Cracked shock towers

[Stock 87 12]

Anyone had any luck with repairing shock towers?

 

It appears that My 69 was cobbled together after what looks like the right front hit something. At this point I'm sure the right side shock tower was replaced. The repair isn't perfect, it's "good enough" for a driver though.

 

While replacing the aprons on the passenger side I noticed the shock tower is cracked. Upon further inspection, I found the drivers side to be cracked and repaired too. Problem is the previous owner wasn't much of a welder. To put it politely they are butchered.

 

I know that over the years people have been adding plates to the towers. Some of them from the frame rail up to the inner side of the tower. Or plates bent around the inside of the tower at the same level as the UCA. This could have been a Shelby mod, I don't know.

 

My question is.. Has anyone ever installed the latter type AFTER your towers have cracked with good results? I'm sure they would help out before the cracking occurred but what about after? My biggest concern is the Heat affected zone (HAZ) Ive seen a lot of thinner materials crack just outside of the weld on/in similar situations.

Should I just replace both towers and be done with it?

[fvike 173]

I would replace them. Or else I would be thinking of those cracks every time I go hard into a corner.

[Ridge Runner 1,113]

I would replace them both ,they are not that difficult to do .Take a lot of measurements first and do one side at a time so you have a reference point .

[70fastbak 16]

+1 on replacing.

If you already have your aprons out then its a pretty easy task.

Use your export brace to locate the towers when welding them back in.

[1969_Mach1 333]

Also, replace them. I had a shock tower reinforcement kit welded onto mine as well. These days I've noticed NPD sells the kit. It is several plates (I think 14) of different shapes that weld into several locations of the lower part of the shock towers to strengthen them.

[Rsanter 152]

Shock towers can easily be fixed if their not that bad currently.

If they are really bad then it's almost easier to replace than repair

 

Bob

[1969_Mach1 333]

If they are butchered. I would not repair them. People often repair small cracks. The cracks you are seeing are fatigue failures. By now the metal has become more brittle so will tend to keep cracking even if repairs are made. Repair or replace, I would definitely install the shock tower reinforcement kit.

[maxum96 32]

Do yourself a favor and replace them. It's probably weakened from being bent. I found my left shock tower and apron butchered after a hack repair job sometime in the past. I ended up replacing everything from the firewall forward. It's so nice have new straight sheetmetal to work with.

[DarkBuddha 107]

You may be able to fix them up with a bit of hammering and welding (and frame shop time?), but given that replacement shock towers are now a click away and not terribly expensive, I vote for replacing them. I definitely also agree with adding the readily available reinforcement kit since it's also just a click away. It won't be cheap, but you won't ever have to worry about it again.

 

BTW, alternatively, if you don't care about originality, or are planning on upgrading the suspension and stuff, and you're going to cut out the towers anyway, maybe look into one of the bolt-in front suspension kits that include rack&pinion and arms and brake upgrades, etc.

 

One last thing, the shock tower reinforcement kit that everyone sells is the same as is specified in the Boss 302 racing chassis preparation manual. Using it as a guide, I made my own abreviated version with some steel plate from Lowes, a cut-off wheel, a claw hammer, and a bench vise. Not easy, but very CHEAP and totally functional. You can find pics here: http://www.1969stang.com/mustang/forum/showpost.php?p=129946&postcount=28

[Stock 87 12]

Do yourself a favor and replace them. It's probably weakened from being bent. I found my left shock tower and apron butchered after a hack repair job sometime in the past. I ended up replacing everything from the firewall forward. It's so nice have new straight sheetmetal to work with.

 

Nothing is bent. The passenger tower was replaced. Just not what I'd consider a satisfactory installation. There are weld beads that I'm 100% sure are cold due to the bead profile. The welds securing the tower aren't in the factory locations. 1/4" plate was installed at the apron tower overlap, should have seen this hack job. Just has an overall appearance of being butchered.

 

I have already corrected the overlaps that usually rot out and was hoping to not replace the towers. If I do replace them it will be two frame rails, the rockers, trunk transitions pan and a roof left from the original car.

[Stock 87 12]

You may be able to fix them up with a bit of hammering and welding (and frame shop time?), but given that replacement shock towers are now a click away and not terribly expensive, I vote for replacing them. I definitely also agree with adding the readily available reinforcement kit since it's also just a click away. It won't be cheap, but you won't ever have to worry about it again.

 

BTW, alternatively, if you don't care about originality, or are planning on upgrading the suspension and stuff, and you're going to cut out the towers anyway, maybe look into one of the bolt-in front suspension kits that include rack&pinion and arms and brake upgrades, etc.

 

One last thing, the shock tower reinforcement kit that everyone sells is the same as is specified in the Boss 302 racing chassis preparation manual. Using it as a guide, I made my own abreviated version with some steel plate from Lowes, a cut-off wheel, a claw hammer, and a bench vise. Not easy, but very CHEAP and totally functional. You can find pics here: http://www.1969stang.com/mustang/forum/showpost.php?p=129946&postcount=28

 

Mine are cracked just above the gussets you installed. Where the tower goes from somewhat plumb to tapered.

Edited November 28, 2014 by Stock 87
Add pic

[latoracing 256]

I made up some beef-up plates for my shock towers from simple cardboard templates. The "big block" reinforcements might be a repair to help with the cracked areas, if I am interpreting correctly. I was more concerned with the tower to frame rail connection, as I will probably push this car a "little" hard, once it is done. If you have any fabrication skills at all, these reinforcements can be made out of a few pieces of 11ga + 7ga CRS on the cheap.

 

 

 

I would grind the PO's welds down, properly re-weld the areas, and install the reinforcements. If you find that the tower to frame rail attachment area is corroded, which it probably is, then replacement might be the best course of action. Post some pics if you get a chance.

[DarkBuddha 107]

Mine are cracked just above the gussets you installed. Where the tower goes from somewhat plumb to tapered.

 

Yeah... I'd say just replace them entirely. It'll a bit more involved, but do it once, do it right.

[Stock 87 12]

 

 

I would grind the PO's welds down, properly re-weld the areas, and install the reinforcements. If you find that the tower to frame rail attachment area is corroded, which it probably is, then replacement might be the best course of action. Post some pics if you get a chance.

 

Nice work,

My issue is... I'd be creating a stress riser exactly where mine is cracked. Just above the outside plates. A MC bar that connects at the UCA mounting point is the only thing that I think will help avoid this. Thoughts?

[Ridge Runner 1,113]

There are a lot of people out there that have no welding skills at all ,can't tell you how many times i have just knocked a piece off with a hammer that some one "welded On".

If the part looks questionable , replace it .Sure wouldn't want a tower breaking off while driving .If you do replace the towers go with the 428 towers ,they are much stronger .Or add the 428 brackets to the new towers .I added the 428 brackets to my 69 Mach.

[Stock 87 12]

here you can see the weld on the drivers side at three o'clock.

[1969_Mach1 333]

I see from the picture your in the middle of a restoration. I'd replace the cracked shock tower and still install a reinforcement kit on both. It reinforces similar to what latoracing's pictures show. At that stage of restoration, even if you have to invest in a MIG or TIG welder its still best to replace. Back in the early 1980's my older brother's Mach 1 cracked both shock towers. The cracks were welded and about 6 months later other fatigue cracks started occurring.

[jagbucket 10]

If you want to repair a common practice is to drill each end of a crack a then weld, this makes sure the ends of the crack are wrapped to stop growing

[Hoover 12]

If you want to repair a common practice is to drill each end of a crack a then weld, this makes sure the ends of the crack are wrapped to stop growing

 

Stop drilling, is the name of the above method. An absolute must, in doing any crack repairs. You are probably better off remove and replacing the tower. If nothing else, for peace of mind. Anything structural, I would use a qualified welder so it won't happen again.

[Stock 87 12]

Stop drilling, is the name of the above method. An absolute must, in doing any crack repairs. You are probably better off remove and replacing the tower. If nothing else, for peace of mind. Anything structural, I would use a qualified welder so it won't happen again.

 

 

I'm not overly concerned about the welding portion of the repair. I have certs in multiple welding disciplines. That is why I'm worried about burning in plates haphazardly around the bases of the towers. Experience tells me that the HAZ will tend to crack. Not the weld, the area just outside of it will end up splitting. I can scab shit all over these things thinking I'm making them stronger. The reality is unless I tie them together at the stress point (UCA) it's going to happen again, new towers or not.

[latoracing 256]

I'm not overly concerned about the welding portion of the repair. I have certs in multiple welding disciplines. That is why I'm worried about burning in plates haphazardly around the bases of the towers. Experience tells me that the HAZ will tend to crack. Not the weld, the area just outside of it will end up splitting. I can scab shit all over these things thinking I'm making them stronger. The reality is unless I tie them together at the stress point (UCA) it's going to happen again, new towers or not.

 

Most of the cracks seen in these shock towers are caused by frozen, or un-serviced UCA pivot shafts. The vertical twisting along with the UCA load bearing configuration leads to these cracks. That and these cars' service life was not meant to last the 40+ years that they have been on the road. The "factory" style beef-up plates were put in place due to Ford's change in design. How many 65-68 shock towers crack, not as many as the 69-70 due to the "hump", right where your towers have cracked. New or old towers, driven enough, they will crack again.

 

Lowering the UCA attachment point would help with the direct load path to the effected week point, (Arning drop) and changing the load bearing arm to the LCA with a coil over setup might help elevate some of the stresses seen around the UCA attachment point.

 

As far as HAZ, the metal used 40+ years ago has no where near the strength of the current metal alloys we have today. I certain the imported parts that we use to reconstruct our cars are sometimes not quite what they should be, but the overall alloying of the materials used is superior. I totally agree with cracks forming at the edge of a weld, and more times than not, is where the joint will fail. Will all the @#$! I personally installed on my towers in order to help with the known cracking issues, along with extra bracing installed on the vehicle help, I plan to find out. Will they crack, probably. Was it fun to do, Definitely. This is just a hobby, and these are old cars that I personally enjoy to work on, regardless of the little quirks. Can we improve on Ford's design, by all means.

 

Whether or not you patch, repair, or replace your towers will ultimately be up to you. Your goals with the vehicle might be different than other's. Which ever route you take with your project, best of luck.

 

Mike

[phlegm 10]

Back in 2008 I had the same dilemma.. I don't drive a show queen or a track star, just a plain old daily driver. I kind of like the visible welds, like scars of the cars past. These repairs have worked flawlessly for the last 6 years, no reoccurrence.

 

Cracks were ground off, no drilled ends. Welded from both inside and out. Then we used a port-a-power to press the stock reinforcement plates against the shock tower, then fully welded those plates to the shock tower. Ground them down, primed and painted..

 

Full Thread

Mustang Upgrades this week (Month) -- FordSix.com

 

This winter I am revisiting my entire front end to install Boss302 style bracing and paint the engine bay to match the exterior color.