How to - M916 5th wheel plate swap

Hey folks. I am swapping my 5th wheel plate on the M916 from the big pin (3" or 3.5" ?) to a standard 2" plate made by Holland. This is the same plate that Soni used on him M920 and others are considering.

I have the original plate off and the new plate staged. I am having bushings machined to adapt the new plate to the truck.

It is too late/dark for pics tonight but I will post some tomorrow.

Justin Wehring
979 997 3112

Can't wait to see !

Justin

I performed the same top plate swap two weeks ago and boy has it made my 920 more useful. One of my friends gave me an entire holland air slide and top plate off an OTR tractor he scrapped and I ended up just using the top plate and making some pin bushings.

A couple of things I noticed: When I sat the new top plate on the kompensator "ears" the smaller bushings holes in the top plate appeared to line up below the center of the stock larger pin bushings installed in the ears. By installing my bushings and pins it slightly lifted the top plate off of the ears and I decided to let it go by the logic that weight on the top plate will cause the factory rubber bushings to distort letting the top plate drop down so the ears and top plate make a propper bearing surface that will carry the load instead of the pins. It is also the possibility my top plate/ mounting ears are worn out of tolerance. I'd be interested to hear how your's line up.

Also below the rubber tubes that limit the side to side oscillation of the fifth wheel I found my kompensator chock full of mud and rust. By far the worst rust I have found on my truck and the center metal piece is actually rusted out to the point it needs to be cut out and replaced. I didn't have time to do it but I will be pulling mine back apart to fix it properly and probably add a drain hole to let the water drain. You might want to clean out that area on yours and check the condition of the paint to prevent further degradation.

Best of luck getting it reassembled and be safe the top plates are heavy.

Tom

Good info Tom ! I had mine off to relocate it but havent switched out top plates yet.

I'm next with the swap. Justin give us a heads up where you got the Holland plate and what the damage was.

pics

Here are some pics

Justin Wehring
979 997 3112

pic

One more

Justin

Justin glad your swap worked out/
Your truck is looking great!!

thanks

Thanks. It is looking pretty different from the pizza cutters you saw in Sedona!

Justin Wehring
979 997 3112

i wonder if you could pull a civy box trailer with that fifth wheel at that height and still be under 13'6".Nice mod.. i think you have to many toys don't forget to share.....

Thanks for posting the info, Justin. I think the 5th wheel spacer might need to go as well. Can anyone shed any light on why that was provided as a kit for these trucks? When coupled to the M172A1 trailer, the spacer makes the trailer sit way high in the front. The only idea I have is that it allows more pitch clearance in rough terrain.

NDT said:

Thanks for posting the info, Justin. I think the 5th wheel spacer might need to go as well. Can anyone shed any light on why that was provided as a kit for these trucks? When coupled to the M172A1 trailer, the spacer makes the trailer sit way high in the front. The only idea I have is that it allows more pitch clearance in rough terrain.

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I think the spacers might be needed for propper clearance for side to side oscillation.

After moving my fifth wheel back and removing the spacers and confirming good swing clearance on level ground, I set my little brother free to go check out how much cool oscillation that kompensator fifth wheel has and he brought my truck back with the most twisted/mangled mud flap bracket I have ever seen. I made him show me me how he did it and he basically backed the trailer up a steep hill while jackknifing the truck. The side to side and front back oscillation combined can really allow a corner to get pretty low.

Presumably with a wide "tongue" trailer like a dry van the edges of the trailer could hit the top of the tractor tires if the top plate is too low (my landing gear got into the mud flap). I think the top of the factory tires is almost the height of a standard civilian tractor top plate.

Tom

are M916 and M920 the same wheel base?

micochico said:

I think the spacers might be needed for propper clearance for side to side oscillation.

After moving my fifth wheel back and removing the spacers and confirming good swing clearance on level ground, I set my little brother free to go check out how much cool oscillation that kompensator fifth wheel has and he brought my truck back with the most twisted/mangled mud flap bracket I have ever seen. I made him show me me how he did it and he basically backed the trailer up a steep hill while jackknifing the truck. The side to side and front back oscillation combined can really allow a corner to get pretty low.

Presumably with a wide "tongue" trailer like a dry van the edges of the trailer could hit the top of the tractor tires if the top plate is too low (my landing gear got into the mud flap). I think the top of the factory tires is almost the height of a standard civilian tractor top plate.

Tom

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The M172 was designed to be pulled behind an M818 which is much lower or the M123 prime movers. I know that it has the swappable pin from 2 to 3.5 but that was for the two tractors above. The m920 was more suited for the 747 trailer and the 870's for the height requirement. Soni has been running without his spacer since 03 with no problems afaik or he would have changed it by now. I too removed the spacer in mine and have had no problems with clearance with a step deck trailer I have been towing.

Not going to put words in Soni's mouth but I believe the running gear (wheelset) he is running on the M747 is smaller than OEM. That compiled with the shear load he uses the trailer for levels it out nice. I think he grosses 160000 with the locomotive...off top of my head I can't remember the exact figure.

ddgoose69 said:

are M916 and M920 the same wheel base?

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No

M916 is 186"
M917, M919 and M920 is 211"

Bighurt said:

Not going to put words in Soni's mouth but I believe the running gear (wheelset) he is running on the M747 is smaller than OEM. That compiled with the shear load he uses the trailer for levels it out nice. I think he grosses 160000 with the locomotive...off top of my head I can't remember the exact figure.

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that is correct about the wheel set he is using, that coupled with the removal of the spacer and the sheer weight of his loads is a great combo for his truck.

eldgenb said:

that is correct about the wheel set he is using, that coupled with the removal of the spacer and the sheer weight of his loads is a great combo for his truck.

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Yeah the lack of a spacer was already mentioned. And it has little effect on the M870. Actually I think the M920's original height was a little over the M870's design. It was after all designed for the standard over the road truck.

I actually seriously looked at both for future applications, the M747 and M870. for me the choice is obvious with the M870. The extra axle doesn't gain any load with standard bridge formula's.

Bighurt said:

. . . the M870's design. It was after all designed for the standard over the road truck.

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Bighurt, I do not think this is entirely correct. I have read here that people have had to shorten the necks on M870's to use with standard height OTR trucks. Look here at the height difference between the 915 and 916/920.

Well in my mind I was comparing an equal heavy haul truck not just highway truck. There is quite the varying 5th wheel heights among equal trucks as well. At work the Sterling and Freightliner's have different pin saddle heights and they are equals as far as the AF is concerned. Sucks picking up a trailer the other dropped off and vice versa...

Cheers