Replacing Crankshaft Bearings

[Driggs]

I melted a piston and it trashed one of my outside bearings on my crank. Is the bearing pressed on or is it something I can pry off and replace myself?

[AKheathen]

best to buy a bearing puller, to prevent damaging the crank. if you already have some regular pullers, that will help, and all you have to buy is the plates for like 35. heat up the new bearing to over 200 degrees, and slide it on. it will press/interfereance fit when it cools, alot better than trying to press/beat it on.

[Driggs]

Ok guys, just now going to replace these things. I just bought a 3 jaw puller but that wouldn't work. What's recommended to pull these bearings off? Also, 200+ degrees and they'll just slide on?

 

 

[AKheathen]

.......they make bearing pullers just for that. i got a 2-1/4" and it barely fits on there. you can use a steeringwheel, or t-puller if you have 6" bolts, or you can grab it with a jaw puller.......and yes, they just drop on there when heated.

[dajogejr]

Trust me...take it to a machine shop and let them do it.

My buddy does a ton of cranks...without a press it's just too much work.

The time you'll spend beating it off and heating it up won't be worth it compared to a press with the right plates to pop it off.

[AKheathen]

"the right plates"? as in a bearing puller/spliter? the same one they have hanging on the wall, or in a drawer at the machine shop? that you use the t-puller on? no beating it off when i do it.....she cums

[dajogejr]

Splitter...as in two halves...

I've seen more cranks broken down and redone than you can imagine...and I've seen 'em done both ways.

 

I will gladly pay someone 25 to 30 bucks to press off and press on bearings....vs using a puller.

[Driggs]

It's just the two outside bearings I'm wanting replaced so I'll look for another puller and if no luck, to the machine shop I go.

[Driggs]

Check out this slick tool...I might just order it. They have a YouTube video and it's a piece of cake with this thing.

 

http://www.rockymountainatvmc.com/productDetail.do?navType=type&webTypeId=140&navTitle=Tools%2FShop&webCatId=22&keyword=TUSK+CRANKSHAFT+BEARING&prodFamilyId=19017

[dajogejr]

60 bucks plus shipping....twice what you'd pay a shop to do it for IMO.

If this is something you plan on doing freequently, the right tool always makes the job go easier...but how many do you plan on doing?

[Driggs]

60 bucks plus shipping....twice what you'd pay a shop to do it for IMO.

If this is something you plan on doing freequently, the right tool always makes the job go easier...but how many do you plan on doing?

 

 

Good point but I don't mind paying because I enjoy doing the work myself.

[AKheathen]

well, you can do that without having to buy that kit..........the bearing splitter is only half that at the parts store, and many have rental tools. also, many people have a steering wheel puller layin around, which can double as the t-puller, and probably comes with the right size bolts to screw into the splitter body. still, that is not a bad price for that size complete kit. otc has just the splitter, or t-puller for that price, lol

[bigborebanshee]

If you have a small cutting torch tip or a small rosebud and a friend,it takes about 30 seconds.I just changed out the end bearings to maxloads.I just wedge 2 flat screwdrivers between the bearing and crank,keeping a little pressure like your prying it off,then have someone heat just the inner bearing race in a circular motion,when the inner bearing race gets hot enough it will start to slide out as you apply pressure.make sure to keep the torch tip moving constantly and focus the flame on the inner race and nothing else.It pretty much ruins the bearing,but if it wasn't bad to begin with,there would be no reason to change it.

[AKheathen]

If you have a small cutting torch tip or a small rosebud and a friend,it takes about 30 seconds.I just changed out the end bearings to maxloads.I just wedge 2 flat screwdrivers between the bearing and crank,keeping a little pressure like your prying it off,then have someone heat just the inner bearing race in a circular motion,when the inner bearing race gets hot enough it will start to slide out as you apply pressure.make sure to keep the torch tip moving constantly and focus the flame on the inner race and nothing else.It pretty much ruins the bearing,but if it wasn't bad to begin with,there would be no reason to change it.

well, i would keep that much localized heat away from the crank, especially that part, which has been known to crack and break

[Driggs]

When I'm putting this new bearing on, can I put it in the oven to heat it up or should I get a torch?