DIY Adjustable Front Bumpstops

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Bumpstops are a very important, and often over looked, part of a properly tuned suspension setup. Bumpstops allow you to maintain control of where the upward travel of your suspension stops and prevents over compression and premature wear to your springs. As you add more lift to your jeep, you need to add more length to your bumpstops. I have found that in most cases, the added length of your bumpstops should equal that of your lift height. For example, if you add 4" of lift, you should add 4" of bumpstop. Now this isn't always the case, but it gets you in the right ball park. The length of your bumpstops is actually a part of an equation consisting of lift height, compressed shock length, tire size, wheel size and backspacing, and amount of trimming on the jeep.

 

The best way to figure bumpstop length is to just get everything together and flex your jeep. Do not figure your bumpstops when your flex has maxed out and tires are rubbing fenders, wheel wells, suspension components, etc. The point of adding bumpstops is to control flex. You want your suspension to stop when you want it to.

 

So we've discussed the importance of having front bumpstops, now the question is where to get them? Many retailers offer front bumpstops, some fixed and than also some that are adjustable. The problem with these is simply the cost. They are very nicely engineered; however the cost is something that is left to be desired. I've used a cheap alternative; hockey pucks. Hockey Pucks are nice, because they are the perfect dimensions to fit inside the coil spring, and are 1" thick, making it easy to figure out how many you need to purchase to get the desired bumpstop settings. The best thing about rubber hockey pucks is the price!

 

So once you've determined how much bumpstoping you need you can determine how many hockey pucks you need for each side. Remember that the hockey pucks are 1" thick, so if you measured 3.5" you'll need to go to 4" (aka 4 hockey pucks).

 

 

The next step is to get the hardware needed. Go to your local hardware store and get a bolt that is .5" longer than the amount of bumpstops you’re adding. So if you’re adding 4 hockey pucks (aka 4" of bumpstops), you'll want to get a bolt that is 4.5" long. It's also recommended to get STAINLESS bolts/nuts/washers to prevent them for rusting. Along with the bolts/nuts I also got 2 washers. For the top of them I get what’s called a "fender washer" as they are a lot wider.

 

 

The next step is to drill the hockey pucks in the center to allow the bolt to pass threw them. You'll want to drill the hole just a tad larger than the bolt size to make it easy for the bolt to pass threw them. You need to do this for every hockey puck you'll be adding.

 

 

Once you have all the holes drilled you can test the bolt threw the holes with the washers and the nut to see how they will work.

 

 

Now it's time to install your newly made bumpstops in your Jeep. You have a few options to do this. You can remove the springs, or as I did you can install them without removing the springs. If you take your bumpstops apart you will be able to slide the hockey pucks and bolt threw the spring just fine. However first you need to modify your coil buckets.

 

If you look at your coil buckets (the part of the axle that the spring sits on) you'll notice a "dimple" in the center of the bucket. You need to drill this dimple out so that your bolt will fit threw it. Now this is definitely easier to do with the coil out as the "dimple" points down. However with some patience you can drill the hole from underneath. The passenger's side is a bit more difficult as you do have the tracbar mount in the way; so make sure you get a long drill bit to accomplish this task.

 

Once the holes are drilled and you're bolt will fit threw them slide your hockey pucks in place threw the spring and put your bolt with the fender washer on the top threw the them. Now fit the bolt threw the hole you drilled in the coil bucket and put the smaller washer and nut on it. You can now slide a wrench in threw the coil and a socket on the bottom nut and tighten everything down.

 

 

The nice thing is that these are adjustable, so if you need to add another 1" to your bumpstops you can simply just add another hockey puck and a longer bolt. Same for if you need to take away a hockey puck to gain another 1". It is much easier now to adjust your bumpstops if you change tires, go higher with your lift etc.

 

Total cost was about $20 to do the fronts. The majority of this cost was in the stainless hardware.

[HOrnbrod]

Nice writeup. But I have a question regarding the last pic below. At the top of the coil is that the end of the stock bumpstop? If so it looks like you only have about 2" of down travel? Or am I blind? :nuts:

 

Thanks

 

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Yes that is the top of the factory upper "snubber". They are rubber and squish so it's actually more like 3.5" of UP travel (not down travel).

 

We're running 33's on 3.5" of lift with very minimal trimming. Up travel is not everything when it comes to suspension like some make you believe it is.

 

EDIT: Here is a pic of the wife's XJ with 33's on 3.5" of lift.

 

[HOrnbrod]

Thanks - meant UP travel. I might just do this using maybe two pucks (3" lift, 31" tires) since it's cheap and easy. Shocks are right. Now if I can just find four hockey pucks in 'Bama. :D :D

[TNT]

Yes that is the top of the factory upper "snubber". They are rubber and squish so it's actually more like 3.5" of UP travel (not down travel).

 

We're running 33's on 3.5" of lift with very minimal trimming. Up travel is not everything when it comes to suspension like some make you believe it is.

 

EDIT: Here is a pic of the wife's XJ with 33's on 3.5" of lift.

 

 

I ran 33" tires with 3.5" lift springs and 2.5" of bumpstop with 9.5" travel shocks in the front. The rear only needed 1.5" of bumpstop extention with 10" of travel. Cutting the fenders is the key. I cut the fenders and ran the 33" tires for 2 weeks without any lift.

 

Normally the amount of bumpstop extention a spring requires is about half of it's amount of lift.

 

Now that I have done more extreme fender work 35"-36" tires will fit with 3.5" of lift. You just have to cut like crazy. The rear winds up with more room then the front on a XJ or MJ.

 

A simple but effective way to hold the hockey pucks in is with silicone. I bent a 3/8 bolt once removed it and siliconed them together and onto the cleaned factory bumpstop pad. They have held for 6 years.

[LEAD_NOT_FOLLOW]

Cutting the fenders is the key.

 

Not everyone wants to hack their fenders and cares about having 10 feet of uptravel. Uptravel really is didly-sqaut in just about everything but pre-running/desert racing.

 

This is my wife's DD and she is just as anal about her stuff as I am. She wants to have flares so bumpstoping was the solution as she does wheel her rig as well.

 

Normally the amount of bumpstop extention a spring requires is about half of it's amount of lift.

 

Your basing that statement on what? Your hacked fenders? Their are way to many variables to make a statement like that. It depends on the width of the tire/offset of the rim. It depends on if the fenders are trimmed. It depends on the length of the control arms and how centered the axle is under the wheel opening. As I stated in the original post the only way to know what you need is to flex it out and measure.

 

A simple but effective way to hold the hockey pucks in is with silicone.

 

I've seen way to may people loose pucks using silicone. Also I'd rather use a bolt so I can easily adjust them down the road if I wanted to. It's easier to undo a bolt, add or take away a puck and tighten it back down.

[HOrnbrod]

Hey TNT, I know you're a hackin' slashin' kind of guy, and good at it. :D I'm not. :cry: But I can handle a couple of hockey pucks, and the silicon is a good idea. No worries in the back with the MT leaf pack. :cheers:

[TNT]

Cutting the fenders is the key.

 

To get the lowest ride height, the most controlled travel with the longest shocks and biggest tires it sure is. :brows:

 

Not everyone wants to hack their fenders and cares about having 10 feet of uptravel. Uptravel really is didly-sqaut in just about everything but pre-running/desert racing.

 

You could bottom out 4" lift springs with 4" of bumpstops on a speedbump. There is more to having uptravel then that... :roll: Get real.

 

In trail use with the same 3.5" lift springs I ran 11" travel shocks. It had 6" uptravel and 5" downtravel. I could fully compress the spring onto the bumpstops when flexing and the other spring was just starting to unseat. It made for a very flexable stable ride. It was great at speed too.

Why get only one or the other when you can get both.

I found that when you have enough droop to unseat the coil a couple of inches stability suffers.

 

This is my wife's DD and she is just as anal about her stuff as I am. She wants to have flares so bumpstoping was the solution as she does wheel her rig as well.

 

I still run XJ flares that are modified to look stock to people who don't know better. They don't looked hacked like TJ flares do. I also gain more room with XJ/MJ flares then TJ flares do.

 

I just use stock flares that are reformed to mount higher and have a wider opening. I even run inner wheelwell liners.

 

Normally the amount of bumpstop extention a spring requires is about half of it's amount of lift.

 

Your basing that statement on what? Your hacked fenders? Their are way to many variables to make a statement like that. It depends on the width of the tire/offset of the rim. It depends on if the fenders are trimmed. It depends on the length of the control arms and how centered the axle is under the wheel opening. As I stated in the original post the only way to know what you need is to flex it out and measure.

 

I'm basing my statment about what the spring requires so it doesn't get over compressed. This allows for an increase in uptravel. I cut my fenders to fit the tires using that amount of bumpstop. I want to use all of the available travel a spring has without overcompression... I make the body/fenders fit the spring and bumpstop combo I decide to use. I also make sure I can steer from lock to lock when flexed.

 

You do the opposite and use the tires determine how much bumpstop you need.

 

 

A simple but effective way to hold the hockey pucks in is with silicone.

 

At least use the entire Quote... :mad:

 

A simple but effective way to hold the hockey pucks in is with silicone. I bent a 3/8 bolt once removed it and siliconed them together and onto the cleaned factory bumpstop pad. They have held for 6 years

 

I've seen way to may people loose pucks using silicone. Also I'd rather use a bolt so I can easily adjust them down the road if I wanted to. It's easier to undo a bolt, add or take away a puck and tighten it back down.

 

I have seen it too. I spent some time prepping like I stated so they would stay put.

 

The best way to do it is to silicone the pucks together and then bolt the stack down. This way the pucks can't flex or slide on each other allowing the bolt to bend.

 

I'm not saying you are wrong, but am showing others that there are different ways to get the job done and have a rig that can go slow or fast. Improved stability is nice too. 8)

 

It's kinda like running KOH... The best set-up is the one that can crawl or haul @$$.

 

I like to think outside the box... :chillin:

 

:cheers:

[92comanche4x4]

ok what is a bumpstop??? sounds like a dumb question but i had 3 hockey pucks on my axel i bought from peter and i took them out is that bad? and whats it gonna do if i don't hhave them?

[MiNi Beast]

Well my next little project, which is a long time coming! :yes:

[Pete M]

ok what is a bumpstop??? sounds like a dumb question but i had 3 hockey pucks on my axel i bought from peter and i took them out is that bad? and whats it gonna do if i don't have them?

 

 

bumpstops are what keep the axle from going up too far. Depending on the setup, going up too far can cause tire-to-fender contact, or the shocks can bottom out, etc. The hockey pucks were acting like a bumpstop extension. Likely he had really big tires on his rig and that was his sure for keeping them out of the fenders.

[comanche87]

got a question. i took out the insulators and put 2 inch coil spacers and 2 inch shock extentions but left the bumpstops alone is that bad or is that ok. i only wanted to lift the front a bit and give it a better stance. i am thinking of putting the insulaters back in to make it sit better.

[MiNi Beast]

got a question. i took out the insulators and put 2 inch coil spacers and 2 inch shock extentions but left the bumpstops alone is that bad or is that ok. i only wanted to lift the front a bit and give it a better stance. i am thinking of putting the insulaters back in to make it sit better.

 

You should be find. But if you are worried about it you can get a set of extented ploy stops for like $29.

[comanche87]

ok kool. thanks. just wanted to make sure.