flex disc bolts sheared off at transmission - Page 2 - PeachParts Mercedes-Benz Forum

vstech · #16 04-30-2015, 11:00 PM

Quote:

Originally Posted by SD Blue

I'm thinking the problem may have been the placement of the washers. The FSM calls for them only on the end with the nut.

Check page 5:
http://www.startekinfo.com/StarTek/outside/12264/disc_2/Program/Chassis/41-050.pdf

Can you post a screenshot of the info for those of us on an iPod, or across the pond?
I was told the washers are to be against the flex disc... So, three would be against the nuts, and three would be against the bolt heads...

biopete · #17 05-01-2015, 09:42 AM

Quote:

Originally Posted by Frank Reiner

bp:

Although it may be simply an illusion, in you most recently posted pic, it appears that the bushing through the rubber that should be seated in the socket of the transmission three-legged flange, is not in the socket of the flange, but is along side of the socket. That would explain why there is so little thread engagement of the nut on the bolt, and why the previous bolts were damaged.

Use of washers:
Washers are used where a nut or bolt head is against rubber (the flex disc).
Washers are not used where a nut or bolt head is against the steel of the three-legged flanges.
Hence, a total of six washers are used per flex disc.

Thanks. it is . What you see is the metal housing for the sleeve. The outer part in this picture diesel911 put up. It is about 1/8 thick but looks a bit bigger in the picture. You can see it is flush on both sides.

biopete · #18 05-01-2015, 09:50 AM

Quote:

Originally Posted by winmutt

Ya something doesnt look right there.

I was popping heads off bolts on flex disks for a year, every several months. Ended up the trans I had got used had a bent flange.

Thanks . i'll keep an eye out for that. I rotated it and checked each leg and they all looked the same angle . that pic is really bad. Somereason all my pics from my phone get rotated when uploaded too.

Seeing how the longer bolts are barely long enough with two washers, i probably used no washers on those when i assembled it and tightened them too much to get them to bite. I've got a washer on both ends now. Put some blue locktite on too.

A thought just occurred to me, i should probably change out the darn hex head bolts i put in the balancer disc to the allen ones as that might effect balance. Damn it! Stupid $EEU$$>>>>$ .

vstech · #19 05-01-2015, 10:48 AM

Quote:

Originally Posted by biopete

Thanks . i'll keep an eye out for that. I rotated it and checked each leg and they all looked the same angle . that pic is really bad. Somereason all my pics from my phone get rotated when uploaded too.

Seeing how the longer bolts are barely long enough with two washers, i probably used no washers on those when i assembled it and tightened them too much to get them to bite. I've got a washer on both ends now. Put some blue locktite on too.

A thought just occurred to me, i should probably change out the darn hex head bolts i put in the balancer disc to the allen ones as that might effect balance. Damn it! Stupid $EEU$$>>>>$ .

don't confuse washer with center lug of the flex disc.

there is ONLY supposed to be a single washer on each bolt. and it is supposed to be in contact with the flex disc, not the flange.
until I see otherwise in the FSM I'm recommending it done this way.
oh. also, the nuts are one time use only. they have a crimped thread pitch at the top of the bolt, and it deforms to lock the nut in place. if you remove it, the nut/bolt is useless, and needs to be replaced.

vstech · #20 05-01-2015, 10:55 AM

Quote:

Originally Posted by SD Blue

I'm thinking the problem may have been the placement of the washers. The FSM calls for them only on the end with the nut.

Check page 5:
http://www.startekinfo.com/StarTek/outside/12264/disc_2/Program/Chassis/41-050.pdf

incorrect... the washers are supposed to be ONLY against the flex disc. one washer per bolt.

SD Blue · #21 05-01-2015, 10:57 AM

Quote:

Originally Posted by vstech

Can you post a screenshot of the info for those of us on an iPod, or across the pond?
I was told the washers are to be against the flex disc... So, three would be against the nuts, and three would be against the bolt heads...

Ah! I stand corrected, you are right. There is a single washer for each bolt that is placed against the flex disc. I should have looked a little closer at the file I posted.

However, in the photo it appears to me that he has a washer on each end of the bolt. I was thinking that may explain why he came up with "short" bolts.

vstech · #22 05-01-2015, 11:12 AM

Quote:

Originally Posted by SD Blue

Ah! I stand corrected, you are right. There is a single washer for each bolt that is placed against the flex disc. I should have looked a little closer at the file I posted.

However, in the photo it appears to me that he has a washer on each end of the bolt. I was thinking that may explain why he came up with "short" bolts.

exactly! I keep posting ONLY ONE WASHER per bolt, but he appears not to read the warning...

Ceristimo · #23 05-01-2015, 12:34 PM

Yup, it has been mentioned several times by several people now in this thread. ONE washer per bolt, the washer goes against THE FLEX DISC.

So, on the transmission side, the bolts go in from the rear to the front. The bolts go in from the drive shaft side, through the flex disc. The bolt heads are always on the side the drive shaft is on.
The bolts that go through the drive shaft and flex disc get a washer on the side you thread the nut on. The bolts that go through the flex disc and connect to the transmission get the washer on the bolt head side.

On the differential the bolts go in from the front to the rear of the car. The bolts that connect the drive shaft to the flex disc get a washer on the side where the nut is threaded on.
The bolts that go through the flex disc and connect to the differential get a washer on the bolt head side.

biopete · #24 05-04-2015, 08:23 PM

Thanks all. I wasn't ignoring you guys. It was just too late. I wasn't going to remove my nuts and destroy them or do all the extra work just to pull off an extra washer on the nut side. I have a washer on bolt head to flex disc and on nut side of propeller shaft with the three new hex head bolts and nuts. So it is covered. It just effectively shortened my bolt a mm or 2.

I can't visualize why it really matters to have washer on flex disc because the flex discs are all metal right there where it hits. But maybe it evens the force around that point. With the small Allen head I can see a washer being ideal there though.

Im 99.9 % sure the problem why they broke was I used the too short of bolts. We will see. That's what I get for thinking. If you ever do it you will see How an Allen bolt with a washer on it seems the better choice when assembling with the balancer.

Cheers