Removing a pilot bearing bushing

[twas_brillig]

I commented on the axle shaft thread and then kind of hi-jacked it by whining about my problems getting the pilot bushing out. Rather than go back and report on my progress/failures there, here's a new thread, capturing the content discussed.

Situation: I want to install a Rivergate kit Datsun 5 speed behind our 948 cc BE engine, and need to replace the pilot bushing with the Riverside one to accommodate the smaller Datsun input shaft diameter. My memory is that the bushing that is in there is not stock and that I'd had to have one made up in the 70s to allow for wear on the transmission input shaft - but there's been a lot of water under the bridge since then, including an engine rebuild when a friend had our car for a few years.
My brother is a legitimate auto mechanic; he suggested getting a puller, or - barring that - running a tap into the bushing until it bottomed out and then that would jack the bushing out.
I rented a puller, but no luck: either the wall on the bushing was too thin or the puller was designed for a larger diameter or ?? Tried the tap trick, but no joy: broke the unbreakable socket I was using to drive the tap (lucky not to have snapped that extremely hard and brittle tap off). Being dumb and having toys, I bought a 1/2" bolt with the proper thread to match the tap and ran it into the nicely threaded bushing and bottomed it out, and tried tightening it in with (first) hand tools (inculding an 18" breaker bar). No luck. Fired up the air compressor to 125 psi and tried my half inch impact; then the 3/4" impact. Went back out tonight with the 3/4" again, and twisted the 1/2" bolt off....

My original thinking had been to cut away the bushing material iwth a a carbide burr. Found one for the Dremel this evening, and bent the shaft on the the burr (my own stupidity again: hadn't properly tightedn the collet down (although had used the proper collet). Okay - got the shiny new hack saw blade out and a couple of small drifts and chisels and was finally successfully: 3 cuts through the bushing sides and got it out. And quit for the evening.
Preliminary measurement suggests that the remains of the busted bolt are in deep enough that I can leave it and still mount the transmission, but more careful measuring tomorrow and and a trial mount. Otherwise, more problems.

Got some good thoughts from :

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Silver Member
Luke Skywalker

Registered: 2006-04-12
Posts: 1611
Loc: Renton, Washington Before you drill the bushing out bigger find a 1/2" steel or aluminum dowel about 4 or 5" long- FILL the cavity FULL of grease until it won't hold any more, insert the dowel into the hole and (carefully) hit it with a hammer.
Be careful of the grease that squirts by! it will be coming out at VERY high speed!
The hydraulic force will push the bushing out. Done it many times.
BillM
_________________________
'69 Sprite Mk IV
'60 MGA
'65 Midget (the OrangeCrate)(Now temporarily a Sprite for the local car show)


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#741158 - Yesterday at 19:43 Re: Snapped an axle [Re: kellysguy]
jlaird
Great Pumpkin

Registered: 2005-11-13
Posts: 19965
Loc: Niceville FL The easy way is like,,,, someone correct me if I have it wrong. Fill hole with grease, pick a drift pin that just fits in input shaft bushing, place on top of grease and hit with hammer.
_________________________
Jack Laird
Retired USAF


AN5L 24515, Eng. 9C-U-H 16218, Apr. 1959
"Miss Agatha" On the road again and smiling.

We were there, Lake of the Ozarks, 2008!!

Eight shows, six firsts and counting.

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#741167 - Yesterday at 20:27 Re: Snapped an axle [Re: kellysguy]
twas_brillig
Jedi Trainee


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#741254 - Today at 10:51 Re: Snapped an axle [Re: kellysguy]
jlaird
Great Pumpkin

Registered: 2005-11-13
Posts: 19965
Loc: Niceville FL Bolt just may not provide the jolt that is required to knock that thing loose.


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Thanks guys; and I'll tell you how things go next.

Doug

 

[dklawson]

Since you have tapped the bushing, see if you can get that broken bolt out. With the broken bolt out, try putting a new bolt in the tapped bushing hole and using a slide hammer to pop the bushing out.

 

[Guest]

Man, I sure am having problems with my axles. :thumbsup:

 

[DrEntropy]

I've used the grease 'trick' to hydraulic 'em out, also had to resort to the hacksaw method. Whatever works, basically.

As for the bolt, get some left-twist bits and drill a hole in it for easy-out, sometimes just the heat/reverse bit motion will see the thing unwind without needing the easy-out.

 

[twas_brillig]

I did a bunch of measuring last night plus trial fitted the transmission and the busted off piece is in far enough that it won't interfere with the transmission input shaft, so I think I'll quit pressing my luck in this area and just leave it as is.

My brother the auto mechanic sent this comment, which is spot on: there is a step behind the bushing.

" so i was thinking about the crank / pilot bushing episode
- the reason the socket and the bolt broke had nothing to do with the pilot bushing; it had to do with the tap and the bolt stopping in the crank itself, not in the bushing
- most american crankshafts that i used a tap on had a uniform diameter blind hole for the pilot bushing, with the entire diameter being that of the outside diameter of the bushing; apparently yours was stepped or tapered or both and after the tap went through the bushing it started cutting threads into the crank itself but the "drilled" hole wasn't the proper size for the tap therefore increasing the resistance, stopping the tap and (lucky for you) breaking the socket; when you used the bolt it went in as far as there were threads and it stopped but you kept going and (lucky for you again) the bolt gave before the crank did"

Darn! on second (& third)thought, I think I'll have a look at centre punching the busted part and trying the drill/ez out approach.

 

[Deleted member 8987]

So, now I see from the other post you have used whitepout to eradicate the issue.....err......give yourself some POM on clearance.

I don't know.
If you are 100% certain the broken off bit won't ever come loose, great!

 

[twas_brillig]

"eradicate the issue": which I'd thought of that!

Doug

 

[twas_brillig]

I'm just going to leave the busted off bolt in place - it's a couple of inches in and there doesn't appear to be any cracking, so I'll cross my fingers...
Doug