new center pins that accommodate the shims, and new center pin spacers/bushings to hold the axle in place (assuming that the tie rod ends and the steering stabilizer are in good working order)? Are there any other parts that should be installed at the same time? I notice some of the installs in the above photos show a near-perpendicular orientation to the ground for the rear shackles. Can this shackle orientation be made to lay more at an angle by removing a spring from the spring pack? Thanks for any guidance from those who have gone before.

I add 4* shims and new pins to all of my 40/55/60/62 lifts. The Dobinsons shackles are close to stock size but in the best of worlds you are still at plus 1 but closer to zero caster. I like more. Chevys at this vintage have 5* from the factory. More is better.

I use a swaybar kit from Autozone that is about 1” longer than stock. They keep them on the shelf here. Don’t know part number


As for the shackles. Dobinsons designs their leaf springs to have perpendicular shackles. I too had to get it out of my mind that a 45 degree shackle makes the ride better.

Sure it does if your springs don’t flex. Dobinsons uses multiple small highly arched leafs that actually move as you drive over obstacles versus the others that usually have thick springs and lots of them.

 

[CruiserTrash]

When installing the Dobinsons springs, is it pretty standard practice to install shims of around 4* to correct caster, extended sway bar links (and possibly sway bar bushings), new center pins that accommodate the shims, and new center pin spacers/bushings to hold the axle in place (assuming that the tie rod ends and the steering stabilizer are in good working order)? Are there any other parts that should be installed at the same time? I notice some of the installs in the above photos show a near-perpendicular orientation to the ground for the rear shackles. Can this shackle orientation be made to lay more at an angle by removing a spring from the spring pack? Thanks for any guidance from those who have gone before.

I run 4* shims up front on a shackle reversal with HZJ75 spring packs. On the rears I have regular 60 series springs with 6.5" shackles to match the height of the front. All springs are Dobinson, as well as the rear shocks. Still haven't figured out which front shocks to use. When I got this truck it had the SR already installed and I had an endless amount of people telling me to cut it off and go back to the stock arrangement - but the thing steers and tracks like a dream with 4* of caster correction. Hit a big bump on the highway at 70mph and it doesn't even flinch. It drives far better than my previous 60 that had the standard OME 2-3" kit.

I went with the HZJ75 springs because they are 1.7" longer than the 60 springs, and with my SR that puts the shackle angle at about 30* laid back from vertical. On the trail the front reacts more like coils, I get almost a foot of uptravel before the body moves and they soak up bumps really well on the road. My shackles in the rear are almost dead vertical and they perform well, but not as well as the front. The fact that they do so well with a vertical shackle is probably as a result of what @wngrog suggested - thinner springs, just a whole different way of engineering the spring pack. anyway, the fronts are so soft that I actually had to go back to running a front sway bar to tame the body roll on the highway. MAF makes great extended links in a bunch of extra sizes. They have a ball joint in them so they allow some suspension movement without snapping. Regarding the center pin, the HZJ75 springs come with 7 leaves and I removed two from each pack, so my pins were plenty long for the shims. Your mileage may vary there. All of the rest would be applicable to a suspension system that is not shackle reversed though.

And fwiw, the IMS shocks I have in the rear are fantastic. Far better than the ubiquitous "yellow shocks" I ran with my previous suspension. No comparison, not even a little bit of a debate about which one feels and performs better. IMS all the way.

 

[crikeymike]

When installing the Dobinsons springs, is it pretty standard practice to install shims of around 4* to correct caster, extended sway bar links (and possibly sway bar bushings), new center pins that accommodate the shims, and new center pin spacers/bushings to hold the axle in place (assuming that the tie rod ends and the steering stabilizer are in good working order)? Are there any other parts that should be installed at the same time? I notice some of the installs in the above photos show a near-perpendicular orientation to the ground for the rear shackles. Can this shackle orientation be made to lay more at an angle by removing a spring from the spring pack? Thanks for any guidance from those who have gone before.

No.

Look at the blue one, that's all the parts from our site and bolted on. Just need to choose the springs that match the added weight. Running stronger than necessary springs will increase the lift which increases all the angles.

The most recent guy has "extreme shackles" which are lifted which changed his rear shackle angle.

New sway bar links and bushings are a great idea on any suspension refresh. I don't offer them, as Dobinsons don't make them.

 

[cheeese]

Is there a more or less factory height Dobinson spring option or are they all 2" lift?

 

[garfieldthecat]

I add 4* shims and new pins to all of my 40/55/60/62 lifts. The Dobinsons shackles are close to stock size but in the best of worlds you are still at plus 1 but closer to zero caster. I like more. Chevys at this vintage have 5* from the factory. More is better.

I use a swaybar kit from Autozone that is about 1” longer than stock. They keep them on the shelf here. Don’t know part number


As for the shackles. Dobinsons designs their leaf springs to have perpendicular shackles. I too had to get it out of my mind that a 45 degree shackle makes the ride better.

Sure it does if your springs don’t flex. Dobinsons uses multiple small highly arched leafs that actually move as you drive over obstacles versus the others that usually have thick springs and lots of them.

Thank you @wngrog for clarifying your approach and the reason for the differences in shackle angles. I'm trying to line up the pieces and lay out the process ahead of time so I can set it and forget it for awhile once I get to the new springs. Got 4 Plus's u bolt flip kits and the 4* shims. Doing it little by little as the budget allows. Will probably apply the year end bonus to the actual springs

 

[garfieldthecat]

I run 4* shims up front on a shackle reversal with HZJ75 spring packs. On the rears I have regular 60 series springs with 6.5" shackles to match the height of the front. All springs are Dobinson, as well as the rear shocks. Still haven't figured out which front shocks to use. When I got this truck it had the SR already installed and I had an endless amount of people telling me to cut it off and go back to the stock arrangement - but the thing steers and tracks like a dream with 4* of caster correction. Hit a big bump on the highway at 70mph and it doesn't even flinch. It drives far better than my previous 60 that had the standard OME 2-3" kit.

I went with the HZJ75 springs because they are 1.7" longer than the 60 springs, and with my SR that puts the shackle angle at about 30* laid back from vertical. On the trail the front reacts more like coils, I get almost a foot of uptravel before the body moves and they soak up bumps really well on the road. My shackles in the rear are almost dead vertical and they perform well, but not as well as the front. The fact that they do so well with a vertical shackle is probably as a result of what @wngrog suggested - thinner springs, just a whole different way of engineering the spring pack. anyway, the fronts are so soft that I actually had to go back to running a front sway bar to tame the body roll on the highway. MAF makes great extended links in a bunch of extra sizes. They have a ball joint in them so they allow some suspension movement without snapping. Regarding the center pin, the HZJ75 springs come with 7 leaves and I removed two from each pack, so my pins were plenty long for the shims. Your mileage may vary there. All of the rest would be applicable to a suspension system that is not shackle reversed though.

And fwiw, the IMS shocks I have in the rear are fantastic. Far better than the ubiquitous "yellow shocks" I ran with my previous suspension. No comparison, not even a little bit of a debate about which one feels and performs better. IMS all the way.

Appreciate the insights regarding the IMS shocks @CruiserTrash . I think I will be doing the same. I also was looking at the MAF extended sway bar links. They look like a nice upgrade.

 

[garfieldthecat]

No.

Look at the blue one, that's all the parts from our site and bolted on. Just need to choose the springs that match the added weight. Running stronger than necessary springs will increase the lift which increases all the angles.

The most recent guy has "extreme shackles" which are lifted which changed his rear shackle angle.

New sway bar links and bushings are a great idea on any suspension refresh. I don't offer them, as Dobinsons don't make them.

Thank you @crikeymike. I had a long-range tank in my truck but am going back to the stock tank for safety purposes. The truck only has a M8000 winch now but is otherwise stock. Not sure if the winch alone would count as added weight? I believe it would still be at less than 80 lbs extra weight up front even if I added a longer 100-foot steel cable.

 

[toy_tek]

Thank you @wngrog for clarifying your approach and the reason for the differences in shackle angles. I'm trying to line up the pieces and lay out the process ahead of time so I can set it and forget it for awhile once I get to the new springs. Got 4 Plus's u bolt flip kits and the 4* shims. Doing it little by little as the budget allows. Will probably apply the year end bonus to the actual springs

I installed heavy springs and definitely needed shims up front. I'm also considering adding shims to the rear axle too, to raise the pinion angle a bit - I have some ready to install when I have a chance.

the list of things I'd plan for in addition to the lift kit

1. Shims
2. centering pins
3. driveshaft length mod (if necessary)
4. LPSV bracket/adjustment
5. spacer bushings for rear centering pin (to eliminate the rubber pad) [edit]

 

[wngrog]

I installed heavy springs and definitely needed shims up front. I'm also considering adding shims to the rear axle too, to raise the pinion angle a bit - I have some ready to install when I have a chance.

the list of things I'd plan for in addition to the lift kit

1. Shims
2. centering pins
3. driveshaft length mod (if necessary)
4. LPSV bracket/adjustment

Keep in mind, standard (non CV) driveshafts are meant to be parallel not pointing at the output. I’ve never seen one that needed a rear shim.

 

[toy_tek]

Keep in mind, standard (non CV) driveshafts are meant to be parallel not pointing at the output. I’ve never seen one that needed a rear shim.

You're saying the rear pinion should be parallel to the ground, regardless of lift?

 

[wngrog]

You're saying the rear pinion should be parallel to the ground, regardless of lift?

Correct.

Driveline Geometry 101

Driveshaft Angle Explained This video will demonstrate the proper angles for a drive shaft in a stock Jeep or Truck and how the rules change when you add a suspension lift. The video below demonstrates what is happening to the shaft at different angles, how improper angles can cause speed...

4xshaft.com

 

[garfieldthecat]

I installed heavy springs and definitely needed shims up front. I'm also considering adding shims to the rear axle too, to raise the pinion angle a bit - I have some ready to install when I have a chance.

the list of things I'd plan for in addition to the lift kit

1. Shims
2. centering pins
3. driveshaft length mod (if necessary)
4. LPSV bracket/adjustment

Thanks @toy_tek. I understand that only USA FJ62s had Load Sensing Proportioning Valves, but not FJ60s? I havent heard of anyone adjusting their 60s's static proportioning valve thats under the master cylinder, but maybe someone who has done this Dobinsons install can clarify? I think one additional upgrade I have read about (maybe in one of @CruiserTrash's threads) was changing brake hoses (T100 rear brake hoses for the rear brakes on the FJ60 and rear FJ60 brake hoses on the front FJ60 brakes).

 

[CruiserTrash]

Thanks @toy_tek. I understand that only USA FJ62s had Load Sensing Proportioning Valves, but not FJ60s? I havent heard of anyone adjusting their 60s's static proportioning valve thats under the master cylinder, but maybe someone who has done this Dobinsons install can clarify? I think one additional upgrade I have read about (maybe in one of @CruiserTrash's threads) was changing brake hoses (T100 rear brake hoses for the rear brakes on the FJ60 and rear FJ60 brake hoses on the front FJ60 brakes).

That’s right - move a 60 rear hose to the front and put a T100 hose in the rear. That gets you some extra length.

I don’t think the 60 proportion valve on the brake booster is adjustable.

 

[S.CarolinaFZJ80]

Thanks, Mike. I’ve purchased both Dobinsons 40 & 60 set ups from Exit Off-road. Superb service, availability & fast shipping.

View attachment 3329151

View attachment 3329152

Looks great!
Interested in the specs of your 40 and 60 Dobinson lifts. What size tires are you running on the 40 & 60?

 

[Flatlanderfj40]

Looks great!
Interested in the specs of your 40 and 60 Dobinson lifts. What size tires are you running on the 40 & 60?

Heavy w/ blistein 5100 series on the 40. Light on the 60 w/ yellow base shock option. Running 33x10.50-15’s on both.

 

[S.CarolinaFZJ80]

Heavy w/ blistein 5100 series on the 40. Light on the 60 w/ yellow base shock option. Running 33x10.50-15’s on both.

Thanks for the reply.

How's the ride on the 40 with the heavies and 5100's?

Light 2” kit. Very happy so far.

View attachment 2990086

View attachment 2990087

Also, how are the light springs on the 60? Did you remove any leaf springs in the rear after initial install?

 

[Flatlanderfj40]

Thanks for the reply.

How's the ride on the 40 with the heavies and 5100's?


Also, how are the light springs on the 60? Did you remove any leaf springs in the rear after initial install?

40-great! Haven’t had the top off yet. On and off-road is much improved.

60-Great. Have around 3k on the setup and it’s superb over stock/saggy. Shocks are just ok. No leaf’s removed on either setup.

 

[S.CarolinaFZJ80]

40-great! Haven’t had the top off yet. On and off-road is much improved.

60-Great. Have around 3k on the setup and it’s superb over stock/saggy. Shocks are just ok. No leaf’s removed on either setup.

Thanks for your feedback. Appreciate the info!

 

[dbbowen]

To really nail it, you really need to install the lift without shims, then measure your angles and then buy the shims. Most times 4* shims will get you close, but your angles will still be off. For example, I have IMS shocks with ome medium springs and the ome add a leafs. 4* shims got me to 0* caster but the rear pinion angle is still off. Ideally id want about 4* of caster in the front. The rear needs more too... 8* shims from Gerorg @ valley hybrids would have been perfect. Without measuring after installing the lift theres no way to know what you need.

This thing is $4 at HF. For the rear Install your lift, put it on both your diff flange and rear t case output flange and calculate the difference between the angles. Buy the shim that is closest to that distance.

Dial Gauge Angle Finder

Amazing deals on this Dial Gauge Angle Finder at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

For the front (if you have a single cardan drive shaft) you can just kinda get a feel for what you want. If you want a stronger return to center from turning on your steering wheel, you can go with 8* shims... but you can use that angle finder to see how out your pinion angles might be with the 8* vs 4*. The thing with the front is you can get really close to 0 to +4 caster but your pinion angles wont be parallel so if you ever drive in 4hi in the snow it will be vibration city with your drivelines. You want to find a good medium if you can.


I use 4* shims on the front and rear and my rear needs more and my front needs less. you dont have to have matching shims om the front and rear

 

[Elbert]

IMS59-50701, INTERNAL RES - MONOTUBE SHOCK ABSORBER - https://dobinsons.com/shop/dealer-order-system/dos_ims59-50701-detail

front shock install / 1986 FJ60. I don't recall getting any specific hardware in the dobinson boxes with the shocks..just the front two shocks.

Anyone encounter an issue with install of these front shocks on FJ60?

I had some OME's and now trying out some Dobinsons. The rear Dobinsons don't see to be an issue. Not clear why the rear would be ok, and the front a problem , I think the lower mounts are the same thing.

I'm also running 4plus ubolt flip kits which have the lower shock mount built in.

But the front dobinson shock at the lower shock mount seem to be "wide" vs the OME.....when the shock is mounted , and I run the nut down that holds the shock to the lower mount, I'm only getting potentially have the thread of the nut...when the nut should at least sit down on the stud and have a few threads be exposed of the stud, above the nut. I'll post a pic later which might explain the issue a little better. I"ve not measured the shocks yet, but just basing that on how the shock sits on the lower mount stud on the front axle.

Anyway unless I'm somehow overlooked something the front axle lower shock mount stud seems to be about 1/2 or 3/4 inch too short to clear the mounting nut properly.