Drivetrain Bolt Torque Settings

[Jon Bradbury]

Hello all

 

I have (as you probably know) a 2B based on the DOHC Sierra. I was not able to establish what the correct torque figures are for the following bolts and had to use the corresponding figures for the Pinto based Sierra:

 

Propshaft to differntial : 50 lbs/ft

Rear halfshaft bolts, both sides : 32 lbs/ft

 

Those halfshaft settings look a bit on the low side, but that's what the Haynes manual says for the pinto engined halfshafts.

 

Also, the flywheel bolts were quite low as well, something like 35lbs/ft.

 

All the bolts apart from halfshafts were reassembled with a thread locking fluid. I didn't renew any of them apart from the propshaft - gearbox output flange bolts which RHE supplied (I know the flywheel ones are supposed to be changed but hey - a bolt's a bolt isn't it?).

 

Any comments..? Is it going to come apart on the motorway and strand (and / or kill) me?

 

Cheers

 

JonB

[Guest Lindsay]

Hi Jonb

 

Flywheel bolts should be torqued to 61/68lbs/ft

New bolts come with locking compound on the bolts. Personally I would take the bolts out clean them up and the threaded holes in the crank, if they are something like 10.9 tensile I would use again with thread lock. Any thinf softer I would get new ones.

 

 

The other 2 torque settings are OK.

 

Lindsay

[Jon Bradbury]

You sure about the flywheel torque?

 

I did exactly what the Haynes manual said with the exception of renewing them. Perhaps it said 68lbs/ft and I forgot (it was a while ago). Whatever, I was very careful setting the torque wrench for that.

 

I was worried they might be like those stretch bolt things that are used on the cylinder head, which really, really must be replaced.

 

Regarding halfshaft bolts, what stops them coming loose when they're only torqued to 30-odd lbs/ft?

Cheers

 

JonB

[Guest Lindsay]

Hi JonB

 

The torque settings are out of haynes manual.

 

If your not to happy regarding half shaft settings keep an eye on them for first 100 miles. If memory serves me right they are 8mm bolts 32lbs/ft is tight.

 

Sorry I can't be any more help

 

Cheers for now

 

Lindsay.

[Guest Phil Slater]

Don't know if this helps but when I had my flywheel lightened, and balanced with the crank, the engineer, who has a very good reputation with pinto engines,k told me to torque up the flywheel bolts to 65 Ft pounds with just a spot of locktite. I cant remember the figure quoted in the Haynes manual but it was less than 65.

 

Phil Slater