Stud SERIUOSLY siezed on gear casing

Neil_Y said:
Or ACF-50 dissolves the corrosion products penetrates and lubricates.
Click to expand...

The aluminium oxides formed by this sort of corrosion are totally insoluble short of strong acids and ACF 50 is basically an oil.. The OP is wasting his time with lubricants anyway. Problem is that the corrosion products are more bulky that the original metal so the further the corrosion goes, the tighter gets the joint. And to make matters worse, aluminium oxides are very grippy abrasives.

The only serious answer is heat but you can often succeed with nothing more than a kettle of boiling water ( safer than a heat gun because it wont ever go more than 100C) since ally expands so much faster than steel and hence loosens its grip quite quickly. Try that
 
nigelmercier said:
Which is odd, because it isn't a penetrating oil. It isn't even a very good lubricant.

Use PlusGas or ACF-50.
Click to expand...

Well they must have put the wrong stuff in my can of ACF50 then :D Technically you may well be right but get some on your hands and it feels very oily. The manufacturer describes it as an effective lubricant. But it wont help in the situation described by the OP.
 
Last edited:
rustybouy said:
alright lads, thanks for all your replys, im still unsure how to go about getting some penetrating fluid into this,a bit more to try and get in some fluid now........
Click to expand...

Backing the nut against packing, to get the casting moving, sounds a good tip.

With the stud upright, apply your oil with a small brush. I have found a 50/50 mix of ATF and Acetone to be outstanding for this kind of work.
 
Trick ive used many times, is heat the seized fastener up then leave it for half an hour or so and then try to undo it.
WD40 is rubbish for just about anything.


Lynall
 
He cannot really get sufficient access to the fastener to heat it


A previously posted picture shows the problem more clearly I think. Less than a centimeter of a stud several centimeters long is accessible.

Heating the casting , perhaps combined with a good penetrating oil, is I think the way forward.

Maybe using the nut to jack the thing apart will help, but only initially . Wedges in the joint may be necessary.

I have had a similar problem but the fastener was a bolt so was able to screw it out with some difficulty.

Fingers crossed that it is only corrosion around this stud that is the problem..... often it is difficult to pull the drive-shaft free from the crank shaft!

attachment.php
 
I think I'm even more puzzled now as to what the problem is. If he's trying to seperate the bottom of the leg at the joint just below the threaded fastener, then it looks to me as if the problem is towards the back of that joint ie above the prop shaft, and maybe as you say the shaft or exhaust running vertically down the leg.

anyway, if the OP is interested in trying juju penetrating type mixes, he might find http://www.bmwlt.com/forums/showthread.php?t=53261&highlight=acetone%2Fatf interesting. ATF and acetone, and seriously tested too! Learn something evey day.

but mr OP , do try copious boiling water if the stud really is stuck.
 
Just in case it is the drive shaft that is holding the thing together, it may be an idea to take the gearbox apart and remove the crown gear from the end of the drive shaft. This would allow the drive shaft to withdraw from the bottom section.
 
alahol2 said:
Just in case it is the drive shaft that is holding the thing together, it may be an idea to take the gearbox apart and remove the crown gear from the end of the drive shaft. This would allow the drive shaft to withdraw from the bottom section.
Click to expand...


It may be possible but looking at the diagrams I rather feel that it is not possible to withdraw the drive shaft in this way. I think the water pump probably has to be removed before the shaft can be pulled from the gear case. Even if the tabwasher and pinion ( not crown gear) retaining screw can be released.
 
wotayottie said:
if the OP is interested in trying juju penetrating type mixes, he might find http://www.bmwlt.com/forums/showthread.php?t=53261&highlight=acetone%2Fatf interesting...
Click to expand...

I think it is worth repeating that post here, as the recipe for the "ATF-Acetone mix" was misleading:

Penetrating Oils Compared

Machinist's Workshop magazine actually tested penetrants for break out torque on rusted nuts. Significant results! They arranged a subjective test of all the popular penetrants with the control being the torque required to remove the nut from a "scientifically rusted" environment.
[table="width: 800"]
[tr] [td]Penetrating oil[/td] [td]Average load[/td] [td] [/td] [/tr]
[tr] [td]None [/td] [td]516 pounds [/td][td] [/td] [/tr]
[tr] [td]WD-40[/td] [td]238 pounds [/td] [td] [/td] [/tr]
[tr] [td]PB Blaster [/td] [td]214 pounds[/td] [td] [/td] [/tr]
[tr] [td]Liquid Wrench [/td] [td]127 pounds [/td] [td] http://www.amazon.co.uk/exec/obidos/ASIN/B000ABCH6E/dolcetto-21 [/td][/tr]
[tr] [td]Kano Kroil [/td] [td]106 pounds [/td] [td] [/td] [/tr]
[tr] [td]ATF-Acetone mix [/td] [td]53 pounds [/td][td][SEE UPDATE BELOW] [/td] [/tr][/table]
The ATF-Acetone mix was a "home brew" mix of 50 - 50 Automatic Transmission Fluid and acetone [FALSE - SEE UPDATE BELOW] ... Note also that "Liquid Wrench" is about as good as "Kroil" for about 20% of the price. [See link above for Liquid Wrench in the UK]

[UPDATE from Piston Heads] The Machinists Workshop test was discredited as they later found out the ATF was mixed with trichloroethelyne not acetone. ATF does not mix with acetone and trichloroethelyne is a poisonous carcinogen!

[UPDATE From Machinists Workshop] "I get more mail about this one little article than any of the others we have printed. Almost all of the mail relates to the fact that the two ingredients in the homemade penetrant do not mix. The fact that the photo in the magazine shows a container of Power Steering Fluid, while the text refers to Automatic Transmission Fluid, has also spurred more than a few people to call or write. The author was kind enough to write a reply to these questions and it appeared in the February/March 2010 issue of Machinist’s Workshop. The following is Lloyd W. Bender’s reply:

The original homemade penetrating oil mixture called for using trichloroethelyne as the solvent. I cannot recommend trichloroethelyne for home shop use and definitely not for anything slightly resembling a business. Both PSF and ATF will form emulsions with acetone under mild agitation sufficient to thin the oil enough to penetrate. Upon standing, these will separate. Acetone performs better than the other commonly available organic solvents, such as methanol, but not as well as trichloroethelyne."
 
Last edited:
i've gone and done it now lads


View attachment 29422

at least its off, i did try boiling water,i tried a bit of heat, ended up packing it out as best i could with wood and a few small chisels, i dont think it was the shaft that was the problem, it's that stud, im not sure how far down it goes into the bottom casing,im guessing a few cm, looks like i'll get better access now, hopefully i can get a replacement stud, thanks for all suggestions, i really appreciated the advice, im dreading opening the impeller housing now, i just know it's going to look fine!! best to check though ,thanks again.

Pete
 
rustybouy said:
i've gone and done it now lads


View attachment 29422

at least its off, i did try boiling water,i tried a bit of heat, ended up packing it out as best i could with wood and a few small chisels, i dont think it was the shaft that was the problem, it's that stud, im not sure how far down it goes into the bottom casing,im guessing a few cm, looks like i'll get better access now, hopefully i can get a replacement stud, thanks for all suggestions, i really appreciated the advice, im dreading opening the impeller housing now, i just know it's going to look fine!! best to check though ,thanks again.

Pete
Click to expand...

You dont need to remove the stud do you ? Or have you damaged it? I think you may find that it is no longer available as a spare

Go gently with the water pump retaining nuts. You really do not want to break the those studs.

Dont even think about refitting the old impeller having gone this far. Fit a new one then you can forget about the water pump for a few years
 
Last edited:
I helped a friend with his Yamaha 4 stroke outboard 9.9HP and all of the nuts came off the studs that held on the gearbox came off ok but the gearbox would not budge. After trying all the usual things ie heat, penetrating fluids, freezing sprays etc it bacame apparent it was not going to comeoff. On close inpection it was then apparent that these studs were MILD STEEL and had rusted in the tubes in the leg they ran down and were swollen with the corrosion inside. We ended up just cutting the leg section apart and it was very badly corroded and whatever we had done it would not have come off. Fortunately it was an extra long leg so it was only a 5" section to be replaced even then it was circa £150. I hope you do not have the same problem and a sheered stud only may be a pretty good result. Lots of good advice already that I cannot add to. Good luck with it.
 
good morning, yes vic i've broken the stud and am off to buy a removal thingmy, i know i cant get a replacement, im sure i'l figure out something, will heed advice about water pump and go canny, i would have put up more pics but it keeps saying i have used my quota, i tell u what - i'l start another thread to see if i can get the photo's up, let you see the bigger picture

Thanks ahabdonal for the good luck :)

Pete
 
Have you tried tightening the nut now that the bottom end is "free"?
It does look like it will be seized all the way up.
Drilling it out of the leg looks like a floor standing pillar drill job. Don't butcher it!
 
got the top part out of the broken stud, just need to drill out the bottom and im good, took out the old impeller.....one paddle missing and two badly corroded, good job i checked, looks like around a centimeter of stud left in the bottom part of the casing, nearly there :) lets hope i can get it all back together, should be ok if i bore a new thread for a bit of stainless steel, im not ordering gaskets yet!!

Pete
 
You must log in or register to reply here.

Share this page

Top