580SL S2 Engine Harp Bolts Broken.

[gggraham]

A parts customer of ours is having some trouble with a 580SL S2. The machine has 9000 hrs on it, about 3 months ago they had no hydraulics. Trouble was a coupler has wrecked the splines and the splines on the pump. After closer investigation he found the bottom 2 bolts on the harp broken. I told him to replace the engine mounts, the coupler and the pump. I also told him to remove the harp completely and inspect the surfaces for flatness as it was loose. He brought the harp in it was fine, he had pictures of the block it was fine. I told him to install fairly tight and check it for runout. All was fine he said. Installed the harp with new bolts with loctite. Installed a new coupler and pump. Now with less than 200 hrs it has broken the bottom two bolts on the harp and ruined the splines in the coupler, the pump was OK. I’ve fixed plenty of these over the years when I was a mechanic done as I instructed him and never had this occur any thoughts??????

 

[Acecadet]

Are you saying the bottom two bolts in the mount (shown as #2) are breaking? Are they beating the hell out of this machine? I’d like to say I haven’t seen that before, then again, I’ve seen the counterweight ripped off a cat 993k before, so anything is possible.

 

[gggraham]

Yep that's the bolts, I've never seen it before.

 

[Acecadet]

Those bolts are only 8.8 standard. Could you bump all of them up to a 12.9 bolt? Maybe that will help.

 

[JBrady]

Are the dowel pins in place between the engine block and pump mount (Item#4 in above schematic)? Also, is the rubber bushing (Item #7) installed the correct way? If I recall, when I changed mine out on my 590SL it was possible to put them in upside down or backwards. There are quite a few threads on this site about this very issue. Enough so that my nervousness about those two bolts caused me to put a wrench on them every few operating hours to make sure they hadn't broken. That was several years ago and they have stayed tight ever since.

 

[gggraham]

I've got the guy checking the harp again to make sure the runout is OK. I'll let you know what he finds.

 

[Tinkerer]

Does anyone remember a long time HEF member Named Goose ?
I haven't seen him post anything lately.
He had this same problem a few times and the fix was expensive and drastic.
https://www.heavyequipmentforums.com/threads/case-breaking-engine-mount-bolts.7199/#post-164664

 

[gggraham]

Does anyone remember a long time HEF member Named Goose ?
I haven't seen him post anything lately.
He had this same problem a few times and the fix was expensive and drastic.
https://www.heavyequipmentforums.com/threads/case-breaking-engine-mount-bolts.7199/#post-164664

I warned the guy about this....now his seems fine but I told him to check it over again . Last I spoke to him it was in a barn. Loader on the ground he was struggling to remove the hood. I will keep you updated.

 

[alrman]

For what it's worth, I've also seen it a few times over here.

Sometimes people say they "checked" things - when they may not have actually done so at all.
It's not that easy to check that crankshaft run out, unless you fabricate a mounting plate for the dial gauge to suit the situation - most folk won't go that far.....

Almost unbelievable that it takes 9000hrs for this to come about - but it was similar situation with the ones I've seen too.
If it isn't "set up" right after the first failure, the dowel holes in the block just get more damaged.

It may be feasable to drill the carrier for new roll pin type dowels, then fit the carrier, adjust it to perfect centre with crankshaft, tighten in place & recheck - then drill through the dowel holes into the block & fit new pins.
They would have to be long pins due to shape of the carrier.

In saying that, I wonder if the crankshaft has some extra movement due to high engine hours that is causing this failure - & if this new dowel idea would even work if this was the cause.

One situation I recall, early on, failed numerous times & the block was badly damaged, so another engine & mount was required for the fix.... $$$$$

 

[gggraham]

For what it's worth, I've also seen it a few times over here.

Sometimes people say they "checked" things - when they may not have actually done so at all.
It's not that easy to check that crankshaft run out, unless you fabricate a mounting plate for the dial gauge to suit the situation - most folk won't go that far.....

Almost unbelievable that it takes 9000hrs for this to come about - but it was similar situation with the ones I've seen too.
If it isn't "set up" right after the first failure, the dowel holes in the block just get more damaged.

It may be feasable to drill the carrier for new roll pin type dowels, then fit the carrier, adjust it to perfect centre with crankshaft, tighten in place & recheck - then drill through the dowel holes into the block & fit new pins.
They would have to be long pins due to shape of the carrier.

In saying that, I wonder if the crankshaft has some extra movement due to high engine hours that is causing this failure - & if this new dowel idea would even work if this was the cause.

One situation I recall, early on, failed numerous times & the block was badly damaged, so another engine & mount was required for the fix.... $$$$$

After asking my initial question and the first couple replies it all came back to me. I haven't been wrenching for 6 years now ( ulnar nerve injury ) and it's been a long long time since I worked on a 580L. In Canada where I am typically machines are turned over every 3-4 years so you don't see the older ones except for a few private guys or farmers. I have advised the guy as much as I can, if it goes back together without the checks I mentioned I am sure it will occur again. I did mention the crankshaft movement to him as well. I told him to take picture (lots) and send them to me. The machine is miles away and in the dead of winter snow flying and -21C ( -6F) I'm not about to drive there to take a peek. I will keep you posted. Thanks again you guys are awesome!!!

 

[gggraham]

OK so I think we found the guys problem. They got the backhoe on a float and brought it to a small repair shop close to work. I stopped by today to take a look and it all came back to me. The welds on the frame were interfering with the washers. I remember grinding those welds back and the washers breaking. Funny a physical look at things and the old brain starts remembering everything. I'm surprised the washers weren't cracked the weld had worn a groove around both of them. The mounts were installed upside down, long piece was up from the bottom and small rubber on top. The mount itself was so badly worn where the mounts sit it was destroying the mounts. The face of the mount was amazingly fine as was the block. The dowels were a little loose and the pump had lots of play in the mount. So he's ordering a new harp/mount, dowels, new rubber mounts and washers. BTW he never did dial it in when it was installed. That will be done also. So what was suppose to be fine was anything but. Should survive to run for a bit yet, but now with 9600 hours the owner is thinking of getting rid of it.

 

[Tinkerer]

No photos, Gil ?? I'm surprised.
An upside down rubber mount. Good grief !
Where are those washers located on the frame ?

 

[gggraham]

No photos, Gil ?? I'm surprised.
An upside down rubber mount. Good grief !
Where are those washers located on the frame ?

The washers are #6 in the picture Acecadet sent. I forgot all-out those welds interfering with the washers sitting flat. But as soon as I looked at the machine my brain clicked in and it all came back to me. The mounts upside down was a surprise, he says he put them I how they were installed hmmmm. Thats why I always hated customers giving details over the phone. One quick look and in 30 seconds I saw things he didn't even know were wrong. No pictures I guess I was in a hurry to get to work. My boss was good enough to let me take a look and get paid so I looked , consulted and headed to work.

 

[Tinkerer]

It is quite amazing about those welds causing the washers to fail.
I wonder how many tractors were produced with that flaw.
And how many pumps and harps have been destroyed as a result of it.
I always wondered why Case only used one rubber mount on that front support.
It seems that for the amount weight and the beating they get there would be two of them.
Sadly it is one of those things that no one sees failing until some kind of damage has been done.

 

[Coy Lancaster]

That failure is one of the main reasons Case moved the hyd. pump back to the tranny and that they changed engines.

 

[Welder Dave]

You'd think in the original assembly Case would grind clearance for the washers if necessary. I've seen lots of assemblies with basically stitch welds. The weld stops and there is a short section unwelded to allow for a bolt or nut to be turned.