Has anyone ever had transom bolts stretch? I think mine have stretched over the last few years. I've marked the bolts and had to tighten them now and then. The transom isn't crushing and it's in great shape.
JW
Printable View
Has anyone ever had transom bolts stretch? I think mine have stretched over the last few years. I've marked the bolts and had to tighten them now and then. The transom isn't crushing and it's in great shape.
JW
Are the bolts hardened #8s stainless? Should also be NY-lock stainless nuts. All bolts should be tightened each year, some will work loose.
Not sure. Will they have a #8 on the heads? They're what Midwest Marine installed the motor with when it was new 3 years ago.
I can't see the bolts stretching. They are stronger then any part of the transom.
A grade 8 bolt will have 6 lines on the top of it. Here is a very simple chart, but these three grades are most common. There may be decimal numbers on the top of your bolt. That would be metric. Grade 8 bolts will rarely stretch or bend. They will...but the hardness of them normally causes a break before a bend or stretch. The threads can stretch some. Grade 5 bolts are VERY common. You will see them alot in hardware stores and such. The nylon lock nut that brush was talking about will have a nylon band on the end. They work well, but are not the best as the nylon will get old and loose its quench. The best I have seen that have the least tendency of loosening are a regular lock nut that is slightly oval in shape at the tip. Forget lock washers...I've seen too many of those break or flatten and do nothing more than what a flat washer could do. If you still have trouble put some blue locktite on the threads. Its medium strength and can be removed with force. Do not use the red....it sets hard and does NOT like to let go. It has its place...but you have to be careful where you use it.
http://cdn.makezine.com/uploads/2011/03/boltimage_4.jpg
Hmm.., my bolts are gold with a numeral "3" and letter "F" on the heads. There are no lines like those in your picture.
My lock nuts do have a nylon ring like you mentioned. Are the good lock nuts all metal like the old chevy rocker arm lock nuts?
Logged in, no ability to edit; After a better look, the bolts do look like they're stainless but the rest of previous post stands.
I doubt the bolts are stretching. Either the transom is compressing (which WILL happen, even if not noticeable.) Or they are just loosening.
In my experience, you usually only have to go back and tighten once or twice if the transom is good, and the nylock nuts are good. The nuts DO wear out after being used numerous times OR after high speed use, like with an air ratchet. If the nylon got hot, you may want to replace the nuts.
-TH
I am with scrapper on the nuts. Nylock nuts tend to loosen over time as the nylon ages. Esna all metal lock nuts work better.
Note: locking hardware is intended for single use, no matter if it is all metal esna or nylock. Blue Loctite is your friend on almost all metal to metal threads except sensitive torque applications.
Do you guys know who sells the nuts locally in K.C.?
Any hardware store. Ace, Lowes, Home Depot.
:hesaid
I'll replace the nuts. Thanks!
By the way, does Locktite work on stainless steel bolts/nuts? Reason I ask is the stuff works by causing a small amount of corrosion and stainless is supposed to resist that. Just curious since I used some on a transducer mount that has stainless bolts/nuts.
I say yes, just due to experience. The link below is a neat read I found. Didn't know there were so many loctite products! lol. Does say inactive metals like stainless should have a primer applied. I have used it with good luck without it. But I'm assuming it would work much better with the said primer. Check out the link...they make alot of stuff. The link also tells the technical aspects of how and why it works. Although it is a "loctite" brand read...its pretty interesting.
http://www.wdarc.org/Loctite%20Guide.pdf
Loctite does not cause corrosion. It actually prevents it. Nuts and bolts are designed with a certain amount of clearance which is called thread depth engagement. There are fancy formulas to determine engagement but in lay terms almost all of the fasteners you see have about 85% thread depth engagement. When it gets above that, it becomes very difficult to start the bolt and requires a wrench to turn it into the fastener. Loctite fills in the last 15% to give 100% thread depth engagement then dries sticking to the metal and seals the threads. At 100% engagement you have an interference fit. Interference fits don't move until the interference is lost. SS primer makes it easier to stick to SS.
I was sent to all kinds of schools when I worked for one of the top NACD. Glad to know some of it still is in there. :) The best bolts I have ever used are stamped CAT on the head. They are almost indestructible.
Loctite is some great stuff.
I'll use the blue stuff.
Quote:
Originally Posted by Sovran
What you say is true about the CAT bolts...you will find that to be true with CAT orings. I have a couple drawers full of them from rebuilds, part replacement, and who knows where else. Use them any time I can. CAT stuff is crazy high...but you do get what you pay for from them for the most part...although alot of their stuff has been contracted out much like most every other business anymore. I think quality control is still very high.
Scrapper gave you some really good advice on the loc tite!!
I learn something new every day on this site!
Loctite is a must on Harleys. The red especially.
Quote:
Originally Posted by wilbur
I use a lot of blue on trucks....out of curiosity...what all do you use the red on when working with Harleys? We have a Harley guy that drives for us. Has a truck that I wouldn't cross the highway in...but MAN...you should see his bike! Left it in the shop one night when he was out. I didn't even want to walk by it, it was so clean! He has rebuilt many.
After looking at the motor installation (Merc 150 four stroke), the installer could've drilled the lower bolt holes closer to an inner brace. This resulted in the inner wall of the transom slightly bowing when the nuts are torqued. The stiffener plates keep it from bowing very far. If it becomes a problem, I'll drill the bottom holes lower, closer to an inner brace. The engine bolt holes are slotted, so I can do that. I replaced the locknuts and used blue loctite.
Thanks for your ideas and suggestions. If nothing else, I learned about bolt types and strengths.
All the engine an trans bolts except for the head bolts.Quote:
Originally Posted by Scrapper
wow...wouldn't never guessed that. Guess they are such good bikes they aren't ever supposed to be taken apart! :biggrin Wouldn't that be nice!
Thanks for that.
Naw Scrapper, they shake so much all the bolts would vibrate out if not glued in LOL
Best shake in the world though and the chicks seem to dig it:biggrinQuote:
Originally Posted by wannabe fisherman
I guess we just going to completely Hijack Searks post, but when I was a youngster I owned Triumph, BSA and Matchless twin and single cyl motorcycles. Talk about vibration, Red Loctite wouldn't hold those things together. Go for a 500 mile trip and you better have your tool kit and tighten everything up every couple hundred miles.
Hijacking never bothered me! :-)
British Wentworth. What a PIA. They were poor fitting fasteners to begin with. During a rebuild on my Rocket 3, I drilled, helicoiled, and replaced everything with metric. It stayed much tighter, and when I lost one from vibration I didn't have to mail order 1 bolt at a time.
Triumph 650 Tiger Charlie. Rest every 100 miles and tighten every 250. Haven't had it for 30 years and still keep my eye out for the next one.Quote:
Originally Posted by cray
I have seen them break!Quote:
Originally Posted by Sovran
I work at Caterpillar's testing facilities. Sometimes the purpose of the test is to determine how much force the bolt will take before failure, and failure comes in many forms. I get to paid to watch all sorts of Caterpillar testing.
As for bolts stretching, they all do when properly torqued to specifications. The purpose of torqueing a bolt/nut is to load the threads which stretches the bolt. This load is the mechanical bond. Over-torqueing bolts/nuts weakens the bolt. Too much load and it will shear in half. Not enough load and they will loosen.
Exactly why you do not reuse many CAT bolts in a new rebuild. The injector hold down bolts for instance, 42lbs...loosen....42lbs...your done. If you replace the injector, you replace the bolt as they are built to stretch during torquing. Good point Hanr!Quote:
Originally Posted by Hanr3
Agreed, but put a CAT bolt side by side to almost any other readily available bolt and there is a clear winner.Quote:
Originally Posted by Hanr3
My favorite jobs were when I was called on to do failure analysis on low hour failures. Nothing quite like taking apart and sorting through the crumbs of a power train component to determine what part failed and what was resultant damage.