just bought new tractor, don't like ROPS installation

[skbruse]

Hi,
I just took delivery of a new AGCO ST32, and have a question about ROPS installation. The bolt was ran up from the bottom plate through the top plate, and then the tops of the bolts cut off. It seems to me that this bolt should be secured by a nut on the top side, or better yet ran from the top down then secured by a nut. Their can't be enough threads in that thin plate to hole that bolt without a nut, or am I missing something. Just want to check before I bother the dealer (who also delivered the tractor with turfs when we agreed to ags - says he will swap them out on the farm this week). I am starting to wonder about this dealer.

 

[JerryG]

The MF1250 that I had, had the ROPS mounted on the fenders like that. I think that the heads of the bolts was on top. Someone that has a similar tractor can hopefully post.

 

[skbruse]

Thanks Jerry,
I guess I am not so worried about whether they come from the top or bottom, but just that there isn't a nut securing that bolt on the other side. So a few threads are holding it from coming apart? The plates aren't thick enough to have a significant number of threads.

 

[JerryG]

I should have said more but I was hopping that someone with the same tractor would post. On the 1250, the best that I can remember, the ROPS assembly under the fender had large nuts welded on for those bolts. It has been a while and my memory isn't as good as it used to be. Maybe some will let us know for sure.

 

[skbruse]

I know that this is the same ROPS that goes on a MF1431, or at least it says so on the ROPS. So maybe someone with an MF1431 could look at their setup.

 

[skbruse]

Jerry,
Do you know if the ROPS are installed by the dealer or at the factory?

 

[BTDT]

I understand your concern about the bolts and the plate, but it looks to me that the weak link is them mounting it to the sheet metal fenders.

 

[skbruse]

I understand your concern about the bolts and the plate, but it looks to me that the weak link is them mounting it to the sheet metal fenders.

Oh, what you can't see from my pics, and what I didn't explain, it that their is a rigid frame beneath the fenders that is tied into the tractor. That is what the bolts are coming up through. So basically the fender is just sandwiched beneath this rigid frame beneath the ROPS and the roll bar above. The fenders themselves would not be expected to bear weight in the event of a rollover, but I can see why you thought that from the pics.
My concern is that with rollover the rollover bar would just have to pop through that very short section of threads coming up through the plate. But maybe I am worrying too much with four thick bolts on each plate, it is just that I have new property and it has LOTS of hills.

 

[RoyJackson]

If it's any consolation, that design had to go through testing to be certified as safe.

I do understand the bolt heads being on the bottom, since the forces in a rollover would tend to pull the bolts through the lower structure...the heads being on the bottom would prevent that.

However, I don't see anything that would prevent the bolts from vibrating loose (such as you mentioned, a nut). Also, it appears the plate atop the fenders is thinner then the bolt diameter, which (if I recall correctly...been a lot of years) is the required or recommended thickness for proper thread engagement (i.e.: The minimum length of thread engaged should one times the diameter of the thread). This all depends upon the strength of the bolt material as well as the plate material as well as the thread design (TPI, geometry, etc.). Is there a lock washer under the bolt heads?

As I had written, this design should have been tested per an ANSI or ASTM spec (whichever one applies to ROPS).

Does your manual say anything about checking the torque of those bolts?

And, yes, I'd feel more comfortable with nuts on the ends of those threads.

 

[skbruse]

If it's any consolation, that design had to go through testing to be certified as safe.

I do understand the bolt heads being on the bottom, since the forces in a rollover would tend to pull the bolts through the lower structure...the heads being on the bottom would prevent that.

However, I don't see anything that would prevent the bolts from vibrating loose (such as you mentioned, a nut). Also, it appears the plate atop the fenders is thinner then the bolt diameter, which (if I recall correctly...been a lot of years) is the required or recommended thickness for proper thread engagement (i.e.: The minimum length of thread engaged should one times the diameter of the thread). This all depends upon the strength of the bolt material as well as the plate material as well as the thread design (TPI, geometry, etc.). Is there a lock washer under the bolt heads?

As I had written, this design should have been tested per an ANSI or ASTM spec (whichever one applies to ROPS).

Does your manual say anything about checking the torque of those bolts?

And, yes, I'd feel more comfortable with nuts on the ends of those threads.

The manual...that wasn't delivered with my tractor yesterday. I will look in that when I get it (the dealer acted surprised when I asked where the manual was, said he would look around for it and send it to me).

The plates thickness is 5/16 inch and the bolt diameter is 7/16. There is a washer under the bolt head but I don't know if it is locking. It is not split locking but it could be internal teeth.

I have no problem with the general ROPS design, but I worry that it is the dealer who cut off the bolts not knowing he was supposed to put a nut and/or washer on the other side. Do dealers normally install the ROPs or does the tractor come from the factor with ROPS installed?

In any case I will go up to the dealers tomorrow, get my manual, ask when my tires are going to be swapped to the ags we agreed on, and ask him if they modified the ROPS installation in any way. Overall I love the tractor and am happy to finally have it (was delivered 1.5 weeks late), but the dealer experience wasn't the best.