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Boostwerks.com
October 6th, 2017, 14:34
So recently I've noticed some common misconceptions about the function of a steering brace on an XJ going around the interweb, so I figured I'd share some of my thoughts here. This thread is not a plug for our product, but simply a means to share my opinion on these topics.

Issue #1: "A steering brace will prevent the unibody from cracking."

While it will certainly help by lessening the amount shear stress from being transferred into the sheet metal, the unibody will still see a tremendous amount of force at the track bar bracket. Any solid axle front suspension that isn't a triangulated 4-link, will utilize a track bar (AKA pan-hard bar) to not only keep the axle centered but to allow the steering force to be transferred to the wheels. The lateral suspension and steering forces are shared by both the steering linkage as well as the track bar. This is why I highly recommend every built Cherokee to utilize a track bar brace to prevent the same twisting forces that the steering box also sees. Once the steering box and track bar are braced, your front end will be a lot tighter and less susceptible to cracks forming. Using one without the other can cause a high stress area by focusing more of the stress in one spot. IE, if you have just a track bar brace, you're more likely to end up with cracks around the steering box. Likewise, bracing just the steering box may result in cracks forming around the upper track bar bracket.

Issue #2: "You can't just support the sector shaft, you need to support the steering box itself as well."

While our steering brace supports only the sector shaft, others on the market support both the sector shaft as well as the lower box portion with an additional clamp. There are also the older style braces that simply support the lower portion of the steering box housing. Supporting just the lower sector shaft is all that is needed, and I'll explain in detail why I feel this is true.

First of all, the ideal location to support the steering box is at the bottom of the sector shaft. This is due to a couple different reasons. The main reason being that the highest amount of stress and movement is going to be at the lowest point of the box due to the location of where the steering is attached. Thus, the most effective way to lessen this stress is by supporting the lowest possible spot of the sector shaft. The leverage the steering will have on twisting at the box is now almost completely eliminated.

Secondly, a lot of the re-manufactured steering boxes as well as many OEM's, utilize a bronze bushing to support the lower portion of the sector shaft instead of a stronger and more precise needle bearing. You might be surprised at just how much play these boxes have even after a fresh rebuild. This is why supporting just the body of the steering box like many of the cheaper braces, may not actually reduce much of the play in your steering. Almost all of the steering stresses are still being transferred directly into the lower portion of the sector shaft, which overtime will reduce the life of the entire box.

Now as for supporting both the sector shaft as well as the lower portion of the steering box, the opinions out there will vary. However, it's my belief that once the lower sector shaft is adequately supported, no additional support is needed. This is assuming however that the area where the box bolts onto the unibody is in good shape and a quality spacer is used. Not only is any additional support not required, it may actually cause a stress riser in the box itself by preventing the stresses to be evenly absorbed by the lower support and the upper unibody attachment. The clamps themselves may also stress the cast housing, eventually leading to failure (especially the U bolt style). I do have to say though that I haven't personally seen a box fail because of this, and that this is simply my humble opinion.

Issue #3: "A Steering Brace will cure your death wobble."

I get this question a lot. While a good steering brace will certainly help, it also won't replace your beat up bushings or worn out tires :rolleyes:. As most DW threads will state, pretty much any loose or worn out component in the front suspension or steering system can lead to death wobble. A good SB and track bar brace will go a long way to preventing the severe death wobbles from killing the front unibody however.

Thank you for taking the time to read this and I hope this write up can help people further understand the XJ's unique need for front end bracing!

:cheers:

Bryson W.
Boostwerks LLC


https://farm5.staticflickr.com/4138/35550962371_1c84dfa68d_c.jpg (https://flic.kr/p/WavYx6)IMG_2151 (https://flic.kr/p/WavYx6) by Bryson Whissen (https://www.flickr.com/photos/150006253@N08/), on Flickr

cal
October 6th, 2017, 15:16
Asking very seriously here;

What about people who do not have good frame support/crossmember bracing, and do this type of upgrade. You'd be allow the chassis to flex and shift, but the sector shaft would not be able to go with it?

old_man
October 7th, 2017, 11:55
Like the man said, a good steering setup will go a long way to help is rarely a cure all.

Boostwerks.com
October 7th, 2017, 20:21
Asking very seriously here;

What about people who do not have good frame support/crossmember bracing, and do this type of upgrade. You'd be allow the chassis to flex and shift, but the sector shaft would not be able to go with it?

Just to make sure I'm understanding you correctly, you're asking if the sector shaft will get unwanted stress placed on it by chassis twist? That's actually a good question. However, I wouldn't think it would be a concern considering the physical distance between the bearing support and the box mounting points. The amount of deflection in that small of a distance would be very small. If it was enough to damage the box, I'd imagine you'd have much bigger issues on your hands (cracking windshields, door frame cracks, trans tunnel cracks...etc).

I had designed our brace to allow some twist in the middle tube section, but not to twist in the bearing support area. This means that any twist in the brace won't be transmitted into the steering box.

FWIW, I haven't had a customer contact me about killing a box.

cal
October 7th, 2017, 21:30
If only it had an integrated winch mount.

cal
October 8th, 2017, 13:36
If only it had an integrated winch mount.

Hah. I wasn't trying to be a smart ass. I just hadn't looked at your website.

http://www.boostwerksengineering.com/assets/images/SjphyZ1384146579.jpg

Maybe we need to talk.

TRCM
October 8th, 2017, 14:00
Hey cal...check this one out too......

http://www.naxja.org/forum/showthread.php?t=1136693