How NOT to replace your rear limit straps

[jburning17]

I thought that replacing the front limit cables went so well that I would move ahead with the rear limit straps and bump stops.

Well,....

Things didn't go as well this time.

I thought that I would post up my follies anyway, just so that other people would see my foolishness and not waste their time. At least I am hoping that there is some benefit in that.

So, here goes again...

[jburning17]

The car came with an interesting homemade set of limit straps. The most interesting part is that they were made of metal. Actually, they were sort of a metal strap with the proper holes punched into it, then bent around on itself.

One of them was actually broken. From the looks of it, the metal straps were no match for the axle springs--they broke it like it was nothing.

The bumpstops were garbage as well, with one of them missing a big chunk of rubber.

Check it out...a bunch of junk.

[jburning17]

I ordered a new set of bump stops from Centerline. The catalog show that they carry the proper curved base stops, but the guy on the phone told me that they are no longer available.

As has been described in other posts, it is possible to bend the straight bump stops to get the proper curve. I read that the bases bent into a nice, even curve for other people, but that wasn't the case for me.

I put one end of the base in the vise and gave them a whack with the mallet. Mistake #1. The bent at an angle where they met the vice. I monkeyed around with trying to get the even bent, but never got that to work. So, I ended up just matching the bend on both sides of the base. It looked like they would be close enough to bolt up, so I went with it.

Below is a picture of my bent bump stop next to a borrowed, original bump stop.

[jburning17]

I bought a set of new limit straps from Alfabb member Targa Florio in Australia (which look great, BTW), but I didn't have the proper hardware to joint the two ends of the straps.

I checked around, and it looked like I would have to kick in about $50+ to get a set of repro's here from England. I thought to myself, "I can make my own for cheap...why not do that?!" Then I thought, "I can make them out of stainless while I am at it. I can make a few sets of them just as easily as one set, too!"

That is where things really went down hill!

I went over to a friends place to take some measurements off of his car and got to work.

I measured everything out with a caliper, and then finally settled on a close size that would use standard bar stock from the metal supply shop.

I ended up using 2.5" X .125" 304 stainless bar stock cut into 1.75" lengths.

As it turned out, the metal was not that expensive, but paying the guy to work the shear was REALLY expensive. Stupid me, I paid the money anyway.

Here is a picture of the raw stainless coupons.

[jburning17]

The coupons had quite a lip on them, so I had to knock those down.

I used a bench grinder and a bench-mounted belt sander to get a smoother edge on all the coupons. That was time consuming, but I had a good time with it, so no worries yet.

I then used layout die on a couple of the coupons and scratched out the center of the four holes that would be needed. With that looking good, I made a paper template to help locate the holes more quickly for the remainder of the coupons. I used a center punch to mark the holes on several coupons as a first-run test.

[jburning17]

I took my first set of coupons over to a friends house to use his drill press. I thought that I was all set for battle. I brought the drill press vice and real machining cutting oil, too.

I was using a super high-grade drill bit for the task. I think that it is a cobalt coated bit, or something exotic like that. Anyway, I chucked that up and went to work on the first hole. I had to re-lube it about half way through the hole, but no big deal.

Well, the bit abrubtly stopped cutting on the 5th hole. I knew things weren't going in my favor when I saw LIGHT coming from the hole.

Drill bit was toast!

I used the bench grinder to put a new edge on it the best that I could, but you can never do a good job on those things free-hand you know. I got a couple more holes out of it before it seamed hopeless.

As luck would have it, I had bought two of those drill bits back in the day. So, out came the second one.

This time, my friend sprayed a pretty steady stream of WD-40 on the hole while I drilled. I was also sure to do plenty of pecking at the hole. This worked much better. The downside was that there was WD-40 running down to my elbows, a puddle of it on the bench and a bigger one on the floor.

I finally got 6 coupons done. I then whipped out my high grade counter sink to take the lip off of the holes. Yeah right. That thing chattered like crazy. I finally found that my larges high speed steel bit on the lowest speed would break the edge nicely.

Two hours later I had six coupons done. I made six because we found that two of them had holes that were a little off due to the dull bit. Small pilot holes are in order for later sets, for sure.

Mercifully, I didn't document this part in pictures. Suffice to say that all we could do is laugh by the time it was over. I know how to get it done better for the next ones, but it isn't going to be a piece of cake no matter what...

[jburning17]

Having come this far, I was deteremined to use stainless hardware to match.

I went down to the hardware store again, and picked up what I needed. I used M6 stainless bolts in the standard thread pitch. I know that Alfa tended to use fine thread hardware, but opted not to do that this time.

A complete set consists of 8 bolts, 16 cut flat washer, 8 star lock washer, and 8 nuts. $5+ Ouch.

At least they fit right when I got them home. Here are some pictures of the setup before installation...

[jburning17]

Aside from the standard Alfa bit where you need three elbows on each arm, have 9" finger, and be amidextrous, installation went without a hitch.

Here you go...

[jburning17]

Pay the money to the guy who know what he is doing! Send off you money to the guy in England, wait for it in the post, and put it on. You will be happier that way, and it is cheaper overall.

If you have to make your own, it can be done. I think that 1/8" is thicker than what is needed; .100" or 12 Ga should do the trick, if you ask me. Also, just be happy with regular carbon steel. You can work with it easier, and it will be cheaper. Paint it, and you will be fine. Plus, your friend won't have stories about your stupidity that they can pass on to your girlfriends and grandkids!

That's all folks. I hope that this helps steer people away from such foolishness in the future. Now what to do with these stainless coupons that I have?

[cstlhn]

Nice result! Stainles cen be tough stuff but worth the effort.

[Peter]

at least it looks awesome!

[jburning17]

Hi All,

After a little feedback, I guess that I need to make a little clarification.

The straps from Australia are terrific and fit right in. But, at least these straps didn't include the attaching hardware, and I didn't have any of my own. They are available from Alfa Stop in England, but I was put off by the price.

Stupid me, I decided to do it the even harder way!!!

Thanks for the feedback everybody!

Jon

[pathung]

Great story. We're now waiting for your write-up on a complete engine rebuild.

[alfazagato]

I too had the steel limit straps on my very early Spider with a very similar plastic sheathing! Was this normal?

[jburning17]

I am told the the metal limit straps that I took off of the car are original equipment on at least the early 750's. I haven't seen or heard of a source for replacements for those.

I'm just as happy with that after seeing how easily one of mine was snapped. I will keep the originals around though, for sake of completeness of the car.

J