Screw size

[69280sl]

One of the machine screws in my soft top framework has backed out and is lost. I want to replace it. It is apparently an 8 mm screw and I have tried 8-1.0 and 8-1.25 screws. They do not go in more than a couple of turns. Does anyone have a suggestion on what this screw might be? I don't want to force it and bugger things up.

Gus
68 280sl

[jameshoward]

It sounds more like you're using the wrong thread size than perhaps the wrong screw diameter. There are differences; e.g. American standard nuts and bolts (UNC - Unified Course Threads) have less threads per inch than machine nuts and bolts (UNF Unified Fine threads).   For example, given a 3/8" bolt, the UNC version has 16 threads per inch (TPI).  A machine style (or Standard) thread for 3/8 bolt has 24 threads per inch - (TPI). Perhaps check the bolt you're trying to use against an existing one on the other side and see if it fits.

JH

[rwmastel]

quote:Originally posted by 69280sl

One of the machine screws in my soft top framework has backed out and is lost.

Gus, pull the same one out from the other (unless your soft top will collapse!) and use it as a guide.  If you think it's something you can't get at a hardware store, then post a picture of it, and where it came from, and we'll help you out.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[69280sl]

Rodd and James, thanks for the response. I have no reason to believe it is anything but a metric screw and I tried the fine thd (1.0 pitch) and the coarser (1.25 pitch).

Like so many things on these cars, it a little bit hard to get at, so I did not try to pull the co-responding screw on the other side, but it looks like I will have to, to see exactly what I have.
Thanks

Gus
68 280sl

[jameshoward]

Great idea, Rodd! Well said  

[glennard]

Check out the other side for size- then get the same size tap and tap out the threads.  Raising and lowering might strain the bolt threads-depending which bolt it is.

[al_lieffring]

This afternoon I took my top frame apart and replaced two of the pivots where the frame folds at the top rear corner of the windows.

The bolts (one on each side) wher broken off, I had an assortment of top frame pivot bolts that I was able to aedapt to fit my top frame, I think they are for a 107 top though.

I looked at the EPC parts listings the 113 frames are not shown broken down into parts, but the 107s are. Dont know what the part numbers for the pivots are they were just some that I had in my box of goodies. I had to make some small modifications to the top frame by enlarging the outside of the bore with a countersink drill.

A 66 and a 68 have slightly different top frames but the 107 pivots still might be adaptable to fit a 280 top also.
 
 I ended up having to peel back the canvas from the frame to get to the components.

Where the studs were broken off I MIG welded a nut to the back side of the stud and when it cooled I was able to back the bolt out of the hole.

I then tapped out the hole from the back side, They are 8x1.0mm threads. and have a larger diameter (10mm) sholder where the frame pivots.
When installed at the factory the pivot bolts are punched from the back side to prevent them from backing out, so the original bolts need to be dressed with a thread file before being reinstalled.



Al Lieffring
66 230Sl
Jones'n for a new gas tank

[Naj ✝︎]

Hello, Gus,

Are these the right screws (the old one come off my frame as well and the threads were damaged)? The pitch is 1mm but the screw is shouldered.



If so, I'll have to find you the part # 113 984 1331 (+ flat washer 113 990 1040).

naj

68 280SL

[RBurg]

MB Dearler still can order the screw shown - the countersunk one (2 reg) age no long available.
Good luck

Ron - Minnesota
71 280SL Tobacco "O GIGI"
03 525 BMW BlACK/BLACk
97 E420 Silver Mist

[69280sl]

Yes Naj, thats the one. I'll contact the Classic Center with the p/n you provided and if they say it is available, I will order a couple.

Thanks all

Gus

68 280sl

[France]

Hi Guys,

On this note, perhaps someone knows what screws hold in the chrome surrounding the inside door locks--He Who Must Be Obeyed has misplaced a couple of mine in trying to cure the wobble in the window crank.  One thing leads to another...

Trice
1968 280SL US, signal red/bl leather, auto, kinder seat
Sarasota FL; Alsace France; Switzerland
Think of your Pagoda as a woman with a past...

[Naj ✝︎]

quote:Originally posted by France

Hi Guys,

On this note, perhaps someone knows what screws hold in the chrome surrounding the inside door locks--
Trice

try:

N 007981 003246 screw
N 000125 004319 washer

naj

68 280SL

[France]

Thanks, Naj!  I'll drop by the Karlsruhe dealership for these, finally.

Trice
1968 280SL US, signal red/bl leather, auto, kinder seat
Sarasota FL; Alsace France; Switzerland
Think of your Pagoda as a woman with a past...