S4 - Tightening torques needed - Alfa Romeo Bulletin Board & Forums
 
LinkBack Thread Tools Display Modes
post #1 of 10 (permalink) Old 11-22-2016, 03:25 PM Thread Starter
Registered User
 
Joseph M.'s Avatar
 
Join Date: Jun 2007
Location: Eelde, Holland, Europe
Posts: 503
S4 - Tightening torques needed

Hi, I need to know the tightening torques for:-

1) the oil pressure switch adapter to the engine block; and
2) the gearbox rear mount bolt (the one with the star washer).

I can't find these anywhere. Any clue?

Thanks and best regards,

Joseph

Alfa Romeo 2000 GTV '73
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
SOLD
Alfa Spider Series 4 '90
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
: with very low mileage
Joseph M. is offline  
Sponsored Links
Advertisement
 
post #2 of 10 (permalink) Old 11-23-2016, 12:31 AM
Registered User
 
spiderserie4's Avatar
 
Join Date: Jul 2011
Location: Cologne, Germany
Posts: 7,081
you mean oil pressure switch under the inlet or low oil pressure tell-tale switch near the oil filter?

O/P switch (under inlet) is 8-10 ft.lb (10.8 - 13.5 Nm)
....just how do you get a torque wrench-socket on that though?

Low O/P tell-tale switch (near oil filter): no torque specified - use common sense, be gentle, remember they're aluminium threads!

The transmission mount: no torque specified, so just make sure it is tight.

Dom - Alfa Spider 1990 S4 - formerly: Alfa 101 Sprint, 2600 Sprint, Montreal - family classics: Jensen Interceptor II, '58 Hooper RR Silver Cloud I, Shadow II, '60 Corvette.

Last edited by spiderserie4; 11-23-2016 at 12:35 AM.
spiderserie4 is offline  
post #3 of 10 (permalink) Old 11-23-2016, 05:07 AM
Senior Member
Platinum Subscriber
 
alfaparticle's Avatar
 
Join Date: Oct 2004
Location: Columbia SC
Posts: 12,683
The oil pressure sender on the intake side uses a copper sealing washer. Either use a new one or anneal the old one to soften the metal. The oil pressure switch on the exhaust side has a tapered thread so use some thread sealant on it.

Ed Prytherch
79 Spider
76 Suzuki GT500
2011 Jaguar XKR

A little government and a little luck are necessary in life, but only a fool trusts either of them. - P.J. O'Rourke
alfaparticle is offline  
Sponsored Links
Advertisement
 
post #4 of 10 (permalink) Old 11-23-2016, 05:11 AM
Registered User
 
jcslocum's Avatar
 
Join Date: Apr 2008
Location: Eastern Shore of MD
Posts: 1,694
Here are the basics by size:



Use as a guide only!

Jon '74 GTV RIP Tifosi
jcslocum is offline  
post #5 of 10 (permalink) Old 11-23-2016, 02:31 PM Thread Starter
Registered User
 
Joseph M.'s Avatar
 
Join Date: Jun 2007
Location: Eelde, Holland, Europe
Posts: 503
Thanks all. I'm familiar with the chart above, this gives the torques required to tighten the bolts to abt. 70 to 80% of the yield strength. What we need is tightening in aluminium so common sense would say the values should be lower (unless the thread engaging length is substantial).

The switch on the exhaust side also has copper washers. Generally speaking only parallel threads would require some suitable sort of sealant. Tapered threads not, as the seal is accomplished by metal-to-metal wedging.

Alfa Romeo 2000 GTV '73
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
SOLD
Alfa Spider Series 4 '90
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
: with very low mileage
Joseph M. is offline  
post #6 of 10 (permalink) Old 11-24-2016, 08:43 AM
Registered User
 
spiderserie4's Avatar
 
Join Date: Jul 2011
Location: Cologne, Germany
Posts: 7,081
imo, an item with a copper seal washer doesn't need sealant at all, the copper, being soft, effects the sealing (think sump, tranny or axle drain plugs....you wouldn't seal those!)
That's why you renew the washer each time.

Dom - Alfa Spider 1990 S4 - formerly: Alfa 101 Sprint, 2600 Sprint, Montreal - family classics: Jensen Interceptor II, '58 Hooper RR Silver Cloud I, Shadow II, '60 Corvette.
spiderserie4 is offline  
post #7 of 10 (permalink) Old 11-24-2016, 08:58 AM
Senior Member
Platinum Subscriber
 
alfaparticle's Avatar
 
Join Date: Oct 2004
Location: Columbia SC
Posts: 12,683
Quote:
The switch on the exhaust side also has copper washers. Generally speaking only parallel threads would require some suitable sort of sealant. Tapered threads not, as the seal is accomplished by metal-to-metal wedging.
I have just checked three used pressure switches and they are all 1/8" NPT - tapered thread. They need sealant on the threads.

Ed Prytherch
79 Spider
76 Suzuki GT500
2011 Jaguar XKR

A little government and a little luck are necessary in life, but only a fool trusts either of them. - P.J. O'Rourke
alfaparticle is offline  
post #8 of 10 (permalink) Old 11-24-2016, 11:45 AM
But Mad North-Northwest
Platinum Subscriber
 
Gubi's Avatar
 
Join Date: Sep 2003
Location: SF Bay Area, CA
Posts: 9,666
Ed is correct. Straight thread connections (e.g., pressure gauge sender, oil drain) are sealed with a crush washer. Tapered threads you want to use sealant or teflon tape.

Theoretically the tapered threads do seal on their own, but the metal-to-metal contact is never perfect and the sealant helps prevent leaks.

Tom

1963 Giulia Spider (1750 engine)
1974 GTV
1991 Spider
Former: 1987 Milano Gold
Gubi is offline  
post #9 of 10 (permalink) Old 11-25-2016, 07:22 AM
Registered User
 
jcslocum's Avatar
 
Join Date: Apr 2008
Location: Eastern Shore of MD
Posts: 1,694
Quote:
Originally Posted by Gubi View Post
Theoretically the tapered threads do seal on their own, but the metal-to-metal contact is never perfect and the sealant helps prevent leaks.
And prevents over-tightening to make the seal. I prefer teflon paste or liquid to tape whenever possible.

Jon '74 GTV RIP Tifosi
jcslocum is offline  
post #10 of 10 (permalink) Old 11-25-2016, 08:03 AM
Senior Member
Platinum Subscriber
 
alfaparticle's Avatar
 
Join Date: Oct 2004
Location: Columbia SC
Posts: 12,683
1/8" NPT is easily confused with M10 x 1.0 by someone who only familiar with metric threads.

Ed Prytherch
79 Spider
76 Suzuki GT500
2011 Jaguar XKR

A little government and a little luck are necessary in life, but only a fool trusts either of them. - P.J. O'Rourke
alfaparticle is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Alfa Romeo Bulletin Board & Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome