trans support bolt thread?

PostPost by: tedtaylor » Wed Dec 06, 2017 1:11 am

S3 Elan transmission rear support bracket mounts to chassis frame with 4 bolts, but I can't figure out what thread size. They are NOT fine, but a course thread. I think they are neither metric or SAE, possibly "wentworth"? or whatever???
I ended up using 5/16 course thread and forcing it to work.
any direction here fellas?
thanks
TED
"Driving a Lotus is a triumph of bravery over intelligence." Stirling Moss
"TaylorMadeClassicCars" on WWW and Facebook
tedtaylor
Fourth Gear
Fourth Gear
 
Posts: 608
Joined: 09 Dec 2012

PostPost by: shaun » Wed Dec 06, 2017 5:08 am

Mine are 5/16 unf
shaun
Third Gear
Third Gear
 
Posts: 227
Joined: 30 Nov 2008

PostPost by: elanman999 » Wed Dec 06, 2017 10:22 am

As Shaun says.
elanman999
Third Gear
Third Gear
 
Posts: 487
Joined: 12 Nov 2005

PostPost by: tedtaylor » Wed Dec 06, 2017 12:50 pm

shaun wrote:Mine are 5/16 unf

the receiving threads look UNC to me, so they are now 5/16 unc.
oh well.... :oops:
TED
"Driving a Lotus is a triumph of bravery over intelligence." Stirling Moss
"TaylorMadeClassicCars" on WWW and Facebook
tedtaylor
Fourth Gear
Fourth Gear
 
Posts: 608
Joined: 09 Dec 2012

PostPost by: elancoupe » Wed Dec 06, 2017 2:34 pm

Ted, just keep in mind that you may not be the first person to work on that support. Thus the term DPO.
Mike
elancoupe
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1055
Joined: 11 Sep 2003

PostPost by: CBUEB1771 » Wed Dec 06, 2017 5:59 pm

tedtaylor wrote:the receiving threads look UNC to me, so they are now 5/16 unc.
oh well.... :oops:


The weld nuts on the chassis certainly started life as 5/16-24. If they have "evolved" to 5/16-18 you may want to helicoil them back to original configuration. They wan't hold a bolt, either UNF or UNC, very securely as they are.
Last edited by CBUEB1771 on Wed Dec 06, 2017 9:08 pm, edited 1 time in total.
Russ Newton
Elan +2S (1971)
Elite S2 (1962)
User avatar
CBUEB1771
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1684
Joined: 09 Nov 2006

PostPost by: elated » Wed Dec 06, 2017 7:52 pm

OE was certainly UNF but I thought 3/8"
Gordon
elated
Second Gear
Second Gear
 
Posts: 100
Joined: 21 Jan 2011

PostPost by: types26/36 » Wed Dec 06, 2017 8:24 pm

From the Lotus fastener manual.......5/16 unf
Attachments
gear-box-mount.-1-copy.jpg and
gear-box-mount-copy.jpg and
Brian
64 S2 Roadster
72 Sprint FHC
User avatar
types26/36
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 3877
Joined: 11 Sep 2003

Total Online:

Users browsing this forum: lotusfan and 25 guests