MS660 crank bearings and gasket

[TRX]

Rebuilding an MS660, and have a few questions................

Do I need to heat the bearings before removing them from the case, or just tap them out with a hammer?

When installing the new bearings, do I use locktite or some other kind of sealant to keep them in place?

When installing the gasket between the two halves of the case, do I use gasket sealant?

Any useful tips or advise?

 

[huskihl]

Don’t need heat to remove bearings from the case, but it doesn’t hurt. Find a deep well socket and pound them toward the inside of the case. Make sure the case is sitting flat so that you’re not putting a point load on one small surface.

Up to you whether you use Loctite or not. Some do. I heat the bearing pockets with a propane torch for a couple minutes after you see smoke form from the residual oil. Make sure the case is hot enough if you use loctite on the bearings. (Although there’s no way to tell if it’s hot enough. Takes practice).

Sealant on the case gasket is up to you also. Need to do it in a way that you get it assembled before the sealant sets up too much

 

[trains]

IR thermometer is real handy to get the bearing pockets up to the required temp.

re case half gasket, a very thin coat of permatex no3 non hardening works well.

 

[stihltech]

Yes, use heat.

 

[TRX]

Used heat but the bearings only went half way. So I did what any self-respecting man does..........I beat them into submission until they fit.

Now I have another set of bearings on order, and an IR thermometer so I know when it is 240 degrees.

Thank you for the help guys! Next time I will do exactly what you say.

 

[ballisticdoughnut]

One way to know if you need any retaining compound or sealant is easy. If it was there when you took it apart then yes. If not then no. Get a copy of the service manual, many here can help you with that. A lot of people seem to develop the habit of using sealant, glue, thread locker, etc in applications that don’t call for it because they think it needs it.

 

[ZeroJunk]

I use a shop press myself. Of course, I wouldn't go out and buy one just for this. But, they come in handy for a lot of things.

 

[bwalker]

Don’t need heat to remove bearings from the case, but it doesn’t hurt. Find a deep well socket and pound them toward the inside of the case. Make sure the case is sitting flat so that you’re not putting a point load on one small surface.

Up to you whether you use Loctite or not. Some do. I heat the bearing pockets with a propane torch for a couple minutes after you see smoke form from the residual oil. Make sure the case is hot enough if you use loctite on the bearings. (Although there’s no way to tell if it’s hot enough. Takes practice).

Sealant on the case gasket is up to you also. Need to do it in a way that you get it assembled before the sealant sets up too much

I've always put the case in a oven until the surface is 150 degrees or so. I leave the bearings in a freezer over night.
In my working life we would heat the pocket with whatever means we're possible and dipped the bearings in liquid nitrogen.
The concept is the same cold bearing and warm pocket.

 

[bwalker]

I use a shop press myself. Of course, I wouldn't go out and buy one just for this. But, they come in handy for a lot of things.

Using a press if you have one is a good practice. Just make sure you stop applying pressure as soon as the bearing is seated.

 

[Automender]

Freeze the bearings and heat the case as stated above. They may just drop right in.