MAin bearings Problems

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enawazh

Member
May 8, 2007
79
0
6
long beach
Here is the dealeo

I got new bearings 0.25 oversize. Crank was machined. I plastigauged it and all of the bearing clearances checkout according to tsrm. I installed the crank and it spins freely by hand. While i was installing the rings one of the oil control rings came loose and scratched my cylinder. I took the block to the machine shop and had the guy re-hone it.

Now i am installling the crank again and for the life of me i cannot get it to turn smoothly by hand. as a matter of fact it wont turn by hand at all. WTF gives???

Anyone have any input??

ps. I made sure all the bearings went back in the same place that they were removed from during the first crank install.
 
gaboonviper85

gaboonviper85

Supramania Contributor
Jan 13, 2008
3,236
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39
Northeast Philly
Remove all bearings and clean everything again...make sure you put rod in facing the right direction...crank main caps facing the correct direction
 
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enawazh

Member
May 8, 2007
79
0
6
long beach
Everything is in the right direction. I undid the rear three caps and the front three and retorqued them and the problem fixed itself.

I have built several 7M's but never seen this before?????It seems like one of the bearings was not sitting properly.

Thnx for the response gaboon
 
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Mark Conte

Supramania Contributor
Nov 3, 2009
44
0
0
Florida
www.realstreetperformance.com
enawazh;1444149 said:
Everything is in the right direction. I undid the rear three caps and the front three and retorqued them and the problem fixed itself.

I have built several 7M's but never seen this before?????It seems like one of the bearings was not sitting properly.

Thnx for the response gaboon
Click to expand...

Take everything back apart and redo it according to the factory service manual. I don't know how you installed it but it sounds like you torqued them 1, 2, 3, 4, 5, 6, 7 and 60% of the time, that will screw something up every time. ;)

The crank doesn't rest on the top half of the main journal at least partially due to the eccentricity of the bearings. It must be pressed/pulled in by the main caps, so if you tighten one cap down at the front of the crank, the rear of the crank kicks up in the air, if you continue along this path you have a twisted crank, how it spun freely the first time (if you did it like this) was just luck of the draw but still not right.

If you do that to a camshaft...it will break. You need to follow the stud/cap and torquing sequence to set the crank uniformly.

Now if you did all that stuff...I don't know why it acted funny. But still I would not run the engine if all you did was loosen the rear few caps and then torque them back down, I definitely suggest pulling it all apart checking everything again and doing it again.
 
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enawazh

Member
May 8, 2007
79
0
6
long beach
Ohh no I would never torque the crank that way.

I go by tsrm in everything that i do except for the headgasket .lol

I used this torquing procedure to tighten the caps down

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EM&P=91

This is what threw me off completely. I had the crank assembled the first time. But on my second attempt it wouldn't work. I removed the crank cleaned all the journals, re lubed bearings and reinstalled everything three times. Then when i loosened them the last time it fixed itself.????

I will pull it apart again and redo it just to be sure.
 
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enawazh

Member
May 8, 2007
79
0
6
long beach
LOL

sorry i was typing my response and missed that.

I haven't checked the end float yet. I don't have a dial gauge. Can I check it with a feeler gauge?? Also i have seen ppl reuse their old thrust washers to preserve their end float? correct me if i am WRONG.

Thnx for the input guys.

EDIT: I mean can I check clearances on either side of the thrust wahsers with a feeler gauge???
 
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