Advice on repairing undercarriage damage (and adding skid plate)

[gitrdun]

Sorry, here is the picture.

 

[steveg_nh]

Thanks guys. I already have a weakened back edge on the belly pan, so I prefer the new rivets in there now, vs rivnuts or even well nuts. That's what I like the idea of either tapping it, or just using the self tapping robertson screws. Pretty flat head too. So is the feeling those screws should hold fine, given the double aluminum panel? I didn't realize that, that makes me feel even better about using them. Very simple solution. And should they ever strip, the hole will be small so I could always expand it and tap it or use a larger rivnut in the future. Just looking to find a good solution now and move on without too much complication, and the trailer self tappers seems like a winner.

 

[TrueBlue]

Agreed, skid plate holes were slightly off so I think I used a chainsaw file to make them exactly right to comfortably fit the Yamaha body panel bolt in the picture. I use that Philips bolt because it has a flat head and less likely to grab a rock and cause damage. I did use rivnuts, and as Apexallday! says, you have to use the up to 6.6mm grip range because the kit used to come with the up to 4.2mm grip range, and guys were complaining that they were coming loose. You will notice that there are two thin pieces of metal that the rivnuts go through, that's why you have to use the 6.6mm range rivnut(aluminum). I'm guessing I've had this combination on for 8 years and works perfect. I torque the body bolts to 25 inch lbs..

I have been putting in skid plates 1994 & never had a problem with the stock rivets coming loose. My last install was on a 2015 Vector with no problems. I am going to install a skid plate on my 2018 Vector & already have the skid plate. What you are saying is that the original rivnuts are too short & need to buy 6.6mm ones. If I remember right aren't the bolts metric. If I decide to buy the longer ones where do you buy them from in metric or do you buy standard rivets and just buy new bolts. Are the rivnuts alum. or steel ? If they are alum. isn't there a saying that your not to mix alum. with steel for corrosion reasons.

 

[gitrdun]

Hopefully we are not straying off topic for this post, but the problems back around 2007 was that the skidplate kit came with rivnuts similar to in my picture, that were up to 4.2mm grip range. A 4.2mm grip range rivnut would have been fine for one thickness of aluminum, but when people were complaining that their rivnuts were falling out, we had a closer look underneath on the 2007 Apex where the 4 rivnuts went, and found that at least in a couple of holes, there is two thickness of aluminum totalling more than 4.2mm, making us realize that we had to go to the next size rivnut which was the 6.6mm grip range. Now I can't tell you if the same is true for a 2018 Vector, you will have to inspect that edge from underneath where the rivnuts go, and even measure the thickness of the aluminum. They may have changed the structure or they may be sending longer rivnuts with the kit. My 4.2mm grip range rivnut measures 15mm in length, and my 6.6mm grip range rivnut measures almost 18mm in length if you want to compare. Those rivnuts are aluminum and metric, you should be able to read the part no. in the picture ALA1-610-6.6, and they came from McMaster Carr about 8 years ago so hopefully part no.'s are still the same. I am not an expert on corrosion, and I am not sure which parts specifically you are referring to, but most of the frame is aluminum, the rivnuts are aluminum, and most Yamaha steel bolts have that coating on them, so there should be minimal to no reaction.

Added note: Part # ALA1-610-6.6 is what is written on the bag, but brings up no result at McMaster Carr, but part no. 94020A387 does work.

 

[TrueBlue]

ets

Hopefully we are not straying off topic for this post, but the problems back around 2007 was that the skidplate kit came with rivnuts similar to in my picture, that were up to 4.2mm grip range. A 4.2mm grip range rivnut would have been fine for one thickness of aluminum, but when people were complaining that their rivnuts were falling out, we had a closer look underneath on the 2007 Apex where the 4 rivnuts went, and found that at least in a couple of holes, there is two thickness of aluminum totalling more than 4.2mm, making us realize that we had to go to the next size rivnut which was the 6.6mm grip range. Now I can't tell you if the same is true for a 2018 Vector, you will have to inspect that edge from underneath where the rivnuts go, and even measure the thickness of the aluminum. They may have changed the structure or they may be sending longer rivnuts with the kit. My 4.2mm grip range rivnut measures 15mm in length, and my 6.6mm grip range rivnut measures almost 18mm in length if you want to compare. Those rivnuts are aluminum and metric, you should be able to read the part no. in the picture ALA1-610-6.6, and they came from McMaster Carr about 8 years ago so hopefully part no.'s are still the same. I am not an expert on corrosion, and I am not sure which parts specifically you are referring to, but most of the frame is aluminum, the rivnuts are aluminum, and most Yamaha steel bolts have that coating on them, so there should be minimal to no reaction.

Thank's for all that information it will be helpful. I will look at the length of the rivnuts that came with the skid plate to see what size they are.
Thank's Rich

 

[Winderallday!]

Thanks guys. I already have a weakened back edge on the belly pan, so I prefer the new rivets in there now, vs rivnuts or even well nuts. That's what I like the idea of either tapping it, or just using the self tapping robertson screws. Pretty flat head too. So is the feeling those screws should hold fine, given the double aluminum panel? I didn't realize that, that makes me feel even better about using them. Very simple solution. And should they ever strip, the hole will be small so I could always expand it and tap it or use a larger rivnut in the future. Just looking to find a good solution now and move on without too much complication, and the trailer self tappers seems like a winner.

On my 2011, I drilled out the rivet holes and tapped 5/16"NF. I bought some stainless pan head Allen bolts that worked slick. Fastenal is a great source for some of these exotic fasteners including longer grip range riv nuts and well nuts.
If you are going to go with the threaded hole idea, I would recommend a fine series bolt instead of coarse because of the limited thickness, it will give you more threads and a better chance of a longer life. If corrosion due to the anode/cathode effect of dissimilar materials are a concern, I would use grease or anti seize on the fasteners, however if you change the oil once a season, the skid plate has to come off anyway, so they won't have time to seize or corrode over an extended period of time. I have not seen this happen with steel bolts or SS bolts and I don't use anything on the fasteners for protection, but to each his own.
Cheers.

 

[steveg_nh]

Thanks. I was thinking that rivnuts actually make belly pan removal more complicated as it’s holding the belly pan to its structure and not easily removed down the road. When I do a track and pull the chain case I will replace the belly pan and bent heat exchanger at that point. So I want to be sure I can get it out.

I’m going to first try the self drilling SS screws. I’ll be able to feel how solid they feel. If enough I’m done. If not I’ll enlarge and tap the holes for a 1/4 fine threaded bolt.

And I love Fastenal!

 

[RTX]

If by chance you are still looking into a better way to mount the skid plate you can try nut plates.
Look them up on google.
Drill out the nutsert hole large enough for the nut plate to drop into. Then use the rivet holes in the nut plate to secure it to the sled.
I have been using them for years and they never fail like nutserts

 

[TrueBlue]

Hopefully we are not straying off topic for this post, but the problems back around 2007 was that the skidplate kit came with rivnuts similar to in my picture, that were up to 4.2mm grip range. A 4.2mm grip range rivnut would have been fine for one thickness of aluminum, but when people were complaining that their rivnuts were falling out, we had a closer look underneath on the 2007 Apex where the 4 rivnuts went, and found that at least in a couple of holes, there is two thickness of aluminum totalling more than 4.2mm, making us realize that we had to go to the next size rivnut which was the 6.6mm grip range. Now I can't tell you if the same is true for a 2018 Vector, you will have to inspect that edge from underneath where the rivnuts go, and even measure the thickness of the aluminum. They may have changed the structure or they may be sending longer rivnuts with the kit. My 4.2mm grip range rivnut measures 15mm in length, and my 6.6mm grip range rivnut measures almost 18mm in length if you want to compare. Those rivnuts are aluminum and metric, you should be able to read the part no. in the picture ALA1-610-6.6, and they came from McMaster Carr about 8 years ago so hopefully part no.'s are still the same. I am not an expert on corrosion, and I am not sure which parts specifically you are referring to, but most of the frame is aluminum, the rivnuts are aluminum, and most Yamaha steel bolts have that coating on them, so there should be minimal to no reaction.

Added note: Part # ALA1-610-6.6 is what is written on the bag, but brings up no result at McMaster Carr, but part no. 94020A387 does work.

Your right on the new part no. for the 6.6 rivnuts from Mc Master Carr. I bought some today. Since the rivnuts are a little longer do you also buy a longer bolt that is used to install the rivnut in the belly pan.

 

[gitrdun]

I suspect you are talking about the bolt that came with the kit. I made a little installation tool( search skid plate rivnut install)(10 years ago almost) so I can't say that I used that bolt. I see that there is about a 1/8 inch difference before the bolt contacts the threads between the 4.2 rivnut and the 6.6 rivnut. Bolts are cheap but you could wait until you get the rivnuts and see how many threads you are grabbing, then decide. My contraption has about 17 mm of threads going into the 17.5 mm long rivnut.

 

[steveg_nh]

If by chance you are still looking into a better way to mount the skid plate you can try nut plates.
Look them up on google.
Drill out the nutsert hole large enough for the nut plate to drop into. Then use the rivet holes in the nut plate to secure it to the sled.
I have been using them for years and they never fail like nutserts

Nut plates? Never heard of them. Need to look that up. Sounds interesting.

 

[Winderallday!]

I suspect you are talking about the bolt that came with the kit. I made a little installation tool( search skid plate rivnut install)(10 years ago almost) so I can't say that I used that bolt. I see that there is about a 1/8 inch difference before the bolt contacts the threads between the 4.2 rivnut and the 6.6 rivnut. Bolts are cheap but you could wait until you get the rivnuts and see how many threads you are grabbing, then decide. My contraption has about 15 mm of threads going into the 17.5 mm rivnut.

The bolt that comes with the skid plate kit is a 6mm hex head as I recall, and the hex-head is not very thick to get a good hold of with a wrench/socket. It takes a fair amount of force to collapse/set the riv nut so having a good grasp of the bolt head is key, I used an Allen head bolt with a hard washer under it to install mine. You need to maintain constant push force on the riv nut/tool when installing so it doesn't pull back when beginning the installation. I also used lube between the bolt/washer and also on the threads to minimize the risk of galling/stripping especially with the aluminum riv nuts.

 

[TrueBlue]

I suspect you are talking about the bolt that came with the kit. I made a little installation tool( search skid plate rivnut install)(10 years ago almost) so I can't say that I used that bolt. I see that there is about a 1/8 inch difference before the bolt contacts the threads between the 4.2 rivnut and the 6.6 rivnut. Bolts are cheap but you could wait until you get the rivnuts and see how many threads you are grabbing, then decide. My contraption has about 17 mm of threads going into the 17.5 mm long rivnut.

When you install the bolt through the tool & into the rivnut it is about 1/16" short of coming through the other end of the rivnut. My concern is that will it compress the entire rivnut so that it is a tight fit. This is with a 6.6 rivnut.

 

[gitrdun]

The compression should take place in the portion of the rivnut where there are no threads. Being well into the rivnut with the threads of the bolts ensures that you won't strip it. Sounds like you will be OK, and if you are not, your package of 10 or 25, will allow you to redo.

 

[steveg_nh]

Well I finished the install and opted to not use the rivnuts. As planned I used the 1” SS self drilling screws. This worked very well and I don’t think it’s going anyway. Very solid. They have a pretty flat head too so snagging isn’t a concern. I carefully let the screws start their holes and then took one last check with the inspection camera, using a rivet pin through the hole. I had plenty of clearance. My belly pan is all tightened up with new rivets and the skid plate covers all the damage I had for the most part. I’m pleased with the install. Between the skid plate and the BOP metal engine cover plate I feel well protected now.