type of bolts used on a Mk2 fuel sender

[Jim Burrill]

Hi folks,'
In the process of opening up two original gas tanks on a Mk2. Luckily, they are sound and no rust through.

There is an AMAZING amount of crap in the tanks though so I intend to take them to a tank shop to be opened, cleaned, and sealed with Red-Kote.

In taking the fuel level sending units and the pickup tubes out, I had some screw casualties. snapped the heads, Some I have been able to grab and remove after the unit was removed, but I still need to drill out a couple and retap.

Question is what thread is supposed to be there? SAE? or BA?

Maybe the bigger question is a rule of thumb for what used BS threads and when did they keep the SAE?

I had generally assumed that engine and tranny parts were SAE and everything else was BSF/BSW or BA.

[Stew Robertson]

Hi Jim
I have always used 10/32 on the sender units
and have never had a problem but I have never really checked them either
I have probably done 20 plus tanks
Just center punch and use a small center drill then drill number 21 drill
(real careful )
Lots of Luck

[Lynn Eades]

If I have read the parts book book correctly (1941 MkI*book), they should be 2BA.
Although the MkII* is later, I think they would have stuck with the same threads. I don't actually know.
The following might help?
2BA is not the same as 10-32 but it is sort of close.
2BA is about 0.182 dia. (these are actual measurements on screws, not from a reference book)
10-32 is about 0.189 dia.
Over about 4 threads one will NEARLY lay into the other
Reality is they don't fit and I can imagine that what probably happens is that they go tight in the thread before the head takes up any real clamping load.(this will depend on how good a condition the thread is in)
If you can't locate the 2BA screws then maybe tapping to 10-32 is an answer.
Keep in mind that the screws go into a blind hole in most tanks, so a plug (bottom) tap is in order.
The holes are blind because the mounting ring is welded to the top of the tank after the ring is made.

[brengunman]

My Illustrated Parts Catalogue, FUC-03, Carrier Universal MkI* and MkII* 1941-4 by Ford Canada page 199 and illustration no. 38 shows under Gauge - tank unit:

P/N 27068 S2, Screw - #10-32 x 5/8" round head, quantity 6 on the Welsh Guard Models only.

It also has an obscure note under the heading "Interchangeable Proprietary or M.T. Part Number" NA/AN44222.

George

[Lynn Eades]

And on page 204 it says it again for the fuel sender screws,10-32, but then it also says for the "Cap and tube outlet", Screw # 2BA x 3/8 round head qty 4.

Isn't that Irish, to have two different, but visibly indistinguishable standards melded together in one fuel tank.

How stupid of me to think they would be the same!

[Stew Robertson]

It must of been engineered by two different engineers