28 replies to this topic

[FTodaro]

I have had some mechanical failures recently that caused some damage but thankfully not to me. However, post-crash or impact mechanical failures can occur if we do not follow good maintenance practices.

 

I thought I would start a thread so we can post some of our experiences with failures, and what we did or what we can do differently going forward to avoid it.

 

Plus i would rather talk about things that are interesting and not PARITY.

 

I have a few examples and hope others will add to it.  

 

Lets start with the easy ones.

 

Front and Rear hub failures:

 

I have experienced both a front and rear hub failure where the hub cracks and separates.

 

My best explanation for the failure was in each instance that i had installed extended wheel studs. I have installed them both with a press, or drawing them in with a bolt on the other side. My opinion, in some cases the stud diameter is to large and it introduces micro cracks in the metals that propagate into a separation and failure. 

 

The remedy in my opinion, is to only run the stock studs. If you do run aftermarket studs, i would examine under magnification every time the wheel is off the car. 

 

Rear wheel bearing failures:

 

I have lost two rear wheel bearings at the track. The first one I heard it coming I could hear it grind and felt it. The second one, was at Watkins Glen, i did not have any warning, (that i detected) and i felt a few high speed wiggles, before it froze up cracked the rear rotor and spun the car.

 

The cause, two issues, one I left it in service for too long, and I had taken the bearing apart before I installed it to repack with better grease.

 

The remedy, I now replace the rear bearings once a year over the winter no matter what, and I just use the stock grease, trying to take them apart without damaging the plastic ball bearing retainer is near impossible. Not worth the risk IMO.

 

Rear Caliper failure:

 

This is an issue at places like Road America where going off line at the exit means big gators. The pins that hold the caliper to the caliper bracket will back out. There is not much warning before they let loose.

 

The issue in some cases was that they painted calipers would have a layer of paint under the contact point of the pin and it would work loose.

 

The remedy, clean the contact surface pin to the bracket, and use red lock tight on them. check them at every tire change, especially if your at a place like Road America.

 

Front Ball Joint failure:

 

This is one that I think about, because if you have ever seen someone with a ball joint failure its not pretty.

 

It generally happens due to age or more likely due to an impact. Its hard to inspect for a ball joint failure and its generally a shear type event where its all good till it goes all bad.

 

The remedy, on a new build or new car to you. I would put this on the list to replace. I would also replace after any type of decent frontal or wheel impact, you have to use some judgment on this but if the impact is sufficient to bend control arms or if its a direct hit on the wheel, I would be replacing it.

 

Steering rack failure:

 

This is my favorite, I have a manual rack. First thing to note is the manual rack is not as durable as the power rack. The Manual rack is light weight, and the housing is aluminum. I had the big one at Watkins Glen in 2015, i damaged the inner tie rod end, and just replaced it. I looked over the rack and did not see any other damage. I did not do this under magnification. I am not sure I would have seen the cracks but there were cracks where the steering gear intersects the shaft and it cracked and failed causing me to hit a tire wall and almost flip the car post impact.

 

The remedy, Run the power rack as its more durable, or be extra careful to inspect the manual rack after any kind of front tire/front end impact. They are fragile.

 

I will post more, others are welcome to add to the mix. 

[MotoFusi]

Great post Frank. I'm an airline safety guy and we have a whole team of people that analyze component failure continually to determine the right time in flight hours or number of cycles to replace before failure. Some times go up but most times the life cycle gets shorter.

 

This thread could be a great place for a newbie like me to learn from everybody else's experience. Of course now if anything breaks I blame Caveman LOL

[davew]

I would like to add a couple of shop policies;

 

Any time a lower control arm is damaged, put in a new ball joint. I have found most ball joint failures follow contact. Or big curbs!

 

Any time an inner tie rod is replaced due to contact/bending, replace the outer. It took a lot of force to bend that inner, and that force went through the outer first.

 

Any time you do trackside repairs after a crash, replace the entire corner. Upper, lower spindle hub etc. Then do a proper inspection at home to see if there is any further damage you may not see on first look.

 

Any time you have suspension damage, inspect the subframe for bending. Advanced makes a pair of simple subframe checkers that will tell you in a couple minutes if you have damage. Not only will this save you a bunch of time when the car won't allign, but I have seen front subframes break off the control arm mounting points.

 

Speaking of subframes, inspect the pickup points very carefully on front NB's for cracking where the front pivot point for the lower control arm attaches. Especially at bumpy tracks like Sebring (on the race surface) or Road America (over the curbs)

 

Everytime the car is on stands, shake and spin the wheels. Feel for play, listen for noise, look for wobbles.

 

Nut and bolt check the car every night. Especially steering, suspension and brakes. Every once in a while check the hardtop bracket bolts.

 

Every time you replace a part, using a reman version, chase every thread. The rear caliper brackets are notorious. We even remove the fixed pin and chase the threads. As Frank said, reinstall with loctite. This is a great time saver (and aggrivation saver) on water pump pulleys. Next time you install any rebuilt part, put a clean paper towel on the bench, then run a tap through the holes and watch how much crud comes out. All these parts are sand blasted before being painted. Any sand left in the threads gets sealed in by the paint. You may think stuff is tight, but it is not.

 

I can hear a wheel bearing noise but can't tell which side? Usually it is the left front if the noise is on right turns and vice-versa. But not always. If you do not feel any play or hear the noise with the tire on remove the the tire, caliper and rotors. Then spin the bare hub. You will be amazed at how much noise the hub alone will make when they just start to go bad.

 

Brakes; check the caliper bracket bolts every night. Check the front caliper pins for bends by slowly unscrewing from the caliper and watching for wobble. At bumpy tracks like Road America and Sebring, remove the rear calipers every night to inspect the pads and check the pins. Be sure to install the pads correctly.

 

Check the rear suspension long bolts by loosening the nut and spinning the bolt. If the bolt is bent, you will see the rotor wiggle. If you have a hoist, you can do this with the tire on the car. It will show even smaller bends.

 

Make sure your battery is secure. I have seen many batteries shift in NB cars and short against the wheel well.

 

If you run hood pins; EVERY TIME you close the hood, put in the hood pins. I don't care if there is no motor in the car. Get in the habit and stay in the habit. My shop policy is whomever left the pins out, pays for the hood, windshield and other damage.

 

I disagree with Frank on the long studs. I have long studs in all my cars and have had only a handfull of failures in all these years. I use only ARP studs, so I am comfortable with their engineering skills. Maybe some other manufacturers have fit problems.

 

Frank, this is way more fun than listening to Davey Dew and the St Lewey Bros complain about discuss parity.

 

Dave

[Bench Racer]

Dave, I deleted my post because I followed your lead and used THE word.

[Tom Hampton]

I've only had a couple on-track failures:


1. Failed front hub bearing. the hub lasted 4 years. I check all hubs after every session. it went bad at about the 20 minute mark of a 45 minute race. It was my first bearing failure and I didn't recognize the noise. The hub remained on the car through the rest of the race. 

 

I don't really know what I'd do differently.  I continue to inspect after EVERY session.  If anything, I'm a little more sensitive when feeling for "play".  I found placing my palms flat on the surface of the tire (top and bottom) and gently trying to rock the tire makes it easier to feel for minute play (rather than grabbing the wheel spokes).  I check all wheels twice spinning the wheel 90 degrees between each check. 

 
2.  Failed CAM angle Sensor connector retention clip.  The harness separated from the connector under G.
3.  Failed Steering column ignition harness retention clip. The harness separated from the connector under G.
 

I created a checklist of every critical electrical connector.  I verify these connections are tight after every session, and as part of my pre-event inspection (aka "nut&bolt" for the electrical systems). 

 

Carry lots of zip ties to the track, to hold something in-place that has come loose. 

 

I'm also somewhat fastidious about my electrical systems.  I'm not as neat and tidy as Adax, but I'm getting much closer to that during the rebuild.  Rules I live by:

 

1.  DO NOT break into the stock wiring harness.  I run separate power with separate fuses and switches for the race systems (gauges, data, lights, etc).  The harnesses are completely separate from the stock harness. 

 

2.  NO CHEAP CRIMP connectors.  All splices and joints are made using high-quality crimp connections with adhesive lined heat-shrink tubing.  These provide sealing against fluids, and corrosion.  Additionally, they provide pull-strength and strain relief. 

 

3.  NO EXPOSED WIRES.  All wire bundles are protected with over-braid or split loom.  This protects them from all sorts of damage opportunities. 

 

4.  RESTRAIN ALL HARNESSES. Everything should be strapped down using adel type clips or zip ties.  Harnesses should not flop loose, and the connectors should not be part of the retention system. 

[FTodaro]

Upper Ball joint/ control Arms

 

I am giving away all my secrets today in an effort to keep people from Crashing me out.

 

I have observed the upper ball joint separate from the control arm. We have discussed this before, but its nice to get this stuff in one spot. I think in my blog I showed a pic where I spot weld or tack weld the upper ball joint to the control arm on the inside and outside top of the ball joint where it meets the control arm.

 

This is good preventative maintenance.

[davew]

Upper Ball joint/ control Arms

 

I am giving away all my secrets today in an effort to keep people from Crashing me out.

 

I have observed the upper ball joint separate from the control arm. We have discussed this before, but its nice to get this stuff in one spot. I think in my blog I showed a pic where I spot weld or tack weld the upper ball joint to the control arm on the inside and outside top of the ball joint where it meets the control arm.

 

This is good preventative maintenance.

 

We do this on every car in the shop. Also on all our spares. Only takes a couple minutes but can ward off disaster.

 

Good thought Frank

[davew]

I will second the idea of never hacking into the oem wire harness. Using an unused power source is ok (i.e. radio power for data system). But proper procedures are very important. I use non-insulated crimp terminals and then heat shrink over them. No blue butt connectors on a race car. No scotch lox on anything. You may notice that on my master switch wireing, there are no small wires that get cut. Fuel pump, injectors etc are untouched. Only the alternator output and the battery cable are touched.

 

Also pay attention to clean grounds and good ground straps. At the battery, the rear chassis, PPF, cylinder head, under the master cylinder, behind the headlights and under the dash

[Tom Hampton]

I started out scabbing onto unused power...the radio.  But, I didn't trust the wire and associated fuse block.  I had a fuse that kept blowing randomly, which I could never figure out why.  It would work fine for weeks, Multiple race weekends, etc.  Then one random session...it would just go poof.  Once I undid my power-tap, and ran a separate fuse block...all has been good since. 

 

So, I prefer to run my own 18 AWG wire (or whatever) with my own fuse, that I KNOW exactly what is on that circuit.  That way I KNOW I'm not overloading any OEM circuit.

 

Not all OEM harnesses are still in the OEM configuration.  My first donor (RIP Kermit) had some type of elaborate of alarm system wired in at some point, and then someone else removed it and returned the harness to a stock-ish configuration.  My second donor (long live Animal!) also had a simple alarm system wired in---which was much easier to return to stock.  My point being, you can never be 100% sure what's been done to the harness unless you trace out ever wire, or buy a new one. 

[Todd Green]

If you have data, log your car voltage.  My car kept dropping off as races went on.  Alternator tested just fine in the garage.  Finally logged my voltage and sure enough every lap it'd keep dropping more and more.  I was also made aware of someone who had the opposite problem of the alternator putting out too much voltage when it got hot.

 

WRT to the upper rear guide pins we've been shearing them lately.  Threads are still in the caliper bracket loctited.  Haven't had time to figure out why.  Well I'm sure crashing curbs is the major reason, but I do that in my other car and it has no issues.  However it has Xidas and the car with issues has  a set of some Chinese eBay crapola coilovers on it.  It's also oversteering madly on the corner where the pins keep sheering.  Aligns just fine.  Going to pull the shock and test this weekend.

 

Thanks for starting the thread and sharing Frank.  Great idea.  Thanks for sharing your wealth of wisdom as well Dave!

[Tom Scheifler]

Great stuff. Thanks.

[EMatoy]

Is it common in a crash for the engine to crush the evap canister? On Saturday mine was smashed and this allowed all of the gasoline vapors and any potential liquid inside to escape. Had there been an ignition source this would not have been good. Would it be good to allow this to be eliminated?

This was caused by both motor mounts failing.

[FTodaro]

Is it common in a crash for the engine to crush the evap canister? On Saturday mine was smashed and this allowed all of the gasoline vapors and any potential liquid inside to escape. Had there been an ignition source this would not have been good. Would it be good to allow this to be eliminated?

This was caused by both motor mounts failing.

I have had a two big ones. never had that issue, although I do have fire suppression system with an outlet pointing at both sides of the motor. I would think you can relocate it if its for safety.

[Rob Burgoon]

I have had a two big ones. never had that issue, although I do have fire suppression system with an outlet pointing at both sides of the motor. I would think you can relocate it if its for safety.

 

 

 

I don't think you can relocate it for any reason.

[EMatoy]

I don't think you can relocate it for any reason.

I don't think so either. Was just asking if it a common failure. If it is then might be worth asking for a change. Is the location on the 1.8 and 99 different? My transmission was also cracked - so it might not have been a common wreck.

[Jim Drago]

Is it common in a crash for the engine to crush the evap canister? On Saturday mine was smashed and this allowed all of the gasoline vapors and any potential liquid inside to escape. Had there been an ignition source this would not have been good. Would it be good to allow this to be eliminated?

This was caused by both motor mounts failing.

It is not common imo and I see quite a few

[davew]

Rare for both mounts to break. Usually only 1 breaks and you dent the hood with throttle body or valve cover/lift hook

[EMatoy]

Rare for both mounts to break. Usually only 1 breaks and you dent the hood with throttle body or valve cover/lift hook

I must be special- when the lift hook and throttle body dented the hood it stuck almost wide open. All while the transmission was stuck in gear. Good thing we have a kill switch.

[Brandon]

Double-check your quick-release (QR) on your steering column too.

My first year racing I managed to have my welded-on QR sheer off the column due to a front-end angled impact.

 

That wasn't a fun ride.

[Danica Davison]

How often is everyone replacing hubs, bearings, ball joints?  I have heard from a few that every 20-24 hours is a good time to replace everything. Is that pretty much the general consensus with other shops or is it shorter/longer?