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EDU: How to 09+ tunnel bumper conversion photo fortress (The cheap way)

Carbon77

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Please read this entire thread as I have made some recent changes in posts below.

Since there is so many threads on this, I compiled all of them (http://www.snowestonline.com/forum/showthread.php?t=288277 and http://www.snowestonline.com/forum/showthread.php?t=233694) to find out what conversion I wanted to do and ended up doing the cheapest. I looked at them all and figured it was not worth it for me to spend over $100 on getting a solid bumper. So I saw what Rixter did and it looked like the best option, costing around $75 depending on your dealer. This will work on any M series sled 05-09. I'll try to make this as simple as possible since it seems people have alot of questions about it.

So when I say the cheapest way possible, this is for certain people that have access to certain tools listed below. Also I have some home made better boards so I can not buy the 09+ side rails which might be easier for some people as the gusset's simply attach to the inside of them and do not require a welder.

Tools you need:

1. Rivet Gun + Rivets
2. Drill + Bits
3. Angle grinder or portaband.
4. Aluminum Welder. (Mig w/ spool gun or TIG) If you dont have a welder, you can take it to any shop and have it done for less than $50.
5. Carbide routing bit (not required but cleans up rough sharp aluminum edges)


Go to your dealer and buy this: (If you have a 153" or 141" the part number is: 5606-477 the difference? I dunno, prolly shorter and $5 less)

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Stock setup for reference:
IMG_0044_resize.JPG


Remove the plastic bumper and taillight

IMG_0046_resize.JPG


Figure out how far you want the new bumper to stick out and mark it on the tunnel. Also put scribe marks down on the tunnel where to cut, I chose to leave the 3/4" underneath the bumper from what Rixter did.
IMG_0048_resize.JPG



Take plastic bumper off and cut the stupid worthless handles off, right at the seam.
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Take a skinny wheel and cut the scribe marks, most skinny wheels are too short to cut through it so you have to get it weak and break it down to cut through the rest, the angle cut at the front where the gussets connect to follows the aluminum skid bracket on the bottom, I just cut that from the bottom up through the top.
IMG_0051_resize.JPG



I took the gussets and cut them short, they were way too far off angle to fit in the stock side rails properly, if you bought the new side rails, you dont have to do this. You literally have to grind everything off of these. I left a little chunk left just for fitment and tack welding.
IMG_0057_resize.JPG



I also cut a little notch out of the side rail to get a better fitment on the gussets, you can tell when you test fit them that they are not the right angle to fit in them, match the angles of the gussets with the angle to make on your cuts on the rail.
IMG_0058_resize.JPG


Done cutting now and test fitting, clean up edges.
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Throw the bumper back on and make sure your test fitment is still good before drilling the holes to rivet into the bumper.
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Notice the black rivet right in front of the reflector, since there is only two bolts holding the plastic bumper on now it needed a bit more support, I threw the two black rivets in there for some extra support on it.
IMG_0076_resize.JPG



Throw the sled on its side to drill the rivets into the bumper easier, I riveted on both the inside of the tunnel and through the bottom into the top. I used 3/16 aluminum rivets.
IMG_0078_resize.JPG



Grab yer welder, tack it on the bottom first, then rivet the top part. It will probably not fit flush, so suck it up to it as much as you can with the rivets. Make sure to drill them at a slight angle AWAY from the coolant lines on the inside of the tunnel.
IMG_0146_resize.JPG



Rivets on the inside of the tunnel
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Weld the gussets completely.
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Completed (Yeah, I got a bit crazy with the angle grinder)
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Now go pour yourself a beer.
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Not as clean as most, but just as effective and cheap. If you have any questions or need any better pictures, let me know. The ATV Gun racks are for holding my ski's in case anyone is wondering.
 
Last edited:

Frostbite

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Nice job, thanks. It looks an awful lot like what Rixster and I did as well.

Unfortunately, now I have a bunch of parts left I can't use and no longer need. If you may be able to use them on your sled let me know.

Here's a link to extra parts I have for sale if anyone needs them.

A flattened heat exchanger, 09 rail egdes that accept new style tunnel to rail gussetts, a used 09 rear flap with a new tail light and a tunnel close out panel.

http://www.snowestonline.com/forum/showthread.php?p=2919196#post2919196

DSC05522.jpg
 
Last edited:

WyoBoy1000

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You have a huge problem.

Because the 07 is longer you had to mount the bumper farther back, on the 09 the bumper goes through the kick up piece, your does not. This is for strength of the tunnel. If you run yours like that and ever over wheelie or land on the tail it will break between the kick up and bumper. Even if you never do those 2 things over time it will crack out. If either happen it will also break the cooler lines and your f cked. I would also run a small strap of aluminum from the out edge of the running board over the kick up and rivet it on for a little more strength.
Since your is already on I would mount a rather large sheet of aluminum to the inside of the tunnel from a few inches in front where the running board is cut to a few inches past where the bumper is attached.

If you search you will find the first BDX setup did the same thing as the bumper butted up to the kick up but did not go through it. They have a plate to fix it but it wont be big enough for the span you have.
 

shadow conspiracy

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You have a huge problem.

Because the 07 is longer you had to mount the bumper farther back, on the 09 the bumper goes through the kick up piece, your does not. This is for strength of the tunnel. If you run yours like that and ever over wheelie or land on the tail it will break between the kick up and bumper. Even if you never do those 2 things over time it will crack out. If either happen it will also break the cooler lines and your f cked. I would also run a small strap of aluminum from the out edge of the running board over the kick up and rivet it on for a little more strength.
Since your is already on I would mount a rather large sheet of aluminum to the inside of the tunnel from a few inches in front where the running board is cut to a few inches past where the bumper is attached.

If you search you will find the first BDX setup did the same thing as the bumper butted up to the kick up but did not go through it. They have a plate to fix it but it wont be big enough for the span you have.

A person could use a bumper from a proclimb. Noticed they're longer but just not sure if the widths are the same.
 

hd4rob

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im with wyoboy on this. You are counting on your coolers to support the rear of the tunnel. yes the rolled edge will help, but will it be enough? I have a project sled that Im building from scratch that the frame is from 06 and I did my own conversion, but i made sure and tied my bumper all the way to the suspension mounting brackets and then added the newer style close off to "box" the tunnel.
 
S

sledfreak89

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I think its a BIG problem right now, id say it will be HUGE when your out riding and she folds! :face-icon-small-win

Did the same conversion and really didnt spend too much buying AC parts, the most expensive thing was the new cooler which was around $100.
 

Carbon77

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im with wyoboy on this. You are counting on your coolers to support the rear of the tunnel. yes the rolled edge will help, but will it be enough? I have a project sled that Im building from scratch that the frame is from 06 and I did my own conversion, but i made sure and tied my bumper all the way to the suspension mounting brackets and then added the newer style close off to "box" the tunnel.
Its not like I'm carrying a dead hooker on the back. If I tomahawk the sled hard enough to bend the rear of the tunnel it will be worth it. Then I'll post a video of it and you all can laugh on how I "made a huge mistake" on taking 27 square inches of aluminum off of the end of my tunnel.

You guys sound like a bunch of Arctic Cat engineers that are mad @ BRP.
 
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hd4rob

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It's not the 27 square inches you removed it's the fact that you removed the edge rolls that tied the tunnel front to back and transferred the weight that is put on the bumper when lifting, crashing, or carrying things on the rear of the sled. Like said above just add something and save yourself the hassle, cheap insurance.
 

Carbon77

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This has worked fine for many people.

Neither one of you had anything to say about the 10 people that did it in the other two threads. Thanks for the input but If I wanted something better I'd go get a $12,000 sled like your guys.
 

Rixster

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You have a huge problem.

Because the 07 is longer you had to mount the bumper farther back, on the 09 the bumper goes through the kick up piece, your does not. This is for strength of the tunnel. If you run yours like that and ever over wheelie or land on the tail it will break between the kick up and bumper. Even if you never do those 2 things over time it will crack out. If either happen it will also break the cooler lines and your f cked. I would also run a small strap of aluminum from the out edge of the running board over the kick up and rivet it on for a little more strength.
Since your is already on I would mount a rather large sheet of aluminum to the inside of the tunnel from a few inches in front where the running board is cut to a few inches past where the bumper is attached.

If you search you will find the first BDX setup did the same thing as the bumper butted up to the kick up but did not go through it. They have a plate to fix it but it wont be big enough for the span you have.


That is why he didn't cut it flush on the bottom of the tunnel. If you leave that rolled edge and a inch or so on the boards you gain a ton of strength.
 

Team Pigeon

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A) Where is it mentioned that we hate BRP? An Assumption?
B) What does the two pairs of skis you're gonna haul weigh? And your fellow sled/skiing buddy weigh? And the spare gas and ski boots? And your sandwiches? Surely it all should weigh less than your dead hooker? Or does it? I know some pretty small hookers out there.
C) Nice work with the zip cut grinder, first time on that one? Doesn't look like one smoothed or straight edge. But you probably already knew poorly cut joints propagate into cracks.


The bitterness of poor work will always outlast the inconvenience of an empty wallet.
Let us know how she works out for ya.
 

hd4rob

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The pride of your work is worth about $5 for a couple pieces of aluminum to tie everything together. It will complete your job and should work good. Next you do need to get rid of your rough cut edges, sandpaper or a file would work fine. I'm not trying to run your work down just trying to save you a big hassle and headache. You do realize that if that tunnel cracks you will be replacing much more than the rear section. Your cooler tubes will most likely get wrecked also. Or you could prove us wrong and save $5. Your choice.
 

Carbon77

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A) Surely it all should weigh less than your dead hooker? Or does it?
C) Nice work with the zip cut grinder, first time on that one? Doesn't look like one smoothed or straight edge. But you probably already knew poorly cut joints propagate into cracks.


A) Depends on the kinda day that I'm having.
C) Thanks for noticing what I already pointed out. This is a learning template for others to work from, if they wish.
 

line8

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Critics galore!!! I found this to be informative, not because it is how I would do it or because I want to be able to do it this way. It just gave some insight on one person's (or combination of) idea. About half way down through the posts when the engineers clocked in, I lost interest. It was nice the time was taken to put some pictures with details. It gave me ideas of my own, so thanks for taking the time.
 

Carbon77

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Complete utter fail and backfire. Come one come all learn from my failure of a bumper setup. I did not want to post this here at first, but I feel like anyone doing this conversion needs to know this can happen. (Yeah, I know you guys said it).

I rode twice the weekend after I completed this, and it was absolutely the most brutal trail riding I've ever had, out of the whole weekend, about 30 miles were spent of 2-3ft whooped out trails. I got back to the sled on Sunday and realized the complete back half of the tunnel had broken because of my ski's that I had mounted on the back.

IMG_0235.JPG

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Notice exactly where it cracked (it did this on the other side too, just not all the way). Its right on my overcut of the tunnel. Honestly regardless of this overcut, I feel like this still would have happened given the conditions.

Including the back tunnel breaking....
The bulb fell out of the tailight
The rear plastic brake light housing also broke from an over cut.
My clevis from my tow rope almost gouged a hole in the tunnel underneath the seat.
3 bolts fell out of my luggage rack and the others were loose.

So, what have I gathered from all this? Since I did not take the time on my last tunnel install, and snowmobiles like these are never designed to have ANY weight on the back of them. Luckily I did not break the cooler lines.

I decided to go with a new 05 rear for stability reasons because I'm still going to have my skis mounted on it still, and I like the stock luggage rack. After getting the rear plastic section off I noticed that the stock 09 bumper was like 4" back from the end of the tunnel because the stock brake light assembly is so long. So in what lieu of what Wyo and others said, I figured I should get the 09 Flap and Tailight (which arrive today) and the closeout piece from fastrax so I can move the bumper forward a couple of inches and get more strength in the area since the 162's are so long, I dont think a 153 would have this problem.

I also bought some 1"1/4 1/16th Aluminum Angle that I'm going to rivet to the bumper and tunnel for more strength to hold the skis. People that are not towing or hauling much on the rear probably do not need to do this.
IMG_0243.JPG



I used the Aluminum also a guide for clean cutting, also decided to do the starter cuts with the dremel for more control, then finished up with the angle grinder, sanded down the edges and hit with a file to smooth them out.

IMG_0245.JPG



Notice how I did the rounded edges now (all with dremel) obviously for added strength and weight transfer, with just leaving that extra material on at a radius, it will probably save it from breaking at that point again.

IMG_0253.JPG



Fit like a glove marking the start of the radius 3 1/4" back from the start. I also removed the 6 rivets on the inner most part of the bulkhead tunnel to run the angle iron all the way to my better boards for more strength. Which I will have more pictures of tomorrow after I get the taillight, bumper and close out piece on.

The 09 taillight is a direct hard wire in with the stock 3 wire system correct? I've seen mixed decisions from people about this.

Learn from my mistake, so it does not happen to you :face-icon-small-dis
 
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