Wednesday, November 10, 2010
It Snapped Clean Away - Replacing the Front Shocks On My Truck
Yesterday I decided to install new front shock absorbers on my rather elderly Ford truck. I've had the parts for a couple months, but decided I'd better get to it before Winter sets in.
Knowing the parts would be rusted, I sprayed them with WD-40 several times in the past week or two. This, in hopes some would penetrate and help the retaining nuts come loose when I removed them.
I started work on the passenger side. The nut on the top stud of the old shock was jammed on and wouldn't budge. Thinking I'd come back to it in a few minutes, I started work on the bottom stud. Within a minute or two,the bottom mounting nut came off all right - with the threaded end of the stud still stuck in it!! The rest of the stud was still attached to the truck and was holding the shock. [See above photo - bottom portion]I knew I was in trouble then - as the stud was a permanently attached part of the lower suspension arm. With the threaded portion broken off, there was no way to retain the bottom end of the new shock. After some proverbial head scratching, I went back in the house and got online to see how other folks handle this sort of problem. I quickly found out I was NOT alone - this problem is quite common. AND there is a reasonably inexpensive fix.
Fortunately, auto parts stores sell generic "Help" kits to replace broken shock mounting studs. Check places such as Autozone, NAPA, ... The new stud in the repair kit consists of a double-ended stud: the shock absorber mounts to the long, mostly smooth end; the short, slightly fatter threaded end goes into a hole in the frame or suspension member and mounts with a washer and nut. The old stud, of course, must be removed before the new one can be installed. Below I'll detail, in words and pictures, what I did.
New shock mounting stud repair kit - probably should get one for BOTH sides of the vehicle
hand-held "angle grinder" - preferably a 4.5" one. The wheel on a larger 5 or 6" one is too big and will be hitting stuff you don't want cut.
"Cut off" wheel and coarse grinding wheel for the grinder
an electric drill - preferably a 1/2" one
a set of drill bits - preferably titanium coated
A drill bit the right size for the new mounting stud in the repair kit you bought
Center punch and hammer
Here, in a nutshell, is what to do:
1) Use the angle grinder with "cut-off" wheel to remove the broken stud, cutting it off flush with the suspension or frame member it's attached to.
2) If necessary, use the angle grinder to cut through the top mounting stud on the shock absorber itself. That top stud is usually made of fairly mild steel, so one can cut partially through it and snap it off by pulling outward on the bottom end of the shock absorber. You may need to rock it back and forth a couple times, but it will break off with some effort. This is what I did, because the radius of the grinding wheel would have cut into stuff I didn't want damaged if I had gone clear through the stud. You will be working in tight quarters, so BE EXTREMELY CAREFUL to NOT cut the vehicle's coil spring or any other parts when using the grinder.
3) Use a center punch to mark dead center where the stud was.
4) Drill a hole where you made the punch mark. Start with a 1/8" drill and work up through your drill sizes to - in my case, a 1/2" hole - to accommodate the mounting stud. When drilling, coat the drill bit liberally with motor oil to help it cut.
5) On my vehicle, there was a 1/4" raised "shoulder" that was part of the old mounting stud - and was still on the lower suspension arm. I had to thin this down by 1/8" with the coarse wheel in the angle grinder so I could get the back mounting nut and washer fully threaded onto the new stud. Below is the picture of the hole drilled out and the shoulder ground down.
[Yes, I got the hole off center. Didn't start out that way, but I think the large drill bit "crept" out of the small pilot hole - I had to skip several drill sizes between my largest pilot drill and the final hole size. I also was drilling with a long bit at a really bad angle. At least there's enough shoulder metal remaining it shouldn't hurt anything. The rubber bushing on the new shock still has plenty of shoulder to bear against, so a washer wasn't necessary.]
6) Once the new stud is able to be nutted in place, you are ready to install the new shock. Below is the picture of the new shock installed.
I got BOTH the shocks replaced within an hour and a half. The driver's side lower mounting stud did NOT break when I removed the nut, so all I had to do there is cut the top mounting stud on the shock and remove it as described in step 2 above.
Frankly, I expected the worst, given what immediately happened when I started the job. Thus I bought TWO repair kits so if the other one broke I'd have the parts right there.
My local auto supply store only had one lower shock mount repair kit in stock, but they were able to locate one in a neighboring area and get it held for me so I could drive over and get it.
I'm keeping my extra repair kit around in case I need it in the future.
I am eternally grateful to my neighbor for the use of his 4.5" angle grinder and 1/2" electric hand drill, as well as to several good folks on the Internet whose posts helped me deal with the problem at hand.