Boxerworks.com

1975 R 60/6
105 K

Hello all..........

I was reading in some tech articles that the proper way to mount a new camshaft gear (sprocket) is with the camshaft removed from the engine.

I was curious if anyone has installed a new heated gear on the cold camshaft with it still in the engine and were you able to get that clearance measurement of .004 to .006 behind that sprocket while getting it seated properly?

I was thinking perhaps that with a couple of long pieces of feeler stock positioned in place, that perhaps a heated gear could be mounted on the shaft with that necessary clearance allowed for.

Cat wrote:1975 R 60/6
105 K

Hello all..........

I was reading in some tech articles that the proper way to mount a new camshaft gear (sprocket) is with the camshaft removed from the engine.

I was curious if anyone has installed a new heated gear on the cold camshaft with it still in the engine and were you able to get that clearance measurement of .004 to .006 behind that sprocket while getting it seated properly?

I was thinking perhaps that with a couple of long pieces of feeler stock positioned in place, that perhaps a heated gear could be mounted on the shaft with that necessary clearance allowed for.

They go on alot easier than they come off. You can pretty much put it on with your gloved hand. The issue is that the heated gear will be expanded making the specified gap to the bearing carrier too large once it's cooled down. I'd just push it on untill it's basically flush with the carrier or use your thinnest gauge to space it. If it ends up too tight, use a puller and apply enough pressure to move it to the right clearance.

I appreciate that sound advice. I was hoping to avoid another engine teardown. Cheers!

You don't need to do a full teardown - there are ways to make this a pretty easy job.

I wish you had a later motor - they're even easier (because of the improved oil-pump drive method). Still ...

Here's what I've done:
* Remove rocker covers, one-at-a-time remove rockers and position them (or remove from shafts) so they don't contact the pushrods. Put some grease on the pushrod's ball end where they contact the tappets, put the pushrod back in place, and gently pull the tappet all the way clear of the cam lobes. They'll generally stay but if you're nervous about that, leave the pushrods in place and secure them with rubber bands. Restore the head/barrel torque to slightly below spec - that should prevent any issues of gasket or seal shifting.
* At this point you can undo the two bolts securing the front cam bearing carrier and carefully pull the cam out of the motor (I'm not bothering to describe front cover removal and chain removal, etc.).
* Carefully note that you got the key that drives the oil pump still in place in the cam.
* Now change the cam sprocket and adjust the end-play
* Reverse this - BUT!!!!! - be careful with the key to be sure it is properly driving the oil pump. A very cautious person would remove the tranny and clutch and oil pump cover and deal with it that way - the later "dog" rather than key method of driving the oil pump is far superior and eliminates this bother.

Anyway ... this approach works and is pretty easy - on a new style motor the whole thing only takes an hour or two to do.

John Falconer wrote:You don't need to do a full teardown - there are ways to make this a pretty easy job.

I wish you had a later motor - they're even easier (because of the improved oil-pump drive method). Still ...

Here's what I've done:
* Remove rocker covers, one-at-a-time remove rockers and position them (or remove from shafts) so they don't contact the pushrods. Put some grease on the pushrod's ball end where they contact the tappets, put the pushrod back in place, and gently pull the tappet all the way clear of the cam lobes. They'll generally stay but if you're nervous about that, leave the pushrods in place and secure them with rubber bands. Restore the head/barrel torque to slightly below spec - that should prevent any issues of gasket or seal shifting.
* At this point you can undo the two bolts securing the front cam bearing carrier and carefully pull the cam out of the motor (I'm not bothering to describe front cover removal and chain removal, etc.).
* Carefully note that you got the key that drives the oil pump still in place in the cam.
* Now change the cam sprocket and adjust the end-play
* Reverse this - BUT!!!!! - be careful with the key to be sure it is properly driving the oil pump. A very cautious person would remove the tranny and clutch and oil pump cover and deal with it that way - the later "dog" rather than key method of driving the oil pump is far superior and eliminates this bother.

Anyway ... this approach works and is pretty easy - on a new style motor the whole thing only takes an hour or two to do.

John's right on here. I've used similar methods to pull cams on early style key and late style cams. But since you already have the pulley off (just my guess), then putting a new one on should be pretty easy in the crank case. If you haven't pulled the bad pulley yet then it is easier out of the case. Don't use a puller on that delicate cam nose, you need to make a sleeve to fit over it or use a handy method I came up with that involves no puller.

That is very helpful info. I haven't started the job yet as I'm still getting my parts order together.
Perhaps taking that camshaft out is the way to go. To manipulate that gear on a removed camshaft in a vise requires a special bmw pulling and pressing tool though doesn't it?

A few weeks ago I picked up a multi tool from Cycle Works so the pulling and pressing could be done as needed with the camshaft in the engine. Yes, take the pressure off the camshaft lobes before hand like mentioned and I figured it was doable .... perhaps a bit of hassle, perhaps not. Otherwise I'd proceed with the bigger teardown if the job required it.

Heres a link to that tool I picked up for those not familiar with it. I can always sell it on ebay later on when the job is done.

http://www.cycleworks.net/index.php?mai ... cts_id=383

It has a machined piece that protects that delicate camshaft nose during pulling.

Cat wrote:That is very helpful info. I haven't started the job yet as I'm still getting my parts order together.
Perhaps taking that camshaft out is the way to go. To manipulate that gear on a removed camshaft in a vise requires a special bmw pulling and pressing tool though doesn't it?

A few weeks ago I picked up a multi tool from Cycle Works so the pulling and pressing could be done as needed with the camshaft in the engine. Yes, take the pressure off the camshaft lobes before hand like mentioned and I figured it was doable .... perhaps a bit of hassle, perhaps not. Otherwise I'd proceed with the bigger teardown if the job required it.

Heres a link to that tool I picked up for those not familiar with it. I can always sell it on ebay later on when the job is done.

http://www.cycleworks.net/index.php?mai ... cts_id=383

It has a machined piece that protects that delicate camshaft nose during pulling.

If you have the proper tools use the standard method. If not.....here's what I've done a couple of times with success. With the cam out you can remove the sprocket this way. Find a stout piece of pipe that has length long enough that the whole cam will fit into with a little room at the bottom. The diameter should be just big enough to easily get the lobes through in such a way that the cam will rest on the inside edge of bearing carrier (an alternative to the pipe is to just drill a suitable sized hole in your work table). Put the cam in the pipe and secure the pipe in an upright position. Find another small piece of pipe to fit over the cam nose and butt up against the front of the cam shaft. Heat the sprocket good and hot with a torch. A couple of good wacks with a hammer on the small pipe and the cam will drop out into the pipe. Warning: Make sure the sprocket is hot enough or it could bind and damage the keyway area, pad the bottom of the big pipe so the cam has a soft landing.
If you decide to replace the bushing get one of the heavy iron ones with the bronze sleeve like MI sells. They are way better than the aluminum ones most bikes came with. Some airheads came with the iron carrier, but most ones didn't.
http://www.motoren-israel.com/product_i ... sings.html

Thought I'd post a follow up on this sprocket swap I did. Pulling the sprockets went easy with the Cycle Works crankshaft sprocket pulling tool and the modified 3 prong puller for the camshaft sprocket included in the same kit.

I wound up following Mr. Falconer's suggestion to pull the camshaft out in order to press on the new camshaft gear. Beforehand I tried heating that sprocket in a oil can to around 275 degrees but when I went to place it on the shaft it only went about 1/3rd of the way before seating. Tried again, but the same results. So I removed that camshaft and bought a cheap 6 ton bench top hydraulic press to drive the gear on and get that .004 freeplay at the back of the camshaft bearing flange. That went well.

Pressing the crankshaft sprocket and nose bearing on was a breeze with the drawing down cycle works tool. I heated those parts in the oil bath beforehand as well.

So pulling the camshaft out of the engine was the way to go. I never would have gotten that gear mounted properly otherwise. Cheers!

Delighted to hear it worked out well - followup posts and success and/or failure are really valued contributions to these threads.

John Falconer wrote:Delighted to hear it worked out well - followup posts and success and/or failure are really valued contributions to these threads.

Yes, glad to hear you completed the task. I wouldn't have used oil to heat the gear, just the oven. 300 degrees would probably have gotten it on easily. You have to move quickly though.