Dolmar 421 crank seal, bearing removal

[fordf150]

And I apparently need a tool to seat the new ones which calls for heating and cooling as well. Correct? I bought the tools for everything else up to this point but I think I’ll let a shop do this work.

bearings will basically fall in the case. no tools needed for install. last one i did i didnt even bother with heating the case.

********you do need to use a bearing/sleeve retainer on dolly bearings when installing them********** they are not press fit like stihl/husky. not using the bearing/sleeve retainer will result in bearings spinning in the case

 

[redhawk23]

bearings will basically fall in the case. no tools needed for install. last one i did i didnt even bother with heating the case.

********you do need to use a bearing/sleeve retainer on dolly bearings when installing them********** they are not press fit like stihl/husky. not using the bearing/sleeve retainer will result in bearings spinning in the case

Bearing sleeve retaininer? Will the average mechanic know what to do?

thanks

 

[Fatherwheels]

Bearing sleeve retaininer? Will the average mechanic know what to do?

thanks

Its a compound to stick the bearing into the housing, get one that will resist high temperatures just in case.
Put the bearing in a plastic sealed bag in the fridge or freezer to shrink it slightly if it wont push into the case,
alternatively you can heat the case in an oven, or use a heat gun or hairdryer, you need to be able to measure
the tolerances and use the most suitable method, that's why I suggested sending it to someone who has the
ability to assess all parameters and work from there. Be careful using the fridge or freezer method to avoid
damp wet or condensed surfaces, this will not end well.
And just as an example, holding a loose fitting bearing in your hands for a while will make it an interference fit
it will expand, that's the type of tolerances one has to know to deal with, its small details that make or break
a build, you either know to deal with them or become a head scratcher when it doesn't work out.

 

[huskihl]

I use Loctite retainer on every Dolmar I rebuild. But I don’t put the bearings in the freezer because of the condensate, as that is where I would put the Loctite. I heat the cases and drop the bearings in

 

[redhawk23]

Will a mechanic who has never seen a dolmar do it correctly?

 

[Fatherwheels]

Will a mechanic who has never seen a dolmar do it correctly?

No one can answer that, like everything else there are those who can and those who say they can.
That was my reason for suggesting sending it to a porter, because they will know all we have already
discussed and can do it.

 

[Fatherwheels]

If you want someone who can do it, then ask on here or on such a site.

 

[Vintage Engine Repairs]

I use Loctite retainer on every Dolmar I rebuild. But I don’t put the bearings in the freezer because of the condensate, as that is where I would put the Loctite. I heat the cases and drop the bearings in

What is your loctite retaining compound of choice? I have had excellent success with 609 in some recent builds.

 

[huskihl]

What is your loctite retaining compound of choice? I have had excellent success with 609 in some recent builds.

Believe it’s 620

 

[redhawk23]

A couple things, first I’d like to find a splitter to borrow. I really don’t want to buy one.
As far as heating the case, is this rocket science?
Also, I apparently need some L torx keys to remove the bolts from the cylinder.
Last thing, does the oiler and chainbreak need to come off?

thanks

 

[turkeybob]

A couple things, first I’d like to find a splitter to borrow. I really don’t want to buy one.
As far as heating the case, is this rocket science?
Also, I apparently need some L torx keys to remove the bolts from the cylinder.
Last thing, does the oiler and chainbreak need to come off?

thanks

You might find this useful

 

[Fatherwheels]

You may not need to heat the case much at all, as the bearings are stuck in, a heat gun might be the best
to apply some heat to the immediate surroundings, don't over do it, the heat is usually to expand the case
to get a tight / press fitting bearing into it, as said these bearings are stuck in the case so heating may not
have the same effect, though it should help, but heat the case not the bearing or shaft, hens my saying a
heat gun to apply heat whre its of best use..
The crank will likely push out through the bearing , or case pull off the crank, which ever way you think of it.
Spray penetrating oil, the type that helps loosen ceased up parts around the crank bearing, between the case
and the crank too, this will help it slide off when pulling, sometimes tension the puller and using a light
hammer give the puller or the case if you can get close to the bearing a few light taps on the case as
it is magnesium, the shock can loosen or realign the parts so they slide instead of bind on each other, its common
sense really, go gently, it won't take much tapping or pressure to get the case apart.

 

[redhawk23]

You might find this useful

Cool. Thanks.

 

[redhawk23]

Piston off then split the case, I think

 

[Fatherwheels]

Piston off then split the case, I think

You better take the brake flag of first, and clean the sides of the engine,
cleaning all of the engine with air before removing the cylinder would have been the way to go,
you don't a single spec of dirt getting in somewhere you can't get it out of, like the bottom bearing on the connecting rod.

 

[redhawk23]

You better take the front handle of first, and clean the sides of the engine,
cleaning all of the engine with air before removing the cylinder would have been the way to go,
you don't a single spec of dirt getting in somewhere you can't get it out of, like the bottom bearing on the connecting rod.

It’s all oily so I don’t think air will work. How about carb cleaner? The handle is disconnected on the other side.

 

[Fatherwheels]

There is a black spec of something visible on the top of the case at about 1 o clock in your picture,
I ask myself how it got in there, how much more will get in there, and why this was not addressed.
Oil will blow off with air, then dry up the residue that is left, a small brush with some engine / parts
cleaner will help loosen anything with a grip, and pull or push it off the case.
No, I would not use carb cleaner, its not necessary and if it gets into the bearings you need to keep nice
and shiny then you are in for trouble.
Remove the piston before you go any further and put it somewhere it won't get dinged up or the ring broken.

 

[redhawk23]

There is a black spec of something visible on the top of the case at about 1 o clock in your picture,
I ask myself how it got in there, how much more will get in there, and why this was not addressed.
Oil will blow off with air, then dry up the residue that is left, a small brush with some engine / parts
cleaner will help loosen anything with a grip, and pull or push it off the case.
No, I would not use carb cleaner, its not necessary and if it gets into the bearings you need to keep nice
and shiny then you are in for trouble.
Remove the piston before you go any further and put it somewhere it won't get dinged up or the ring broken.

I didn’t know I had to be so careful. Shouldn’t I be able to clean it up once the case is split?

 

[Fatherwheels]

I didn’t know I had to be so careful. Shouldn’t I be able to clean it up once the case is split?

You can certainly clean it up when you split it, but what happens if the dirt on the case ends up in
the bottom bearing of the connecting rod, there is no way to ensure you get it all out, the answer is
to not let it in there.
Engines are put together in a clean environment with no contamination or dirt flying around, they
are not assembled with dirt falling off the workers cloths that will end up in the engine, clean means clean,
there is no in between if you want to succeed.
Honestly, if you have to be told this you should not be in an engine, but its your engine, I can only advise you
to keep dirt out of the picture.
I have seen people assemble engines with dust falling off their work wear, right onto cranks that had oil on them
for assembly, and I have opened up these same engines and seen the damage that did, all scored up.
I know other people who could build an engine in the middle of the street and keep it spotless.
Same reason some people can't clean a carb, they put more crap into it than was there to start with
from dirty hands, surfaces tools and rags that they think are clean.

 

[redhawk23]

The whole point of working on the saw was to learn. I am succeeding! I bought a replacement saw as soon as this one crapped out.