6.0 starter bolt sizes

55431 Views 7 Replies 3 Participants Last post by Riddick, 5 mo ago

rickou812

Discussion Starter · Mar 4, 2017

My 2003 f250 stopped turning over, found the that the starter bolts had backed out. The lower bolt is gone, the top bolt is broke and the middle bolt has what is left of the broken starter flange.

So after searching, I have this is a common issue and the question about bolt sizes asked a hundred times..but I have not been able to find post giving the actual bolt sizes...especially the bottom bolt...other than it is an odd size...lol

Would someone be so kind to give all three bolt sizes and make it a sticky....lol

Thanks,
Rick

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bismic

· #2 · Mar 4, 2017 (Edited)

Pretty sure these are the sizes:

Starter bolts:
2-m8x1.25 40mm w/ a 13 mm head (top two) - 10.9 (Metric) or grade 8 (SAE).
1-m12x1.75 40mm - grade 8 - can't recall the head size. Also 10.9 (Metric) or grade 8 (SAE).

Use loctite on the larger bolt to keep it on (low strength). The theory is that the aluminum threads set the torque spec and that the spec is insufficient torque (don't want to strip the aluminum threads) to "stretch" an M12 bolt (tty bolt).

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bismic

· #3 · Mar 4, 2017 (Edited)

Torque value in the WSM is 25 N-M (18 ft-lbs) for the three bolts.
Solenoid nut torque spec - 6 Nm or 53 in-lb
Positive cable nut torque spec - 12 Nm or 9 ft-lb

I believe that the M12 bolt also has a 13 mm head.

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rickou812

Discussion Starter · #4 · Mar 5, 2017

Thanks Mark,

Just for future purposes, I was able to pick up bolts from tractor supply in the following sizes:
M8-1.25 x 40mm
M12-1.75 x 60mm
I went to 60mm and plan to place a lock washer on the bolt.

Rick

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bismic

· #5 · Mar 5, 2017

Good idea on the longer bolt!

Glad you got it!

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rickou812

Discussion Starter · #6 · Mar 5, 2017

Just a follow up,
the M12-1.75 x 60mm is on the long side, but does not go into a blind hole, the extra just passes through the starter.
A M12-1.75 x50mm would be perfect with a split washer/lock washer, however, 50mm length is not common hardware store item.

Another option, a nut could be used on the backside of the 60mm long bolt for insurance purposes :grin2:

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bismic

· #7 · Mar 6, 2017 (Edited)

You could always cut a 60mm bolt down. Put a nut on it at the proper length and then cut it. The nut protects the threads during the cut and then the nut will "dress" the threads when you remove it.

Found this video, it has good description on the installation at the end.

https://youtu.be/r7JwYkvvHVk

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Riddick

· #8 · 5 mo ago

bismic said:
Pretty sure these are the sizes: Starter bolts: 2-m8x1.25 40mm w/ a 13 mm head (top two) - grade 8 1-m12x1.75 40mm - grade 8 - can't recall the head size. Use loctite on the larger bolt to keep it on (low strength). The theory is that the aluminum threads set the torque spec and that the spec is insufficient torque (don't want to strip the aluminum threads) to "stretch" an M12 bolt (tty bolt).

I want to confirm i just used these and its 100% on. using these measurements with gr8 bolts also i used the 60mm long bolt and put a nut on the protrusion as insurance also worked perfect.

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