» Site Navigation | | » Recent Threads | | My 318ti build 05-21-2024 04:48 PM 05-21-2024 04:48 PM 0 Replies, 1,180 Views | | | | | 01-02-2012, 05:52 PM | #1 | Member Join Date: Sep 2010 Location: Keller,Texas Posts: 55 | Flywheel Bolts Broke and Fell Out ! Setup: Boosted S52/ZF with UUC M5 clutch and LW flywheel in a 318ti. All poly mounts front to rear. Alright so I had a bad "knock" in the bell housing area of my bimmer and after reading numerous threads I concluded that it was probably the TOB again. The first one lasted 82 miles (it was used and I learned my lesson). I replaced it quickly with one from a local auto parts store so I thought it had failed again. I removed the engine and tranny just in case I had to do some engine work too. I split apart the engine/tranny expecting parts to fall out on the ground but nothing. TOB looked good. Pivot pin was good. Shift fork was good. Pressure plate was good. I removed the PP and found ALL of the flywheel bolts were about to fall out. The only thing keeping them in was the clutch disk ! Upon further inspection I found 3 FW bolts had broken off in the end of the crank ! Theres your knock... Now hindsight is 20/20 and Ive been battling loose bolts for a while now.Front accessory pulley came loose. PS pump pulley came loose. All motor mount bolts were loose this time. Im thinking that my driveshaft might be out of balance causing this but NVH is minimal and I contributed it to all the poly mounts. I mean it is pieced together from 2 different cars for the ti swap but I did offset the balance weights 180*. Or would a bad center support bearing cause all the loose bolts ?? Any suggestions would be greatly appreciated as pulling the drivetrain every 3000 miles is going to get old quick ! __________________ BMWs and SHOs... | | | 01-02-2012, 06:33 PM | #3 | Member Join Date: Sep 2010 Location: Keller,Texas Posts: 55 | Quote: Originally Posted by spidertri | Oh wow...didn't see those threads. Of course I didnt search for "blue flywheel". Thanks ! MikeD. __________________ BMWs and SHOs... | | | 01-02-2012, 06:36 PM | #4 | Senior Member Join Date: Aug 2008 Location: Globally Posts: 1,162 | Stupid question but did you replace them after you swapped the flywheel? They are a stretch bolt and are considered one time use. | | | 01-02-2012, 06:42 PM | #5 | Member Join Date: Sep 2010 Location: Keller,Texas Posts: 55 | Quote: Originally Posted by M-technik-3 Stupid question but did you replace them after you swapped the flywheel? They are a stretch bolt and are considered one time use. | When I first installed the FW it had new bolts but when the first TOB failed I checked/ re-torqued them so that could have been a no no ?? __________________ BMWs and SHOs... | | | 01-02-2012, 07:18 PM | #6 | Member Join Date: Jul 2011 Location: so cal Posts: 44 | You would be in the gray area there. unless you took them out and froze them -200*, even so stretch bolts can go 82mi.... | | | 01-02-2012, 09:34 PM | #7 | Senior Member Join Date: Aug 2008 Location: Globally Posts: 1,162 | Agree with fact on stretch bolts, but they are cheap enough to replace. I have reused them and not had a failure but I was not using an FI engine been in basic 2.5's and 2.8's when customer cheaps out and says no to replacements. | | | 01-02-2012, 11:01 PM | #8 | Senior Member Join Date: Dec 2007 Location: Gulfport, Florida Posts: 3,208 | I would put some red loctite on those new bolts. I also use red on the pressure plate and rear driveshaft nuts. You might already know this: If you ever get one that is loctite and you think you will snap the bolt use a torch and it will melt the Loctite at around 500Fdeg. Any bolt that gets heated for removal is destroyed. | | | 01-16-2012, 09:00 PM | #9 | Member Join Date: Sep 2010 Location: Keller,Texas Posts: 55 | I just spoke with Rob at UUC extensively about my issues and he was very helpful. We believe the possible cause is that stock FW bolts were used and bottomed out thus not allowing them to reach the proper torque. When the engines natural frequency is exceeded then the FW bolts back out and the engine starts tearing itself apart. Im compiling a parts list of things that will be replaced just to get everything to a known state. "Looks good" isnt gonna cut it this time ! Thanks for all your suggestions I will update when I get it back together. Cheers ! MikeD. __________________ BMWs and SHOs... | | | | Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | | Posting Rules | You may not post new threads You may not post replies You may not post attachments You may not edit your posts HTML code is Off | | | |
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