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#1
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Torque Value Needed
91 560 SEL - 115k
Here is a puzzler for ya! I need to finish reassembly of the front cover after chain and rail replacement and I need the tightening value for the lower right guide rail. Part #117 050 18 16 Its attached with two bolts with spring washers and get this - they were only hand tight- when I removed them! The manual has no torque value and does not mention - hand tight! The rail seems to flop around a bit when the bolts are loose and when tight the rail is stationary. Would that be a problem? Are they supposed to be loose so the rail "moves" to take up slack in the chain? Would Locktite be a good idea on the bolts? I would hate to leave them -hand tight- and then have the bolts back out from vibration and cause a chain snap. Someone must have some thoughts on this one.
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Gerry 59 Ranchero 83 928 Euro S 84 928 Euro S 87 300D Turbo-Frybrid "WVO, Tastes Great - Less Filling" 90 750 IL 91 560 SEL |
#2
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normal torque for a 8mm bolt of 8.8 hardness is 10-12 ftlbs, not really very tight.
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MERCEDES Benz Master Guild Technician (6 TIMES) ASE Master Technician Mercedes Benz Star Technician (2 times) 44 years foreign automotive repair 27 Years M.B. Shop foreman (dealer) MB technical information Specialist (15 years) 190E 2.3 16V ITS SCCA race car (sold) 1986 190E 2.3 16V 2.5 (sold) Retired Moderator |
#3
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M.B. Doc:
Thanks for the reply. I am still at a loss to tighten them up because anything more than "hand tight" and the rail can't 'wobble' like it should - I think. They also have spring washers on them and that indicates to me that they should not be torqued. Furthermore, why would these two bolts come off "by hand" to begin with, if they were not like that from the factory. I mean, every other darn bolt on an MB is tight as hell and never loosens up.
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Gerry 59 Ranchero 83 928 Euro S 84 928 Euro S 87 300D Turbo-Frybrid "WVO, Tastes Great - Less Filling" 90 750 IL 91 560 SEL |
#4
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Mine were "snug", not tight when i took them out. Doc's 10 to 12 ft lbs sounds about right as i recall. Trying to remember, but i don't think there is enough clearance between the bolt head and the cover for them to ever come out with the cover on. Only been a few months, but the details are growing fuzzy already...
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Earl McLain '02 C230 Kompressor '89 560 SEL "Frau BlueCar" (retired April 2004) |
#5
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I don't see why you would want the rail to wobble. Isn't the purpose to steady the chain after it makes the turn around the crank? The tensioner is responsible for keeping the chain tight. And it seems to me that MB would have spec'd a pin-type bolt had they wanted it to wobble, and not relied on a finger-tight fully-threaded bolt.
My $.01.
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Chuck Taylor Falls Church VA '66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe |
#6
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Chuck: Sure the crank is pulling the chain around the crank gear from right to left (looking at the front of eng) and it would be tight on the right side and slack on the left. Thats where the tensioner comes into play, however, the wobble in the lower left rail follows the chain as it bunches up. Like the track on a military TANK.
This rail moves quite a bit, not side to side, but LONGITUDENLY and follows the flex in the chain. All the other rails are FIXED on pins except this one which is rather LOOSE. The more I dig into this engine the more I love it!
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Gerry 59 Ranchero 83 928 Euro S 84 928 Euro S 87 300D Turbo-Frybrid "WVO, Tastes Great - Less Filling" 90 750 IL 91 560 SEL |
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