Getting towed, things you need to know...

[SargeW]

We had our first breakdown on the Cummins in the motorhome two days ago and needed to get towed out of the RV park we were in and taken to a repair facility (yea CoachNet!!) A pressure sensor on the high pressure fuel rail was dying and the rig would not idle or maintain speed. There is a post detailing the incident in the Cummins forum.

The heavy duty tow showed up and began preparing us for tow. As usual he lifted the rig by the front tires, and crawled underneath to disconnect the driveshaft. That was when I learned that the previous time I was towed over two years ago, the Freightliner shop in Portland Oregon failed to replace the bolts and straps that bolt the driveshaft to the motor and transmission with new bolts and hardware as is required by Freightliner whenever the driveshaft is removed. Instead when they reinstalled the driveshaft the tech used the old hardware, and put the bolts back in with an impact gun. The bolts that Freightliner uses have a 12 point cone shaped head that takes a special socket to remove. Re-using the bolts will often, and did in my case, strip the heads of the bolts. Out of the eight bolts used, two were nearly rounded off and two more were in poor shape. Four of the eight were new and made of a different metal. So obiviously the tech new that the bolts were different.

That caused my poor tow truck driver an extra hour and a half laying under my rig pounding on the bolts with a socket and a hammer to force it on far enough to get the socket to bite.

The lesson here is if you get towed and need to drop the drive shaft, make sure that the shop replaces any hardware that is single use. A different driver may have given up or refused the tow, and I would have really been sunk.

The Freightliner dealer in Hagerstown PA really took care of me in that respect. They were able to pull up my history on my coach and could see that the previous shop had put the driveshaft back on, and could obiviously see the contdition of the old bolts. They replaced all the bolts and straps with no charge from Freighliner.

Funny thing is that I recall that when the rig got towed the first time to Portland Oregon Freightliner, I was standing next to the rig when the tech came out to put the driveline back on. He was mad as a wet hen because the shop foreman made him come out and crawl under the rig. I guess it wasn't his job description. It was late at night, and I couldn't see what he was doing, I could only hear him. That and he had the worst attitude I ever saw. That's why I hate other people to work on my rig, but sometimes you have no choice.

Sarge

[SargeW]

We had our first breakdown on the Cummins in the motorhome two days ago and needed to get towed out of the RV park we were in and taken to a repair facility (yea CoachNet!!) A pressure sensor on the high pressure fuel rail was dying and the rig would not idle or maintain speed. There is a post detailing the incident in the Cummins forum.

The heavy duty tow showed up and began preparing us for tow. As usual he lifted the rig by the front tires, and crawled underneath to disconnect the driveshaft. That was when I learned that the previous time I was towed over two years ago, the Freightliner shop in Portland Oregon failed to replace the bolts and straps that bolt the driveshaft to the motor and transmission with new bolts and hardware as is required by Freightliner whenever the driveshaft is removed. Instead when they reinstalled the driveshaft the tech used the old hardware, and put the bolts back in with an impact gun. The bolts that Freightliner uses have a 12 point cone shaped head that takes a special socket to remove. Re-using the bolts will often, and did in my case, strip the heads of the bolts. Out of the eight bolts used, two were nearly rounded off and two more were in poor shape. Four of the eight were new and made of a different metal. So obiviously the tech new that the bolts were different.

That caused my poor tow truck driver an extra hour and a half laying under my rig pounding on the bolts with a socket and a hammer to force it on far enough to get the socket to bite.

The lesson here is if you get towed and need to drop the drive shaft, make sure that the shop replaces any hardware that is single use. A different driver may have given up or refused the tow, and I would have really been sunk.

The Freightliner dealer in Hagerstown PA really took care of me in that respect. They were able to pull up my history on my coach and could see that the previous shop had put the driveshaft back on, and could obiviously see the contdition of the old bolts. They replaced all the bolts and straps with no charge from Freighliner.

Funny thing is that I recall that when the rig got towed the first time to Portland Oregon Freightliner, I was standing next to the rig when the tech came out to put the driveline back on. He was mad as a wet hen because the shop foreman made him come out and crawl under the rig. I guess it wasn't his job description. It was late at night, and I couldn't see what he was doing, I could only hear him. That and he had the worst attitude I ever saw. That's why I hate other people to work on my rig, but sometimes you have no choice.

Sarge

[becks]

SargeW...Sorry to hear about your breakdown, but thanks for passing on the driveshaft info. Keep your good posts comming, as you sure made my LCD TV upgrade easy. Now get back to enjoying your travels.

[lthrnk]

Sarge,

Thanks for the update and heads up on the driveline bolt situation.

Another in the annals of travels on the road. At least it all worked out and you're back on the road.

[SargeW]

Thanks for the kind words guys. I figure as long as I learn something from it, it's not a wasted experience. The DW and I have developed a mantra whenever things get off track, "Hey, it's all part of the adventure".

[chasfm11]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The bolts that Freightliner uses have a 12 point cone shaped head that takes a special socket to remove. Re-using the bolts will often, and did in my case, strip the heads of the bolts. Out of the eight bolts used, two were nearly rounded off and two more were in poor shape. Four of the eight were new and made of a different metal. So obiviously the tech new that the bolts were different. </div></BLOCKQUOTE>

Thanks for sharing this, Sarge. I'm really sorry about your luck with this. As one who will go miles out of his way to try to prevent problems, my first response is to order the "kit" and to find the socket.

Can anyone shed more light on this matter with the specifics needed to order either? As usual, when I went to Access Freightliner for the information, it wasn't there. Here is the description for what I believe to be the screw in question SCREW-CAP,12 POINT,3/8-24. It shows P/N GAF R85169. There are two screws and a strap that hold the U-Joint to the drive shaft so I'm assuming that those are the parts that have to be removed.

[SargeW]

Yeah, I think you nailed it Chas. The tow driver was cussing because he rounded out one of his sockets trying to beat it on the bolts to re cut the bolt head. He said it had to be a 12 point socket to have any chance of working.

The drive line takes two "strap kits" as they were refferd to. One for each side of the drive line. When I spoke to Coach Net on the phone about the extra time it took to remove the drive line, they informed me that they tell the tow drivers and the repair facilities that it's their policy to insist that new strap kits are put on every time the drive line is dropped. Coach Net allowed the driver to "bump" the miles that he charged in order to cover his time he spent under the rig.

The tow driver guessed that the strap kits run about $40 per side. The shop called Freightliner and got them to comp the strap kits, which I was really shocked. I think it was because the last time the driveline was dropped it was also replaced at a Freightliner shop and they were able to verify my story. I was ready to dig in my own pocket for the kits, and probably the labor as well.

Sarge

[lthrnk]

Marty,

Glad to hear Coach Net really came through for you. Good thing you had a determined guy driving the tow truck.

Where did you have the work done. was it Freightliner or Cummins?

[chasfm11]

I don't consider myself to be a great mechanic but my experience says that a 12 point socket is typically worse than a 6 point one. The walls of each of the 12 "points" are thinner, allowing a bolt to get rounded off more quickly. It amazes me when engineers use them in places where there is potentially a lot of pressure required to remove the fastener.

Of course, Freightliner's parts information gave no hint about what that socket is supposed to look like. I would imagine that if I contact my local Snap-On tools guy, he probably understands better than anyone else the specifics about the socket.

Based on my luck, if I don't go after figuring this out and buying the socket, I just know that a tow truck will be in my future....

[SargeW]

I actually got taken to a Freightliner shop that also worked on Cummins. I was apprehensive at first, but it really worked out to my advantage in the end with the drive shaft straps and stuff.

I think you are right Chas. I have heard other mechanics complain about the 12 point sockets not holding up as well either. It seems that the six point or sided fasteners would be beefier. It was probably some engineer with 8 years of schooling figured out that the 12 point fastener would be better..........

[DAN L]

almost all aircraft and aircraft engine bolts are 12 point.
SNAP-ON, as well as some other quality manufacturers, have what snap-on calls "flank drive".
this helps shift the load from the tips of the bolt heads, making it harder, but not impossible, to "round off" the bolt head.
my experience is that bolt heads get rounded off primarily by using the wrong size wrench (eg metric for an sae bolt) or not having the wrench straight on the bolt head.

[chasfm11]

Dan, at issue here, at least for me, is what makes these 12 point sockets "unique"? I have a whole set of 12 points, in both 3/8 drive and 1/2 drive. I also have some of Snap-On's flank drive sockets because I've bought them in the past for situations just like this one.

Given Sarge's problem (which appears to have been caused by folks not following Freightliner's instructions), the 12 point solution from the engineer just doesn't seem like a wise decision. Not even all of the tow truck operators are going to own Snap On flank drive sockets. In Sarge's particular situation, I'm not positive that even a properly used flank drive socket would have worked. As you point out, they are good but not infallible.

I hope that we won't loose sight of my request to help the rest of us learn for Sarge's problems. What IS the socket that is needed?? What makes it "special"??

[chasfm11]

How about the "word from the horse's mouth?" I just got off the phone with Freightliner Custom Chassis support line. I had another issue to discuss with them and while I was talking to them, I asked them about the driveline bolts.
Here's what the tech said:
1. There is nothing "special" about these bolts. They are simply normal 12 point bolts and any good 12 point socket will handle them. He claimed to have put on hundreds of them with his Craftsman socket. He also claimed that he'd had to wrestle his share of difficult ones off and had no problems without owning a Flank Drive style socket.
2. The reason that they are 12 point and not 6 point or with a larger head is that the angles that the drive shaft can get into might cause a 6 point bolt to make unwanted contact. It is a clearance issue.
3. I confirmed that the part number for the bolts that I posted is correct for my chassis. He said that replacement of the straps would 90% of the time not be required but the bolts themselves should be replaced when the drive shaft is replaced.

So, on my next trip to Freightliner, I'm going to be the proud owner of 4 new bolts. I'll probably pick up a Flank drive socket, too, since the Snap On guy lives close by. And, yes, I do wear both a belt and suspenders

[Eddie Foy]

12 pt bolts are used in areas where clearance is tight. They actually offer more contact with bolt head vs less. The thickness of the walls of the socket has diddly to do with it.

Maybe the Engineers know a little more about these things than you?



<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by chasfm11:
I don't consider myself to be a great mechanic but my experience says that a 12 point socket is typically worse than a 6 point one. The walls of each of the 12 "points" are thinner, allowing a bolt to get rounded off more quickly. It amazes me when engineers use them in places where there is potentially a lot of pressure required to remove the fastener.

Of course, Freightliner's parts information gave no hint about what that socket is supposed to look like. I would imagine that if I contact my local Snap-On tools guy, he probably understands better than anyone else the specifics about the socket.

Based on my luck, if I don't go after figuring this out and buying the socket, I just know that a tow truck will be in my future.... </div></BLOCKQUOTE>