Lister Engine Forum

How to / DIY => Engines => Topic started by: ube on March 20, 2020, 09:57:20 AM

Title: Extension shaft
Post by: ube on March 20, 2020, 09:57:20 AM
Morning everyone.....I have a lister ha2 in my narrowboat and I am trying to remove the crank...my problem is I can not remove the extension shaft...I've removed the 4 bolts that hold the oil spinner and shaft in place but can i for the hell of it remove the shaft.....am i missing something here?
Title: Re: Extension shaft
Post by: cobbadog on March 21, 2020, 10:43:09 AM
G'Day ube,
Are you able to post some clear pics of your problem please?
If you have not posted pics before they will need to be compressed first.
Title: Re: Extension shaft
Post by: snowman18 on March 21, 2020, 02:44:51 PM
G'Day ube,
Are you able to post some clear pics of your problem please?
If you have not posted pics before they will need to be compressed first.

Think you may have meant resized. postimages.org/ (http://postimages.org/)

(https://i.postimg.cc/bvZQ67f2/image.png)
Title: Re: Extension shaft
Post by: cobbadog on March 22, 2020, 03:43:42 AM
Same difference snowman, just different countries call it something different.
Here we compress the pixels to reduce the size of the file to post and is the same procedure as you do when you resize.
Title: Re: Extension shaft
Post by: ube on March 23, 2020, 04:07:13 PM
This is the shaft I'm having problems with ....was going to run a 12 mm tap down the holes that the oil spinner locates then using 4x12 bolts and a plate attach a slide hammer and try removing it this way....unless I'm missing something?
Title: Re: Extension shaft - Yes, hammers aside
Post by: sirpedrosa on March 23, 2020, 07:47:39 PM
Hi Ube

Yes, you are missing that cast iron is fragile. That extension shaft has the notch and pin, and it must come off straight.

Cheers
VP
Title: Re: Extension shaft - Yes, hammers aside
Post by: ube on March 23, 2020, 09:45:44 PM
Hi Ube

Yes, you are missing that cast iron is fragile. That extension shaft has the notch and pin, and it must come off straight.

Cheers
VP
......so its steady away with the slide hammer......gently does it......not like a NCB fitter😉
Title: Re: Extension shaft
Post by: glort on March 23, 2020, 10:38:32 PM

If there are no pins or grub screws holding it on and they haven't been galled over so you can't see them,  My guess would be the thing is a shrink fit.  Probably put on red hot and maybe the bit it was attached to was frozen and attached with that.  Shrink fit is a powerful way to lock things together. 

Some rapid heat from an Oxy or MAAP torch may help free it up.
Title: Re: Extension shaft
Post by: cobbadog on March 24, 2020, 05:05:11 AM
I'm looking at it a little bit differently. I feel as if the extension shaft and the flange are one piece. Maybe the bolt holes are for jack bolts to push it out and off? The flange looks as if it is sitting well inside of that gear. It is a bit unclear but also looks on the flange that there is the end of a keyway.
I know nothing about these shafts but just looking at it that is how I would approach it, unless those four holes bolt to something. Then if you are going to use a slide hammer be very gentle.
Title: Re: Extension shaft
Post by: glort on March 24, 2020, 08:01:51 AM

Yeah I agree they are one piece but I'm thinking there could be a shaft, maybe a taper one inside the extension shaft. I have one on an engine like that and come to think of it, it's a screw fitting. You turn the extension shaft opposite rotation and it unscrews. There is a thin threaded section that locks them together on the taper.  When the engine is running it's always tightening them although with a good couple of wacks on the pulley that sits on the extension, it breaks free and comes apart quite easily.  The thread is only about 10mm. Not a lot but it has no trouble holding 12 Hp.  Taper is the key i'd say.

I have no idea what this engine is like but mine has a stubby taper shaft for a gen head. The extension takes it back to a standard 3/4" in this case.

Might be worth a try unscrewing this extension? If it won't pull, that could be why?



Give the thing a few belts in the holes with some wood and a hammer or a soft drift opposite to engine rotation and see how you go.
Title: Re: Extension shaft
Post by: ube on March 24, 2020, 11:32:56 AM

Yeah I agree they are one piece but I'm thinking there could be a shaft, maybe a taper one inside the extension shaft. I have one on an engine like that and come to think of it, it's a screw fitting. You turn the extension shaft opposite rotation and it unscrews. There is a thin threaded section that locks them together on the taper.  When the engine is running it's always tightening them although with a good couple of wacks on the pulley that sits on the extension, it breaks free and comes apart quite easily.  The thread is only about 10mm. Not a lot but it has no trouble holding 12 Hp.  Taper is the key i'd say.

I have no idea what this engine is like but mine has a stubby taper shaft for a gen head. The extension takes it back to a standard 3/4" in this case.

Might be worth a try unscrewing this extension? If it won't pull, that could be why?



Give the thing a few belts in the holes with some wood and a hammer or a soft drift opposite to engine rotation and see how you go.
.....its a lister ha2.....there is two locating dowels so it's not going to screw and yeh if I tap it with the mallet it does move side to side....if I can get away with it I dont want to use heat because of the gear behind it....the 4 holes for the oil spinner bolts are unthreaded but they are the right clearance size for a 12mm tap so I can tap them and hopefully use the slide hammer......I will keep you guys posted
Title: Re: Extension shaft - hammers aside again
Post by: sirpedrosa on March 24, 2020, 12:54:47 PM
Hi Ube

Take a look of the pics! Shaft extender and gear are distinct parts.

This is the PAZ1, you can attach extender both in crank and cam, because is the same pattern.

Pay attention to crank, do you see that bolt hangs gear to crank? I think it will be something like that. but blueprints will help... totally.

Cheers
VP

PS: how was bolted shaft extension to crank? with 4 screws?
Title: Re: Extension shaft
Post by: ube on March 24, 2020, 02:42:20 PM
Yes at last
Title: Re: Extension shaft
Post by: ube on March 24, 2020, 02:45:36 PM
Slide hammer👍
Title: Re: Extension shaft
Post by: ube on March 24, 2020, 02:48:25 PM
Thanks guys for taking time out to help me......no doubt I'll be back picking ya brains.....hope ya all stay safe n well in these hard times
Title: Re: Extension shaft
Post by: cobbadog on March 25, 2020, 04:59:47 AM
Well done and good progress for you. I meant to say to remember to mark the gear before removal so the timing does not get upset. I had an engine where the timing marks will never align as it had the wrong model cam gear inside but same size and teeth number. Luckily I did make my own marks before stripping it down.
Title: Re: Extension shaft
Post by: ube on March 25, 2020, 08:33:34 AM
Well done and good progress for you. I meant to say to remember to mark the gear before removal so the timing does not get upset. I had an engine where the timing marks will never align as it had the wrong model cam gear inside but same size and teeth number. Luckily I did make my own marks before stripping it down.
[/quote........oh yeh I've made that mistake before so yep the center pop was out doing its thing👍]