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Discussion Starter #1
I've been contemplating the idea of using a combination of spacers to achieve 3" of front lift using a strut spacer that is as long as possible without achieving coil bucket contact, then adding an in-coil spacer of some length to pre-load the spring, therefore raising the truck the rest of the way to 3".

The reason being... The strut spacers drop the coil-over shock down to create the lift and I like that, but I have no desire for coil bucket contact issues, so I don't want this spacer to be too big. The in-coil spacer will pre-load the spring, but since it doesn't drop the entire shock, it wouldn't create coil bucket contact - all that's really happening is that the shock is running slightly more extended than it would in stock form. The spring rate has not changed, and the actual spring load hasn't either (we haven't increased the weight of the truck, just the ride height).

Combined, this "should" provide a stock (soft) front suspension, with more ground clearance and no coil bucket contact. Since I'm only doing moderate rock crawling, I'm not concerned with a soft spring rate. I also don't want to pony up for the cost of new shocks.

My gut feeling is that a strut spacer that creates 1.75" lift combined with an in-coil spacer that achieves 1.25" lift would be about right. More total lift and no CB contact.

Has Nisstech thought of this combo? Any thoughts?

Thanks.
 

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If you're going to go through the trouble of disassembling the front coilovers so you can install coil spacers, you might as well just get some lift coils. Essentially you're doing the same thing, and not reducing travel like I believe you would with the coil spacers. Right now I have the front TJM med duty coilovers with 1" top plate spacers. I also have spc UCA's.

Now, you don't NEED the full tjm coilover, you can just buy the springs and install them on your stock shocks, however I'm not sure how they would ride because the stock shocks aren't valved for them. My other concern is, I'm still not convinced that you won't get coil bucket contact either way (lift and coil spacers, or lift coils and spacers), unless you only used a 1" spacer on top. Some people with 2" spacers on top get cbc. There is only one way to find out though...is to try it.
 

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I believe you'll need new upper control arms to go 3" because the stock ones will be maxed out.

Also if you put coil spacers or lift coils on you're gonna lose down travel. The shock can only extend so far and if you gain lift you lose that distance in down travel. I replaced my coils and gained 1.5" of lift but as a result only had about 1" down travel which sucks on rough roads or trails.
 

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As others have said, you need to re-think your logic on this. With an internal coil spacer, you are pushing the spring down, which pushes the lower control arm down...which is directly connected to the upper control arm by the spindle.... No matter how you lift the front, at 3" you would have coil bucket contact.

All you would accomplish with this is grossly limiting your up travel and leaving yourself almost no down travel whatsoever.
No new ground being broken there....
 

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Discussion Starter #7 (Edited)
Follow my logic on this guys. Keep in mind, I'm a mech engineer. Coil bucket contact occurs when the UCA moves down. Right? The stock shock has an extended limit that does not cause UCA/CB contact. It's only when a strut spacer (2.0"or more) is added, which moves the entire shock assembly down (and the UCA with it). So, if a 1.75" strut spacer drops the shock, UCA, spindle, etc., down but does not lower the UCA enough to contact the bucket, there is no problem. Right?

Now, add a pre-load in-coil spacer. The shock does not move down in relation to the frame any more. What happens is the spring is preloaded more, which simply extends the shock and the ride height increases, but the UCA can't drop further than the limit set by the shock's extended length.. Get it?

I've read a bunch of threads about adding lift springs to 5100's or even stock shocks, and with higher rate springs, the problem seems to be the shock topping out, not UCA/CB contact (unless there's a strut spacer installed as well). I'm not in a position to spend $$$ on coil overs and aftermarket UCA's.

The Nisstech in-coil spacers are supposed to raise the ride height 2.0", but they do that by effectively moving the shock towards its extended limit. There is less available extension in the shock, but actually more shock compression - since coil bind is not occurring. It's like if the shock travel was measure from 0 - 10, with 0 being fully compressed and 10 fully extended. Stock, the ride height would be at 5, even amount of travel in either direction. With the in-coil spacer, the shock is moved to 7. Only 3 left to extend, but 7 for compression... Make sense?

I can't see how either of these spacers can reduce total shock travel. The shock's extended and compressed lengths have not been changed.

I'll be waiting for Nisstech to respond before giving up on this...
 

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Oh, well if you are a mech engineer then by all means, DO IT! You are a level above the general population and are definitely right. I'll call Nisstec and tell them the latest and greatest is passing them by.

And yes, the shock DOES move down with the internal spacer. The lower shock mount is pushed down...which pushes the LCA down, which pulls the UCA down via the spindle. I followed your logic perfectly...and it's flawed.

EDIT: Maybe a question to answer your question would be more suited for your high level of education. With an internal spacer, it still creates over all lift correct? If the UCA is not moving closer to the coil bucket, where is that lift coming from?
 

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Lol. Man you are still going to have coil bucket contact, but I'm happy to watch. :) The UCA, spindle and LCA are all directly connected. The only way the X gets lifted up is moving that whole connected group downward. Spacers, in or above coil, stiffer springs, and drilled out pieces of 2x4 all serve to achieve lift this same way, which brings that UCA within striking distance of the coil bucket. You are way overthinking, and are so lost in details that you have blinded yourself from seeing the big picture. Take a step back to the basic suspension geometry and reexamine it. Otherwise, go nuts and have fun. Some lessons are much better learned the hard way.
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OK so you've got all this lift with your stock shocks, which have limited travel. Then you hit a pothole, what will happen? The whole truck is going to fall in that hole because you will more than likely have 0 down travel and you will still probably have coil bucket contact. Good luck.
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Discussion Starter #12
EDIT: Maybe a question to answer your question would be more suited for your high level of education. With an internal spacer, it still creates over all lift correct? If the UCA is not moving closer to the coil bucket, where is that lift coming from?
Answer - the lift comes from more spring pre-load and the UCA movement is limited by the maximum extended length of the shock (which doesn't change).


Take the spring off the shock and move the wheel up and down. The UCA's movement is limited by the shock's travel limits and the POSITION of the UCA will depend on where the ENTIRE shock is in relation to the frame.

Travel limits have NOTHING to do with the spring (unless there is coil bind). Adding a spacer INSIDE the coils also has NOTHING to do with HOW FAR the shock can extend or compress (again, without coil bind). That means the in-coil spacer CANNOT create CB/UCA contact if the stock shock can't create CB/UCA contact. This is also what Nisstech says in their description of this spacer.
 

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Answer - the lift comes from more spring pre-load and the UCA movement is limited by the maximum extended length of the shock (which doesn't change).


Take the spring off the shock and move the wheel up and down. The UCA's movement is limited by the shock's travel limits and the POSITION of the UCA will depend on where the ENTIRE shock is in relation to the frame.

Travel limits have NOTHING to do with the spring (unless there is coil bind). Adding a spacer INSIDE the coils also has NOTHING to do with HOW FAR the shock can extend or compress (again, without coil bind). That means the in-coil spacer CANNOT create CB/UCA contact if the stock shock can't create CB/UCA contact. This is also what Nisstech says in their description of this spacer.
Correct, but you will not achieve 3" of lift only using spacers inside the coil.
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Rocknhd is on track in that so long as you dont change the overall length of the stock coilover very much you wont get coil bucket contact. Its such a small ammount that you can lengthen the stock coilover without getting CB contact- with a top plate spacer that it doesnt add up to very much lift. There is MAYBE about 1/4" worth of space to play with and only with a stock OEM shock. Now add some extra length to your coilover with the deflection of shock bushings that happens as anything unsprung pulls down on your coilover at full droop and you will need to take away an 1/8", at least. So now you are left with a 1/8" (MAYBE) top plate spacer which isnt going to give a whole lot of lift. Im not sure how strong it will be either..
In the end, the very minimal thickness you can add to the top of a stock coilover without creating CB contact may not be worth the trouble. While more expensive, aftermarket UCAs really are the way to go with any top plate spacer or extended travel coilover/shock
 

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Discussion Starter #18
Thank you for the reply. I guess that spacer would get pretty thin, huh? OK. Good to know.

BTW - it's really nice to have a sponsor that monitors their threads! :D
 

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Discussion Starter #19
Correct, but you will not achieve 3" of lift only using spacers inside the coil.
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I know. That's a portion of the lift, not the whole lift, but since Nisstech posted their response, I don't think this would be viable due to the spacer thickness.
 
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