Good day my friends, I have just replaced the undercarriage on a customers 2011 CAT D5K. We have removed all systemone components and installed Salt components. The existing sprocket segment bolts had no washers. We were supplied washers for the new segments and have installed these behind the nuts facing outwards, now the customer suspects the nuts are protruding out past the segment and may get caught in the track chain. I checked this but couldn’t see it it. Machine is a YYY prefix
Not sure if I can shed any light but here goes. All info is for YYY prefix D5K machine The one-piece sprocket calls out only bolts (2.1" long) & nuts - no washers. The parts manual illustration appears to show the nuts on the outside but no sign of the washers. See below. Are the washers supposed to be on the inside under the bolt heads I wonder.? The 6-piece segmented sprocket calls out the same bolts (2.1" long) and the same nuts, but also a 3.5mm (1/8" approx.) thick washer. I may be interpreting it wrong but the illustration appears to show the bolts installed from outside to inside and with the washers under the bolt head. For a bolted joint that does not make sense to me, but that's what the illustration appears to show. All the above comment apply to Cat undercarriage, not aftermarket which you installed. Are the nuts thicker than the bolt heads..? Also from your photo I would ask if those bolts are long enough. The end of the bolt should be flush with the nut IMO, not about 1 thread inside as your photo shows. One-piece sprocket Segmented sprocket
It looks like the nuts are out to far they should be flush with
Looks like the nuts and bolts would be the correct length without the washers.
Or that the aftermarket sprocket segment flange is 1/8" or so thicker than an OEM one.
I would put the question to the supplier of the parts and make them commit to any future problems that might show up.
Yeah, supplier should be able to clarify unless they just ship all the hardware with washers whether you need them or not. Do sprocket segments on dozers generally use washers or just nuts? I know the torque is very important so they don't come loose and maybe Loctite is a good/better idea? When I replaced bottom rollers an experienced shop recommended Loctite so they wouldn't come loose. I found some blue medium strength Loctite that was surface insensitive and not affected by a little oil on the threads from re-tapping all the holes. High strength Loctite might be better for sprocket segments though. Sprocket bolts coming loose can be a problem on MX race bikes too and a lot of guys use high strength Loctite so they don't ruin the hub from the bolts coming loose. It's cheap insurance.
The jury has been out for years on washers for sprocket bolts. Some people think that since the bolts are a one time use, they don't need washers. Others believe that flat hard washers are imperative. My preference is to go without them as I don't like to pay for extras unless they can be justified. If the manufacturer specifies them, then I use them. The bolts usually are not a problem on the rings but many times are on the segments. In my experience, if a segment comes loose once, it will always come loose again. The normal attempt at a fix is to weld the bottom corners of the segment to the wheel. The bolts in this application don't come loose by unscrewing, they come loose by stretching. It happens because the holes in the wheel lose the tight fit and the flat mating area becomes not so flat. Loctite might make you feel better, but in this application is does little else.
What we used to do on our fleet of D6's to tackle bolt loosening was to weld all the sprocket segments together once the bolts were installed and tightened, effectively transforming the six individual segments into one ring gear. Bolt stretch/loosening issues disappeared overnight.
Did the welding affect the segments (life) at all?
Nope.
We weld our segment ends together too. Eliminates any loosening problems. We use never seize on bolts so they torque down properly.
I'm always cautious about using anti-seize on a bolted joint if the D&A procedure doesn't specifically call for it. I well remember a close shave installing a 789 spindle/brake/wheel unit where the ring of (new) bolts securing the spindle to the taper on the front suspension came apart like a zipper. The mechanics had used anti-seize on the threads when it wasn't called for and the bolts had stretched past the yield point as a result of the reduced friction when pulled up with the torque wrench. In tests afterwards we found that the bolts went an extra half-turn with anti-seize over and above what they went without it when the same torque was applied. My 2c.
Afternoon gents, sprocket segments are genuine cat, cat couldn’t supply the bolts or nuts so part number was sent to our supplier who also supply cat, they supplied the bolts and nuts. I’m off the opinion after what nige had posted in that the bolts are on the incorrect way and nuts need to face the inside of the machine. I’ve never had this issue before but nobady we know has converted a D5K from system one to salt. Tomorrow we are converting a D6K from system one to SALT
What I posted is based on what I see from the Parts Manual illustrations. It's the best I can do but if I was you I wouldn't place absolute faith in those illustrations because it won't be the first time something shown in a parts manual page has been subsequently proved to be incorrect. Also bear in mind if you reverse the orientation of the bolts that it appears from the illustration that the washers go under the bolth heads. Have you compared the thickness of the bolt head versus that of the nut..? A thinner head on the bolt would suggest that the washer goes under the bolt head - although I can't for a moment think of a good reason why it should be done that way. Also I suggest to check that the bolts are the correct ones if they are non-Cat. They should be 2.1" long according to the parts list.
Having slept on it, unless the washer was classified in the design as a "spacer" that was necessary to get the correct amount of bolt stretch when torquing..? Usually spacers are a little thicker than a washer, but there must be something different between the iron of the single ring sprocket and the segment-type for the bolts to require a washer in one assembly and not in the other. I can only reiterate what I said above that in view of the bolts being aftermarket IMHO you should measure the length and ensure that it is correct according to spec - i.e. 2.1". It wouldn't surprise me at all if they were 2" TBH, because 2.1" is somewhat of a weird size. If that is the case then the 0.1" difference in length would explain why the bolts do not come flush with the outside of the nut when tightened as they should do.
I've always seen the nuts facing out. The nuts are generally what are turned not the bolts.
Even if the bolts were installed from the outside it would still be perfectly possible to access the inside and turn the nuts if required.
Depending on if the segments (or bolts) were being replaced (or switched around) with the tracks still on might be a little more difficult to turn the nuts from the inside.
Interesting thread. On my D8R and D8T,they both have bolts,spacer/washer and nuts. That’s how they came to me from previous owners. I keep them that way.The spacer/washer shows up in the parts books of both tractors and is fitted on the inside of the rim on the bolt head,not the nut. I note Nige’s comments on the anti seize thing.I use only new engine oil on the threads of segment bolts and the torque turn method. I’ll confess to using anti sieze compound on much bigger idler and roller bolts for the D8 and D9 tractors. I may have been doing it wrong??
In general terms you're correct. However what you need to bear in mind is that on a threaded fastener setup that is being torqued, generally what gets turned is the element of the fastener that has the washer under it. Unless there are washers under both ends in which case it makes no difference which end gets turned. Therefore in this case with the washer under the head of the bolt and the nut on the inside then the nut would be held fixed and the bolt head would be turned. Not exactly usual but there must be a reason for doing it that way, even if it is down to the difference in thickness between the bolt head and the nut as I mentioned earlier.
I have always done the same thing. The stuff the is captured tends to corrode and get stuck. Rollers, rock guards and front idlers tend to get broke off when doing replacements. We welded a lot of straps across the bolt heads on the oval track machines trying to keep bolts in place.
I'm not against anti-seize per se. I agree with Nicky & John regarding thinking about the next guy who has to remove that bolt, or simply trying to make sure it stays tight. In that respect IMHO engine oil is as good as anti-seize. What I try to keep in mind is that if the installation procedure doesn't call for anti-seize and we decide to use it then I tend to back off the applied torque a bit to compensate for the reduced friction and to avoid over-stretching the bolts.
Don't fasteners that call for a critical torque usually require a light oil to get the proper torque because dry threads can sometimes bind a little and give a false reading? I watched an experienced Detroit mechanic rebuild an engine and he dipped all the head bolts in oil before installing. The grade 9 nuts and bolts I've bought from the heavy equipment shop have an oily coating. It prevents rust but also makes the nuts thread on easier.
Fasteners requiring a ciritcal torque normally have clear instructions in the Service Manual. That might be anything from a coat of light oil to anti-seize on the bolt threads, to "full-fat" anti-seize not only on the threads but also under the bolt heads and on the washers. But whatever it is it will be clearly and unequivocally stated. A track master link below as an example........... Clean the bolt head contact area on the track shoe (5) and apply Loctite C5A Copper Anti-Seize to the bolt head contact area. Attach Tooling (B) to track shoe (5). The weight of track shoe (5) is approximately 45 kg (100 lb). Install track shoe (5). Apply Loctite C5A Copper Anti-Seize to the threads of bolts (6). Install bolts (6). Tighten bolts (6) in a "X"pattern to a torque of 870 ± 90 N·m (642 ± 66 lb ft). Tighten bolts (6) in a "X"pattern for an additional turn of 120 degrees. Black bolts are generally "phophate & oil coated". That coating not only serves to prevent corrosion while they are stored but also serves as a thread lubricant the first time they are used.
Where would you find a grade nine bolt?
The independent heavy equipment shop I get parts at sells grade 9/L9 black oiled bolts. Not sure what brand but McMaster-Carr among others sells grade 9 bolts. I think cutting edge bolts are grade 9 as well. https://www.mcmaster.com/grade-9-steel-bolts/
That's interesting because I can't find any other industry rating for a grade 9 bolt anywhere but that catalog. Does anyone know if Cat sells a grade 9 bolt?
Cat bolts are generally considered stronger so may be similar to grade 9 or L9. Some people think there is a grade 12 bolt but there isn't. Grade 9 is the strongest. When I worked for large industrial supplier the fastener expert said it's a common misconception there are grade 12 bolts.
All the Cat bolts I've used had the grade 8 markings on them unless they were made of something different than alloy steel.
Would have to compare the tensile strength ratings. I found below on a Cat website for their bolts. Cat® Bolts are engineered to exceed SAE Grade 8 standards and ISO 10.9 strength specifications for longer wear life and improved reusability.
I’ve seen grade 12 stamped on aftermarket bolts before,but they weren’t genuine Cat so they could simply have been fraudulent.
Be aware that SAE and metric fasteners use different systems. Metric bolts are produced up to CLASS 12.9 which is probably where the confusion arises
An SAE Grade 8 bolt (marked with six radial dashes on the head) is pretty much equivalent in strength to a Class 10.9 Metric bolt. The highest SAE fastener Class in general use is Grade 8. There is no SAE standard for Grade 9 bolts whatever a hardware supplier may say.
There is no such thing as grade 12 bolts but grade 9, commonly referred to as L9 do exist. They may not be recognized in SAE but do exist. Kind of like some high strength specialty welding rods don't meet an AWS specification but have been proven to be better than AWS spec. rods. Lots of info below. I worked beside someone with 30 years fastener experience. He was a wealth of knowledge. Metric grade 12.9 is listed as exceeding grade 8 (metric 10.9 equivalent) so are probably very similar to the L9 fasteners. https://www.rcfastener.com/products/l9-fasteners.html#:~:text=They are domestically made in,Grade 8 at 150,000 psi .
Again, there is no such thing as Grade 9. L9 is not the same as Grade 9. From the link - " They are similar to Grade 8 but have a tensile strength of 180,000 psi compared to Grade 8 at 150,000 psi." In fact looking at the technical data sheet it would appear as though the "9" refers to nine engineering design features that the fastener possesses, and is not an implication of strength. I am not doubting that there are threaded fasteners available on the market that are manufactured to a higher tensile specification than Grade 8 (150,000 lb), the above example proves that. Is there a need or a use for these high strength fasteners.? Apparently so, otherwise they wouldn't be making them. What I am saying is that there is nothing listed in SAE Standard J429 for anything higher than Grade 8. Any fastener manufacturer can use whatever specification that takes their fancy so long as it is higher than Grade 8 and call it whatever they like - (L9 as per your example above). However the manufacturer should neither claim or imply that the product specification meets a published standard, and you'll note that nowhere do they do that. https://law.resource.org/pub/us/cfr/ibr/005/sae.j429.1971.pdf
There is grade 9 but they are not an SAE specified bolt. The link I posted is just one. There are others that say grade 9. There is obviously a need for a stronger bolt than SAE specifies. If Cat bolts exceed grade 8 tensile strength can they still be considered grade 8 or are they considered a higher strength non SAE bolt? What is the cut off point where a bolt no longer meets the SAE specification? 12 raised radial lines on a bolt head indicates an alloy steel rated higher than grade 8. Perhaps Cat bolts aren't officially SAE but referred to as exceeding SAE grade 8 because that's the standard that people associate with quality? Note that many manufacturers (e.g. Caterpillar, Bowman) manufacture bolts to specifications that exceed those for SAE Grade 8 bolts. These fasteners (Figure 7) are often marked in a similar fashion to SAE graded hardware by means of dashes embossed on the head of the bolt. Despite this, it is not technically correct to refer to these bolts as “Grade 12” or such, as no such SAE specification exists. Bowman calls their line “Bowman Special Alloy.”
Regarding Grade 9. Simply put - how can someone say that a product meets a specification that does not exist..? IMHO all they can say is that their product "exceeds specification whatever". I have no problem with that. Cat bolts are supposed to manufactured to exceed the standards of SAE J429 Grade 8 but as far as I'm concerned they are simply guaranteed to be good Grade 8 hardware.
Perhaps using a tensile rating would be a better way to identify them. There are other standards than SAE.
But the discussion here revolved around "Grades" which implicitly assumes SAE Grades, unless I'm missing something, because that is the accepted standard for threaded hardware.
Maybe there needs to be another grade added to SAE standards? Seems to be several brands of bolts exceeding grade 8 by 30,000 tensile or more. Grade 5 up to 1" is 120K tensile, Grade 8 is 150K tensile. Bolts referred to as grade 9 or exceeding grade 8 list 180K tensile. Not sure why SAE doesn't have an official grade for them? Maybe they will in the near future? They aren't uncommon.
Maybe they should. I would imagine that this type of high-strength fastener is a relatively recent development.
I know Bowman has had Bowmalloy fasteners for quite some time. I think they were considered the strongest bolts available back in the day. Do you know who makes Cat bolts?
Wow,I never stop learning. There’s is some great info here chaps. I still have great confidence in most Cat products such as oil,filters,components etc ,but my faith is slowly getting eroded by parts availability,customer service and uneconomical GET products and undercarriage parts. Back in the day,I was happy to plump up the extra 20% or more to enjoy the parts quality,rapid service and the reassurance from our Cat dealers.That’s no longer the case.There are far too many horror stories of Finnings shying away from their responsibilities,and I’ve gotten abit long in the tooth for those kind of fights. There are plenty of rubbish quality parts and GET products about no doubt,but some of these manufacturers have really upped their standards and are battering Finnings and Cat in the UK right now. To be fair,I can notice the difference between a Cat bolt and a Micky mouse bolt,but it’s nothing I can’t live with,and it’s not like they’ve ever become slack or sheared etc.
Here's a brochure for Bowmalloy fastening systems. Up to 200,000 tensile and they claim 30% stronger than grade 8. https://docplayer.net/43622002-Bowmalloy-fastening-system.html