Binding crankshaft (1 Viewer)

[Stevepipeman]

I've had the 1F engine out of my 71 FJ40 for over a year. The machine shop cleaned, bored cyls. .020 over, .010 off crank, installed cam bearings, rebuilt head and milled deck. I bought my bearings from SOR and replacing cam and lifters. I've inquired on this forum about the .20 / 8mm shims found under the bearing caps and have gotten good replies from a few a nice and helpful folks. My problem is that the damn crankshaft is binding when I turn it with a wrench on the crank nut and will barely budge when forcing the counter weights by hand. I have correctly placed the bearsings, torqued them in sequence with a light coat of only on the face only. I have measured the crank journals over and over and and they are within spec for .010 under crank. I've tried to measure the ID of the installed and torqued bearings but I don't trust the cheap plunger type ID guages I have. I've used a ton of plastigauge and seem to be in tolerence for oil clearence but the binding scares me to death. I've installed and reinstalled this crank so many times, I'm sick of it, including isolating particular sticky journals and seem to jump from bearing to bearing. I've gone to a local expert that restores investment concourse cars to 70's muscle cars. He told me to give the bearing caps a "hard smack" with a heavy hammer to "nest" the bearings, otherwise, he has no interest in what he calls my "basket case". It's obvious that most of my local machine shops are run my younger guys and there a few with old guys, my age, that have the experience with older type engines. I've got over $2500 in parts and machine shop costs. The engine had 2 broken rings prior to disassembly @ 180k original miles, but was otherwise in good shape.
Does anyone have a procedure for starting from scratch to figure out what's my issue? I'm sorry I didn't farm out the rebuild, but I'm not so sure someone else wouldn't have assembled it tight.

 

[CHU TOY]

Does the crankshaft spin by hand without the pistons and camshaft?

 

[Splangy]

How’s the thrust gap? The main bearings you bought may have an oversized thrust surface and the thrust surface on the crank may not have been cut by the machine shop.

 

[ceylonfj40nut]

I presume you have used assembly lube putting these in? No mention of it above.

 

[Stevepipeman]

Does the crankshaft spin by hand without the pistons and camshaft?

No. Haven't even installed cam or pistons.

 

[Stevepipeman]

How’s the thrust gap? The main bearings you bought may have an oversized thrust surface and the thrust surface on the crank may not have been cut by the machine shop.

That was my 1st point of concern but it gauges on the low side of allowable tolerance.

 

[Stevepipeman]

I presume you have used assembly lube putting these in? No mention of it above.

No, I've only used a couple shots of break in oil on the bearings because I'm just testing the fit before I permanently install it with the rear main seal, cam lifters and pistons. I have lubriplate assembly lube, which I will be coating the cam and lifters. It sounds like you'd recommend it. I'll give it a try. It;'s not locked, by any means but, but too tight to bet on possibly ending up with an expensive boat anchor.
thanks

 

[pb4ugo]

I take it you have oiled the bearings b4 laying the crank in the blk and the caps when installed. Have you mic'd the main journals in multiple spots to confirmed their dimensions? Does the crank spin freely with no bearing caps installed? Do you have a dial indicator? With the crank laying in the blk, maybe check the run out on the the main journals while turning the crank. The crank could be slightly bent or the blk may need to be align bored. The crank should spin freely with the caps installed.

 

[Whiskerz]

Plasitgage is the answer you seek.

 

[reddingcruiser]

How long was the crankshaft out of the block, and was it stored standing on end, or laying down? Was it ever dropped?

 

[Stevepipeman]

How long was the crankshaft out of the block, and was it stored standing on end, or laying down? Was it ever dropped?

The cranks been out for 9-10 months, stored horizontally, in wooden rack supporting journals. I checked run out on all journals with a mounted and fixed dial indicator after spinning crank and removing crank. Nothing out more than a .002 or .003.

 

[reddingcruiser]

Sounds like you know why I asked the question. Laying a crankshaft down unsupported (especially for a long time) or dropping it is no bueno.

 

[Whiskerz]

Do you have all of the bearings in the correct location ? I know it seems simple

 

[Splangy]

You sure it’s not just a lubrication issue?

 

[Luis peralta]

I have the exact same problem. Still can’t figure out but I think the issue is the trust bearing does nor have the correct width. By the way I order the main bearing set from SOR. was this the reason why you had binding?

 

[Stevepipeman]

I have the exact same problem. Still can’t figure out but I think the issue is the trust bearing does nor have the correct width. By the way I order the main bearing set from SOR. was this the reason why you had binding?

Hi Luis, Definitely check your thrust clearance at #3. Mine has been corrected but didn't completely solve the binding problem. I've gotten some great input after measuring crank journals, inside diameters and used up a half mile of Plasti-gauge until I'm ready to jump off the roof. I've had a few good chats with Paul @ Spector Offroad (SOR) and he's telling me exactly what an old master machinist has also alerted me to, and that's the slight changes in shape, size and dimensions in engines approaching 40-50 years old, particularly after almost infinite cycles of heating, cooling and possibly some overheating at a time or 2 during a long life. The machine shop I used initially, cleaned, bored cyl's .020 over, replaced cam bearings, core plugs and rebuilt head. I've taken my block, crank and bearings to a highly regarded machine shop that will confirm my lack of tolerance and binding which will, most likely, result in align honing the main bearing recesses so that the new bearings will be going into completely round and aligned cavities. It's about the only answer left and makes perfect sense, knowing my crank was machined to near perfection. I should have it back next week and will be glad to give you an update on how it works, including any necessary changes to bearing shims, if necessary. Good luck with your build.

 

[Reeve Kook]

Sounds like you know why I asked the question. Laying a crankshaft down unsupported (especially for a long time) or dropping it is no bueno.

I have the same issue with a stiff crankshaft after installing new bearings. Mine has been out for about a year and stored horizontally most of the time. this reply by Reddingcruiser caught my attention. is there any way of correcting this?

 

[Living in the Past]

Before adding any lube did you plastigauge the bearing clearance?

 

[Malleus]

I have the same issue with a stiff crankshaft after installing new bearings. Mine has been out for about a year and stored horizontally most of the time. this reply by Reddingcruiser caught my attention. is there any way of correcting this?

I'd have it balanced to find out if it's really bent or not. If it was, it can be bent back. The balancer will know what's needed.

Before I did that though, I'd do what @Living in the Past suggested and verify the clearances are correct.

 

[greenbeasty]

I don't know a lot, but it seems the align honing is the next logical step.
Interested to see how this turns out.