Torque wrench settings

[Chris59]

Hello,

I try to find the torque wrench setting of a crankshaft extension bolt, the big one in the middle of the fan.

 

I haven't find it in my manuals, and still ask myself how I have done correctly my previous TR3 to 4' engines rebuilts ......

 

Another subject : a friend of mine own a spare crankshaft/fan extension (was on a TR4 engine), in alloy (or equivalent), with a yellow plastic fan.

 

Do you have seen this before ?

 

Chris.

[pfenlon]

Hello,

I try to find the torque wrench setting of a crankshaft extension bolt, the big one in the middle of the fan.

 

I haven't find it in my manuals, and still ask myself how I have done correctly my previous TR3 to 4' engines rebuilts ......

 

Another subject : a friend of mine own a spare crankshaft/fan extension (was on a TR4 engine), in alloy (or equivalent), with a yellow plastic fan.

 

Do you have seen this before ?

 

Chris.

 

 

Hello Chris,

 

I cant remember the size of the bolt but this may help

 

for grade 5 bolts ( 3 nicks in the bolt head)

 

5/8" is 128 ft lbs

3/4" is 223 ft lbs

 

for grade 8 bolts ( 6 nicks in bolt head )

 

5/8" is 180 ft lbs

3/4 is 315 ft lbs

 

if its 11/16" go between....

 

But check on the net there is also a difference if the bolt is dry or lubricated.

Edited December 5, 2009 by pfenlon

[vivdownunder]

Hi Chris,

 

If you are talking about the large starter handle dog bolt, I can't recall seeing a torque wrench figure quoted. Where I've been able to get a socket onto it, I've tightened it to the same as the flywheel to crankshaft bolts which is 42 to 46 ft lbs. For more security you can use low grade loctite, but don't use the high grade stuff or it's almost impossible to get the dog bolt off again.

 

Where I've found it loose with the radiator in, and had to tighten it with a 12" adjustable wrench, I've just gone as tight as possible with whatever purchase you can get in the confined space.

 

Regards,

 

Viv.

[TR 2100]

Another subject : a friend of mine own a spare crankshaft/fan extension

(was on a TR4 engine), in alloy (or equivalent), with a yellow plastic fan.

Do you have seen this before ?

 

Hi Chris,

 

I've seen these listed on eBay once or twice, but only recently.

Does it look like the fan extension is fairly new?

 

Or maybe someone machined one specially, maybe to allow the

fitting of a special plastic fan?

 

've not heard of a factory alloy hub extension.

 

AlanR

[vivdownunder]

Hi again Chris,

 

Alan's post reminds me I didn't respond to your second question.

 

There were two factory cast iron fan extension hubs, one longer than the other.

 

I recall that someone, perhaps from America, made up some short fan extension hubs in alloy as a lightweight racing part. The short extension was used to fit the yellow plastic fan introduced during TR4A production.

 

This fan was wider and had more blades of steeper pitch than the shallow TR3A/TR4 metal fan, for improved cooling.

 

Regards,

 

Viv.

[RAHTR4]

Chris,

 

Frank - Angelfi - in America raised this question about different length fan extensions earlier in the year, plus he also found a short one made of aluminium.

 

Here is the photo he posted :

 

 

Totally unsure of the correct way to do a link, but hopefully below will get you to his final posting :

 

http://www.tr-register.co.uk/forums/index.php?showtopic=17247&st=0&p=117098&fromsearch=1entry117098

 

Regards, Richard

[Chris59]

Hello Pete, Viv, Alan and Richard, and thanks for your replies.

 

Yes, I am talking of the large bolt, the one I can see on Richard' picture between the aluminium tall and cast iron extension.

If my memory is good (I haven't seen this part since 6 years), the alloy extension is a "moulded", then machined, one.

It's not a new one, as my friend has bought it 25 years -or more- ago with a spare TR4AIRS engine (forget it was from an IRS ), but it was in "as new" condition.

 

Should be the one you are talking about, Viv ?

 

I will have a look on Frank' post now.

 

Cheers,

 

Chris.

[ianc]

I had never noticed this before, but the torque for this bolt is not specified in the Workshop Manuals for any of the TR models, from TR2 to TR6. How very odd!

However, 42-46 lbf.ft sounds like a good figure, and the use of Loctitie's "Lock and Seal" can do no harm - I use it on almost every thread on the TR.

Ian Cornish

[RogerH]

Hi Ian,

I would imagine there is no figure given as the rotation of the engine keeps it tightened.

So an initial, non-specified, tightening would suffice. There is little chance of over-doing it, due to it's size.

 

Roger

[Chris59]

I can't agree with you on this, Roger : I have found, on a friend' TR2, this bolt unloosed (despite the hexagonal retainer washer..), allowing the fan extension to move, as the crankshaft sprocket.

The 2 keys may have not last longer : a few more miles, and the crankshaft sprocket may have turn free on the crank.....

Unfortunatly, the interior of the extension (where it should have a tight fit on the crank), as the exterior (where the leap of the seal is) are now worn

Will see tomorrow if I can repair the extension...

Chris.

Edited December 6, 2009 by Chris59

[RogerH]

Hi Chris,

bang goes the theory .

 

Roger

[Chris59]

I had never noticed this before, but the torque for this bolt is not specified in the Workshop Manuals for any of the TR models, from TR2 to TR6. How very odd!

However, 42-46 lbf.ft sounds like a good figure, and the use of Loctitie's "Lock and Seal" can do no harm - I use it on almost every thread on the TR.

Ian Cornish

 

 

Ian,

This torque is specified for the 6 cylinders TRs in the Haynes books : crankshaft/pulley attachment is 90 - 100 lb ft, ie 12.44 to 13.82 m.Kg for a "metric" guy as me

The problem is that the crank extension is supposed to be firmly pressed on the crank sprocket, but will the large, long wet liners dog bolt accept this kind of torque ?? Not sure of this

Chris.

[stuart]

Ian,

This torque is specified for the 6 cylinders TRs in the Haynes books : crankshaft/pulley attachment is 90 - 100 lb ft, ie 12.44 to 13.82 m.Kg for a "metric" guy as me

The problem is that the crank extension is supposed to be firmly pressed on the crank sprocket, but will the large, long wet liners dog bolt accept this kind of torque ?? Not sure of this

Chris.

 

I wouldnt go up that high a torque as if it did fail you would be in deep sh1t. I would stick with the figure of mid forties with loctite and check after a few miles.

Stuart

[Chris59]

I agree with Viv, Ian and you, Stuart, and will certainly not apply the 6 cylinders torque .

 

I want to stay far enough from the brown thing

 

 

Chris.

Edited December 7, 2009 by Chris59