Torque settings for Fox shocks in the Dynatrac 2" Lift

wwood

New member
The bushings on the factory shocks are bonded rubber and a higher torque value is needed to hold it in place. Fox shocks use a polyurethane bushing that rotates freely. There should be no reason for the nut to come off at 65 ft lbs but if you’re concerned, apply some loctite to it.


Sent from my iPhone using JL Wrangler Jeep Forum mobile app

Thanks Eddie, you make a good point that I did not consider - the factory shocks use bonded rubber bushings that require more torque to hold in place whereas the Fox shocks use polyurethane that rotates freely on the sleeve. Makes sense that less torque is needed to hold the Fox crush sleeve still. This info is very helpful, wish I thought of it myself. :)
 

OverlanderJL

Resident Smartass
The bushings on the factory shocks are bonded rubber and a higher torque value is needed to hold it in place. Fox shocks use a polyurethane bushing that rotates freely. There should be no reason for the nut to come off at 65 ft lbs but if you’re concerned, apply some loctite to it.


Sent from my iPhone using JL Wrangler Jeep Forum mobile app

Thanks Eddie, you make a good point that I did not consider - the factory shocks use bonded rubber bushings that require more torque to hold in place whereas the Fox shocks use polyurethane that rotates freely on the sleeve. Makes sense that less torque is needed to hold the Fox crush sleeve still. This info is very helpful, wish I thought of it myself. :)

Cool. So the factory shocks use bonded rubber bushings that require more torque to hold in place whereas the Fox shocks use polyurethane bushings that rotate freely and don’t need as much torque.

Now that we have repeated this three times I think we are set.


Sent from my iPhone using JL Wrangler Jeep Forum mobile app
 

wwood

New member
Cool. So the factory shocks use bonded rubber bushings that require more torque to hold in place whereas the Fox shocks use polyurethane bushings that rotate freely and don’t need as much torque.

Now that we have repeated this three times I think we are set.


Sent from my iPhone using JL Wrangler Jeep Forum mobile app

Pretty funny!! I like your sense of humor, I really do. :)

But, in all seriousness, we are not all set. There are 2 issues here:

1) Why does Fox use a flimsy crush sleeve that will not handle factory torque spec? Why do users have to deal with that issue in the first place. I have put a lot of aftermarket parts on my stuff (cars, dirt bikes, Jeeps) over the years and never had to use less than factory torque spec.

2) Will 65 ft/lbs torque work or not? I don't know. It depends on how the Jeep is used. And who is standing behind the recommendation of 65 ft/lbs if something happens. I agree that less torque will probably work as Eddie suggests for ordinary street driving but what about wheeling or unexpected hard hits to the suspension on the highway? The free rotation of the rubber bushing on the sleeve of the Fox shock won't mean diddle when the suspension bottoms or tops out hard offroad or an unseen pothole, etc. The Jeep factory torque setting is computed by engineers to hold the crush sleeves from moving inside the brackets during normal driving and hard hits. My point is we don't know if 65 ft/lbs will work and I don't like being a guinea pig. Fox and Dynatrac don't know either (Fox doesn't say anything and Dynatrac has changed their numbers repeatedly). Do you have this lift kit on your Jeep? Are you going to sail down a road with big whoops or obstacles that slam your suspension to full stuff or full droop?

As I have said before the problem here is Fox using a flimsy, undersized crush sleeve on these shocks. They should fix it.
 

OverlanderJL

Resident Smartass
Pretty funny!! I like your sense of humor, I really do. :)

But, in all seriousness, we are not all set. There are 2 issues here:

1) Why does Fox use a flimsy crush sleeve that will not handle factory torque spec? Why do users have to deal with that issue in the first place. I have put a lot of aftermarket parts on my stuff (cars, dirt bikes, Jeeps) over the years and never had to use less than factory torque spec.

2) Will 65 ft/lbs torque work or not? I don't know. It depends on how the Jeep is used. And who is standing behind the recommendation of 65 ft/lbs if something happens. I agree that less torque will probably work as Eddie suggests for ordinary street driving but what about wheeling or unexpected hard hits to the suspension on the highway? The free rotation of the rubber bushing on the sleeve of the Fox shock won't mean diddle when the suspension bottoms or tops out hard offroad or an unseen pothole, etc. The Jeep factory torque setting is computed by engineers to hold the crush sleeves from moving inside the brackets during normal driving and hard hits. My point is we don't know if 65 ft/lbs will work and I don't like being a guinea pig. Fox and Dynatrac don't know either (Fox doesn't say anything and Dynatrac has changed their numbers repeatedly). Do you have this lift kit on your Jeep? Are you going to sail down a road with big whoops or obstacles that slam your suspension to full stuff or full droop?

As I have said before the problem here is Fox using a flimsy, undersized crush sleeve on these shocks. They should fix it.

Jesus Christ.

Its not a factory shock. Fox has been making shocks for 40 years. Dynatrac changed their number to 65 back when this thread started. It’s been the same since.


Sent from my iPhone using JL Wrangler Jeep Forum mobile app
 

Pretty funny!! I like your sense of humor, I really do. :)

But, in all seriousness, we are not all set. There are 2 issues here:

1) Why does Fox use a flimsy crush sleeve that will not handle factory torque spec? Why do users have to deal with that issue in the first place. I have put a lot of aftermarket parts on my stuff (cars, dirt bikes, Jeeps) over the years and never had to use less than factory torque spec.

2) Will 65 ft/lbs torque work or not? I don't know. It depends on how the Jeep is used. And who is standing behind the recommendation of 65 ft/lbs if something happens. I agree that less torque will probably work as Eddie suggests for ordinary street driving but what about wheeling or unexpected hard hits to the suspension on the highway? The free rotation of the rubber bushing on the sleeve of the Fox shock won't mean diddle when the suspension bottoms or tops out hard offroad or an unseen pothole, etc. The Jeep factory torque setting is computed by engineers to hold the crush sleeves from moving inside the brackets during normal driving and hard hits. My point is we don't know if 65 ft/lbs will work and I don't like being a guinea pig. Fox and Dynatrac don't know either (Fox doesn't say anything and Dynatrac has changed their numbers repeatedly). Do you have this lift kit on your Jeep? Are you going to sail down a road with big whoops or obstacles that slam your suspension to full stuff or full droop?

As I have said before the problem here is Fox using a flimsy, undersized crush sleeve on these shocks. They should fix it.
If I am understanding this correctly, it's due to the bushing construction calling for a different sleeve design. Clamping forces aren't everything. Fox's bushing does not need as robust a sleeve as factory. Why overbuild it? You wouldn't put an International truck frame under a Ferrari.

2018 JLUR. V6. Auto.
 

wayoflife

Administrator
Staff member
Pretty funny!! I like your sense of humor, I really do. :)

But, in all seriousness, we are not all set. There are 2 issues here:

1) Why does Fox use a flimsy crush sleeve that will not handle factory torque spec? Why do users have to deal with that issue in the first place. I have put a lot of aftermarket parts on my stuff (cars, dirt bikes, Jeeps) over the years and never had to use less than factory torque spec.

2) Will 65 ft/lbs torque work or not? I don't know. It depends on how the Jeep is used. And who is standing behind the recommendation of 65 ft/lbs if something happens. I agree that less torque will probably work as Eddie suggests for ordinary street driving but what about wheeling or unexpected hard hits to the suspension on the highway? The free rotation of the rubber bushing on the sleeve of the Fox shock won't mean diddle when the suspension bottoms or tops out hard offroad or an unseen pothole, etc. The Jeep factory torque setting is computed by engineers to hold the crush sleeves from moving inside the brackets during normal driving and hard hits. My point is we don't know if 65 ft/lbs will work and I don't like being a guinea pig. Fox and Dynatrac don't know either (Fox doesn't say anything and Dynatrac has changed their numbers repeatedly). Do you have this lift kit on your Jeep? Are you going to sail down a road with big whoops or obstacles that slam your suspension to full stuff or full droop?

As I have said before the problem here is Fox using a flimsy, undersized crush sleeve on these shocks. They should fix it.

I hope you don't take this the wrong way but you are way over-thinking this and imagining problems that simply do not exists. To be clear, I am NOT suggesting anything. I am pointing out that a bonded rubber bushing REQUIRES that the crush sleeve be held firmly in place so that it does not rotate. This will allow the RUBBER bushing to rotate and do it's job and without causing the bolts/nuts to work themselves free. This is why the crush sleeves are made out of thicker steel and why a higher torque value is needed for it. I have run a myriad of monotube shocks just like these Fox and can tell you that ALL OF THEM have thinner crush sleeves being that they use polyurethane bushings. Being that the bushings rotate freely on the crush sleeve, you only need to tighten the bolts to keep them in place.

The right torque setting is needed for the right application and just because the factory shocks require on thing does not mean aftermarket monotube shocks will require the same. Comparing the two bushing is like comparing apples and oranges. The only thing they have in common is that they're both bushings just like apples and oranges are both fruit.
 

wayoflife

Administrator
Staff member
If I am understanding this correctly, it's due to the bushing construction calling for a different sleeve design. Clamping forces aren't everything. Fox's bushing does not need as robust a sleeve as factory. Why overbuild it? You wouldn't put an International truck frame under a Ferrari.

2018 JLUR. V6. Auto.

This ^^^^^^
 

wayoflife

Administrator
Staff member
Just for reference, here's what my thin and flimsy crush sleeves look like on my King coilovers.

20170217093352-75676d84.jpg


20170217093358-3a55770f.jpg
 

JP223/3USA

Member
Torque settings for Fox shocks in the Dynatrac 2" Lift

Damn, thought I would convince you that time! :crazyeyes:


All of our concerns have been answered. Torque specs have been updated and installation techniques have been suggested to maximize full function of the bushings. There should be no more posts on this topic. Contact Dynatrac if you have anymore concerns.
 

Last edited:

wwood

New member
I hope you don't take this the wrong way but you are way over-thinking this and imagining problems that simply do not exists. To be clear, I am NOT suggesting anything. I am pointing out that a bonded rubber bushing REQUIRES that the crush sleeve be held firmly in place so that it does not rotate. This will allow the RUBBER bushing to rotate and do it's job and without causing the bolts/nuts to work themselves free. This is why the crush sleeves are made out of thicker steel and why a higher torque value is needed for it. I have run a myriad of monotube shocks just like these Fox and can tell you that ALL OF THEM have thinner crush sleeves being that they use polyurethane bushings. Being that the bushings rotate freely on the crush sleeve, you only need to tighten the bolts to keep them in place.

The right torque setting is needed for the right application and just because the factory shocks require on thing does not mean aftermarket monotube shocks will require the same. Comparing the two bushing is like comparing apples and oranges. The only thing they have in common is that they're both bushings just like apples and oranges are both fruit.

Don't worry I do not take disagreements personally and I appreciate all of your explanations. I understand and agree with your point about bonded rubber bushings. My complaint is that the Fox crush sleeves are too flimsy and cannot handle factory torque or even the significantly reduced torque of 65ft/lbs without deforming. Your photo of the King shocks proves my point. The King crush sleeves are not deformed. :)

When I installed the original Fox shock sleeves at 65ft/lbs they deformed badly and were forced into the gap between the bolt and the bracket hole. That is totally unacceptable and I feel certain that would not happen if I used King shocks. The original Fox sleeve is simply too thin and weak to handle this application. The sleeves would not hold even 65 ft/lbs. I could not get 2 clicks on the torque wrench without the bolt moving and when I re-checked torque a few days later the bolt again moved before the wrench clicked at 65 ft/lbs. It is obvious that the crush sleeve is slowly deforming under the 65ft/lbs of torque and will get looser over time. If I keep re torquing the bolt the sleeve will just keep deforming. I could use loctite but that is a band aid on a problem that should not exist. And the sleeve will still continue to deform from use as the suspension is flexed.

Furthermore Fox has tacitly admitted the original sleeves are defective for this application because they issued replacement flanged sleeves. The idea of the flange is to prevent the super thin sleeve from being pushed into the gap between the bolt and the bracket hole. The problem with the new sleeves is that Fox made the hole in the sleeve too large in diameter so that there is lot of slop between the sleeve and the bolt which will allow the 2 sleeves to misalign where they meet in the middle of the bushing. Plus the overlarge hole caused the wall thickness of the new sleeve to be less than the original sleeve which was too weak in the first place. When I tested these new sleeves on a bare bolt they deformed where they met in the middle at about 65ft/lbs. I have not tested these new sleeves on my Jeep inside the bushings because I don't think they will work and don't want to tear the shocks off again to test them until other customers try the new sleeves and let us know what happens. On my Jeep I bought a new set of the original factory Fox sleeves and put on grade 8 washers that fit snug on the bolt so the sleeves will not get forced into the gap in the bracket holes. These sleeves are deforming somewhat at 65 ft/lbs but they will work until a permanent solution is found.
 

Attachments

  • DSC02086.jpg
    DSC02086.jpg
    107.7 KB · Views: 77

JTCO

Meme King
Hmmm, are you saying the old sleeves were deformed by torque?

He rebuilt his old ones because the bushings were worn out from time/miles. He was just trying to show what a King crush sleeve looked like for comparison, that's all.
 

wayoflife

Administrator
Staff member
Hmmm, are you saying the old sleeves were deformed by torque?

What I'm saying is to install your bolts with LESS TORQUE. More torque is NOT REQUIRED with bushings like this. Still not happy with 65 ft. lbs.? APPLY LESS torque and use loctite to secure the bolts/nuts in place. AS I'VE SAID, these are NOT factory bonded rubber bushings and you are wrong to assume that these bushings require anywhere near as much torque. It really is that simple.

He rebuilt his old ones because the bushings were worn out from time/miles. He was just trying to show what a King crush sleeve looked like for comparison, that's all.

Thank you.
 

Top