Coupling Bolt Torque Value

[Briankinley2004]

Does anyone know the torque value for the 5/8" bolts that connect the 2 1/2" shaft coupling to the transmission on a 46C? Transmissions are Allison M20's on 8V71TI. The blueprints gave the procedure for pulling and putting the coupling off/on and gave a torque value of 100-120ft lb for the castle nut but do not mention the coupling bolts.

 

[SKYCHENEY]

AI says a 5/8 grade 8 bolt has a torque spec of 180 lb-ft

 

[Briankinley2004]

AI says a 5/8 grade 8 bolt has a torque spec of 180 lb-ft

My skinny butt is going to be in pain. They were pretty tight and had to use a breaker bar with a cheater pipe but I thought that was from rust. Apparently not.

 

[osprey]

The drawings for my 46C with 2 and 1/2 inch shaft says coupling bolt torque to be 125 ft/lbs.

P

 

[SKYCHENEY]

Just replaced stabilizer seals. Torque spec on the bolt that holds the fin on is 250 ft-lbs. Glad I have a 5ft torque wrench.

 

[Briankinley2004]

The drawings for my 46C with 2 and 1/2 inch shaft says coupling bolt torque to be 125 ft/lbs.

P

That makes me feel a bit better. I think I will go with that since its same boat and shaft size (unless someone has something more specific to my boat). Thats on the upper end of the 100-125 ft/lb for the castle nut so shouldn't be too hard to do.

 

[Briankinley2004]

Just replaced stabilizer seals. Torque spec on the bolt that holds the fin on is 250 ft-lbs. Glad I have a 5ft torque wrench.

Im not sure I could fit a 5' torque wrench in my engine room

 

[SKYCHENEY]

Im not sure I could fit a 5' torque wrench in my engine room

It resides in the shop at the limestone quarry. It gets more use there.

 

[jmooney]

Im not sure I could fit a 5' torque wrench in my engine room

My stabilizer bolts are 350 ft lbs . I use a 6 to 1 torque multiplier. It probably wouldn’t fit on the coupling bolts though. I split my couplings two years ago to remove the shafts , this probably was the hardest job I had . Hate to admit that when I put them together I used German torque.