blind bearing

[drlapo]

I'm rebuilding a couple of old triumph engines
A transmission layshaft rides on a needle bearing pressed into a blind hole
The bearing is toast
How do I remove the outer bearing race from the case?
I tried threading a large bolt into it but that only broke off the remaining sections of the outer race lip
I tried cutting the race with a dremel but its too hard
Will it need to be machined out?

[NCAmother]

If you are single, or your significant other doesn't mind, and if this is a complete disassembly........ put it in the oven at 350-400 degrees for an hour or two. (please wrap up the transmission good in heavy duty aluminum oil, or your next steak will taste like an Applebees steak. They should come right out.  I've tried localized heat (Mapp Gas torch) with no luck

[Antietam Classic Cycle]

If you're in a cold climate and have a woodstove, that can be used to heat the case too. Only takes 15-20 minutes for the bearing race to drop out of a Guzzi rear drive housing laid on top of my double-barrel stove in the shop.

[Rough Edge racing]

 Hmm, you working on a 500?  I work on 650 Triumphs a lot and the 650 units don't have blind countershaft bearings and the pre units I've seen aren't blind....Maybe some are?

[drlapo]

its a 250 single
I can heat the case but I can't figure out how to grab the remaining outer bearing race
its a small needle bearing and the race is around 3/4"
the small lip on the race is broken so there is nothing to grab on to

[twhitaker]

The bearing is made of steel and the housing is aluminum which expands more than the steel. As you raise the temperature about 50 degrees this will provide the clearance needed and the race will fall out. Get a hot plate.

[Wayne Orwig]

I've used heat from a small propane torch to do it. It takes time to heat all of the metal.

I've also used a hot plate to heat the entire case. The races just dropped out.

[drlapo]

into the oven it goes
what's a good temp to heat it too?

[twhitaker]

If you are single, or your significant other doesn't mind, and if this is a complete disassembly........ put it in the oven at 350-400 degrees for an hour or two. (please wrap up the transmission good in heavy duty aluminum oil, or your next steak will taste like an Applebees steak. They should come right out.  I've tried localized heat (Mapp Gas torch) with no luck

Recipe above.

[Chuck in Indiana]

Here, the Kid uses my Heat Gun from Hell to remove blind bearings in a couple of 5 speed cases. Belle supervises..

Nothing to it.

[redrider]

Then there is the Norton Procedure. Almost fill the hole with grease and position a piece of round stock or old shaft on top. Wrap a rag around the contraption and smack the shaft with a hammer.

[drlapo]

heat plus a blind bearing puller set from fleabay should do it
thanks

[dl.allen]

I do old Triumphs as well.

I have the blind bearing puller kit from Horror Fright and just heat around the bearing with a propane torch once you get the puller in place then a couple whacks.

[Rough Edge racing]

 250.....that's a BSA 

[oldbike54]

250.....that's a BSA 

 In a round about way .

  Dusty

[drlapo]

I'm using a triumph crankshaft and cases
A BSA head cylinder. And gears
Taking parts from3 motors to make 1 good one

[jbell]

into the oven it goes
what's a good temp to heat it too?

Meatloaf.

[cruzziguzzi]

What I do since I have a lathe and a neighbor with a "chucker":

Cut a slug of aluminum to mimic the bearing profile.
Put it in the freezer.
Heat the casing and its attendant race.
Drop the aluminum into the race.

Somewhere between 8-9/10 the race shrinks and nearly , if not completely, falls out.

A couple three times I've given a rap to the slug as it had expanded more than the race had shrunk.

I generally have the same luck with blind pullers as I do at the black-Jack table but they seem to work for the rest of the world.


Todd.

[Muzz]

If the inner has completely gone and you can see the inside of the outer shell you can run a real rough weld with a stick welder around the inside of the race outer. The weld shrinks when it cools and the outer just falls out.

[Muzz]

250.....that's a BSA 

Out here we got the Triumph 250 Trophy and the BSA Starfire 250.  Wot came first, the chicken or the egg?

[Rough Edge racing]

Out here we got the Triumph 250 Trophy and the BSA Starfire 250.  Wot came first, the chicken or the egg?

The Triumph 250 was a clone of the BSA 250 and both were built in the BSA factory. This engine was developed by BSA engineers from the C15, a BSA design using some aspects of the 1950's Triumph Terrier. The Triumph Terrier/Cub was the last in house Triumph designed single.

[racasey]

I suspect the bearing in question is the one displayed in the image below.  They are generally called "drawn cup bearings", and can be open on both ends, or closed on one end.

If you lack an expanding internal puller, the time honored dodge is to heat the case to a bit over 100C, water or spit will dance on the hot surface, invert the case so the bearing can fall out, and assist its release by sharply slamming the hot case down on a wooden bench top. 

Ciao,
Dick Casey

[drlapo]

yes, that's the bearing
I'll apply heat via the kitchen oven but I also ordered an inexpensive puller just to be safe
a BSA B25 was my transportation for 2 years in 1968 and 1969
took me to college and a concert in a field in NY state, August 1969

I've had 3 of them and my youngest son showed up with 2 Triumph TR250W last year
he quickly blew one up and I'm going through my "spares" to rebuild the motor
this weekend I'm taking oil pumps apart to build a good one

[drlapo]

Update
The eBay blind bearing puller came in today
15 minutes and a bit of heat with a torch and the failed bearing is out
It feels so good when things go right