280zone, you find that bearing?

[Guest bastaad525]

I was looking thru the victoria british catalog today, getting ready to order the main bearings to do this half assed fix... and I see that they sell them in like 3 or 4 different sizes.... ????

 

 

Okay so... since I"m not gonna be taking the crank out or pulling the engine at all, how do I know which bearings to get?? Keep in mind there is a very good chance that I'll ONLY be replacing the center/thrust bearing, if this makes any difference at all. The reason for that is a) to cut down on the hassle that this job is sure to be, and when I replaced the rod bearings a few months ago along with the piston rings, the rod bearing wear surfaces actually looked in very good shape, hence I"m going to guessume that the main bearings may not need to be replaced... but since I have to buy a whole set either way, once I pull the center cap and see how the bearing looks I'll make a more informed decision at that point.

 

 

So... back to the question... I was REALLY hoping to just order the bearings and have them in hand by the time I did this so I could hopefully get it in, done and back on the road in one day. Should I just assume that the crank is within original spec and get the stock size bearings? Is there a way to measure and know for sure with the engine/crank still in place? Can I just compare the bearings side by side or might the difference be so small as to be indescernible? Not to mention the condition of the old bearing might not be a good comparison point.

 

Please tell me I dont have to let the car sit there on jackstands for a week while I wait for the right size bearings to come in.

[Guest bastaad525]

Also, I'm just curious... been trying to find good pictures of a stock L28 center bearing but can't get any good ones.

 

When you look at a new center/thrust bearing, about how much/thick of material is there for the thrust parts? From the pics I've seen it looks pretty thick. I hope this question makes sense.

[fl327]

good luck getting those bearing caps out of the block with it still in the car, i did it on a stand and it was still a royal pain in the butt, but at least I know that bottom end is TOUGH. good luck again. What I would do is see if you can still use a standard bearing once you get the caps off, once you do that and you can get away with polishing them back up and throwing the crank back in, you should be ok, just a pain in the butt inside the car.

[280Zone]

I imagine this will be a very difficult task without removing the engine. You will probably not be able to "see" any difference between the bearings even if you get them side by side.

I would also anticipate waiting much longer than a week for Vistoria British to get the order right. they trid three times to send me my bearings and I got opened scratched bearings everytime. I ended up buying them through my local machine shop. I might still have the thrust bearing if you would like it. I'll double check and make sure it is worth mailing.

[JMortensen]

I think the special tool is a slide hammer, because the thrust and rear mains have a threaded hole in them. Might be some type of puller, but I used a slide hammer attached to a bolt screwed into the mains with the engine on a stand.

 

The different size bearings are probably for cranks that have been turned. They would be undersize, probably .010, .020, and .030. The regular size bearings are called "standard". I would imagine your engine would use standard bearings, unless it has been rebuilt before and had the crank turned (not usually necessary on an L series).

 

What the others are saying is true.

 

Jon

[fl327]

The biggest pain doing it in the car has to be the center and rear caps. The way the L6 bottom end is designed, the main caps press into the skirts of the block pretty far and wedge themselves in there, then the two bolt mains hold them in place. This makes for a hell of a time getting them loose sometimes, and this is with full access and full arms length strikes with mallets and a slide hammer to get the suckers off.

[wheelman]

Bastaad525,

 

Just to address your actual question about measuring for the correct size. The only way you'll be able to verify you have the correct size is to use plasti-guage. To use it will require removing the bearing cap, inserting the new bearings with plasti-guage in the them, remove the caps again and measure the pasti-guage. If you decide to use it be sure to follow the instructions on the package.

 

I'm not familiar with how the Datsun thrust bearings are installed. Some engine's are integral with the main bearings some are not. Either way you'll need a feeler guage that you insert between the cranks thrust bearing surface and the bearing to verify it's the correct size.

 

I also agree with most of what has been said already. I don't have experience rebuilding an L6 but I would pull the engine if I were you. It will save you a ton of frustration in the long run. It will also be much easier to keep everything clean while you're installing the bearing(s) if you aren't on your back under the car.

 

Wheelman

[Guest bastaad525]

Haynes manual shows some special kind of puller, not a slide hammer though. Looks very similiar to the 'Popsadent' thing they keep showing on TV lately, for anyone who's seen that. I wont be ordering the bearings thru Victoria British, most likely I'll just get them from Napa, or order them from MSA. Seems everyone is pretty confident in the strength of the crank, so hopefully you guys are right and it's never had to have been ground down, and standard bearings should be fine.

 

 

How far into the block does the main cap go? I'm going to show the guy who's gonna help me some pics in the haynes... he's built a few engines and has pretty much a full shop at his house... I want to see what he thinks we can use to pull the cap off, and let him decide based on that if it's worth pulling the engine or not. I will do it if it comes down to that. Also... even if I try to get it out from under the car, and worse comes to worse I can't get it for the life of me, it's not like I'd have to start over or anything to get the engine out, just continue from there... start disconnecting stuff until it's ready to come out. I wont have to reattach the oil pan or anything right? But I'd LIKE to try it in the car first just to save the time if possible. I don't plan on spending hours attempting it though... it will let me know pretty much right off the bat how hard it's going to be to budge it or not. If Technicalninja has done it many times I have to at least give it a try

 

 

How thick are the wear surfaces of the thrust part of the main bearing? From the few blurry pics I've seen they look pretty darn thick.

[Guest bastaad525]

I imagine this will be a very difficult task without removing the engine. You will probably not be able to "see" any difference between the bearings even if you get them side by side.

I would also anticipate waiting much longer than a week for Vistoria British to get the order right. they trid three times to send me my bearings and I got opened scratched bearings everytime. I ended up buying them through my local machine shop. I might still have the thrust bearing if you would like it. I'll double check and make sure it is worth mailing.

 

 

yeah dude I'm very interested if you have it and it's in good shape, could save me some bucks for sure.

 

I finally found a good clear pic of a stock thrust bearing in place... man the thrust wear surfaces aren't as thick as I thought... if my crank is moving that much the bearing must be pretty much gone...

 

been pouring over a lot of pictures in the haynes manuals and other places... you know I think technicalninja was right I dont think this is gonna be that hard to do afterall... of course pics aren't gonna tell me just how hard it's gonna be to pull that center cap but I think with a bolt threaded in there and a good prybar it shouldn't be too hard to get out.