DCT pan with 1 bolt missing.....

[CamasM3e93]

I serviced my DCT over the weekend, changing the fluid, suction filter, pan, and bolts. The bolts are tightened down to 7 N/m. Either my torque wrench failed or one of the new bolts was shit, because I sheared a bolt on the passenger side of the transmission off. While I await a proper sized bolt extractor, the pan is holding fine with no sign of leaks after several hour long spirited drives. Makes me wonder whether how quickly I need to get to it.

I can't be the only person to have done this and wonder anyone's thoughts on how long I could expect the new pan and gasket to do its job with a bolt missing.

[brettcp]

Those bolts are indeed fragile.. fortunately they were in stock at my local dealer (so cal) so no need to order online and wait for shipping. I can't comment on how long its going to hold up, but if you can pick it up at a local dealer it'd be an easy fix.

[Gossypiboma]

Hindsight is 20/20 but in the future don't use a tq. wrench on bolts that require such little tq.

[tbuck]

Originally Posted by Gossypiboma

Hindsight is 20/20 but in the future don't use a tq. wrench on bolts that require such little tq.

^This!!! I work in an engine assembly plant as a QA tech. We have a few m5 and m6 bolts that will snap if you look at them wrong. My boss (an engineer) always wants thing torqued to spec, and I always tell him, sure I torqued it just so. But I never use a torque or click wrench on these. We have an electrical connector that is a nut on an m4 stud, and, no shit, it has a spec of 2nm.

7nm is at the bottom of my 1/4 inch drive inch-pound torque wrench and I simply don't trust it that low. Just snug it up and call it good. Maybe come and check it in a week or so, just to be sure.

[amrazM]

Originally Posted by Gossypiboma

Hindsight is 20/20 but in the future don't use a tq. wrench on bolts that require such little tq.

Use a torque wrench on all hardware which has a specified torque rating, the purpose of the 7NM on the pan is to spread the force equally throughout the sealing surface. Diy guys should invest in a good torque wrench and have it calibrated every two years depending on how it’s used.

[Gossypiboma]

Originally Posted by amrazM

Use a torque wrench on all hardware which has a specified torque rating, the purpose of the 7NM on the pan is to spread the force equally throughout the sealing surface. Diy guys should invest in a good torque wrench and have it calibrated every two years depending on how it’s used.

Its more reasonable to simply tighten the bolt with a little common sense than spending hundreds of dollars buying a "good" tq. wrench and having it calibrated every two years.

I've never seen a forum more concerned with tq. values for every fastener than this one, its almost comical.

To each their own though.

[M43S7RO]

Agreed, I use a meter to tie my shoes to spec.

Originally Posted by Gossypiboma

Its more reasonable to simply tighten the bolt with a little common sense than spending hundreds of dollars buying a "good" tq. wrench and having it calibrated every two years.

I've never seen a forum more concerned with tq. values for every fastener than this one, its almost comical.

To each their own though.

[CamasM3e93]

Originally Posted by Gossypiboma

Its more reasonable to simply tighten the bolt with a little common sense than spending hundreds of dollars buying a "good" tq. wrench and having it calibrated every two years.

I've never seen a forum more concerned with tq. values for every fastener than this one, its almost comical.

To each their own though.

I hear you. I'm close to three-quarters German. The detailed nature is programmed in my DNA and working on the BMW seems to bring it all out.

Your point is well taken, though. I've never worried much about torque working on other cars. That said, this car with it's high revs, aluminum block, aluminum screws, use of plastic or other alternative materials in various areas does raise the bar for torqueing to spec.

[CamasM3e93]

All is well. I used a bolt extractor kit and pulled the broken bolt out this morning without any damage to the pan. I'm not sure what material these bolts are - tungsten? - the bolt shaft was very hard to drill into even with a 1/16" titanium bit. Thankfully the shaft wasn't broken off flush with the transmission housing, because the extractor seated between the broken shaft and the aluminum sleeve and that was enough to back the broken bolt out by hand. The sleeve popped right back into place and I hand tightened a replacement bolt back into place, plus another 45 degree turn.

To answer my own question, the transmission was not leaking any fluid around the missing bolt position but the pan was not seated snug against the transmission housing. I think left unaddressed, it would have eventually started weeping.

Cheers everyone. Thanks for your input.

[amrazM]

Originally Posted by Gossypiboma

Its more reasonable to simply tighten the bolt with a little common sense than spending hundreds of dollars buying a "good" tq. wrench and having it calibrated every two years.

I've never seen a forum more concerned with tq. values for every fastener than this one, its almost comical.

To each their own though.

you can purchase a set of of 1/4, 3/8 and 1/2" drive torque wrenches from tekton for $135 instead of snapping aluminum fasteners in half and having to extract bolts and redo jobs.

https://www.tekton.com/torque-wrench-bundle-trq99901

its not really being overly concerned, the majority of people come here asking how to do a job, why not do it properly?