N H 451 Pittmanless Mower

[Oliver550Dave]

Bolt broke that locks the push bar in proper tilt on my NH451 pitman-less hay mower. When I picked up the lock (part #63752) from the local CNH dealer, I asked for and got the bolt, lock washer, and nut that I supposed would fit, but there is no way that I have found to turn that bolt and get it into the hole on the inside of the push bar assembly. Measuring it, the bolt is G5, 5/8 x 2.5 cap screw. Thinking I had too long a bolt, I picked up a 2.25 bolt but that is also too long - or I haven't figured out how to position the bolt to get it to go in the hole!

Looking at Messick's/New Holland parts diagram, I now see that there is are entries for Hex Bolts, 5/8-18 x 1.75, G5, but is doesn't seem like these would be carriage bolts (machine bolt, round head, short square neck) which the application calls for.

What do I really need to get this mower back together? A shorter carriage bolt, or use a hex-head 5/8 bolt with lock washer and nut?

Any other advice appreciated!! I use this mower behind a Ford 3930 tractor.

 

[charlie n]

This might help.

 

[charlie n]

I posted before the text got typed. Its a carriage bolt. You can snake it up from the bottom with long pair of needle nose pliers maybe . Good luck.

 

[Oliver550Dave]

Charlie, many thanks! That may help a lot! Seems to verify that I actually need a 1.5 carriage bolt with square shoulders. I've looked on my old 1975 parts list plus a current online parts list for the mower, and never found a clear link to what size bolt was clearly needed for the repair. Joe's Machinery lists a bolt for the repair but doesn't give the dimensions. The online parts list includes a carriage bolt short neck, G5, 5/8 x 2.25 and another Bolt, Screw, Cap, HH, G5, 5/8-18 x 1.75 but doesn't indicate the exact application for either bolt. That's why I turned to YT discussion board!! Again, many thanks - I think you have helped me solve my problem!

 

[grandpa Love]

I love Joe's Machinery!

 

[Oliver550Dave]

Again, thanks for your help! I picked up some G5 5/8 Carriage bolts of varying lengths - 2.25 & 1.5! In the end, I had to use the 2.25 bolt in order to have enough threads open to engage the nut with the lock piece and lock washer also in place. I had picked up the 2.25 bolt last Friday and tried it, probably in too much of a hurry on Saturday, and wasn't able to get it in place. I guess yesterday, when I finally got back to the mower and after the 1.5 bolt was too short but did go in easy, then I guess I held my mouth just right and the 2.25 bolt did go in and draw up tight as needed. Just to be able to say I tried, I again tried the 2.5 bolt, but still wasn't able to make that work. At least now the problem is repaired! With rain predicted tomorrow afternoon here in central NC, and with help to put the idiot cubes into shelter mostly on the weekend, looks like I'll wait until Monday to cut more hay. A neighbor that I work with put some hay down Monday night that I hope to rake tomorrow for him to round bale. Again, thanks especially for the pictures - they gave a good perspective!

 

[wore out]

Good job!

It's always a good feeling when when we solve a puzzle like that and get parts fished into a tight place and functioning, isn't it!