Loctite for main crank bearings?

[joeym4130]

Just got all the parts to re-assemble the rm motor, when I split the cases the one bearing stayed on the crank shaft instead of staying in the case.

I was told this could be from the cases being old, and the bearing tolerances not as tight.

I was told to use a loctite adhesive product to keep the bearing in the housing next time to make up for the lost tolerance, and to keep the bearing from spinning.

Anyone have a reccomendation? Loctite makes so many damn products I dont know which would be the best for this application!

 

[76GMC1500]

If you use anything, you want Loctite Retaining Compound. Retaining Compound 603, 609 seem like they would be well suited for this application. I don't think you want too high of strength as it may make the bearing difficult to remove in the future. Loctite also sells a product called Quick Metal for repairing oversized bearing housings. This is for more severe damage, however, and I think you'd be better off with the retaining compound.

 

[joeym4130]

If you use anything, you want Loctite Retaining Compound. Retaining Compound 603, 609 seem like they would be well suited for this application. I don't think you want too high of strength as it may make the bearing difficult to remove in the future. Loctite also sells a product called Quick Metal for repairing oversized bearing housings. This is for more severe damage, however, and I think you'd be better off with the retaining compound.

Cool.... yeah I didnt want to end up using some of loctites strongest stuff, because or being unable to remove the bearing later. i'll check out the retaining compounds you mentioned. thanks

 

[Pete Payne]

Why not measure to see if there is an interference fit of .002"-.003" between the bearing and the cylinder case Like there should be . This way you would know if there was a problem . There also could have been a burr on the crank that caused the bearing to stay on the crank and not in the cases.

 

[darringer]

It's not uncommon for one bearing to remain on the crank. There should be no need to loctite the main bearings in the case. Stick the bearings in the freezer for a few hours. Heat the case up with a propane torch until water just sizzles when dropped on the cases. Take the frozen bearings and drop in the cases. There is only a slight interference fit between the case and the bearing, so when the case cools, the bearing should not fall out. If it does, then use retaining compound.

 

[joeym4130]

I looked at the one case side quick, and there are what looks like skidmarks where the bearing sits, like little black streaks. Is this like from the bearing spinning?

And no, its not bad enough that the bearing drops into the housing

I'll go measure it later when i can find my micrometer! haha

 

[76GMC1500]

You're going to need an inside micrometer, bore guage, or a snap guage as well as an outside mic. to do this measurement. .002-.003" interference is too much for this installation. The bore should be equal to or even .0005" or so larger than the bearing outer diameter. You should take some pictures of these skid marks. Spun bearings is more of a journal bearing thing, not so much a rolling element bearing problem. It takes a very loose housing along with some internal bearing problems to cause one to spin.

 

[hd50el]

Loctite also makes a Press Fit Repair product that works very well. It was designed for problems such as yours. I have used it many times in situations like this, and it has never failed. The Retaining Compounds work very well, but I think that the Press Fit Repair material would be more appropriate in this instance.

 

[76GMC1500]

The Quick Metal I mentioned earlier was part of the press-fit repair system.

 

[1BAD250]

:cool: .yes use loc-tite white..be carfull put a small bead around & smooth it with your finger replace the bearing & let it sit i use it in my chevy race engine for 7500rpm or more.good luck. :nod: