Torque Rating On Transfer Case Cover

Would be of help if someone could post the torque rating for the ten nuts holding the transfer case to the bellhousing.

Have a tiny oil leak and want to check their torque in case they have loosened up over the past couple of years.

The car is an '82 308GTSi.

Cheers-Colin Firth
Ontario Canada

 

They are std M8 nuts I think so around 18 lbft from memory. There is no gasket there, its usually sealed with an anearobic sealer - something like Loctite 518.

 

See Chapter M in the 308GT4 WSM (which you can download at www.ferraridatabase.com). If the stud size is M8 x 1.25P, I believe the specified value is 2.5 Kg-m (the translations aren't always clear so always good to use the thread size as a double-check).

 

The WSM does seem to specify 2.5kgm for most of the M8 x 1.25 stuff (which is 18lbft). Out on the web, a number of references to "standard" torques settings of 24/25lb ft for that size & thread. Wonder why the Ferrari spec is less than that?

 

Here is the leak I am chasing down coming from on top of the transfer case just underneath the oil cooler.

Colin
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The torque values have to take into account the materials and the arrangement -- e.g., a steel bolt and steel nut (or a steel nut on a steel stud mounted in a steel base) will have a higher failure load than steel bolt and an aluminum nut (or a steel nut on a steel stud mounted in an aluminum base).

In this case, the (lower) Ferrari limit is set by pulling the steel stud out of the aluminum base (not the failure of the steel threads nor steel stud). The chart posted by Matt is based on fastener load = 75% proof load of a lower grade bolt (IIRC, no markings = wimpy ) so those torque values are "derated" for a different reason.

 

Found the leak. Looks like a pin hole in the bottom of the oil cooler where it sits above the transfer case. I started the car and gently lifted up the base of the oil cooler where it was touching the transfer case and saw drops of oil coming out. Musta vibrated a little hole where it contacted the transfer case bolt casting.

Looks like I will be taking off the oil cooler and seeing if my rad shop can patch the leak.

Anyone have any experience with repairing tiny leaks on 308 oil coolers?

Colin

 

I was just going to ask if you'd checked the oil cooler itself Glad that it was an easy find.

 

Forget it, buy a new one. Most radiator shops will not touch that.

 

Picked up another oil cooler. Had my local rad shop repair the old one so I now have a spare.

Thanks-Colin Firth

 

I'm glad that it was a simple fix and that it worked out.

 

Installed the new (used) oil cooler today and ran it through a couple of heat cycles and 20Km run. No drips, no leaks.

Thanks to my buddy Veet (Vito) for picking it up for me from Roc's in Toronto.

Cheers - Colin Firth
Ontario Canada

 

Wow,

I read this post last night and thought it could have been a hose then went to dinner and after driving the GT4 yesterday trail of oil into the garage and about a cup or two under the car looks like oil radiator is failing too. Can I ask where you found the new one? It looks like the old 016965 has been SS to 145712. Is this what you got and is it the same as I dont want to do any modifications unless necessary....

Rob