crankshaft nut torque. - Alfa Romeo Bulletin Board & Forums
 
LinkBack Thread Tools Display Modes
post #1 of 10 (permalink) Old 08-03-2016, 05:30 PM Thread Starter
Registered User
 
Join Date: Jul 2009
Posts: 49
crankshaft nut torque.

hi,am trying to find out the correct torque for the front crankshaft nut ,i've read few post and they make it a litle more confused some say 120 ft other 140 ft ,can somebody clarify it for me please.
Thks. by the way it's the 85 Quadrifoglio

Last edited by giorgiofrette1; 08-03-2016 at 05:32 PM.
giorgiofrette1 is offline  
Sponsored Links
Advertisement
 
post #2 of 10 (permalink) Old 08-03-2016, 06:19 PM
Moderator
Platinum SubscriberModerator
 
Alfajay's Avatar
 
Join Date: Jan 2005
Location: San Juan Capistrano
Posts: 9,840
My manual says 70 - 72 ft-lbs for a 2L. 140 sounds very high.

Jay Mackro
San Juan Capistrano, CA

'65 Guilia Sprint GT
'67 Duetto
'91 164L
Alfajay is online now  
post #3 of 10 (permalink) Old 08-03-2016, 06:31 PM
Senior Member
Gold Subscriber
 
Vintre's Avatar
 
Join Date: Nov 2006
Location: Waterdown, Ontario
Posts: 3,471
The Engine Overhaul manual I have for 2.0L engines, model years 1982 - 1991 says

Name:  Torque specs.jpg
Views: 1495
Size:  45.0 KB

Good luck,

Vin

1991 Spider Veloce - Red on Tan - Rosa Bionda
1987 Spider Quadrifoglio - Red on Grey - Rosa - Sold
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


Honey, this is the last thing I have to do, then I'm finished. It'll just be a minute.
Vintre is offline  
Sponsored Links
Advertisement
 
post #4 of 10 (permalink) Old 08-03-2016, 06:52 PM
Registered User
Platinum Subscriber
 
Andrew's Avatar
 
Join Date: Mar 2004
Location: Berkeley, CA
Posts: 21,043
Non-Spica are like 80, Spica are like 140.
Andrew
Andrew is offline  
post #5 of 10 (permalink) Old 08-03-2016, 07:21 PM
Senior Member
Gold Subscriber
 
not2old4toys's Avatar
 
Join Date: Feb 2012
Location: Sisters, Oregon
Posts: 2,461
Garage
Vintre figures are correct from Spider shop manual
My old Shankle( which is indispensable) shows 140 on 2L up to 1978( last printed year?)
and 87 ft lbs on 1300 and 1600
Cheers, Jon

Present:
1967 Spider
1974 GTV (1969 Tribute)
1993 Spider ( project)
2018 Stelvio
Past:
1964 Giulia Sprint. 1966 Giulietta 101 Sprint
1967 Super 1968 GTV 1974 Berlina
1979 Alfetta Mille Miglia 1987 Milano
Non Alfa:
1953 MGTD 1958 TR3 1962 AH 3000 MKII
1969 AMX
not2old4toys is offline  
post #6 of 10 (permalink) Old 08-03-2016, 11:06 PM
Registered User
 
hunttheshunt's Avatar
 
Join Date: Mar 2012
Location: Western Germany
Posts: 1,031
You guys donīt forget that all the works data are just referring to a specific thread size ?

There are at least 3 DIFFERENT sizes possible; have a look here:

http://www.alfabb.com/bb/forums/engi...shaft-nut.html

Depending on the crank type/thread size in a specific car, the highest torque range is eventually way too high and will be followed by a cracked pulley boss soon.

Tell me which thread sizeīs in your engine and I can provide you with the correct torque figure for that.

Itīs presumably correct that a 85ī engine needs the torque listed in Vintreīs sheet, but what if somebody replaced the crank or the engine to an earlier spec ?

Last edited by hunttheshunt; 08-03-2016 at 11:19 PM.
hunttheshunt is offline  
post #7 of 10 (permalink) Old 08-04-2016, 06:09 AM
Senior Member
Platinum Subscriber
 
alfaparticle's Avatar
 
Join Date: Oct 2004
Location: Columbia SC
Posts: 12,955
I've heard of a few cracked pulleys and I presumed that they were due to mishandling or a manufacturing defect but I can see now that it could be due to confusion regarding nut torque. Is there a downside to using the lower setting on the bigger thread if you use loctite 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 online now  
post #8 of 10 (permalink) Old 08-05-2016, 01:52 AM
Registered User
 
hunttheshunt's Avatar
 
Join Date: Mar 2012
Location: Western Germany
Posts: 1,031
Ed,

meanwhile Iīm using the lower torque setting (85 ft-lbs) for all three thread sizes in combination with some Loctite and never had any self-loosening issues (as long as one doesnīt reuse a cracked one). Only with a late double or triple groove pulley in combination with the biggest thread size Iīm going to the high torque setting in Vintreīs list (140 ft-lbs).

Cracking issue occurs in my opinion mainly from either using wrong torque figure and/or using an air impact tool for tightening. Unscrewing with impact tool is ok, but never tightening. Cracks are always aligning following uncontrolled axial compression with air tools.

The biggest thread size (M26) can easily be identified as itīs the only one which has the same dia. as the rest of the crank body following the thread area. Both smaller threads are smaller in dia. and not in same line with the following area.

D.
Attached Images
 

Last edited by hunttheshunt; 08-05-2016 at 02:02 AM. Reason: Adding pic
hunttheshunt is offline  
post #9 of 10 (permalink) Old 07-11-2017, 10:23 AM
Senior Member
Gold Subscriber
 
jclark's Avatar
 
Join Date: Feb 2004
Location: Livermore, CA
Posts: 441
And what is meant by 'wet'? Water ( most common use of term )? Oil ( what kind )? Dish soap ( hey, it gets wet too! )?

And what about the big concave washer? Concavity facing tailpipe, or the front of car?

And that washer has a small cutout - looks like it maybe had ( past tense ) a little tab that has over the years gotten lost/broken off - prolly originally used to bend over the large nut to keep it from backing out? Is it necessary to put new one in? Do fresh ones exist?

Inquiring minds, etc.

jeff

1982 Spider Veloce
1999 BMW R1100S
jclark is online now  
post #10 of 10 (permalink) Old 07-04-2019, 08:59 AM
Registered User
 
IRONBLOCK's Avatar
 
Join Date: Feb 2008
Location: Georgia
Posts: 3,654
Garage
Old thread...wet usually refers to oil on the threads or in the case of head nuts and studs where they get re-torqued a few times; anti-seize compound for me.

The big concave washer in the crank pulley has a 'slot' for the key way on the crank shaft, like a Woodruff key. Not a tab washer, although the washer itself can be bent over a flat on the nut to keep it in place.

Mark

Quote:
Originally Posted by jclark View Post
And what is meant by 'wet'? Water ( most common use of term )? Oil ( what kind )? Dish soap ( hey, it gets wet too! )?

And what about the big concave washer? Concavity facing tailpipe, or the front of car?

And that washer has a small cutout - looks like it maybe had ( past tense ) a little tab that has over the years gotten lost/broken off - prolly originally used to bend over the large nut to keep it from backing out? Is it necessary to put new one in? Do fresh ones exist?

Inquiring minds, etc.
IRONBLOCK 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