Rebuild torque specs
 

Hey gang,
I'm in sight of reassembling my 305e after tear down for a spun rod bearing. Got the crank back from the machine shop, it's all shinny and new looking. (See my post on "nock at high RPMs")
Waiting on another rear main seal set, the first one I ordered was lacking the two short little seals that sit vertical on the rear main cap. Ideas about where to find those welcomed btw.

Thought I would try for a conscise conversation and assembly a reference list of torque specs.

From the bottom up:

Mains: 120lbs??? (I think I heard that in a military chevy video)
Rod caps: 80?
Oil pump: ?
Oil pan:?

Flywheel:?
Clutch disk:?
Bell housing:?

Heads:?
Intake:?
Valve covers:?
Carb:?

Water pump assem:?

Pertinent others I'm omitting???

Re: Rebuild torque specs
 

Alot of this stuff doesn't actually HAVE to be torque to spec.
According to the book:
Mains at 130-140 ft pounds. I did 135.
Be sure to torque the two rear main 1/2 inch cap bolts at 55-65. I did 60.

Rods at 55-65 ft pounds. I did 60.

Oil pump I did Tight because I didn't know the spec(No book at the time).

Oil Pan 10-15 I'd say, If you use a good gasket and gasket maker.

Flywheel bolts at 100 ft pounds.

Heads 65-72. I did 70.



The clutch pressure plate bolts I'd say no more than 35 foot pounds as they are small and can snap easily. But since someone below makes it a huge issue, be sure to find the correct spec. Truth be told....I have never actually torqued those and have never had a problem. But there is always a first time.

Bell housing 50-60.

Intake 20-25. I didn't calculate when I did mine.

Valve covers. I snugged mine down. They don't need to be Sinched.

Carb. I also snug the bolts down on those in an even order.

Re: Rebuild torque specs
 

Go by the GMC manual. It's already in the manual 50 years ago, *somewhat repeated above.

Manual X-6023:

Rod bolts 55-65 *
Head bolts 65-72
Main Brg cap bolts (except 1/2" rear) 130-140* Rear 1/2" bolts 55-65* Flywheel to crank bolts 100-105 Intake manifold bolts 20-25 Exhaust man bolts 15-20 Front cover to block bolts 22-27 Camshaft thrust plate screws 4-5 Fuel pump eccentric bolt 60-70 Oil pump cover screws 10-15 Oil filter by-pass valve plug 35-40 Spark plugs 23-27 Rocker arm shaft bracket bolts 20-25 Damper to crankshaft bolt 135-145 Flywheel housing bolts 50-60

* Oiled with SAE no. 10 engine oil

You are not assembling a motor without a manual are you? If torque values are not given, use an approved torque chart for size and material of fastener, and consider if there is gasket squeeze involved. Creating a reference list on here is not a good idea, as regards to motor assembly torque. It's too risky not to check out official documents. *The book gives oiled thread torque values and dry values. It speaks of %10 reduction for oil vs. dry and other pertinent assembly info. So we have already created misinformation (Ref X-6023). Unless you don't care about accuracy. Also: I don't see "snug" and "tight" in the book for motor work. I don't know what "I didn't calculate" means.

Re: Rebuild torque specs
 

All the specs I gave were from the manual. Snug and tight were for things that don't REQUIRE a torque spec unless your really crazy about book specs. I may be nuts but I highly doubt many here actually use a torque wrench on Spark plugs and Intake manifold bolts!

Re: Rebuild torque specs
 

Yes, you don't have to doubt, I do torque Plugs and Manifold. I also highlighted some of the concise info the poster asked for. And you advise someone not to be "crazy" about book specs? Are you kidding?

Re: Rebuild torque specs
 

Because I'm still learning, I treat the specs like gospel.... so if the book says 23-27 ft lbs of torque on the spark plugs, then that's what I'm going to do.

Re: Rebuild torque specs
 

And did I say there was anything Wrong with that? No.

Re: Rebuild torque specs
 

Never said you did.

Anyway, if I want to argue with folks about nothing, there's more than enough opportunities to do that in my day to day. I'm not going to encourage that sorta thing here.....

Like the song says, that's my story and I'm stickin to it.

Re: Rebuild torque specs
 

I agree! But unfortunately you have trolls on these forums who like to bad mouth and down people. Rather than simply post something better they have to blow things out of proportion. I may contribute to it...but only when my name or other members names are being wrongly accused. Oh well, life goes on. Hope the OP got what he needed.

Re: Rebuild torque specs
 

This topic has covered the original poster's question and has now flown off the rails with petty bickering. It is now closed.



-Jeannie

6066 GMC Club