Long travel rear for a 100 series

[BurnsCrew]

FWIW, the Ironman rep did tell me that the 4” 80 series landcruiser shock has an internal bump stop built into it as well. That, plus I’m running timbrens in the rear. So my bottom outs are pretty cushy back there (if I do). Mostly on whoops

 

[FamilyCamper]

Made spring retainers and extended bump stops just in time for some new 3.5" 80 series springs that don't need the retainers haha. Now I should have some good down pressure at full droop. Did some hard trails this past weekend and super happy with the performance.

 

[BurnsCrew]

Made spring retainers and extended bump stops just in time for some new 3.5" 80 series springs that don't need the retainers haha. Now I should have some good down pressure at full droop. Did some hard trails this past weekend and super happy with the performance.

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Good stuff!

 

[Lazarus556]

Made spring retainers and extended bump stops just in time for some new 3.5" 80 series springs that don't need the retainers haha. Now I should have some good down pressure at full droop. Did some hard trails this past weekend and super happy with the performance.

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Nice. I can't wait to get back on some trails.

What springs did you go with? I ended up going with the same ones that Burns is running along with GX470 spring retainers from Slee.

 

[FamilyCamper]

Nice. I can't wait to get back on some trails.

What springs did you go with? I ended up going with the same ones that Burns is running along with GX470 spring retainers from Slee.

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Nice it's gonna make a big difference!! I think mine are just progressive lightweight springs 3.5inch lift. Got them off another mudder who wasn't exactly sure the spring rate.

 

[FamilyCamper]

Nice. I can't wait to get back on some trails.

What springs did you go with? I ended up going with the same ones that Burns is running along with GX470 spring retainers from Slee.

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How are these springs working for you? Ride quality on road and off? How high are you sitting in the rear/what normal weight are you carrying around. The dobinson 80 series coils Im using definitely give good flex and are comfortable but im sitting so high in the rear now id like to bring it down a bit. Ive got bumper and 35inch spare tire but am only loaded more than that when camping.

 

[PharmerDan100]

Suspension gurus, I’m considering going with the rear setup @NearJetties referenced: MRA59-A687 (26.5” ext / 16.5” comp), but had some questions.

1. Would these shocks be too long for a 2” rear lift? I’m running OME 2860 springs that give me about a 2” lift in the back, and I’d like to stay at this ride height. 1.5” lift in the front and I’d like to stay here as well (no diff drop).

2. Are there potential issues with running these long-er travel shocks in the rear and pairing them with not-so-long shocks in the front (MRA59-A782 - 17.9” ext / 12.3” comp)?

3. Besides having to potentially get different springs or add spring retainers, brake line extensions, and bump stops, are there any additional drawbacks to going this route (as opposed to just keeping it simple and getting the MRA59-A682 - 24.4” ext / 15.3” comp) for the rear?

I know with suspension lifts its a game of pros and cons, so I just wanted to take everything into consideration before pulling the trigger.

PS, Tinker’s Adventure dropped an interesting vid on sway bars and showed the optimal articulation was achieved by removing the front and keeping the rear (probably touching concepts @hoser was alluding to in his earlier post):


The data is posted around the 8:00 mark on the vid. Wondering if anyone else has experimented with this? I’m thinking of just getting the TT extended links for the rear and trying it out myself.

 

[FamilyCamper]

Suspension gurus, I’m considering going with the rear setup @NearJetties referenced: MRA59-A687 (26.5” ext / 16.5” comp), but had some questions.

1. Would these shocks be too long for a 2” rear lift? I’m running OME 2860 springs that give me about a 2” lift in the back, and I’d like to stay at this ride height. 1.5” lift in the front and I’d like to stay here as well (no diff drop).

2. Are there potential issues with running these long-er travel shocks in the rear and pairing them with not-so-long shocks in the front (MRA59-A782 - 17.9” ext / 12.3” comp)?

3. Besides having to potentially get different springs or add spring retainers, brake line extensions, and bump stops, are there any additional drawbacks to going this route (as opposed to just keeping it simple and getting the MRA59-A682 - 24.4” ext / 15.3” comp) for the rear?

I know with suspension lifts its a game of pros and cons, so I just wanted to take everything into consideration before pulling the trigger.

PS, Tinker’s Adventure dropped an interesting vid on sway bars and showed the optimal articulation was achieved by removing the front and keeping the rear (probably touching concepts @hoser was alluding to in his earlier post):


The data is posted around the 8:00 mark on the vid. Wondering if anyone else has experimented with this? I’m thinking of just getting the TT extended links for the rear and trying it out myself.

I've been running no front sway bar with extended rears (custom 1 inch longer than TT) and I have not ripped out a mount yet after several hard trips. It's really nice Offroad with extended front shocks and no sway bar. Not as jerky anymore side to side over medium speed rocky trails. It leans a decent amount on road but I've gotten used to it and drive mountain roads no problem. I know that when I went to longer shocks that are not as long as those dobinsons it raised my rear end a little bit so I would expect your rear to go up a little as well just due to the shocks

 

[hoser]

Suspension gurus, I’m considering going with the rear setup @NearJetties referenced: MRA59-A687 (26.5” ext / 16.5” comp), but had some questions.

3. Besides having to potentially get different springs or add spring retainers, brake line extensions, and bump stops, are there any additional drawbacks to going this route (as opposed to just keeping it simple and getting the MRA59-A682 - 24.4” ext / 15.3” comp) for the rear?

I see nothing wrong with using the MRA59-A687 option granted everything you mentioned in #3. 100s have been using that length rear shock since the N74L days. The AHC w/ shock spacer is about that same extended length too.

 

[PharmerDan100]

Ok went further down the rabbit hole and found this thread in the 80 forum:

Negative impact of longer then needed shocks ?

forum.ih8mud.com

It’s a lively discussion, with mixed opinions, but post #8 caught my attention regarding the 60% available shock stroke at ride height.

Got under the truck to do a quick measurement and some back of the napkin calculations for my rig.
My rear shock length is 20.75” at current ride height.

ASSUMPTION #1: If I swap in the MRA59-A687 (26.5” / 16.5”) they will also compress to approximately this length of 20.75” at ride height (given that springs support the weight and determine ride height, not the shocks).

If this assumption is correct, then that would mean approximately 57.5% of the shock stroke length is already eaten up, leaving only 42.5% more travel before the shock bottoms out.

If I do the same calculations above but plug in the MRA59-A682 specs (24.4” / 15.3”), I get a reversal of the ratio with only 40.5% compression at ride hide and 59.5% remaining up travel.

My question to the group: is above assumption and calculations valid? If so, it would seem the only advantage of a longer travel shock setup is more droop at the expense of ride quality at higher speeds on bumpy roads? Am I missing anything else?

 

[TysonLC]

Im thinking about doing some mra59 687s on the back with the long travel perry parts bump stops, does anyone know if it would be necessary to do a bumpstop drop? what is the point of dropping the bump stop? is it to prevent shock damage, tire hitting fender or smth else? im on 33s

 

[GerLC100]

Without the bump stops you might bump into a full mechanical stop in your shocks and destroy them.
Daily driving typically no problem as you usually don’t fully compress. But offroad or heavy towing will change the game

 

[hoser]

Im thinking about doing some mra59 687s on the back with the long travel perry parts bump stops, does anyone know if it would be necessary to do a bumpstop drop? what is the point of dropping the bump stop? is it to prevent shock damage, tire hitting fender or smth else? im on 33s

The conservative approach would be to compare the compressed length of the OE shock and the proposed shock and lower the bump stop by that amount. For fine tuning, there are a lot of variables like tire diameter, wheel offset, hardness rating of bump stops, etc. The point of the bump stop is stop suspension movement from bottoming out the shock and tires from hitting the wheel well and body. Every vehicle is different... especially when modified.

 

[FamilyCamper]

Update is I'm back to the shorter springs with spring retainers. The 80 springs were awesome but I had too much lift and too much rake for everyday driving. Would have kept this setup if I did majority offroad. Pic now.

 

[Lazarus556]

Update is I'm back to the shorter springs with spring retainers. The 80 springs were awesome but I had too much lift and too much rake for everyday driving. Would have kept this setup if I did majority offroad. Pic now.

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What rear springs are you running now? Are you getting noticeably less flex in the rear with the shorter springs?

I'm running the C97-146VT (need to double check) and I still think I have too much lift in the rear but they flex great

 

[Lazarus556]

How are these springs working for you? Ride quality on road and off? How high are you sitting in the rear/what normal weight are you carrying around. The dobinson 80 series coils Im using definitely give good flex and are comfortable but im sitting so high in the rear now id like to bring it down a bit. Ive got bumper and 35inch spare tire but am only loaded more than that when camping.

Sorry Im just seeing this post. Springs are working well but like you I'm really high in the rear. Normally my truck as very little weight as I dont have any seats in the rear and its empty on the inside, only my rear bumper and spare tire on the exterior. I have more than the recommended 1" of rake. I'm not sure if that has any negative effects. I do notice my truck seems to not handle as well. I'm not sure if wheel alignment, lack of rear sway bar or the rake but it seems unsettled in corners.

 

[FamilyCamper]

What rear springs are you running now? Are you getting noticeably less flex in the rear with the shorter springs?

I'm running the C97-146VT (need to double check) and I still think I have too much lift in the rear but they flex great

I tried another club members dobinson springs from his 80 I think medium weight standard 2 inch lift dobinsons. Although I'm not positive because I have about a half inch of lift up front with a 1 inch rake so only about 1.5" rear lift. I have not flexed them off road yet.

Okay cool thanks for the update! Can you measure what your hub to fender in the rear is??
I was at 22 in the front and 24.75" in the rear I think with those longer dobinsons so lotta rake

 

[BurnsCrew]

Ok went further down the rabbit hole and found this thread in the 80 forum:

Negative impact of longer then needed shocks ?

forum.ih8mud.com

It’s a lively discussion, with mixed opinions, but post #8 caught my attention regarding the 60% available shock stroke at ride height.

Got under the truck to do a quick measurement and some back of the napkin calculations for my rig.
My rear shock length is 20.75” at current ride height.

ASSUMPTION #1: If I swap in the MRA59-A687 (26.5” / 16.5”) they will also compress to approximately this length of 20.75” at ride height (given that springs support the weight and determine ride height, not the shocks).

If this assumption is correct, then that would mean approximately 57.5% of the shock stroke length is already eaten up, leaving only 42.5% more travel before the shock bottoms out.

View attachment 3730424

If I do the same calculations above but plug in the MRA59-A682 specs (24.4” / 15.3”), I get a reversal of the ratio with only 40.5% compression at ride hide and 59.5% remaining up travel.

My question to the group: is above assumption and calculations valid? If so, it would seem the only advantage of a longer travel shock setup is more droop at the expense of ride quality at higher speeds on bumpy roads? Am I missing anything else?

Generally, you want to stay mid stroke or be slightly biased for down travel. As long as you’re maintaining around 4-5” of uptravel minimum, you would want to maximize downtravel. 4-5” of uptravel is plenty for the shock to dampen “hits” if properly valved for your truck and weight.

 

[Lazarus556]

I tried another club members dobinson springs from his 80 I think medium weight standard 2 inch lift dobinsons. Although I'm not positive because I have about a half inch of lift up front with a 1 inch rake so only about 1.5" rear lift. I have not flexed them off road yet.

Okay cool thanks for the update! Can you measure what your hub to fender in the rear is??
I was at 22 in the front and 24.75" in the rear I think with those longer dobinsons so lotta rake

I just checked I'm at 24.5" rear and 21.5" front

 

[OwnerCS]

Thank you, @BurnsCrew, and all who contributed to this thread. It looks like I need to start collecting parts. I would like to do this with my existing Dobonsons IMS.

I already have a set of Timbren rear bump stops.
I've been running without swaybars for a couple of years.
I would like to keep running the DeltaVS PCK. To me, the PCK provides more benefit than sway bars.
I was getting this kind of rear lift with Dobinsons C59-171 – 1.5″ lift, linear rate, with 880LBS constant rear weight

The springs and suspension from this LX470 are moving to a much lighter 02 model LC100.

I agree rear flex is way more important than front -- especially in my environment.