2018 jack/drive shaft swap on '17 MC

High Life · Nov 25, 2018

I'm looking at replacing the jack shaft, drive shaft and brake rotor on my '17 mountain cat after looking at the prices in parts vs. the weight savings;
2018 driven shaft 2602-995, saves 2.25 lbs for $111
2018 drive shaft 3602-147, saves 3.0 lbs for $80
BDX superlite brake rotor, saves 2.5 lbs for $110.

So that's almost 8 lbs of weight loss, all in rotating mass for roughly $335 including shipping. This seems like a good deal, but what am I missing here? I haven't heard of other guys doing this. Has anyone else done this swap? If so, what is all involved and what other parts would be needed? I'm running a TKI belt drive, but I don't think that should matter...

Cat00 · Nov 25, 2018

That 2.5 lbs for the break rotor in the difference in the solid one that came on the 12 and 13s. If I remember correctly it's like 1.2 on the 14 and up sleds

High Life · Nov 25, 2018

Ok, Thanks Cat00. So instead of about 7.75 lb savings it is about 6.45 lb savings, most of which is in the shafts, but I figured it would be a good time to do the brake rotor while its apart...

Still seems like a pretty good bang for my buck. The 2018 shafts will fit my 2017 MC right?

Old & slow · Nov 25, 2018

It's a great idea, the brake rotor will be a one pound or less saving as your MC has the lighter rotor already. BDX compares that to the old rotor. Still 6-7 lbs of rotating weight. That will be a huge gain. You will need a press for the drivers, and they are timed on the shaft. One thing guys do is true the drivers once mounted. Put them is a lathe and even them up. Not required but an extra if you want. I can't say on the TKI stuff but from what everyone is saying Tom has excellent customer service. I'd call and ask if you have problems. The 17 and 18 have different part numbers for the top gear, most likely not the same. You may need a different top gear not sure. Call Tom. I would like to hear your thoughts on this if you go ahead with it.

High Life · Nov 25, 2018

With the weight savings on the brake rotor getting less and less, maybe I won't even do the rotor and pocket the $110! :face-icon-small-hap I would still likely get almost 6 lbs in weight savings for a little over $200, plus whatever I might need for a top gear...

Good call on calling Tom at TKI, will definitely do that. Thanks!

boondocker97 · Nov 25, 2018

For this to work you need to get the aluminum track shaft from BDX as well. Using the cat one you have to change out the brake caliper and run the cat brake rotor, spacer, and nuts as well.

sno*jet · Nov 25, 2018

its a good bang for the buck, but a lot of banged knuckles too. might as well do the rotor too imo. ill do it if im in there for some reason. anyone know the blend of AL. they're using on the DS?

High Life · Nov 25, 2018

boondocker97 said:
For this to work you need to get the aluminum track shaft from BDX as well. Using the cat one you have to change out the brake caliper and run the cat brake rotor, spacer, and nuts as well.

Thanks for the heads up boondocker! Just ordered the BDX aluminum shaft.

Was 2018 the first year of the hollow driven shaft (jack shaft)? Even though Cat changed the jack shaft from year to year, I'm guessing that the weight didn't change much between 2012 and 2017 and a shaft from an '18 will be about 2.25 lbs lighter than my '17 MC shaft, as advertised by Cat.

Can I run my stock brake pads with the superlite BDX rotor?

stahlecker · Nov 26, 2018

Just an FYI. BDX is a little tricky with the weights. Their "Lightweight" rotor won't really save you any weight. The "Superlightweight" will save some. I think they compare it to the solid 2013 rotor. I have ran the factory brake pads on both my Viper and now on my Sidewinder.

Here are the differences from my Sidewinder:

Super Lightweight Rotor 1lb 3oz
Aluminum Trackshaft 2lb 12oz

The trackshaft was weighed with the same drivers on both trackshafts.

High Life · Nov 26, 2018

stahlecker said:
Just an FYI. BDX is a little tricky with the weights. Their "Lightweight" rotor won't really save you any weight. The "Superlightweight" will save some. I think they compare it to the solid 2013 rotor. I have ran the factory brake pads on both my Viper and now on my Sidewinder.

Here are the differences from my Sidewinder:

Super Lightweight Rotor 1lb 3oz
Aluminum Trackshaft 2lb 12oz

The trackshaft was weighed with the same drivers on both trackshafts.

Thanks for the info! I went ahead and ordered the superlite brake rotor and aluminum track shaft. Curious to see what my actual savings is when it is all said and done...

triedit · Nov 26, 2018

I am in the middle of doing this to my MTN Cat right now i did BDX aluminum drive shaft with drivers on it ,super light rotor and light weight jack shaft i would recommend getting the clutch side jackshaft bearing as mine would have required a press to remove it so i just got a new bearing ,also i would use bearing mount on the clutch side drive shaft bearing as there have been reports of plenty of them spinning on the shafts

kanedog · Nov 26, 2018

triedit said:
I am in the middle of doing this to my MTN Cat right now i did BDX aluminum drive shaft with drivers on it ,super light rotor and light weight jack shaft i would recommend getting the clutch side jackshaft bearing as mine would have required a press to remove it so i just got a new bearing ,also i would use bearing mount on the clutch side drive shaft bearing as there have been reports of plenty of them spinning on the shafts

Would you mind to post some pics of the bearing mount and swap on the clutch side? Thx

Sent from my SM-G920W8 using Tapatalk

triedit · Nov 27, 2018

when i said bearing mount i meant bearing retaining compound ,to keep it from spinning on shaft

ArcticJunkie · Nov 28, 2018

I swapped out my 16 jackshaft and trackshaft and rotor. To the 18 stuff and BDX rotor and TKI MC belt drive. It dropped 7.7 pounds of rotating mass. Hope this helps

Suzzy-Q · Nov 28, 2018

I’m swapping out the jack and drive shaft on my 17 MC, 5.5lbs rotating mass. Also doing headlight delete and lightweight chain case/oil tank should be about -15 to -16lbs, on top of the -20 or so lbs from the SSI full exhaust already on, this sled just is more fun every year.

Joe.G · Dec 13, 2018

Id peen the shaft instead of using a Bearing compound, If you loctite it on there you will need a press and or heat to get it off and that may cause an issue. Peen it just enough to make it a snug fit. And yes it is a issue I ruined two shafts and one brake rotor from the inner race spinning and two different sleds.

High Life · Dec 30, 2018

UPDATE I finally got my sled pulled in the shop and am in the process of doing the swap. Here's what I have measured for weights;
'17 Stock brake rotor 2.98 lbs.
BDX "superlightweight" rotor 1.81 lbs.
Rotating mass savings 1.17 lbs.

'17 Stock driven (jack) shaft 7.21 lbs.
BDX lightweight driven shaft 5.49 lbs.
Rotating mass savings 1.72 lbs.

I backed out on getting the driveshaft, so I'm not sure what the actual savings are going with the BDX aluminum shaft vs. the '17 stock 'lightweight' shaft. Does anybody know that figure?

I couldn't salvage the bearing on the secondary end of the jack shaft, so I will have to source one of them. The new brake rotor is installed and I didn't do address the brake caliper housing bearing. Where does a person peen it? Peen the drive shaft where the bearing rides? Don't really want to pull it back apart to peen it. How likely is it to spin? What does the factory do different that it doesn't spin after the original install?

Joe.G · Dec 31, 2018

To peen it you have to do it where the bearing rides, Depending how far along you are all you have to do is take the caliper off ( don't split it ) so its a clip and three bolts. I highly recommend you doing this and you should clean and grease the bearing also. This is a very simple job after you have done it once. I suggest you take an old stud and I peen it about 8 times around the shaft. Just trying to cause a little friction. I had to replace both of mine this year and also the rotor on one was worn were it rides against the bearing.

summ8rmk · Dec 31, 2018

Anyone with the aluminum shaft have a bearing spin?

Joe.G · Dec 31, 2018

That I am unsure of but if it did I am sure it would be a mess quick. If the aluminum has better tolerances I guess you would be fine.

2018 jack/drive shaft swap on '17 MC

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