Hi,

Need some advice on removing the crankshaft idler pinion on my A65 lightning 71' engine. The user manual advises that BSA extractor tool 61-3676 should be used, but what I'm not sure about is whether this is just a small puller or some special tool.

Also, the pinion only has one machined slot (see picture), so I'm not sure if a puller will work.



Cheers,

UNF

I use a puller kind of like this one:


I had to grind the tips of the jaws down a little bit to make it fit in the slots.

The idler gear needs some kind of a puller, the gear on your picture however will usually get off with the aid of two suitable screwdrivers. If still stuck, try a little heat.

Best regards

Thanks for the feedback. Hopefully, one way or another I'll be able to get the pinion off!

Cheers,

UNF

That's the first one I've seen that just has one slot. I wonder if you could cut another slot with a die grinder/dremel. If its on there real tight, the large screwdriver method can be kinda ugly.

Holy crap, I just now noticed that it only has one slot after Leon pointed it out. That's gonna make it kinda tough...kinda like the odd philips screw you get with no slots...

try to use a socket under a big screwdriver

Maybe I'm not sure what y'all mean, but my 71 parts book shows only one keyway and one "slot" in the crankshaft.
In any case, , I'd use two Wonderbars to ease the gear off the shaft, at least until you have enough space behind the gear to use a gear puller.

I don't think we are talking about the crank keyway. I think the 'slots' are the grooves for use with a puller. This shot shows the top groove reasonably well and the bottom groove if you really look. I have never seen this gear with only one slot for pulling it off.

Gordo

Now I see what you're talking about. Shame this didn't come up last week when my timing side covers were off. I could've inspected.
Guess I'll find out this Winter when I need the cases open.

I use a puller just like the one Alex has pictured. I have ground the tips of the jaws to fit and hardened them for this application. I also take a large hose clamp and tighten it around the jaws so it won't slip off. It works every time to get this stubborn little gear off.

Mr Mike

This pinion is sometimes difficult to extract. It is possible to heat it slightly, but you should still use a strong puller. If you can weld, this puller will not cost you anything, and you'll enjoy using your own tool. When the puller is clamped, it is impossible that it breaks. Needless to heat.

Mr Mike and Serge have both skipped over the fact that little gear only seems to have one slot in it.

Leon, or Winslow if I recall...you are right. I went back thru the thread and it appears that one slot is missing. Gotto go to the heat and screwdriver method and hope I. For most of us that have the two slots, a simple modification to in inexpensive two jaw puller and a hose clamp really work wonders. I put a little tension on it and then just warm it with the tip of a small butylene torch ond off she comes.

Mr Mike

If it doesn't come off easily by prying, don't much up your cases. Extract the oil pump studs and use one of these bearing pullers:

This is an obvious manufacturing error. I have a dozen engines from 1962 to 1970. Everyone has a pinion with two slots. In such a case, do not hesitate to machine a second slot, using a grinder equipped with a narrow disk. These slots are the best solution to remove the pinion without risk for the cranckcase and sprocket teeth.

Why don't you continue to split the cases leaving the crank and this gear where it is.
Once they are split with some help holding the half case hit the
end of the crank with a rubber or copper mallet.
Or a block of timber and a hammer. Good luck.
Where thers a will thers a Way. Kelvin.

Kelvin,
You run great risk in damaging something else, by beating out the crank. Methods suggested should get it done. The bearing or gear pullers posted by Alex are handy and the come in a wide range of sizes but most of us don't have them in our shops as they are infrequently needed. Over the yeas I have made a few tools for specific task on BSA's and the special puller for this job was easy and works well...if you have the two slots on the gear like it is supposed to be.

Mr Mike

Hi all,

Well, I took a chance and knocked the crankshaft through the casing, with a rubber mallet I might add. No damage to crankshaft assembly and pinion, but the plain bearing got a bit scored. I was intending to replace this, but obviously will have to now!

Next task: remove the pinion. New slot 180 degrees opposed to the existing one is the option I'll investigate first.





Thanks for all the feedback.

Cheers,

UNF

I have mine off, any advice on getting it back on without upsetting anything?

Cheers!

Tap, tap, tap, put a deepwell socket over it. They go back on pretty easy, make sure the key fits nice.

Here is my recent project picture: pinion came off easy with this setup.