Ford 302/347 eating thrust bearings.

Cncproformance · Dec 21, 2015

Backround: Built a 347 for my 88 Ranger. Eagle rotating assembly (fully forged), Clevite bearings, March Serpentine kit, TCI 157 tooth flexplate, TCI 3,000 stall Torque Converter and TCI C4 Transmission (Auto Valve Body). Crankshaft endplay was set to 0.005. Dropped the motor in, properly broke in and at the 300 mile mark changed oil and cut open the filter to find normal break-in shavings and copper. Immediately Ripped the motor out and the thrust bearing was ate up badly. No other bearings showed any abnormal wear. The crankshaft had almost 0.014 endplay. Installed new thrust bearing and re-set endplay to 0.005. Re-installed the motor. Grounded it out properly, it has a single trans cooler which is not linked to the radiator at all and all lines are free of kinks. After starting it up and doing a few electrical tests and some free revving for a few days, removed the filter to find no copper what so ever. (Note: Did not drive truck at all during this time. Never went into gear). Installed new filter, drove it for about an hour and removed the filter. Cut it open and found glorious copper. I hooked my Go-Pro to the oil pan to take a video of the converter while driving around the block. While under a 2,000 rpm load it appears this thing is moving quite a bit. I rechecked endplay and its now at 0.008. Also, while cranking, I noticed the flexplate would wobble more than I would like to see. All parts are new out of the box. Let me know if you need pictures of what the old thrust bearing and filter looked like. I'll send them over as requested along with the video. What would be causing the premature wear of the thrust bearing? :dunno:

Cncproformance · Dec 21, 2015

Pictures of first worn thrust bearing

Attached are pictures from the first thrust bearing.

85_Ranger4x4 · Dec 21, 2015

Is the crank and flexplate true?

Cncproformance · Dec 21, 2015

Yes. Everything measures to specification. I've built quite a few of these along with other motors in the past with no issue like this at all.

faststang90 · Dec 21, 2015

how much space did you have between the flexplate and tq convertor?

gsp · Dec 22, 2015

Cncproformance said:
I noticed the flexplate would wobble more than I would like to see.

warped torque converter or mount points are not machined true, it would make some noise, still hard to see loading up the crank to eat up the bearing like that...... post the video on you tube and link it here

Cncproformance · Dec 22, 2015

Video link is attached below

https://www.youtube.com/watch?v=4o0YAQh9qJY

Cncproformance · Dec 22, 2015

Time to get the cherry picker out.

Verdict is in: When I left this morning to go to work, the crankshaft endplay was 0.010. Once I got home, I measured the endplay again. The crankshaft endplay is now......drumroll........0.015! Time to take the motor back out and play doctor again. I'm not in the business blowing up motors and wasting money, so this is my only option...again. Any advice on what I should be looking for during the surgery? Last time I did it, 50 miles or so ago, I checked EVERY SINGLE BEARING and corresponding service for abnormalities and the only one that measured out of specification and looked like hammered dog **** was the thrust bearing. :annoyed:

85_Ranger4x4 · Dec 22, 2015

alwaysFlOoReD · Dec 22, 2015

http://www.atraonline.com/gears/2005/2005-01/2005_01_064.pdf

Jbrown1238 · Dec 22, 2015

I have been following along and decided to chime in. I would suggest contacting Eagle Tech, several of their crankshafts come with a disclaimer that they can not be used with OE style converters. I know you used an aftermarket converter but it wouldn't hurt to get their opinion. Probably a good idea to have all the associated part numbers at hand as well, bearings, rods, pistons, converter, trans, etc.

Looking at the video it looks as though the converter is ballooning a little more than I would expect. You mentioned that all the cooler lines were free from kinks, what about any other obstructions in the lines, the cooler, or possibly the trans?

I also read that you checked crankshaft end play at the time of assembly. Did you lightly "set" the thrust bearing, first on the front side, and then on the back side before running through the final torque sequence on the crankshaft fasteners?

I am no expert but I think your issue is probably parts compatability related, more than likely in the converter or the trans and not so much the assembly process.

gsp · Dec 23, 2015

Cncproformance said:
https://www.youtube.com/watch?v=4o0YAQh9qJY

OMG man that is F*cked up big time, flopping around 1/8" one of the following:

1. flex plate to crank not seated flat

2. torque converter not flat to flex plate

3. torque converter warped or improperly machined at the flats, lay it on a flat surface and check mount points

4. if torque converter uses bolts to flex plate they are to long, if nuts are used to torque converter studs should not be issue unless they are loose

5. flex plate not machined flat at crank or at torque converter mounts

6. Flex plate to crank bolts are to long

My best guess is the torque converter is F*cked Up Big Time

Cncproformance · Dec 23, 2015

Thanks for the article. Talked with TCI. They said use 0.080 washers for additional spacing on top of my 0.060 flexplate. Once I get this all put back together, I'll repost the results. I'm also going to apply the tips and tricks that were presented to me along the way. Thanks everyone for the help and support. Busy week ahead of me.

Cncproformance · Dec 23, 2015

Jbrown 1238: Ill give Eagle a buzz after the holidays. The first time I took it apart, I had the crank looked at by my local machine shop and I was told the crank thrust surfaces looked brand new and were issue free. Also told me that I was lucky and smart not to continue to run the truck after the issue was found. As for the transmission, all pressure readings are normal. I ran a pressure test today and the readings were within a few PSI of the TCI dyno sheet. I have a few spare coolers and new lines around the garage that will get swapped during this teardown. Setting endplay: I did it the same way I do on all my motors, snug and pray! Just kidding! I find humor during this time of frustration therapeutic. Yes, that's how I set endplay, just the way mentioned. Never had an issue before. I have another 347 that I have in my mustang and I have a beefier Trans with a lot higher pressure than this one and that thing revs to the moon and gets abused. I have never (knock on wood) had a problem with that set up what-so-ever. The bellhousing is different from the ranger's 347. I'm going to take measurements for comparison soon.

GSP: Thanks for all of probable causes of the wobble. I will check and recheck the trueness of the flexplate and torque converter once its out.

Cncproformance · Dec 30, 2015

302 (347) thrust bearing issues (Update)

So just to update everyone, I took the motor out yesterday and did an inspection on the engine only for now. It was getting late so I didn't have the time or the proper light to do any real measuring. I did measure the final endplay after driving it around the driveway a few times and it ended up being 0.017. After talking to TCI about using washers as spacers to get the right clearance, I got curious and found this old thread from 2006 discussing the same issue I was having.

http://mmb.maverick.to/threads/torque-converter-clearance-problems.28619/

Once I get the newly ordered parts in and installed, I'll post some pictures and results for your entertainment.

As for the flexplate wobble, the flexplate is true and straight however, the ring gear is not welded straight. There is about an 1/8 inch difference 180 degrees out from one side to another. I'll be calling TCI this morning about this.

Thanks in advance for everyone's help so far. Hope you guys had a Merry Christmas and I wish all of you a Happy New Year. :beer:

Ford 302/347 eating thrust bearings.

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