C4 Diff Skid for KDSS and Sonoran Steel Trac-bar

[mteolus]

Installed the C4 Diff Skid for KDSS Saturday. No problems interfering with the Sonoran Steel Trac-bar as you can see the trac-bar is way above the diff skid. Pretty easy install, just a little neck fatigue laying down under there installing it. Really good product.

Painted the diff skid with a rattle can semi-gloss paint and primer combined in one.

I think these diff skids are part of C4's Black Friday deals plus an additional 10% off. Would be a good time to get one.

 

[comtn4x4]

Have you taken it off road with a heavy load at all? I am having some issues with my trac bar contacting my diff under extreme compression. (I don't have a diff skid) Steve and I have been working extensively to figure it out, however, it seems unique to my setup. My rig is pretty heavy so Steve thinks that when it's very compressed and at a higher speed the rear axle deflects into the trac bar due to the force.

 

[mteolus]

No issues with mine hitting the diff. I haven't really had a heavy load though. But I did notice some rust above where you have to cut off the piece of metal when installing it. Obviously the rust where I cut is there but perhaps the rust just above that was caused by some light rubbing of the trac-bar? I painted it so I'll check again after some 4x4 to see if the paint has been rubbed off. It's possible I rubbed the paint off when making the cut.

 

[SpeedyKevin]

Have you taken it off road with a heavy load at all? I am having some issues with my trac bar contacting my diff under extreme compression. (I don't have a diff skid) Steve and I have been working extensively to figure it out, however, it seems unique to my setup. My rig is pretty heavy so Steve thinks that when it's very compressed and at a higher speed the rear axle deflects into the trac bar due to the force.

interested in seeing what the solution will look like! How much weight (other than the rear bumper) are you carrying in the rear?

 

[oldschoolpl510]

Good info, Thank You. I was wondering if there would be any fitment issues.

 

[comtn4x4]

interested in seeing what the solution will look like! How much weight (other than the rear bumper) are you carrying in the rear?

It's hard to say exactly but as a rough estimate:
Unloaded the rear end is as follows:
bumper at 250#
2 Gallons Fuel 14#
figure half of the weight of my roof rack so 55#?
The rear skids are maybe 45#
I don't know how much moving the spare tire back on the rig to the tire carrier changes things. Either way the spare IIRC is 20# heavier than the stock tire (the tire is 68.5# plus rim)
Tools recovery gear etc maybe 50#
So maybe 350# over stock? Not sure how much the removed items would weigh

Full add 56# water
Hi Lift 35#
The rest of the gear etc. in and on is probably another 300# plus people and dogs

As far as a solution goes we are kind of stumped right now. Initially we thought the trac bar hitting the diff was being caused by a bent rear lower control arm. Those have been replaced so that's not it although that seemed to help. I have ground some off the trac bar which also seemed to help but on a big hit it still hits it. Full is obviously worse than empty.
I have some bigger coils to put on but I have also been chasing a newly developed death wobble on the rear that I haven't quite got resolved yet.
Next step is to get the trac bar repainted this weekend and look for where it's hitting.
Steve has been really helpful and responsive. The whole think kind of has us stumped

 

[comtn4x4]

No issues with mine hitting the diff. I haven't really had a heavy load though. But I did notice some rust above where you have to cut off the piece of metal when installing it. Obviously the rust where I cut is there but perhaps the rust just above that was caused by some light rubbing of the trac-bar? I painted it so I'll check again after some 4x4 to see if the paint has been rubbed off. It's possible I rubbed the paint off when making the cut.

I noticed something like this also. This may have been/be where I am getting some contact. After I repaint the bar I hope to see what's going on better

 

[SpeedyKevin]

Glad to see Steve has been helpful in resolving this issue. About to purchase one and was a little worried about contact (also getting the diff skit) but Im not carrying nearly that much weight in the back so hope all is good!

Hope you guys are able to resolve the issue!

 

[comtn4x4]

Glad to see Steve has been helpful in resolving this issue. About to purchase one and was a little worried about contact (also getting the diff skit) but Im not carrying nearly that much weight in the back so hope all is good!

Hope you guys are able to resolve the issue!

I would not be at all concerned with rubbing if I was you. Steve said he has shipped about 1400 of these IIRC and never had any issues like mine. I'm just the lucky one. And yes he thinks the weight has something to do with it

 

[SpeedyKevin]

I would not be at all concerned with rubbing if I was you. Steve said he has shipped about 1400 of these IIRC and never had any issues like mine. I'm just the lucky one. And yes he thinks the weight has something to do with it

Any update on a solution for your set up?

 

[Mutant138]

Have you taken it off road with a heavy load at all? I am having some issues with my trac bar contacting my diff under extreme compression. (I don't have a diff skid) Steve and I have been working extensively to figure it out, however, it seems unique to my setup. My rig is pretty heavy so Steve thinks that when it's very compressed and at a higher speed the rear axle deflects into the trac bar due to the force.

Read sonoran steels webpage for the trac bar. The kdss sway-bar is known to contact the diff. It's part of the reason they developed the bar from my understanding.

I need to get under my truck this week. I'll check to see if mine has made contact.

 

[comtn4x4]

Read sonoran steels webpage for the trac bar. The kdss sway-bar is known to contact the diff. It's part of the reason they developed the bar from my understanding.

I need to get under my truck this week. I'll check to see if mine has made contact.

I'm not sure what you're talking about. I already have the Sonoran Steel trac bar installed and I am having trouble with it hitting the diff during compression. I'm the only one so far that's had the issue and have been working with Steve extensively to remedy the situation.

 

[honda250xtitan]

I'm not sure what you're talking about. I already have the Sonoran Steel trac bar installed and I am having trouble with it hitting the diff during compression. I'm the only one so far that's had the issue and have been working with Steve extensively to remedy the situation.

If it's axle deflection what about adjusting the upper or lower links to push or pull the axle to create more space?

interesting side note: PRG is selling a link kit that eliminates the driver side upper link. FJ/4 RunnerGX470 4-Link Kit | PRGProducts.Com

 

[comtn4x4]

Any update on a solution for your set up?

So far I haven't had a chance to get it the trac bar painted. With the holidays my work and life schedule has been nuts. However, I did get the heavier coils installed and that seems to have helped. I have had it out on a couple trails recently and tested it and haven't had any issues at slow speed. It seems to be a combination of things, first the rig is pretty heavy. (Steve didn't seem to think to many others that had his trac bar were running a heavily loaded setup.) Second, hitting an elongated speed bump at say 40 mph and coming down hard seems to deflect the axle backwards causing the contact. So the obvious solution there is don't do that... It did seem to improve with grinding the bar out in the diff area. When running a couple trails at 30-40 mph I wasn't able to duplicate the issue anywhere else.
I really don't want people thinking this is a common issue. I seem to be the only lucky one to have it.

I'm not sure I really answered your question but that's my update at the moment

 

[comtn4x4]

If it's axle deflection what about adjusting the upper or lower links to push or pull the axle to create more space?

interesting side note: PRG is selling a link kit that eliminates the driver side upper link. FJ/4 RunnerGX470 4-Link Kit | PRGProducts.Com

I was thinking of that myself. However, Steve thinks that playing with the length of either the upper or the lower will cause problems in the first place. Part of how all this came about was I bent the drivers lower rear control arm. I thought that was causing the issue so I replaced those with the Sonoran steel non adjustable ones. I also replaced the bushings in the stock uppers as well. That change definitely freed up travel in the rear end so that may have exasperated the issue.
Right now I need to get the Sonoran steel trac bar re painted and start looking for areas of contact. Then possibly make additional adjustments as you suggested.

That PRG link looks interesting

 

[honda250xtitan]

I was thinking of that myself. However, Steve thinks that playing with the length of either the upper or the lower will cause problems in the first place. Part of how all this came about was I bent the drivers lower rear control arm. I thought that was causing the issue so I replaced those with the Sonoran steel non adjustable ones. I also replaced the bushings in the stock uppers as well. That change definitely freed up travel in the rear end so that may have exasperated the issue.
Right now I need to get the Sonoran steel trac bar re painted and start looking for areas of contact. Then possibly make additional adjustments as you suggested.

That PRG link looks interesting

If youre lifted at all than adjusting the links could get your axle back to where it was originally. Which might help? It's hitting at full bump than maybe you need taller bump stops? which sucks cause limiting travel is ghey.


yea i messaged PRG on IG and he said daily drivability is amazing, no issues at all, but the kit allows the suspension to cycle freely etc. Dude knows his stuff so it is interesting to me, especially since he mentioned he's had customers come to him with aftermarket links having repeat issues which caused him to built those links (which are basically OEM but with Heims and deleting the one upper link) :shrug:

 

[comtn4x4]

If youre lifted at all than adjusting the links could get your axle back to where it was originally. Which might help? It's hitting at full bump than maybe you need taller bump stops? which sucks cause limiting travel is ghey.


yea i messaged PRG on IG and he said daily drivability is amazing, no issues at all, but the kit allows the suspension to cycle freely etc. Dude knows his stuff so it is interesting to me, especially since he mentioned he's had customers come to him with aftermarket links having repeat issues which caused him to built those links (which are basically OEM but with Heims and deleting the one upper link) :shrug:

I'll definitely look into the PRG setup, however, I'm not sure about compatibility with the Sonoran Steel trac bar. I've got a lot of time and money in the rig right now so it might be a while before I can justify it. Assuming I can get my current setup running right. Just changing to urethane bushings on all the rear links was a noticeable improvement in the rear suspension freedom of movement. I can only imagine what bearings would be like.

The whole premise of the Sonoran steel trac bar is that you improve up travel in a KDSS setup. So therefore you use stock length bump stops along with the extended up travel Radflo shocks that Steve has made especially for him. (I don't have these shocks yet, just the regular Radflo 2.5's) I had the extended bump stops on at first and we were concerned that they are causing the axle to deflect so I pulled them off and went to stock length. There was no difference in the contact with the diff with either set of bump stops. And I'm positive the suspension wasn't getting compressed enough to hit the extended stops let alone the stock length.
I'm not disagreeing that the links may need to be adjusted, I just need to keep trying to trouble shoot everything one thing at a time. That being said, All of the exsisting Sonoran Steel KDSS setups are using stock length upper and lower links without a problem.
Steve has been a great help through all of this and I may drive the rig down there at some point to get his help

 

[Mutant138]

I'm not sure what you're talking about. I already have the Sonoran Steel trac bar installed and I am having trouble with it hitting the diff during compression. I'm the only one so far that's had the issue and have been working with Steve extensively to remedy the situation.

I read it as if you had a stock sway and it was making contact. Idk why I read it like that.

 

[honda250xtitan]

I'll definitely look into the PRG setup, however, I'm not sure about compatibility with the Sonoran Steel trac bar. I've got a lot of time and money in the rig right now so it might be a while before I can justify it. Assuming I can get my current setup running right. Just changing to urethane bushings on all the rear links was a noticeable improvement in the rear suspension freedom of movement. I can only imagine what bearings would be like.

The whole premise of the Sonoran steel trac bar is that you improve up travel in a KDSS setup. So therefore you use stock length bump stops along with the extended up travel Radflo shocks that Steve has made especially for him. (I don't have these shocks yet, just the regular Radflo 2.5's) I had the extended bump stops on at first and we were concerned that they are causing the axle to deflect so I pulled them off and went to stock length. There was no difference in the contact with the diff with either set of bump stops. And I'm positive the suspension wasn't getting compressed enough to hit the extended stops let alone the stock length.
I'm not disagreeing that the links may need to be adjusted, I just need to keep trying to trouble shoot everything one thing at a time. That being said, All of the exsisting Sonoran Steel KDSS setups are using stock length upper and lower links without a problem.
Steve has been a great help through all of this and I may drive the rig down there at some point to get his help

youd think that upgrading bushings would eliminate most of the deflection too. interesting. come on down to sunny 602!

Yea i just threw out that little PRG bit just for fun. it comes with a generic style trac bar. i wonder what he'd charge for just the 3 links.

 

[comtn4x4]

youd think that upgrading bushings would eliminate most of the deflection too. interesting. come on down to sunny 602!

Yea i just threw out that little PRG bit just for fun. it comes with a generic style trac bar. i wonder what he'd charge for just the 3 links.

Yeah I'm not 100% convinced it's the axle deflecting.

If you get a price on the 3 links let me know