What causes a bulkhead closeoff to crack? 2019 Axyx 850

[tb123]

My bulkhead closeoff plate is cracked near the rear right engine mount (see attached photo). I'm curious if anyone else has seen this? There really isn't any other damage that I can see, but the sled was purchased used so I don't know what the PO might have already replaced.

I'm in the middle of replacing the plate as I believe clutch alignment will be effected as the engine torques. What else should I carefully inspect for while I have everything torn down?

 

[tb123]

Well, after further inspection, I found a tiny crack in the the left side bulkhead. You couldn’t see it until I pressure washed the exterior (which wasn’t even that dirty).

 

[kanedog]

Post the guys name that sold it to you. Let’s stir up sum chit!

 

[tb123]

Post the guys name that sold it to you. Let’s stir up sum chit!

Ha, I’m not going to do that, although it’s tempting as I assume he was aware of the damage. The close off plate damage is very visible with the silencer removed. The sled had a stock exhaust on it when I bought it, but given the other mods, I doubt he was running the stock silencer. I’m sure the seller took his can off right before selling and couldn’t have missed the damage.

All that matters now is getting it fixed before the snow gets good!

 

[Sheer]

Mine cracked in the exact same spot, not as bad as that one, it was strange it wasent from an impact - i give my sled a brief checkover after every ride and saw that crack one day - the ride prior was pretty tame with no tree hits, i rubbed the outside of my ski agenst a very small tree (missed the tree but the tree turned me) that ride, and i was wondering if that caused it, and i rolled it over a few times to get un stuck and maby from the chassies twisting did it, i dont know, but ive defently hit things harder and done much worse with no damage to the frame, there wasent even one point in that ride where im like i hit something hard i should stop and check tipe of thing.. anyway it was still under warrenty at the time and that piece broke and with no external damage i wanted it fixed, polaris sortof half came through and authorized to have it welded and said if it continues to crack after that they would replace it, its been a few years since and its been fine but my crack was only about 1.5 in long

 

[tb123]

Mine cracked in the exact same spot, not as bad as that one, it was strange it wasent from an impact - i give my sled a brief checkover after every ride and saw that crack one day - the ride prior was pretty tame with no tree hits, i rubbed the outside of my ski agenst a very small tree (missed the tree but the tree turned me) that ride, and i was wondering if that caused it, and i rolled it over a few times to get un stuck and maby from the chassies twisting did it, i dont know, but ive defently hit things harder and done much worse with no damage to the frame, there wasent even one point in that ride where im like i hit something hard i should stop and check tipe of thing.. anyway it was still under warrenty at the time and that piece broke and with no external damage i wanted it fixed, polaris sortof half came through and authorized to have it welded and said if it continues to crack after that they would replace it, its been a few years since and its been fine but my crack was only about 1.5 in long

After further inspection, I also found a hairline crack in my left bulkhead casting. My sled has been down all winter so far... good year for it with no snow.

I pulled the bulkhead and closeoff plate and I'm currently reassembling. Does anyone know if I am to use Lord 406 adhesive on the mating surface between the tunnel sheet metal and the closeoff plate (I already riveted it on without it so I hope not)? There was no adhesive used in this location from the factory (upon inspection after removing my cracked plate), but the 2020 155 service manual shows it being used here if the sled has a cooler. I have a 2019 163 without a closeoff cooler. Does anyone have a copy of the 2019 163 service manual to check this for me? Thanks!

 

[IdahoSledder#09062006]

After further inspection, I also found a hairline crack in my left bulkhead casting. My sled has been down all winter so far... good year for it with no snow.

I pulled the bulkhead and closeoff plate and I'm currently reassembling. Does anyone know if I am to use Lord 406 adhesive on the mating surface between the tunnel sheet metal and the closeoff plate (I already riveted it on without it so I hope not)? There was no adhesive used in this location from the factory (upon inspection after removing my cracked plate), but the 2020 155 service manual shows it being used here if the sled has a cooler. I have a 2019 163 without a closeoff cooler. Does anyone have a copy of the 2019 163 service manual to check this for me? Thanks!

View attachment 414099

After further inspection, I also found a hairline crack in my left bulkhead casting. My sled has been down all winter so far... good year for it with no snow.

I pulled the bulkhead and closeoff plate and I'm currently reassembling. Does anyone know if I am to use Lord 406 adhesive on the mating surface between the tunnel sheet metal and the closeoff plate (I already riveted it on without it so I hope not)? There was no adhesive used in this location from the factory (upon inspection after removing my cracked plate), but the 2020 155 service manual shows it being used here if the sled has a cooler. I have a 2019 163 without a closeoff cooler. Does anyone have a copy of the 2019 163 service manual to check this for me? Thanks!

View attachment 414099

Hi!

I have a 2019 AXYS 850 that also cracked in the same spot. Pretty bad if not worse than the original picture in this thread. I am in the porcess of replacing it right now and have the parts, adhesive, etc... but was wondering how you guys went about replacing this? Did you support the sled in any way when you removed the ASM brackets/supports? Slighly worries that once I remove the bolts and head the metal to seperate the Lord Adhesive, it will make the middle of the sled structurally weak. Any info you guys can provide would be greatly appreciated. Thanks,

Justin

After further inspection, I also found a hairline crack in my left bulkhead casting. My sled has been down all winter so far... good year for it with no snow.

I pulled the bulkhead and closeoff plate and I'm currently reassembling. Does anyone know if I am to use Lord 406 adhesive on the mating surface between the tunnel sheet metal and the closeoff plate (I already riveted it on without it so I hope not)? There was no adhesive used in this location from the factory (upon inspection after removing my cracked plate), but the 2020 155 service manual shows it being used here if the sled has a cooler. I have a 2019 163 without a closeoff cooler. Does anyone have a copy of the 2019 163 service manual to check this for me? Thanks!

View attachment 414099

I have a 2019 AXYS 850 that has the same exact ASM closeoff bulkhead crack on the same engine mount spot. I’m in the process of replacing it but was wondering if you guys supported the sled in any way when you removed the ASM brackets/support bars that run from the tunnel to the front bulkheads as highlighted in the picture. I worry that the sled will be structurally very weak when I remove those bolts and heat to separate the Lord 406 adhesive. Any thoughts or input that people can provide would be greatly appreciated. Thanks,
Justin

 

[tb123]

Hi!

I have a 2019 AXYS 850 that also cracked in the same spot. Pretty bad if not worse than the original picture in this thread. I am in the porcess of replacing it right now and have the parts, adhesive, etc... but was wondering how you guys went about replacing this? Did you support the sled in any way when you removed the ASM brackets/supports? Slighly worries that once I remove the bolts and head the metal to seperate the Lord Adhesive, it will make the middle of the sled structurally weak. Any info you guys can provide would be greatly appreciated. Thanks,

Justin

I have a 2019 AXYS 850 that has the same exact ASM closeoff bulkhead crack on the same engine mount spot. I’m in the process of replacing it but was wondering if you guys supported the sled in any way when you removed the ASM brackets/support bars that run from the tunnel to the front bulkheads as highlighted in the picture. I worry that the sled will be structurally very weak when I remove those bolts and heat to separate the Lord 406 adhesive. Any thoughts or input that people can provide would be greatly appreciated. Thanks,
JustinView attachment 425998

Since I also ended up finding that the bulkhead itself was cracked, I completely disassembled the cracked side of the bulkhead so there wasn't much left that I needed to worry about supporting. If you are just replacing the closeoff plate, then yes, there won't be much left to support the middle section. I can't remember exactly, but I think those right/left supports (circled) might attach to the tunnel sheet metal too, giving enough support to allow the closeoff to be removed. Can you take some photos from the side?

I suggest that you carefully inspect your bulkhead for cracks while you are in there. I could only see my crack after I pressure washed my bulkhead. I bet more bulkheads are cracked than we realize

 

[snocattin]

Just found "the crack" so I went ahead and did the right thing and fixed it proper. LOL (hopefully some of you watch Vice Grip Garage)
Looks like a structural design anomaly/deficiency, replacing it with the same casting will probably result in another crack in short time.
I'm just going to run it and keep an eye on it.
I did drill a 1/4" hole at the end of the crack to hopefully stop propagation.

Who else is seeing this issue..??

 

[kmed2]

i also own 2019 850 pro rmk
just noticed the same kind of crack in same location
why is this happening?
because this baby is being retired from mountain riding to enjoy more casual ice fishing trips
the plan is to drill a small hole to stop the crack(green dot)
drill a hole for a rivet (blue dot)
release the pressure from the motor mount so the new rivet should pull the plate back to the bulk head
and weld a small piece of aluminum over the crack....
sounds good
but if it doesn't work can always spend the money to fix

 

[kmed2]

ok
it worked
used a 1/4" bolt instead of a rivet -- sucked the bulkhead back flush
now weld a small piece of metal to strengthen
pics when available

 

[tb123]

Yes, please post photos!

I just picked up another 850 and the close off has the slightest crack starting to propagate. The bulkhead otherwise looks great, no signs of any impacts or damage. This is proving to be a very common thing! I’m curious if it’s just the 850 closeoff (this is the same as the 650 and 9R if I’m not mistaken) or if any other chassis have this issue too.

 

[kmed2]

from what i have learned is there may be no glue used in some of the 2019s early versions plus there was only 3 rivets holding it
on the 2024 9R the glue is clearly visible
welding a piece of metal on the crack and rib to strengthen