Solid steel rivets vs grade 8 or 9 bolts

[Sedgehammer]

I've tried finding this information on the interwebs and so far I haven't had any real luck. The part that we're using to attach to the new engine for the Bobcat had 12 rivets in it securing it to the plate that bolted to the flywheel. We had to remove those rivets to enlarge the new plate from the new motor to fit over the spine shaft that drives the hydrostatic part of the Bobcat. Does anyone know what the shear strength differences are? I can use grade 9 or grade 8. Will be bolted and will use metal lock nuts with red lock tight

Pictures attached of the old and the new. Well, the new motor is actually older then the old motor ....... 🤔

Replacement motor is a D242 Ford diesel. 175 ft lbs of torque. Old motor is a F227 Continental gas

The gray plate with the splined hub came off of the old motor. The yellow plate was on the D242 that came from the Onan power plant is now mated to the splined hub. Just deciding on bolts or rivets

On the old setup the splined hub steel shaft fit into the flywheel to act as a pilot. This new setup will not have that. The yellow 'drive' plate will need to be spaced about 3/4" from the new engines flywheel. Will use 1.25x.750x.375 cold rolled washers that we'll make




 

 

 

 

 

 


 

 

 


 



 


 

 

[TroyC]

I'm a long way from being an authority on this sort of thing, but it is my understanding rivets are pounded in and the pounding would expand the rivet shank and take up any slack in the hole, thus tightening everything up. Putting a bolt in the hole might leave a little wiggle room that could work loose and cause the assembly to fail. I see some tails coming from the original rivets. Was there any looseness in them when removing them?

[moodnacreek]

At least itis not a reversing load as that will make any joint fail if not done right.

[chevytaHOE5674]

I would use bolts with all metal lock nuts and red lock-tite and not 2nd guess it personally.

My skid steer has the center hub bolted to the drive disk with rubber in between. Supposed to cushion some of the harmonics of the engine. The rubber lasts about 3k hours from what I've seen. It uses 8 or 10 3/8" bolts and thats with a 110hp powerplant.

[Sedgehammer]

Troy C. None that we could feel

ChevytaHOE5674 that's the plan unless I get a no, no from someone based on a math difference

[Crusarius]

I wouldn't even think twice about using bolts. But I would not use carriage bolts  I am guessing those are just temporary? 

[Sedgehammer]

Crusarius yes, just had some laying around. They wouldn't work very well ...... 🤣

[LeeB]

I wouldn't think the rivets were grade 8. 

[hedgerow]

I have swapped a lot of engines into a lot of different equipment over the years and always just use grade eight bolts with all steel lock nuts and red lock tight. I have drilled the holes to the next size sometimes to get a tight fit with the bolts or used a metric size to get a tight fit. Have done it on three or four hundred HP power units and have never had a issue with using bolts.  

[Sedgehammer]

LeeB. Agree, can't even find shear strength on them

[Sedgehammer]

hedgerow. I would drill these out to 3/8, but the hub is hardened and can barley make a scratch over the hole with a cobalt. I'd need to get a carbide and prolly a few since they break so easily $$$$

[Wlmedley]

I wouldn't worry about the bolts replacing rivets as much as shaft not being supported by flywheel like your old setup.The metal plate that bolts to flywheel is(what anything I worked on )defined as a flex plate  and is made to absorb shock.I have saw these cracked.Shaft not being supported by flywheel May let it flex in different way than it was designed to do.Can always give it a try and see what happens.May hold from now on.

[Sedgehammer]

Wlmedley I know. Worries me some. They also had a diesel from the factory. They had a clutch setup. Can't find any parts anywhere to copy that. If we have an issue, will need a thicker plate that bolts to the flywheel most likely

[Wlmedley]

May be okay like it is.Before I retired Komatsu was using a plastic flex plate on some fairly large hydrostatic wheel loaders and the only one I ever replaced was because of a factory update.If yours would happen to fail it shouldn't hurt anything else.

[Wlmedley]

Found some pictures.Don't know what kind of plastic they used but it must be pretty tough.This is drive plate for a Komatsu WA320 wheel loader.

 

 

  

[Sedgehammer]

😱😱😱

[Crusarius]

Plastics and synthetic materials have come a very long way from when most of you guys were younger

There used to be a time I would not trust plastic. Now I am much more willing to accept it and use it. The stuff I have made with a 3dprinter would blow your mind. One of the items was a tool to press two bushings together. It held up better than I thought it would.

[Sedgehammer]

Yeah, I see it on a lot of parts that never were.  Amazing how it's come along

[chevytaHOE5674]

The plastic/fiber drive plates are used in lots of construction and foresty applications. They hold up real well as long as everything is supported and running true. If a bearing starts to wear and the driven spline starts to have any run-out then the fiber drive plate doesn't last.

I too would be more concerned about the unsupported shaft than the rivets in this application. 

[Sedgehammer]

ChevytaHOE5674 yeah, that's a thought

[charles mann]

You can try AC 43.13 and see what that manual says on substituting rivets for bolts. When i worked on big trucks, we would replace huck bolts/rivets with bolts. We reamed the holes up to the next bolt size and had to tap them in with a hammer and rattled the nuts on. 

[Sedgehammer]

Charles mann. Looked that over. Can't find any good cross for that info. Can't drill the hub unless I use carbide drill bits. That's kinda spindy. Would prolly break a few with that many holes. I think I'll get some grade 9 bolts, metal lock nuts and red lock tight and 🙏🏼 that'll be alrighty. I'll not be using it as a dozer, so it'll not see max work load