154 drive shaft pin (bolt)

[A/C guy]

I've been using a grade 8 bolt for the drive shaft to engine flywheel coupler joint. I see that the sets that Hamilton Bob offers use a hardened bolt for the transmission flywheel to input shaft and a "soft" one for the front joint. Anyone have thoughts on this?

[john2189]

I have read in another post that you put the soft one in front because it is easier to get to to change.

[A/C guy]

Yeah, the front one is definitely easier to change.

[IndyFord2]

I've had mine apart (Clutch) I put a grade 12 in the rear (black Allan head type) and a grade 8 in the front. been mowen for 2 years, haven't broke one yet. (in my 185) Had a 154 and broke 2 over a 5 year period. wasn't really no rime or reason when they broke, just mowing along and the tractor stops. Good luck.

[gitractorman]

I definitely would NOT use the hardened steel bolts as the previous post suggested. This is a common wear point and the bolts are designed to wear and fail instead of the driveshaft and couplings. If you use harder bolts than the driveline parts, you'll eventually wear the driveline parts out to the point of them failing instead of the bolts. So, $100 to $200 in driveline parts to replace, or $2 in bolts!?! You make the call.

Put in grade 5 bolts and change them out every few years if needed!

[SONNY]

I never heard of them breaking! I have 2- 185's and a 154 and have never broke anything on them. AND I use them hard! --- Maybe I just got lucky!
I agree with using the softer bolts if that is whats s'posed to be in there! ---- wrong bolts easily destroy expensive parts in a heartbeat!

[BigBill]

The shoulder bolt you can tighten up so it can’t rock on the shaft. It’s no harder than the Allen screw we’re using. I’ve seen the bolts on my 154’s wear on the threads. So the shoulder bolts is in shear it’s not going to shear or break.

It’s a 8 mm diameter on the shoulder part. The shear is in the machinists hand book.