6600 Drawbar Bracket Bolt Holes Damaged

jsp5755 · May 1, 2017

The drawbar bracket bolts got loose. The front pair (?5/8"-11) threads are gone on 1/3 of the tapped hole. The grade bolt is 12.9. My plan is to go to grade 8 bolts that are longer to get up into the other 2/3 of the threads still present. Also going to use Nord-Lock washers. Also going to replace the rear pair ?7/8"-9 with longer bolts.

Anyone else had this problem? If yes, then how did you repair?

Considering using helicoil to repair, but thought I'd try this other method first. I've had good luck with this method on loader brackets on the bell housing.

Thanks

showcrop · May 1, 2017

I had my bracket fall off from my 8240 0nce. I lucked out on the tractor, there was just a little damage to the holes and just a good clean-out and Locktite and a long wrench took care of it. I wasn't so lucky with the baler that was behind the tractor however.

RodinNS · May 1, 2017

Been there, done that... I think I kept the 5/8" on front and drilled the rear to the next size. I thought the rear was 3/4 and I went to 7/8". There is only so much meat in that housing to get and you'll be through it. There is also limited room in the drawbar housing to take a larger bolt head.
What I ended up doing was installing a strap across the rear of the housing to hook the two big holes below the PTO on the rear. Also bottom tapped all the underside holes and installed bolts to full depth. So far, no problems and that's been 15 years or so. BUt mine regularly had well over 5 ton on the bar...

Rod

showcrop · May 1, 2017

(quoted from post at 09:36:07 05/01/17) Been there, done that... I think I kept the 5/8" on front and drilled the rear to the next size. I thought the rear was 3/4 and I went to 7/8". There is only so much meat in that housing to get and you'll be through it. There is also limited room in the drawbar housing to take a larger bolt head.
What I ended up doing was installing a strap across the rear of the housing to hook the two big holes below the PTO on the rear. Also bottom tapped all the underside holes and installed bolts to full depth. So far, no problems and that's been 15 years or so. BUt mine regularly had well over 5 ton on the bar...

Rod

Rod, I came across another Ford that had had the exact same thing done to it.

Bern · May 1, 2017

This is a common problem when the bolts are not installed tight in the first place.

If you had a "12.9" metric bolt in a standard hole, that could be the reason it came out. That said, where I used to work we made a custom plate that bolted to the rear of the center housing and was then welded to the drawbar support. It was a permanent fix for sure.

jsp5755 · May 1, 2017

Glad someone noticed that grade on the bolt. It was stamped on the head 12.9. Both the 5/8 and 7/8 bolt are stamped 12.9. I thought this was a metric grade fastener. When you got to the New Holland Parts Web Site the 7/8 bolt is listed as a grade 12.9. The 5/8 bolt on the site does not state the grade, but as I said it is stamped is 12.9

Bern · May 1, 2017

I've never heard of a standard bolt being marked with a metric grade, but I suppose it's possible. I do know that 5/8" and 16mm are very close in size, and will thread in the same hole, for a little ways anyway. Learned that lesson the hard way.

jsp5755 · May 1, 2017

Yep. This is bothering me as well. The tractor was bought new by my uncle's fater-in-law. It spend a few years at another local farmers place before I got it back. I only lost one of the 5/8 bolts. I still have the two 7/8 bolt and one 5/8 bolt. They are all stamped 12.9. I'm going to try and get a picture and post. I judge the bolts to be original, because the parts page states the bolts have serrations under the bolt head....and I observed this is the case. Wonder if the 7/8 is a M22 & 5/8 is a M16? Surely they did not use a metric bolt in a standard hole....unless the thread profiles are very close????

Bern · May 1, 2017

I have a really hard time believing that a tractor made in the 1970s would have a standard bolt with a metric marking on it, despite what the NH catalog says. You should be able to measure the thread pitch with a gauge and tell for sure. Or, grab a true 5/8" bolt and hold it up alongside your old one. If the thread matches perfectly, it's a 5/8. If it's off a tad, it's 16mm.

RickB · May 1, 2017

Those OEM bolts have metric hardness markings on the heads and USS thread specs. Goofy but true. I also have repaired this problem by welding tabs on the support and tying it to tapped holes on the vertical surface above the rear of the support.

RickB · May 1, 2017

Believe it or not, I've seen it several times. But only in this exact application. The thread diameter is most definitely not 16MM.

Bern · May 1, 2017

Interesting....I learn something new everyday!

sunbeam · May 2, 2017

You might use EZ Lock inserts. They are thicker than helicoils.

showcrop · May 2, 2017

My local hardware recently stared carrying some bolts with hardness numbers like those. The number jumped a lot from 8, way up to something like the 12.9 or even higher. Now I see what it is about.

jsp5755 · May 2, 2017

Here's a picture that shows the old bolts silver in color and new bolts in gold. New bolts are grade 8, 7/8 & 5/8

Bern · May 2, 2017

Were they metric or standard bolts?

showcrop · May 2, 2017

(quoted from post at 08:50:07 05/02/17) Were they metric or standard bolts?

I am pretty sure that they were standard (SAE?) I am usually after SAE. Metric only very rarely.

Bern · May 2, 2017

It's going to be pretty hard to teach this old dog new tricks. Metric marks on standard bolts - ugh! Just what we need, more confusion. What's worse, someone will grab a 16MM bolt now and put it in a 5/8" hole. It will go most of the way, and he will think it's tight, but it really isn't.

Bern · May 2, 2017

I just had a conversation with the manager of my local hardware supplier. He said a standard bolt with a metric marking is extremely rare - he said it "must be an OEM thing". I was glad to hear that it was not getting to be more common.

I'd sure like to know why someone at Ford thought that was a good idea, or even necessary.

RickB · May 2, 2017

This particular bolt is a flange head with an undersized hex relative to the bolt diameter. It's been a while since I've had my hands on one, I'll say they take a 13/16" socket up thru the hole in the lower web of the support. It's tough to use a standard 5/8" bolt because a 15/16" socket won't fit the hole. You gotta go in from the back with a box wrench.

Bern · May 2, 2017

That would certainly explain the design of the head, but not the metric markings. They could have just as easily put hash marks on it.

Some engineer didn't think that one through, because it would be very easy to look at a bolt like that and substitute a 16MM in its place. It will go in, most of the way, making the person who put it in think it's bottomed, when it's not.

The larger question for me still remains: why put a metric grading system on a standard bolt?

RickB · May 3, 2017

Agreed.

Jo-ker · May 5, 2017

I have mine fall to the ground on my 5200 several years back. I was sowing grain so nothing serious happened.But i rent a farm 2 miles away on a busy paved road and i drive on that road frequently,so it could be a serious situation. Looks like we have to inspect those bolts everytime we change the oil.......John

showcrop · May 5, 2017

(quoted from post at 13:40:20 05/05/17) I have mine fall to the ground on my 5200 several years back. I was sowing grain so nothing serious happened.But i rent a farm 2 miles away on a busy paved road and i drive on that road frequently,so it could be a serious situation. Looks like we have to inspect those bolts everytime we change the oil.......John

I was checking mine regularly for three years or so after putting it back on but none of the bolts loosened up again. I am sure that after cleaning the bolts and holes well that I used red thread locker.

6600 Drawbar Bracket Bolt Holes Damaged

Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Member

Well-known Member

Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Member

Well-known Member

Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Member

Well-known Member

Similar threads