I hate Dzus fasteners

[Rondo]

My 1985 Reynard has the "large" Dzus fasteners. Seems like they are always coming loose over time and ulimimately good-bye bodywork. Am I missing something? Are the latch springs (S springs) bending? Should I switch to camlocs. Wise old sage advice very much appreciated.

[Garey Guzman]

....Should I switch to camlocs. Wise old sage advice very much appreciated.

I'm not wise or old but camlocs are a lot easier to deal with. A TON easier. One of my winter projects will be changing the dzus fasteners on my Zink to Camlocs. It won't be cheap or easy but it'll be worth it just for ease of use.

[Joefisherff]

If they are properly installed they won't loosen, the key is to buy a variety of lengths in the fasteners and springs (Pegasus has a nice kit with a variety of sizes). Trial fit them so you really have to torque them to get them fastened. The other key is how you fasten them to your body work - I always rivet them with aluminum rivets that have steel shanks from the inside of the body work out and I put a spreading washer on the outside. This really holds them in place and keeps them from moving around on your bodywork and cracking your fiberglass. If they have been moving around on your bodywork and worn out the area, take the time to fix it with some fiberglass and re-drill - I drill just under the inside bevel size of the fastener and then take a rat tail file to the fiberglass to get a nice fit. Lastly invest in a dzus fastener tool to use to close them versus a screwdriver - it makes it much easier to put the grunt behind fastening them and when it slips off it doesn't scratch your paint. Like Garey I would much rather use camlocs but if your bodywork is already drilled for Dzus they can be made to work, after all they were designed to hold aircraft panels in place - so you know they are a viable option. Good luck and if you have any question feel free to email me.

Joe

[stephen wilson]

I just put a piece of "racers" tape over them!

[Suskevichracing]

I've been using Dzus fasteners for the last 5 years on my race bikes, when they get used alot, the "S" springs do get weak and the fiberglass wears thinner. I have 2 suggestions:

1- Put a nylon washer under the head of the Dzus fastener. It protects the fiberglass from friction wear and tightens the connection.

2- If you use the D-Ring style instead of the screw head, put a small piece of duct tape over the D-Ring to keep it from turning by vibrations.

Good Luck!

[Fred Michael]

Dzuz fasteners will always loosen up with use due to the springs getting weak and bending slightly and the slot in the button wearing.
My suggestion is convert to camlocks. They are also a pain but they usually stay put when you put them in place.
Tape is good insurance but I prefer helitape over racer tape as I have had cases where the racer tape did not hold the dzuz down even though the tape stayed in place.
Yes I know helitape is super expensive but if it saves one piece of bodywork...

Fred

[lancer360]

There is a great book by Carroll Smith dealing with this issue and many other fastener issues. "Nuts, Bolts, Fasteners, and Plumbing Handbook". I was amazed by the wealth of information in this book, especially with rivets. If you do your own work on the car, this is a must have reference book.

Carroll talks about Dzus fasteners and Camlocks. Although he really didn't like any 1/4 turn fasteners since something was always going wrong with them, he agreed that they are a necessary evil to make it easy to get panels on and off quickly. He used Dzus and Camlocks, but leans towards Dzus because they are easier to find and more forgiving of minor misalignment. He also swore by using an 0.031" aluminum backup plate on the inside of the fiberglass panel. The panel should have roughly 4x the area of the dzus plate and be dimpled in the center to match the dimple in the dzus plate. This makes the Dzus, much less likely to rip out. The draw back is if you have contact or an off, the dzus fastener now rips a much bigger hole in the fiberglass.

[Frank C]

I think the theory behind taping Dzus fasteners is that it keeps the heads from rotating. If they are not too loose, this keeps things connected.

I might start a thread on what is viewed as the best way to fasten a DB1 nose. Mine has a Camloc in the center and two Dzus fasteners behind the rockers. These connections are a continual pain because the receptacles are on easily bendable aluminum tabs. I quit setting up a new nose for installation, as I decided I wanted to redo the fasteners first.
- Frank C

[RussMcB]

I was all set to replace my Dzus fasteners with camlocs. Ever since I saw the type held in place with spring metal straps I've wanted them.

Then I priced them and nearly sh1t my pants.

[rickb99]

My 1985 Reynard has the "large" Dzus fasteners. Seems like they are always coming loose over time and ulimimately good-bye bodywork.

We have an 89 Reynard. Two big Dzus up under the A-arm shroud on the front and 4 on each of the engine side covers. We've never had one come loose while racing. Even if the ones under the A-arm shrouds come loose, there's the nose clip on the top holding the cockpit surround and there's NO WAY that body will come off unless the nose fastener come undone and the rear of the body lifts so the surround can slide back off the A-arms.

They can be a bugger to keep adjusted especially the one under the right hand front shroud. Yes, the S-springs can get a touch bent. I had to go to Pegasus and purchased a few flavors of 'reach' because some of ours seemed too short/too long. If you put too much pressure on the fastener as you're trying to tighten it and it's not linged up, it wll bend the spring but in that case you can reach in with some needle nose and readjust it. This is caused by the through panel holes being sloppy (nothing worse then a sloppy hole. But Sloppy Joes are good).

If they don't snap in tight, try adjusting the S-spring. If for some reason the reach is way off (due to panel wear, maybe) get some new fasteners of different lengths and try them. ALL of ours have a 'solid' snap when they engage.

Sounds goofy, but on our engine side covers there always seems to be ONE of the fasteners that wants to be engaged FIRST so all the others line up properly.

Would Camloc's be better? Maybe, and there's only 10 of them to do. On the other hand, we remove all of those panels every time we come back to the paddock. So there'd be a lot of wear on the Camlocs too and how long does it take of 'rush' jobs to bugger the phillips head on the Camloc's? I think we'll stay with the evils of Dzus.

Oh, and keep a rivet gun handy with a few of the teeny-tiny rivets and backing washers used to attach them

[Tom Sprecher]

Having worked with both I love Camlocs. They seemed reasonable from here.

http://www.milspecproducts.com/index.html

[EYERACE]

if you use either fastener long enough you will eventually decide you don't like them.....for some picky reason. my car's held together by camlock and dzus......when the small rod comes out of the end of the camlock it won't work of course......but you can double over a very short piece of safety wire and slide it into the hole now left by the small rod's absence and that works. i tape over both type of fastener's heads with duct tape. this thread has made me think i should put a small wad of silicone in the connection of the camlock rod/shaft to keep the rod from vibrating or falling out

[JHaydon]

As everyone has said, Dzus fasteners do loosen and wear over time -- and it's everything in the sandwich that's wearing out: the spring, the stud, and the fiberglass. If the body gets bumped, that's more strain on the spring and the stud.

Taping Dzus fasteners should be mandatory. Not only does it help to reduce the chance that the stud will turn, it will also help to hold the stud down (in the latched position) in case it does turn, or if the spring breaks. Use fresh bits of tape every time, and clean off the old tape residue occasionally so the new tape can actually stick.

I set my car up with fasteners that required no tools. I'm always paranoid that I'll need to take the engine cover off and there won't be a screwdriver for miles. Hood pins, draw latches, and "Terry" body springs hold everything together now. I give up a little bit of aero for the sake of ease of use. On the other hand, a CFF isn't the most slippery design around, so it probably doesn't make a bit of difference for me.

The latches I used are the adjustable type, which can be tightened to compensate for wear and stretching. Still, after several seasons, a couple are at the limit of adjustment because the mounting holes have elongated.

[RussMcB]

Having worked with both I love Camlocs. They seemed reasonable from here.

http://www.milspecproducts.com/index.html

I can't find the spring tabs on that web site to see how much they are. When I was looking into it, the spring tabs were the big attraction for me. Once I added up the costs ($200?) it was much more than I wanted to spend. Maybe peanuts in the scheme of race car parts, but seemed steep.

http://www.pegasusautoracing.com/pro...asp?RecID=4339

I ended up getting this instead:

http://www.pegasusautoracing.com/pro...asp?RecID=4384

It has been handy to have a selection of Dzus sizes near by.

BTW, when I got a good Dzus tool (screwdriver type), it was way better.

[Peter Horvath]

[quote=rickb99;189666]
Sounds goofy, but on our engine side covers there always seems to be ONE of the fasteners that wants to be engaged FIRST so all the others line up properly.

This is true. With each panel, if I start with a certain fastener, the rest of them snap into place perfectly. If I start with the wrong fastener, it always causes problems.

[Dave Welsh]

I do composites repairs for a local drag race car builder.

I have observed Dan setting Dzus fasteners, and have learned a lot from watching him.

First he uses smash rivets instead of pop rivets. They last much longer than pop rivets.

Secondly, he uses a spring setting tool to set the spring to the proper tension. He places the tool through both body panels as turns a screw to adjust the spring tension.

Dave Bean has such a tool. This tool makes life much easier in installing and maintaining dzus fasteners.

http://www.davebean.com/Tools.htm#DzusTools

Another tool found here. I did a Google search on Dzus spring tool.

http://www.jerrybickel.com/dzus-and-...-jbrc4007.html

[steve zemke]

Dave is right. Correct spring tension is the secret to Dzuss fasteners stayting fastend. Too much tension ruins the little S spring. Once the spring looses its tension, the fasteners will start to fall out. Set the tension correctly, do a routine maintenance check, and keep the fasteners in place.

[jerry freeman]

Dave Welsh is right. I use Dzus fasteners on all the drag cars I work on. There are a lot of places that sell the adjusting tool. It's cheap and that is the way to keep the springs in the proper adjustment. They hold on TF dragster bodies at 330+ MPH so they work just fine if they are installed correctly. Thats the only thing I would use because of the cost and avalibility.

Jerry

[drdestructo]

Go to www.skybolt.com and check out the adjustable 4000 series camlocs. These are the best thing going. Just remember to hang on to your wallet. They don't give 'em away!

Solid rivets are the only way to do any of them.

[BILL LOMENICK]

Here is the link to Dzus buttons that use a hex key and are used by
Stohr race cars. http://www.fullborerace.com/superbutton.html
Bill Lomenick

[Dragnmorad]

we race racecars, not street cars. Nothing is really made to last more than a season or two. I see it as just part of racing to replace items like dzus, hymes, universals excetera. These items are made alot lighter than they would ever be on a street vehiche. Part of weight savings is parts that dont last as long. Just part of our game

[sccadsr31]

[FONT=Verdana][FONT=Verdana]These guys who are also mentioned above sell a variety of fasteners and most important the tool for adjusting the springs.[/FONT]
[FONT=Verdana] [/FONT]
[FONT=Verdana]http://www.milspecproducts.com/tool.htm[/FONT]
[FONT=Verdana] [/FONT]
[FONT=Verdana]Good prices very helpful.[/FONT]
[FONT=Verdana] [/FONT]
[FONT=Verdana]David[/FONT]
[/FONT]

[Rondo]

Great responses and lot's to keep me busy this winter. For the Dzus adjusting tool, I assume you move the spring forward and back, as appropriate, to get a tight fit when the dzus snaps closed. Any other "tricks"?