Frame rail bolt size??

[TNan]

I'm working on my 72 02' and I was hoping if someone who recently received their new frame rail from W&N could tell me if the original bolts that ties the NEW frame rail to the original subframe fits the same?  I'm finding my original bolts will not go into the frame rail smoothly - I don't want to force it as I'm afraid to damage the inner thread. (See photo).  Can someone verify which size bolts fits.

[Mike A]

Smoothly? Or not at all? It may be just some corrosion or a burr. If you’re sure your bolts correct that’s probably the issue. I’m not near the garage to confirm the size , but when  you know for sure, buy a tap and clean them up. I shouldn’t guess , but I’m thinking they were 12mm and maybe fine thread 1.5 ...??

Edited October 13, 2019 by Mike A

[02Les]

If it's #4 & #7 on the pics below, then #4 is M10 x 30 and #7 is M10 x 50.

 

[xr4tic]

Get a thread chaser kit, works great for cleaning up holes and bolts and doesn't remove as much material as a tap set would.

 

Your original bolts probably have some rust on them and the new pieces probably have paint on the threads.

 

This is the kit I got, picked it up from a local auto parts store, I've used it a ton in my rebuild, just a little oil and it cleans them right up

https://www.amazon.com/Lang-Tools-2584-15-Piece-Restorer/dp/B000XJ48V0/ref=sr_1_9

 

[Get2theBimmah]

Yes, those are M10's.  As it's already been mentioned, chase the threads and you'll be good to go. 

[tech71]

Looked at the pic at highest magnification I could manage. Clean up that (or better yet replace) old bolt as well, some kind of crud in the threads.

[TNan]

On 10/12/2019 at 8:19 PM, 02Les said:

If it's #4 & #7 on the pics below, then #4 is M10 x 30 and #7 is M10 x 50.

 

24 minutes ago, Get2theBimmah said:

Yes, those are M10's.  As it's already been mentioned, chase the threads and you'll be good to go. 

 

4 minutes ago, tech71 said:

Looked at the pic at highest magnification I could manage. Clean up that (or better yet replace) old bolt as well, some kind of crud in the threads.

 Thanks everyone for your replies... however, I have an UPDATE!

 

1. I purchased NEW M10x30 bolts to replace my 'sludge' original bolt and the new ones won't even make a full rotation. In other words, the issue wasn't the sludge on the bolt M10's simply didn't fit.

 

2. A buddy used his tap and die kit to get the exact measurement of the bolt to be used and he said it was not an M10 bolt (as what the original bolt was) - but instead he concluded it was an imperial US Standard 3/8"x1 1/4" (with a 16 thread).  This boggled my mind.

 

3. So I raced over to the hardware store and got me a 3/8" x 1 1/4" (with a 16 thread).  And surprisingly, it fit ONLY 2 of the 3 holes perfectly.  Now I'm struggling to understand how the 3rd hole is not the same as the other two holes.  I tried to apply some force to that third hole but no matter what that 3/8" bolt will not go. 

 

Again, if anyone who purchased a W&N frame rail for their 02, can you please verify the proper bolt size to all three holes. I understand the original one is M10.  I'm wondering if I happened to get a manufactured defect.

 

 

[halboyles]

Contact W&N about this issue.  They need to be aware of it and they should make it right.

[02Les]

Yeah, what Hal said.

Can't imagine Germans using anything but metric, but, where did W & N get it made?????

[TNan]

18 minutes ago, halboyles said:

Contact W&N about this issue.  They need to be aware of it and they should make it right.

I just sent W&N a detailed email.... we shall wait and see.

[TNan]

15 minutes ago, 02Les said:

Yeah, what Hal said.

Can't imagine Germans using anything but metric, but, where did W & N get it made?????

You're right if it was indeed manufactured in Germany - but I believe it was built in Taiwan.

[Get2theBimmah]

Well that throws a monkey wrench into the equation.  Report back when they respond.  Preferably you'd want matching hardware on mirrored pieces to make life easier for servicing in the future, but if they're going to provide different sized pieces, the least they can do is note that.  I'd say supply hardware too, but chances are they would supply a lesser grade hardware than you'll get.  

 

Don't forget to make a note in a manual or service book in that section so you later on or the next guy/family members knows too. 

[VWJake]

I’m imagining that the odd sized hardware and larger top sheet (among other variances) is what will keep the manufacturer out of trouble with BMW. Exact copy parts of a licensed part... they end up in a courtroom or at the very least they get a cease and desist letter. Ill fitting/incorrect hardware nets them a raised eyebrow... 

 

just a thought. I’ll be interested to hear their response as well. 

[TNan]

23 minutes ago, Get2theBimmah said:

Well that throws a monkey wrench into the equation.  Report back when they respond.  Preferably you'd want matching hardware on mirrored pieces to make life easier for servicing in the future, but if they're going to provide different sized pieces, the least they can do is note that.  I'd say supply hardware too, but chances are they would supply a lesser grade hardware than you'll get.  

 

Don't forget to make a note in a manual or service book in that section so you later on or the next guy/family members knows too. 

 

14 minutes ago, VWJake said:

I’m imagining that the odd sized hardware and larger top sheet (among other variances) is what will keep the manufacturer out of trouble with BMW. Exact copy parts of a licensed part... they end up in a courtroom or at the very least they get a cease and desist letter. Ill fitting/incorrect hardware nets them a raised eyebrow... 

 

just a thought. I’ll be interested to hear their response as well. 

 

W&N just responded and they simply said “The pattern is an M10”

 

What they neglected to tell me despite asking the question “Can please verify the bolt size/pattern with s frame rail you are currently selling and not just respond by telling me the spec size which is supposed to be used. Because i can guarantee an M10 will definitely not go in - so I would like to know if this is a manufacturer defect which can cause a problem in the 02 world”

 

I’ll keep everyone posted. I just sent a follow-up email.

[Son of Marty]

I think your problem is the bolt your copying is the wrong thread pitch why not take the rail down to the hardware store and start trying bolts until you get one that you can put 4 or more turns by hand with no binding and your set.