Expected extra bumpstop for 2.5" lift

UKTJ

UKTJ

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Hampshire, UK
I am looking to install OME spring and Blackmax shocks, weather permitting this weekend. I plan to follow the hockey puck route for bump stop extension. Ice hockey is not a big thing in the UK, so I need to order pucks online. My question is, how many am I likely to need? Pucks seem to be 1" thick, what is a typical bump stop extension requirement (front and rear) for a 2.5" lift?
 
To answer your question; the forum members would need to know which Blackmax shock absorbers you are installing since the bump stop saves the shocks from bottoming out during compression.
 
There are to many variables to give you a definitive answer. Assuming you are otherwise stock, aren't trying to squeeze 33's, and ordered the B8516 and B8518 I would start with 2" front and rear. Cycle the suspension and use some fender washers, if needed, to adjust from there. If you are using the OME rear track bar bracket pay attention to the fuel lines so they don't get crushed on full bump. If you haven't already, I would recommend reading the following thread.
https://wranglertjforum.com/threads/how-to-set-your-bump-stop-on-a-jeep-wrangler-tj.2474/
 
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I needed slightly more than 2” in the front with B8525. Pretty much exactly 2” in the rear with B8518.
 
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06lj said:
There are to many variables to give you a definitive answer. Assuming you are otherwise stock, aren't trying to squeeze 33's, and ordered the B8516 and B8518 I would start with 2" front and rear. Cycle the suspension and use some fender washers, if needed, to adjust from there. If you are using the OME rear track bar bracket pay attention to the fuel lines so they don't get crushed on full bump. If you haven't already, I would recommend reading the following thread.
https://wranglertjforum.com/threads/how-to-set-your-bump-stop-on-a-jeep-wrangler-tj.2474/
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Yes, have read that thread. I have also watched the BFH YouTube video on the topic, which I thought was excellent

I have a new adjustable front and rear track bar to install.
 
OK, so despite only having one shock until a new bushing comes I am trying to cycle my suspension (once one side is done I will move the shock to the other side to cycle that - hopefully that is OK).

I just want to check one thing, another idiot stupid question I guess. I have the shock in with the rubber boot on it. When I raise the axle the boot gets fully compressed way before the shock is at its compressed length of c.13.5". Should I cycle without the boot on? Have I got the boot zip tied in the wrong place - currently at the bottom of the 'can, where the shaft enters it? I am trying to do this right my my own ineptitude is defeating me!
 
UKTJ said:
OK, so despite only having one shock until a new bushing comes I am trying to cycle my suspension (once one side is done I will move the shock to the other side to cycle that - hopefully that is OK).

I just want to check one thing, another idiot stupid question I guess. I have the shock in with the rubber boot on it. When I raise the axle the boot gets fully compressed way before the shock is at its compressed length of c.13.5". Should I cycle without the boot on? Have I got the boot zip tied in the wrong place - currently at the bottom of the 'can, where the shaft enters it? I am trying to do this right my my own ineptitude is defeating me!
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I'm inferring from your reference to the shaft entering at the bottom of the can that these run can-up, boot down. If that's the case I wouldn't run boots on those. It'll just fill up with junk. Just take them off.
 
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UKTJ said:
OK, so despite only having one shock until a new bushing comes I am trying to cycle my suspension (once one side is done I will move the shock to the other side to cycle that - hopefully that is OK).

I just want to check one thing, another idiot stupid question I guess. I have the shock in with the rubber boot on it. When I raise the axle the boot gets fully compressed way before the shock is at its compressed length of c.13.5". Should I cycle without the boot on? Have I got the boot zip tied in the wrong place - currently at the bottom of the 'can, where the shaft enters it? I am trying to do this right my my own ineptitude is defeating me!
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Cut the boots off. They’re not necessary anyway
 
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OK, with boots removed it is much clearer. Though I appear to have less bump stop extension required than I thought I would. With my shock almost fully compressed to the minimum 13.5"...
TL17PA.&owa=outlook.live.com&scriptVer=20220311006.jpg


It looks like I need a bump stop extension of just about an inch...

TL17PA.&owa=outlook.live.com&scriptVer=20220311006.jpg


(I know ideally I would remove the jounce bumper, but it is the original one I think and I am concerned it is more likely to disintergrate than come out cleanly.)

In that position I have moved the steering fully both ways and I get no rubbing anywhere. I do not know the fully compressed length of the OME 933(HD) spring, but looking at other springs around the 19.5" mark the 9 inches of space available looks plenty, so that will not be a limiting factor. I do not have my new tyres yet, but measuring from the centre of the wheel hub up into the wheel arch it looks like I have more than enough room for 285/75/16s.

I was expecting more like 2" of bump stop extension, so surprised at 1". From the description and pictures above, can anyone see anything I am obviously getting wrong in working out the extension needed?
 
UKTJ said:
OK, with boots removed it is much clearer. Though I appear to have less bump stop extension required than I thought I would. With my shock almost fully compressed to the minimum 13.5"...
View attachment 317202

It looks like I need a bump stop extension of just about an inch...

View attachment 317203

(I know ideally I would remove the jounce bumper, but it is the original one I think and I am concerned it is more likely to disintergrate than come out cleanly.)

In that position I have moved the steering fully both ways and I get no rubbing anywhere. I do not know the fully compressed length of the OME 933(HD) spring, but looking at other springs around the 19.5" mark the 9 inches of space available looks plenty, so that will not be a limiting factor. I do not have my new tyres yet, but measuring from the centre of the wheel hub up into the wheel arch it looks like I have more than enough room for 285/75/16s.

I was expecting more like 2" of bump stop extension, so surprised at 1". From the description and pictures above, can anyone see anything I am obviously getting wrong in working out the extension needed?
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It looks like you're doing everything right. You'll still want to put a tire on and turn the wheel from full lock to full lock to check clearance to the top and back of the wheel well.

If the tires clear then 1/2"-3/4" bumpstop would be all you need. If those jounces are on the verge of disintegrating I would remove and replace them. They may disintegrate on the removal but it shouldn't be hard to get the rest out. You'd just pry what remains out of the cup. Cup could use clean up and paint too. LOL
 
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JMT said:
It looks like you're doing everything right. You'll still want to put a tire on and turn the wheel from full lock to full lock to check clearance to the top and back of the wheel well.

If the tires clear then 1/2"-3/4" bumpstop would be all you need. If those jounces are on the verge of disintegrating I would remove and replace them. They may disintegrate on the removal but it shouldn't be hard to get the rest out. You'd just pry what remains out of the cup. Cup could use clean up and paint too. LOL
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Brilliant, thanks for the confirmation. Think I will put in an inch to be safe, not sure I want to try and shave the hockey puck down. Once I get the new wheels tires on I will check for rubbing and if necessary can adjust at that point. I have noew jounce bumpers on the list of parts for the next time I make an order, but with shipping costs so crazy I try to wait until I have a few things I need.

Thanks again for the help, this time and previously. I have read a lot of your threads including your and your son's builds. The fact you started as a novice working on Jeeps has been both inspiration and comfort to me when I find myself worrying whether I can do something or not.
 
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UKTJ said:
Brilliant, thanks for the confirmation. Think I will put in an inch to be safe, not sure I want to try and shave the hockey puck down. Once I get the new wheels tires on I will check for rubbing and if necessary can adjust at that point. I have noew jounce bumpers on the list of parts for the next time I make an order, but with shipping costs so crazy I try to wait until I have a few things I need.

Thanks again for the help, this time and previously. I have read a lot of your threads including your and your son's builds. The fact you started as a novice working on Jeeps has been both inspiration and comfort to me when I find myself worrying whether I can do something or not.
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You got this! You're doing a great job. Not many of you over in the UK, so not as much of a local support group. It's nice to have the forum. I'd love to come to UK some day. I was a futbol player, but it's not that popular over here, so I've always wanted to come over the UK and go to some matches and pubs. 🍻
 
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UKTJ said:
Brilliant, thanks for the confirmation. Think I will put in an inch to be safe, not sure I want to try and shave the hockey puck down. Once I get the new wheels tires on I will check for rubbing and if necessary can adjust at that point. I have noew jounce bumpers on the list of parts for the next time I make an order, but with shipping costs so crazy I try to wait until I have a few things I need.

Thanks again for the help, this time and previously. I have read a lot of your threads including your and your son's builds. The fact you started as a novice working on Jeeps has been both inspiration and comfort to me when I find myself worrying whether I can do something or not.
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Oh and a 1" bumpstop will be fine. If you haven't already and you add a 1.25" body lift you shouldn't need any bumpstop.
 
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Do you know what your wheel back spacing is? Chances are pretty good your tires will rub the sway bar and possibly the lower control arms at full lock. Just something to look for.
 
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bobthetj03 said:
Do you know what your wheel back spacing is? Chances are pretty good your tires will rub the sway bar and possibly the lower control arms at full lock. Just something to look for.
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At the moment I have stock wheels with 5.25" back space, but that is only with 29" tires (225/75/16). I am going to either need new wheels or spacers for the new, larger tyres.
 
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