NR 21 bearing removal

[tracerbob]

I'm about to help my brother replace the bearings in his short stroke 21 and I noticed Speedmaster sells a bearing removal tool. I was wondering, is there a special procedure for removing the bearings or would the usual method of heating the case work just as well?

 

[John Knight]

Bob,

Heating the cases has always worked for me. Don't use a removal tool.

John

 

[RaceCraftBearings]

Robert I sent out Keith's bearings so he should have them in a day or so.

Call me and I will give you some pointers. PS I sent him a 2005 Winter Nats entry form as well, make copies and get Glover, Keith, Chris and yourself down here to race if you can!

See ya ............Ron

 

[tracerbob]

Ron, good to hear from you. We'll be in Orlando for sure (we can swap hurricane stories). What I planned to do was just bolt the case to my handy dandy aluminum bar, and do the heat and tap thing till they fall out, then pull the crank/bearings out of the fridge and drop them in while the case was still warm. Have gotten pretty good at doing this on my Macs. I was looking at the speedmaster website to price out a new NR 21 LS when I noticed a "bearing removal tool". What the h#$$ . So I was putting out feelers to see if I had to use this thing.

 

[Lay26]

i dont use a torch or anything like a vise to remove my bearings, i put the case in the oven and heatup the motor case. when i take it out the bearing just pop right out on their own( sometimes). the large one comes out first without any effort, the smaller one sometimes need some encouragement.

 

[Preston_Hall]

Remove evrtything from the case and heat it in an oven at 400 F. After 10-15 min pull it out and tap on a piece of wood. The large bearing will fall out and the small will need to be lightly tapped. I use a glow plug wrench to tap.

Clean the case and reheat. The large bearing is a very tight fit going in so be careful. I install the small and then the large. Immediately after seating both bearings, install the crank to insure alignment. Let cool and then lube.

 

[tracerbob]

If my wife caught me using the oven, I'd be in the doghouse for sure. What I have been doing is:

Bolt the engine to a 12 inch piece of 1/4 x 2 inch piece of aluminum flat stock,

Put the large bearing on the crank and put this along with the small bearing in the freezer for about 2 hours,

Heat the case evenly with a propane torch for a few minutes, tapping on the flat stock occasionally with a hammer until the bearings pop out.

Pull the crank assembly out of the fridge and drop it in the case. Then I immeadiately flip the case over, holding the crank assy in with a long piece of round stock mounted to the bench. Take the small bearing, drop it on the crank and seat with a long socket that is the same O.D as the bearing and viola...It's done.

Come to think about it, I've got a small pizza oven just sitting around, I might give that a try. So I guess I don't need a special tool to do this as the NR is just like any other engine.

 

[waterbug]

A heat gun or a very high watt hair dryer works wonders and for the most part cheap...!!!!

JUST DON'T GET CAUGHT WITH THE WIFE'S HAIR DRYER !!!!!!! :lol: :lol: