torque setting for drive shaft bolts?

levedr

Member
I just bolted in a driveshaft using torque+angle and monitored the actual torque, which was a lot higher than the simple torque spec of 52 ft-lb for the driveshaft attaching bolts. I used the Mercedes spec of 15 Nm (11 ft-lb) + 70 degrees, and the torque wrench showed about 75 ft-lb (around 100 Nm). But it's naturally not that simple. The original M10 bolts on the Dodge chassis were Mercedes p/n N000000003435, which had an E14 head. The current N000000007445 grade 10.9 bolts have an E16 head, resulting in significantly more surface area between the bolt head and driveshaft flange. Does this affect the torque value? And in which direction? 75 ft-lb is way above the torque chart values for M10 10.9 bolts. So are my bolts torqued more correctly that they would have been using Dodge's 52 ft-lb spec, or are they way over-tightened? Darned if I know!
My local (and highly untrusted Sprinter) MB service shop charges $173 to "...retighten rear axle U-bolts...". Everytime I ask for a quote they give me different prices.

I have a nice 1/2 inch Craftsman digital torque wrench and the proper sockets and would DYI but all this "torque plus angle" talk has me thoroughly confused.

Can wanyone make it simple for me?

2013 3500 bought used, doubt previous owner ever had service performed...no service records. Ciurrently 43000 miles.
 

Bobnoxious

Made in the USA Qualité Supérieure
My local (and highly untrusted Sprinter) MB service shop charges $173 to "...retighten rear axle U-bolts...". Everytime I ask for a quote they give me different prices.

I have a nice 1/2 inch Craftsman digital torque wrench and the proper sockets and would DYI but all this "torque plus angle" talk has me thoroughly confused.

Can wanyone make it simple for me?

2013 3500 bought used, doubt previous owner ever had service performed...no service records. Ciurrently 43000 miles.
Torque sequence can be found here http://www.suspensionspecialists.com/techinfo/Ubolt_Information.pdf

Torque 125 foot pounds. Do not lube threads or you will have to recalculate torque.

Screen grab is from WIS Workshop Information Service. No angle is involved other than 45° for loosening prior to retorquing.
 

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Bobnoxious

Made in the USA Qualité Supérieure
FYI the MB torque spec is 160 NM which is 118 ft. lbs. not 125 for the 906 chassis.
You are correct and thank you for the correction. Got confused with earlier models. I even marked on my vehicle. Notice I marked sequence as well.
 

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Mike DZ

2016 View 24V (2015 3500)
My local (and highly untrusted Sprinter) MB service shop charges $173 to "...retighten rear axle U-bolts...". Everytime I ask for a quote they give me different prices.

I have a nice 1/2 inch Craftsman digital torque wrench and the proper sockets and would DYI but all this "torque plus angle" talk has me thoroughly confused.

Can wanyone make it simple for me?

2013 3500 bought used, doubt previous owner ever had service performed...no service records. Ciurrently 43000 miles.
The earlier discussion about torque plus angle was for drive shaft bolts. The quote you had from MB dealership you got was for rear axle U bolts - the ones that hold the rear springs and rear axle tube together. No torque plus angle on those, just torque only, with the caveats (dry, loosen first etc) given by others.

Those should have been re-torqued at the first A service, but some have reported the need for routine rechecking.
 
The earlier discussion about torque plus angle was for drive shaft bolts. The quote you had from MB dealership you got was for rear axle U bolts - the ones that hold the rear springs and rear axle tube together. No torque plus angle on those, just torque only, with the caveats (dry, loosen first etc) given by others.

Those should have been re-torqued at the first A service, but some have reported the need for routine rechecking.

Thank you. Some people could overlook that the conversation changed from driveshaft bolts torque procedures to Spring U-bolt torquing. I could see the drive shaft bolts snapping off at 125 ft-lbs!!
 

Bobnoxious

Made in the USA Qualité Supérieure
According to the Almighty Sprinter Guru Dennis, 135 foot pounds is minimum U-bolt torque. My question, what's the difference between the earlier and later version U-bolts? Anywho, I would not recommend 135 foot pounds.
 

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According to the Almighty Sprinter Guru Dennis, who claims 135 foot pounds is minimum. My question, what's the difference between the earlier and later version U-bolts? However, I would not recommend 135 foot pounds.
I'm probably not going to get to that with my 1/2 inch drive torque wrench. It looks like a trip to Harbor Freight for the 3/4 inch drive torque wrench and the 3/4 to 1/2 inch adapter for my impact socket set. But seriously, U-bolt torque is a different story from how this thread started.
 

VanGuy6678

New member
Mercedes Benz Sprinter of Arrowhead (in Peoria, AZ) just answered this exact question for me for my 2010 2500. He says tech tells him 40nm plus 60 degrees. Can anyone else concur?
 

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