Featherweight 40 driveshaft

[mattrobbins]

Hello
I have a Featherweight 40 bought new by me in December, 1988. The driveshaft warped around a rusty bit and I have managed to extract about half through the top of the driveshaft tube. How do I extract the rest? The gearbox bearing is sealed and I would rather just knock the gearbox, with gasket intact, off the bottom of the driveshaft tube - is this possible?
Matt Robbins

[RickUK]

Hi Matt - not completely sure quite what your problem is, but to get the driveshaft out, you will need to split the gearbox from the water pump housing (the casting directly above the gearbox) by means of two screws - one in front and one behind the drivetube. The gasket between them is normally reuseable multiple times.
Separation is necessary because there is a plastic impellor at the lower end of the drive tube, meaning that the drive tube cannot be withdrawn without splitting the castings as above.

If corrosion is bad as you appear to describe, you may have problems removing the two screws, but heating the region where the screws are threaded into the castings will help.
If you want to get the water pump casting off the drive tube, put in the pinch bolt from the 'wrong' side and a sturdy washer in the slot and tighten the bolt onto the washer to release the grip, but only do this a turn or so as it is possible to crack the casting by this method. Clean up the tube and the casting before reassembly.

[mattrobbins]

Hello Rick
Thanks for your advice which I will follow later this morning.
I have taken those two screws out but I cannot remove the countersunk screw in the middle. Do I have to remove this screw as well?
Thanks & kind regards, Matt.

[40TPI]

Rick doesn't seem to be around......

Unfortunately yes. The screw between the exhaust and driveshaft casing tubes has to come out if you want to separate the water pump housing from the gearbox.

This is usually not an easy task. Probably the most difficult fastener to remove on a Seagull if there is any corrosion present. Suggest you search back over the old posts to see all the tips and experience of people who have contributed on this subject in the past. Prerequisites are a large propane torch plus a tight, accurately ground screwdriver tip that you can really lean on to generate torque . Usually needs the power unit un-shipped and the exhaust pipe removed to gain access.

Peter

[mattrobbins]

Hello Peter
Thanks for your advice. I have gone as far as you have suggested, this stubborn screw being about the last remaining screw on the entire outboard. I have heated up the damn screw and housing and attempted to remove the stubborn thing with a impact cordless drill and an air-driven impact drill. Next step is a mechanical impact driver, after which I'll have to drill the screw out. Wish me luck.
Matt Robbins

[40TPI]

.......... Next step is a mechanical impact driver, after which I'll have to drill the screw out. Wish me luck.

You can never have too much heat applied...............the gearbox box needs to be hot enough to boil gearbox oil and beyond......... literally! Frequently it is the steel /ali corrosion on the bolt shank above the threaded section that causes the problem. Hot/ cold cycling plus a well fitting screwdriver with 15 mins of back and forth torquing a la Palfreeman technique plus patience may be a route to success here....... failing that try declining French irregular verbs ............ Using the electric drill is to admit defeat ; and it rarely drills straight down the bolt core.

Peter

[RickUK]

Matt - hoping you haven't starting drilling yet, and that the screw slot is still in reasonable condition!

As Peter has said, you need a lot of heat, all around the problem area - fix the gearcase in something solid - eg a vice, but with wooden strips/blocks to avoid damage to the aluminium gearcase - this is a fundamental for the ensuing wrestling match.

Find a screwdriver with a tip that will take maximum advantage of the available slot, with a long a shank as possible (longer shank means less sideways lean) and a Stilson wrench to grip the srewdriver shank to help you mightily increase turning force.

Get casting v. hot, and apply screwdriver?Stilsons, putting a lot of end-pressure on the screwdriver to keep it engaged in the slot.
If all this fails, you can then try drilling, but only attempt to drill off the screw head, which is about the same depth as its diameter, so you can then separate the castings and wind out the offending screwshank at you leisure.
If yuo have the luxury, run a tap (1/4"BSF) into the vacant thread 'ole before reassembly, and use coppergrease or similar on the thread to make life easier in the future. John has replacement screws in stainless steel.

[mattrobbins]

Thankyou 40TPI and RickUK for your continued interest in my plight. 40TPI, yes I have infinite patience, which is why, RickUK, I haven't started drilling yet and the screw slot is still in good condition.
I have heated the screw and surrounds and (gently) tried an impact driver, but I thought too much heat would crack the aluminium.
I will at it again and heat the gearbox until the oil boils before trying the #*@& screw again. I have already unsuccessfully tried irregular verbs in most languages.
Thanks again and I will let you know.
Matt Robbins

[rosbullterier]

If you can use a fine Oxy/acetylene torch tip, try heating the bolt itself as red/hot as possible. The thread expansion and heating the alloy oxidation could work to start the unscrew.
Don'y try to unscrew in one go. Very small screw movement, then unscrew a little - repeat.
As you are patient, after it has cooled, without success, pour some Redex to form small pool in bolt recess. Wait overnight. Repeat.

[mattrobbins]

Thankyou rosbullterier, I will try what you advise.
Matt Robbins