Hey guys,... got the trailing arms out (finally)! Now the big problem is that I have to put them back in. I went to my local Tractor Supply store and bought a set of Grade 8 3/8-5 Bolts to use to reinstall the trailing arms. Then I realized that the old bolts had holes where cotter pins went through to protect the nut from coming off. I can see this as potentially being a problem. I was thinking Lock-tite, and then I thought a little harder and didn't feel comfortable putting my life in the hands of lock-tite. The bolts themselves are $40 for both from Zip Products and on top of that I would have to wait another week to get them! I paid $2 for the ones I have. Any ideas, or do I need to buy the set from Zip? (I was thinking of drilling a hole through the end of the bolt and sliding a pin through) Just want to get your thoughts???

Dan

 

Use what you have and drill holes for the cotter pins. The factory bolts were only grade 5 and alot of the ones you will buy from parts houses will be grade 5 also with the exception of VB&P and Vansteele.

 

Yep Drillem

 

The bolts I just got from ecklers were $15 for both. I'd try to drill a hole in the ones you already have though, worst case you mess up a $2 bolt

 

Thread the nut on before you drill and then back it off to clean up the threads. Use a castle nut and use one of the slots as a guard for the drillling the hole.

 

 

You had better have a good drill bit and a drill press. Have you ever tried to drill a grade 8 bolt in the threads. It is no picnic. If you can do this they should work fine.

 

Are you sure you have the correct diameter bolt ?? If I recall, they should be 7/16 or 1/2inch.

 

Nylock Nuts...no cotter pin required.

 

Daaah...pushed the wrong button...edit instead of quote....

Anyhoooo...those nuts will work

 

You sure about that?

 

If you're going to drill the bolts, better use a drill press, a hand drill you're wasting your time. If you purchased grade 5 bolts, think twice about using them. You should use Grade 8 an drilling Grade 8 is no picnic.

 

Try xxxxx They have a grade 8 bolt kit for $10. If you spend $20 or more shipping is free. I ordered several parts from them and they are a quality organization to deal with.

Edit: C'mon now, you know the rules...no links to vendors that compete with forum supporting vendors...IM or email is what you want to do..GD

 

The corvette resto shop that rebuilt my vette before I purchased it used a regular bolt and nut. No cotter pin or nyloc nut. And this was a vette resto shop. Cheap bastards they are. I purchased a set of stainless shims and bolts of ebay for around $35.00. VB&P sells a complete kit. Trust me you will want the stainless steel shims too.

 

Yes, the trailing arm bolts are grade 5, which is often a better choice for dynamically stressed susp. fasteners.

 

I used the correct bolt for my rebuild. The grade 8 bolt will more than meet the requirement. Is the shoulder the correct length? If it is then use the bolts you have, if they are the right diameter, and use a self locking nut that has the metal type locking mechanism; the nylon type could get hot enough to be rendered useless and allow the nuts to back off. Definately use stainless steel shims and coat the bolts with anti sieze and you should be good to go!
Bernie

 

unfortunately I am sure, unless of course the 3 dashes on the head of the original bolts is just meant to fool us.

 

unfortunately?

 

When you take a stock trailing arm bolt and push it through the frame, you will see that the "shank" portion of the bolt; i.e the unthreaded part of the bolt, mates to the frame hole. The threaded parts of the factory bolt appear only when the bolt is pushed entirely through the frame. Then, of course, the threads only accomodate the castle nut that is added to hold the bolt in place. The stock trailing arm bolt really functions as a pin, not a bolt.

However...if you buy repro bolts, you will see that the end of the bolt is extensively threaded. When you push the repro bolts into the frame, the threaded part of the bolt will contact the frame. (The outside part of the frame.) I think this is really a problem. The entire acceleration thrust of the rear end axles is transmitted to this bolt to accelerate the body of the car. If part of the bolt contacting the frame consists of the relatively sharp edges of bolt threads, I think this will dig into the frame and chew the frame hole out.

..........Where can you get a stock trailing arm bolts??? The FIRST place to look is to remove the two bolts that mount the differential torque bracket to the differential. These are the same bolts used in the trailing arms. They will most likely be in much better condition than the trailing arm bolts themselves. These are the bolts I used on my 68 rebuild. For the replacement bolts for the diff bracket, I bought some long grade 8 bolts and just cut them down in length. One reason, you just don't want to try to cut down a grade 8 bolt for the trailing arm attach bolts, is that you won't be able to duplicate the little short knib on the trailing arm bolt that makes it easier to push through, and grab on the other end with a pair of extra long nose needle pliers.

...............And finally. someone was selling a really nice differential torque bracket on ebay. The price was very cheap. But the bracket included the bolts!! I bid and won. I ended up with two bolts, the same as the stock trailing arm bolts, in almost NOS condition. Really a lucky shot in the dark. Often, I find my ebay purchases are of poor quality due to unethical sellers. I've bought a lot of people's trash can stuffings on ebay.

 

You need to be more careful, then. I've never gotten less than what I expected from an eBay auction.