treemuncher Posted September 27, 2007 Share Posted September 27, 2007 (edited) I've started to troubleshoot and nitpick on the new-to-me dog. I have two broken exhaust bolts in two different heads and the exhaust gaskets were shot. All of the bolt heads are in rough shape from salt damage and weathering so I plan to replace them all. 20 pieces total plus the other 4 that connect to the 90 degree elbows. I've gotten pricing from 2 different Mack dealers and they both quoted me roughly the same price right at or near $15 each piece. That adds up to over $300 for bolts! What is so special about these shouldered bolts that makes them such a high priced item? I can purchase grade 8 or 9 bolts for $1-$3 each. These bolt don't encounter exhaust gasses directly and there is nothing special looking about them except for the shoulder. A shiny new washer under a shiny new grade 8 bolt will act just the same.A dog on the top of the bolt is not worth that price to me. Sounds like someone moved a decimal point the wrong way.OK members, what say you???UPDATE: I've purchased bolts through Fastenal to replace the original Mack bolts that were so severely corroded. I ordered stock # 19765 and #19761 in case any one else runs into the same problem. The cost for 15 units of each stock number was $58.20 and $26.70, respectively, or $3.88 and $1.78 each. Total bolt cost was $84.90 + tax. There should be about 6 bolts left over for back up. These are grade 8.2 flange head bolts. Although both numbers are listed as serated shoulder type, only the 19761 bolts are serrated. All threaded holes were re-tapped prior to installation. All threaded surfaces were liberally coated with antisieze and torqued to 55 ft-lbs. No fold - over bolt locks were included with the upper gasket set so I drilled out the bolt heads and installed safety wire locks to help keep anything from coming loose. Total machining time was 1.0 - 1.5 minutes per bolt and 3 drill bits. As time permits, I will try to post on the Wiki link for tips on machining these hardened bolts, rebuilding joint problems on the exhaust manifolds and other problems solved on the E9 Edited October 22, 2007 by treemuncher Quote Link to comment Share on other sites More sharing options...
Maxville Truck Posted September 27, 2007 Share Posted September 27, 2007 I've got an 84 superliner (e-9 440) :SMOKIE-RT: myself that need some exhaust work.... I hope that it doesn't cost a fortune to replace all my leaks.. I agree that sounds a little steep for bolts, I cant speak for the special nature of the bolts but my experience with my e-7 and e-6 ,motors is I'm better off with the mack studs versus plain bolts. because the plain bolt always seem to work loose first... just my observation. Quote Link to comment Share on other sites More sharing options...
theakerstwo Posted September 27, 2007 Share Posted September 27, 2007 I've started to troubleshoot and nitpick on the new-to-me dog. I have two broken exhaust bolts in two different heads and the exhaust gaskets were shot. All of the bolt heads are in rough shape from salt damage and weathering so I plan to replace them all. 20 pieces total plus the other 4 that connect to the 90 degree elbows. I've gotten pricing from 2 different Mack dealers and they both quoted me roughly the same price right at or near $15 each piece. That adds up to over $300 for bolts! What is so special about these shouldered bolts that makes them such a high priced item? I can purchase grade 8 or 9 bolts for $1-$3 each. These bolt don't encounter exhaust gasses directly and there is nothing special looking about them except for the shoulder. A shiny new washer under a shiny new grade 8 bolt will act just the same.A dog on the top of the bolt is not worth that price to me. Sounds like someone moved a decimal point the wrong way.OK members, what say you??? Quote glenn akers Link to comment Share on other sites More sharing options...
theakerstwo Posted September 27, 2007 Share Posted September 27, 2007 I've started to troubleshoot and nitpick on the new-to-me dog. I have two broken exhaust bolts in two different heads and the exhaust gaskets were shot. All of the bolt heads are in rough shape from salt damage and weathering so I plan to replace them all. 20 pieces total plus the other 4 that connect to the 90 degree elbows. I've gotten pricing from 2 different Mack dealers and they both quoted me roughly the same price right at or near $15 each piece. That adds up to over $300 for bolts! What is so special about these shouldered bolts that makes them such a high priced item? I can purchase grade 8 or 9 bolts for $1-$3 each. These bolt don't encounter exhaust gasses directly and there is nothing special looking about them except for the shoulder. A shiny new washer under a shiny new grade 8 bolt will act just the same.A dog on the top of the bolt is not worth that price to me. Sounds like someone moved a decimal point the wrong way.OK members, what say you??? Ok i will try this again but if you try to drill those old bolts dont try putting heat on them because that only makes them harder and remember if a bolt is hard to get out when it has a head on it just think how hard it is ti remove with out a head so when you start to lossen bolt just tey to work back and forth for a while and get the inpack off of it and when you drill it keep in the center of the bolt and you may get out glenn Quote glenn akers Link to comment Share on other sites More sharing options...
treemuncher Posted September 27, 2007 Author Share Posted September 27, 2007 Regarding the broken bolt removal, that will be up to the machine shop to do. Although I have a vertical mill myself, I will leave it to the professionals at the machine shop. At $15-$20 per removal, it is money well spent while I make money elsewhere.The exhaust valves show some minor leakage so all 4 heads will be sent out for cleaning, inspection and whatever else needs to be done to make them 100%. I only want to fix it once. Although I have to be a mechanic most all of the time, projects like this do not make my day.And, while the heads are off, out comes the motor to replace the rear main seal and possibly, the transmission front seal. The clutch will be inspected and a new throw out bearing installed if necessary. The radiator will be sent out for rodding and cleaning while it is removed.In for a penny, in for a pound. I want it done right the first time and I don't want to see any oil on the ground after I'm done. It is far less expensive money and timewise to get all of this done at one lick.I'm seriously considering allen head cap screws for the manifold bolts. These are extremely tough and reasonably priced. Quote Link to comment Share on other sites More sharing options...
Rob Posted September 27, 2007 Share Posted September 27, 2007 Regarding the broken bolt removal, that will be up to the machine shop to do. Although I have a vertical mill myself, I will leave it to the professionals at the machine shop. At $15-$20 per removal, it is money well spent while I make money elsewhere.The exhaust valves show some minor leakage so all 4 heads will be sent out for cleaning, inspection and whatever else needs to be done to make them 100%. I only want to fix it once. Although I have to be a mechanic most all of the time, projects like this do not make my day.And, while the heads are off, out comes the motor to replace the rear main seal and possibly, the transmission front seal. The clutch will be inspected and a new throw out bearing installed if necessary. The radiator will be sent out for rodding and cleaning while it is removed.In for a penny, in for a pound. I want it done right the first time and I don't want to see any oil on the ground after I'm done. It is far less expensive money and timewise to get all of this done at one lick.I'm seriously considering allen head cap screws for the manifold bolts. These are extremely tough and reasonably priced.If you are going to get away from a hex head bolt in this application, put some serious thought to using a Torx head instead of socket head. I've found that the Torx head bolts are easier to remove after usage and the socket headed ones have a tendency to round out defeating the original purpose.Fifteen bucks seems a bit steep for bolts of the size you require.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
Barry Posted September 27, 2007 Share Posted September 27, 2007 I have had customers try to use regular bolts but they wouldn't hold for long...not sure why, but the Mack bolts worked fine for the extra money...I do think they have some kind of high temp thread locker on them. Quote Barry - Watt's Truck Center Parts Manager and BMT Webmaster...1-888-304-MACK Link to comment Share on other sites More sharing options...
theakerstwo Posted September 27, 2007 Share Posted September 27, 2007 I have had customers try to use regular bolts but they wouldn't hold for long...not sure why, but the Mack bolts worked fine for the extra money...I do think they have some kind of high temp thread locker on them.I think they are a different metal and a grade 8 bolt will stretch under heat and i know they will rust real fast and deteirate from the heat . cummins bolts are the samr way i have tried to use grade 8 bolts in cunnine exhaust and it what stay. glenn Quote glenn akers Link to comment Share on other sites More sharing options...
ThaddeusW Posted September 27, 2007 Share Posted September 27, 2007 The reason standard bolts might not hold is because they have different pitch diameter limits or H number. Yes thats right, even though a thread might be a 3/8-16 there are slight variations in pitch diameter that are numbered H1-H7 for over and L1-L3 for under. The number indicates how many thousandths the diameter is over or under the standard size. A standard 3/8-16 might be an H3-H4 which is 1-2 thousandths over to ensure the bolt easily threads in. Those Mack threads might be larger on the block for a larger thread pitch diameter. I believe the head studs are an H1 or L1 which is five-ten thousandths (.0005") over or under to ensure such a tight fit they nearly bind together. Possible the pitch diameter on standard bolts is too small and they come loose. You would need a very accurate thread gauge to see that or possibly use a micrometer to check. Quote -Thad What America needs is less bull and more Bulldog! Link to comment Share on other sites More sharing options...
HK Trucking Posted September 27, 2007 Share Posted September 27, 2007 When you install the new bolts or studs, forget the thread locker (loctite).Use a liberal amount of anti seize compound instead.You'll thank yourself next time you have to remove them! Quote "If You Can't Shift It Smoothly, You Shouldn't Be Driving It" Link to comment Share on other sites More sharing options...
chris88 Posted September 28, 2007 Share Posted September 28, 2007 neverseize is a wonderful tool. Almost everything that i put together gets a nice coating. Quote Link to comment Share on other sites More sharing options...
Maxville Truck Posted September 28, 2007 Share Posted September 28, 2007 neverseize is a wonderful tool. Almost everything that i put together gets a nice coating. I agree whole heartedly, I use antisieze religiously on my manure equipment, pretty much never fails me for coming apart!! :D Quote Link to comment Share on other sites More sharing options...
mudslut28 Posted October 1, 2007 Share Posted October 1, 2007 Anti-seize and PB Blaster are 2 things I cant work without Quote Link to comment Share on other sites More sharing options...
waslucky Posted October 1, 2007 Share Posted October 1, 2007 cant speak for V8 exhaust bolts but my expirience with my 237 an e6 i have used Stainless Steel Allen Head bolts on mine w thick flat washers and spring washers complete with liberal Anti sieze on threads and shanks , tech tip run tap thru heads an blow out with commpressed air before installation as clean threads on new bolts will make life easier if you have to remove again an that way ensures you get correct torque value,s when installing almost eliminating chance of under torque an subsequent chance of them coming loose .Thick washers are a Must as thin washers tend to distort an let manifolds work loose Quote Link to comment Share on other sites More sharing options...
treemuncher Posted November 2, 2007 Author Share Posted November 2, 2007 Many thanks to all respondents for their input. Please see the update that I editted into the first post for alternative methods of securing the exhaust bolts. If and when I get time, I may try to post a Wiki page regarding my experience with this matter. I sincerely hope that this post will help others in the future. Quote Link to comment Share on other sites More sharing options...
Barry Posted November 2, 2007 Share Posted November 2, 2007 Many thanks to all respondents for their input. Please see the update that I editted into the first post for alternative methods of securing the exhaust bolts. If and when I get time, I may try to post a Wiki page regarding my experience with this matter. I sincerely hope that this post will help others in the future.Nice job! Yes, please make a wiki topic on this when you have a chance! Quote Barry - Watt's Truck Center Parts Manager and BMT Webmaster...1-888-304-MACK Link to comment Share on other sites More sharing options...
rodperformance Posted November 4, 2007 Share Posted November 4, 2007 thaddeus w you"re correct also those bolts are grade 8 for torque but they are expensive because is a metal alloy that stretches and contracts in different temps so they hold torque and heat changes as well.I end up doing the same thing i went to fastenal and bought a set back in june when i repaired my 235hp 675 engine. by the way a 237 and a 235 engines are the same Quote Link to comment Share on other sites More sharing options...
jward Posted November 21, 2007 Share Posted November 21, 2007 neverseize is a wonderful tool. Almost everything that i put together gets a nice coating. yea, until you put it on you're wheel studs like my buddy did one time. lol !!! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.