Extended length bolts for front beams with caster shims

Does any know about how much longer these extended length bolts are over stock? Reason I ask is while looking around under the chassis, I noticed the bolt ends did not protude past the welded on "nuts" on the back side of both upper and lower beams. I measured how far short the bolt end was from the being flush with the "nut". I was shocked to find all four bolts were over an inch short of being flush with the end of the threaded fitting. Is this normal? Where I was brought up a bolt always extends past the threads that secure it. This vehicle has over 6000 miles of fairly hard cornering on it. It was assembled by others and I know hardly anything about stock VWs. The manual is not a help. Opinions?
If these bolts are to be replaced, can it be done one at a time on a fully assembled and running vehicle without screwing up the front end? Thanks for any help.

Yes, the bolts can be replaced one at a time, no worries. Contact John Connelly at aircooled.net to order the longer replacement bolts or perhaps he will give you their size/length and you can purchase them locally at a fastener supply store. The bolts hold the axle beam securely against the frame head.

I'm no whiz bang on these particular bolts, but it's always been my understanding that bolt/faastner strength does not increase once the threaded portion of the bolt in the fastner equals the diameter of the bolt. Might check to see how much bolt is threaded in there.

Bill, David,
I have to do this work too, since caster shims will have to be added to my car. My plan was to take one out and to a hardware store nearby that has a variety of metric bolts, and purchase the two lower ones I'll need.
I would seriously replace the bolts if they don't extend past the fasterner; that's free clamping force not being used. There are particular formulas for calculating thread engagement requirements for specific applications (if you're interested) but 'rule of thumb' is 1-1/2 x bolt dia. = thread engagement. It's very rough, and assumes a variety of things, like the bolt an nut being made of the same material, and a general class 2 thread tolerances. The purpose is to engage enough thread so that the stress area of the threads is greater than the stress area of the bolt (bolt fails before threads). Bottom line; fill the nut! It's cheap, and will give you the security to increase the sfinkter factor around corners...(how DO you spell that word!?)
-Tim

No bolt expert here either but if you do go the hardware store route be sure you get a bolt of sufficient strength (grade 8 or better?). While I have not done any testing, I assume that those bolts are subject to some significant stress.

Jeff
A good assumption, but I'd rather not test it! I'm looking at putting a second set of caster shims in place, as the first ones don't do the job (another subject). My bolts also did not extend through the 'nuts' so I'll also replace all four, with the same grade of bolt. Most of the stuff I've worked on on the car has been made of very soft metal. These bolts might be different, as I forgot to check the grade indicator on the heads, but the nuts are soft. 1/2" bolts are good to ~12,000lbf. in tension around grade 3, depending on your specific reference literature (lots of opinions here), so I'm guessing some over-engineering won't hurt. If I quickly and inadvertantly convert the speedster to a two wheeler, I'll be sure and let everyone know!
-Tim