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sumdoode

F2t crank walked pics of main bearings

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Hey guys got the oil pan dropped on my 88 626GT and the main all out. The crank had a slight play I wanted to check it out. I did slide all the top halves in place so far and gave the crank a yank and could not move it anymore so seems promising. 

I wanted to post some pics of the main bearings seeing how I don't know jack about what I'm looking at lol. Wanted to see if anyone could explain the wear im looking at, if they look normal or what. 

A little history of the car is...

had it about two years bought it with a bad atx, swapped it with the mtx the car had 84k miles when I bought it has about 87k since the swap. I was getting a intermitted vibration when I stepped on the clutch with the car in gear and it took me awhile to figure out the crank took a walk. Anyway here's the pics of what came out let me know what you guys think

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Alright guys I know I haven't gotten much attention but let me add this in here. I was tapping the top halves of the bearings up over the crank and I bugered up the end a bit where the bearing halves meet. Am I asking for trouble putting this back together? I'm debating on grabbing another set of bearings and trying again. 

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I'd recommend a new set. You could be lucky but it would suck having to replace other parts as well as doing the job all over again.

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8 hours ago, GT_FE3 said:

I'd recommend a new set. You could be lucky but it would suck having to replace other parts as well as doing the job all over again.

Thanks for the reply. That's what I figured. I deffently don't want to do it again lol I have a set coming for Monday hopefully by Tuesday I'll have a video of her running again. I probably would be okay with these bearings but it's not something I'd like to risk. Thanks again!

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It may pay to have a look at the crank for runout too and see if it is within spec, check the thrust and clearances, use plastigauge. This way you'll know for sure everything is good in the bottom end.

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That is sound advice. I did mic the crank it seemed good I will double check it though. Along with the thrust. The engine ran smoothly the only issue I had was when I was stopped with the car in gear and foot on the clutch it would SOMETIMES buck , it would only do it while giving it revs, I could literally grab the crank pulley and move the crank in and out. Once I slid in the new top halves of the bearings in I could not move the crank. All the rod bearings looked brand new and the engine looks very clean

its been a learning experience for me seeings how I never messed with any engine internals. That's why I'm kind of relying on others opinions so I appreciate your time and any tips anyone may have.

Doing this job was kind of an experiment. If i find out it's a fail I plan on pulling the motor and doing it right! I really don't want to yank the engine but I love this car and the body is in amazing shape!! The engine has not even 90k miles on it!!!!

i do truely appreciate your input and will keep updating as I go. 

Edit: when you said check runout I have a feeling I'm not exactly sure what you mean. Are you you suggesting using a dial indicator to make sure the crank is straight?

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On 9/8/2017 at 11:06 PM, sumdoode said:

That is sound advice. I did mic the crank it seemed good I will double check it though. Along with the thrust. The engine ran smoothly the only issue I had was when I was stopped with the car in gear and foot on the clutch it would SOMETIMES buck , it would only do it while giving it revs, I could literally grab the crank pulley and move the crank in and out. Once I slid in the new top halves of the bearings in I could not move the crank. All the rod bearings looked brand new and the engine looks very clean

Was the flywheel replaced or machined? This will cause bucking and shuddering while moving off. If the Micrometer is good it should be fine.

On 9/8/2017 at 11:06 PM, sumdoode said:

Edit: when you said check runout I have a feeling I'm not exactly sure what you mean. Are you you suggesting using a dial indicator to make sure the crank is straight?

Yeah pretty much - check the crank is still round although this is more likely to happen with more than 90,000 miles

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48 minutes ago, GT_FE3 said:

Was the flywheel replaced or machined? This will cause bucking and shuddering while moving off. If the Micrometer is good it should be fine.

Yeah pretty much - check the crank is still round although this is more likely to happen with more than 90,000 miles

This car WAS an automatic when I bought it. The old automatic trans was garbage, put it in drive the car went nowhere. My theroy is the torque converter ballooned causing this issue

the flywheel was machined and it doesn't shudder while releasing the clutch pedal, only while it is down and in gear

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1 minute ago, sumdoode said:

This car WAS an automatic. My theroy is the torque converter ballooned causing this issue

Could be possible, I'd think you'd see this in high power drag cars. Were the parts used for the mtx swap new or re-used?

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43 minutes ago, GT_FE3 said:

Could be possible, I'd think you'd see this in high power drag cars. Were the parts used for the mtx swap new or re-used?

I think someone was treating the car as a high power drag car while the transmission was meeting its slow demise.... 

All of the mtx parts were sourced form a mx6 turbo, transmission, pedal Assmbly. New master new slave cyl. Shifter linkage has all new bushings, I machined the flywheel myself to 0.020" all new engine mounts. Even put a mtx throttle body on in.  I can't remember what else. But everything was used with exception of master and slave cyl engine mounts and the clutch assembly. 

This will be the end all tell all. If the problem exists after the new engine bearings (doubt it will so long I do it right) the transmission will be coming back out. 

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On 9/8/2017 at 11:06 PM, sumdoode said:

 The engine ran smoothly the only issue I had was when I was stopped with the car in gear and foot on the clutch it would SOMETIMES buck , it would only do it while giving it revs, I could literally grab the crank pulley and move the crank in and out. Once I slid in the new top halves of the bearings in I could not move the crank.

A quick double check of the specs, new bearings and it should be good!

15 minutes ago, sumdoode said:

All of the mtx parts were sourced form a mx6 turbo, transmission, pedal Assembly. New master new slave cyl. Shifter linkage has all new bushings, I machined the flywheel myself to 0.020" all new engine mounts. Even put a mtx throttle body on in.  I can't remember what else. But everything was used with exception of master and slave cyl and the clutch assembly. 

This will be the end all tell all. If the problem exists after the new engine bearings (doubt it will so long I do it right) the transmission will be coming back out. 

 I was going to say a failing pressure plate could also cause bucking too sometimes, disregard that its fine, see above. Hopefully I didn't make you second guess yourself - I just wondered if there was a powertrain issue contributing.

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You have contributed more then you think. i was looking for someone to mention something I may have overlooked And we pretty much went right down the line and I feel pretty confident my problem will be solved once this is all done. 

How I wish I dident dicker those new bearings up because it would probably be all together by now that's the only part I'm second guessing as of now. 

However I thank you for brainstorming with me and I will have a walk around video of this baby purring in due time.

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Unfortunately I torqued all the caps down gave the crank a pull and the play is still there. This is a huge disappointment. 

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9 hours ago, GT_FE3 said:

Oh damn sorry to hear that

Thanks man. Nothing left to do now but pull the engine. I should have known it wasn't gonna be that easy. Keeping my fingers crossed that the block is OK. 

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