Fitting new crankshaft bearings GL1000

[kndw]

I'm currently rebuilding a GL1000 motor. The main bearings needed to be replaced, and I managed to source replacements based on the codes on the different engine parts.

I have just put the new bearings in, with a generous amount of assembly lube, and torqued the bolts of the crankshaft retainer blocks. While torquing the bolts (in small increments), I noticed that it becomes harder to turn the crankshaft. It does not become impossible to turn the crankshaft, but the increase in force necessary to turn it is noticeable. Is this normal, or does it mean something is wrong? To be sure, I also took the blocks off, cleaned everything, and put it back. The (potential) problem remained.

Any help is much appreciated.

[virgilmobile]

Before assembly the bearings are dry fitted with plastigauge set in each bearing.Then each bearing cap is torqued to specs..The caps are removed and the plastigauge is measured.
This measurement reflects the gap.Some trimming may be necessary to get the gap within specs.
Once each recheck has the correct clearance,then it is assembled with the assembly grease.
The same method applies to each rod bearing.
Absolutely do not just torque them down and hope there ok.

[kndw]

alright, thanks. I'll take it to a machine shop then.

[virgilmobile]

Not really needed.Plastigauge it available (at least here) at a good auto parts supplier.
And there's plenty of online info of how to "adjust" the clearance.
Personally I just filed just a touch of the end of the bearing and recheck when there too tight.
Also (if your doing the Pistons) do check the end gap on the piston rings in the jug it's going in after it's been honed.Trim if necessary for end gap tolerences and don't forget to offset the gap of the rings.

[thrasherg]

I haven't worked on a GL10000 engine, but have rebuilt many other engines and the main bearing sleeves are usually sold in different thicknesses based on the plasti gauge results. Most engine service manuals explain how to perform the plasti gauge test. Plasti gauge is a thin Plasticine type material which when squashed obviously gets wider as you squeeze it thinner, by measuring the width of the squashed material you can look at a chart and know how thick it is, that number is then used to calculate the size/thickness of the plain bearing sleeve. If your crankshaft is getting tight as your tighten the main bearing caps, I suspect your clearances might be too tight, the only way to really know is to use the Plasti gauge and check them. It is very cheap to buy the plasti gauge and very easy to use, definitely something you can do at home. I would suspect the honda service manual probably explains how to check the main bearing clearances, if not purchase some plasti gauge and just follow the instructions that come with it.

Gary

[kndw]

I haven't worked on a GL10000 engine, but have rebuilt many other engines and the main bearing sleeves are usually sold in different thicknesses based on the plasti gauge results. Most engine service manuals explain how to perform the plasti gauge test. Plasti gauge is a thin Plasticine type material which when squashed obviously gets wider as you squeeze it thinner, by measuring the width of the squashed material you can look at a chart and know how thick it is, that number is then used to calculate the size/thickness of the plain bearing sleeve. If your crankshaft is getting tight as your tighten the main bearing caps, I suspect your clearances might be too tight, the only way to really know is to use the Plasti gauge and check them. It is very cheap to buy the plasti gauge and very easy to use, definitely something you can do at home. I would suspect the honda service manual probably explains how to check the main bearing clearances, if not purchase some plasti gauge and just follow the instructions that come with it.

Gary

The engine case and crankshaft are marked with letters/numbers, and according to the manual you can determine which bearings you need based on these markings. That is what I did, so the new bearings I have are (should be) the same as the old.
I know about plastigauge, but figured I wouldn't need it if I would just use the same bearings. Guess I was wrong! Anyway, I'll take it apart again. Little use going through all this effort to rebuild an engine otherwise.

[virgilmobile]

You are not necessarily wrong..This is just procedure.
Tolerences are very close on Honda engines.
The new bearings may need to be touched to fit them properly.Remember this is not a new engine so new bearings may not exactly match

[kndw]

Personally I just filed just a touch of the end of the bearing and recheck when there too tight.

Can you elaborate on the procedure? I take it you check the clearance with plastigage, and then if you find it to be to tight, you file a tad off the edge and check again? Also, if you find it to be too tight, wouldn't you just need thinner bearings, rather than file a bit off the edge?

[virgilmobile]

Decisions are made after the plastigauge measurements.What can be done is determined on each bearing set separately.
There may be just one pinch point,a tapering of the journal,a thick splatter of babbet in one spot.Out of round journal,warped crankshaft.Lots of variables that can cause binding.

[DenverWinger]

... and filing bearing edges allows them to be tighter if too loose. If you are binding already you may need to get looser bearings.

[Old Fogey]

Since you have already bought bearings this may come too late but it may help you determine that you have/ have not bought the correct ones.
http://www.wingovations.com/choosing-yo ... 4588152247

[kndw]

Since you have already bought bearings this may come too late but it may help you determine that you have/ have not bought the correct ones.
http://www.wingovations.com/choosing-yo ... 4588152247

Thanks for all the help, gentlemen.

I have bought plastigage and checked all the clearances. These were all in order, and I put everything back together.

As a matter of fact, the engine is back in the frame and has just run for the first time! Perfectly smooth, no noises.

[thrasherg]

Congratulations and well done.

Gary

[ekvh]

What? No pictures????

[kndw]

Alright, here she is (just before I installed the radiator):

Unfortunately, the engine has to come out again, as the starter won't engage anymore... I re-used the old springs, followers and rollers. Anyway, that's an entirely different problem which I believe I can handle.

Thanks for the help