fuzzy buzzard Posted February 14, 2020 Share Posted February 14, 2020 Last night I stumbled on to a thread on B model king pins. H67 had a post about a set of pins he had which measured same as mine. My front axle is FA505, his is FA511. Both are rated as 8000 lbs. Does anybody know what difference is between these axles? Quote Link to comment Share on other sites More sharing options...
41chevy Posted February 14, 2020 Share Posted February 14, 2020 My books show the FA511 as used under R600. R685 R685ST and R 686ST and a slightly different shape. Maybe some one swapped it in ? Quote "OPERTUNITY IS MISSED BY MOST PEOPLE BECAUSE IT IS DRESSED IN OVERALLS AND LOOKS LIKE WORK" Thomas Edison “Life’s journey is not to arrive at the grave safely, in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘Holy shit, what a ride!’” P.T.CHESHIRE Link to comment Share on other sites More sharing options...
KKERGALL Posted February 15, 2020 Share Posted February 15, 2020 Looking at the front of truck / axle pass. side where axle goes up to spring and where u-bolts come down, there is a wide web and front axle number is stamped in there. 1QHA Quote Link to comment Share on other sites More sharing options...
Rob Posted February 20, 2020 Share Posted February 20, 2020 What are you wanting to know as far as differences? Width, caster/camber angles, SAI, usage? Let me know as I have all that information. The FA-511 was used in more than the early R series. 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...
fuzzy buzzard Posted February 22, 2020 Author Share Posted February 22, 2020 Rob, The FA511 was in an H67 that Carl owns. He had found a king pin set which he did not use. We compared dimensions on king pin and bottom plug. They all matched up with my FA505 axle. 20 years ago I put king pins in my axle BUT could not find thrust bearings and I have always felt this was causing a lot of my crazy steering problems. Carl's pin set had thrust bearing and since bottom plug and pin dimensions match, I am hoping thrust bearing are same. Will find out in morning - the old draggin' wagon comes apart in morning. Will update tomorrow night. Quote Link to comment Share on other sites More sharing options...
Rob Posted February 22, 2020 Share Posted February 22, 2020 34 minutes ago, fuzzy buzzard said: Rob, The FA511 was in an H67 that Carl owns. He had found a king pin set which he did not use. We compared dimensions on king pin and bottom plug. They all matched up with my FA505 axle. 20 years ago I put king pins in my axle BUT could not find thrust bearings and I have always felt this was causing a lot of my crazy steering problems. Carl's pin set had thrust bearing and since bottom plug and pin dimensions match, I am hoping thrust bearing are same. Will find out in morning - the old draggin' wagon comes apart in morning. Will update tomorrow night. Pretty sure I have a set of roller thrust bearings for an FA-505 at the shop. Both the FA-511, and FA-505 used the same king pin set if close in the same year of manufacture. The main differences were either needle bearings, ream to fit bushings, or presized bushings. Both axles are of the "Type III" design. I've never seen a king pin set not supplied with new roller thrust bearings myself. 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...
fuzzy buzzard Posted February 22, 2020 Author Share Posted February 22, 2020 Interesting - I kinda thought the orginal thrust bearings where rollers. Bearings in this pin set are ball. Reason there were no bearings in first set installed - my parts man had to order all the components separately as Mack no longer had the set complete. - Quote Link to comment Share on other sites More sharing options...
Rob Posted February 22, 2020 Share Posted February 22, 2020 The thrust bearings have always been rollers. The upper king pin stem could use needle, or bronze bushings. 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...
fuzzy buzzard Posted February 23, 2020 Author Share Posted February 23, 2020 Guess my memory ain't so good after all. Got thrust bearings out today and they were ball bearings. And they were not too awful bad. The Moog Kit 8482B is the correct kit for this axle. So I don't really expect a large improvement in steering quality but I got fresh packed wheels bearing Quote Link to comment Share on other sites More sharing options...
Rob Posted February 23, 2020 Share Posted February 23, 2020 Describe in a bit of detail these steering problems you are speaking of. 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...
fuzzy buzzard Posted February 23, 2020 Author Share Posted February 23, 2020 I have to constantly chase the steering out on the road. Get on a skinny 2 lane and I got my hands full. New king pins, tie rod ends, drag link tight, second set of new radial tires; then added Sheppard p/s (model 49) and problem is amplified because the Sheppard box is so slow and too easy to turn. There is almost no free play in box, truck been to front end shop twice. Got to reading R model front axle book - R with manual steer 1 1/2 - 3 degrees castor and R with Sheppard 4-6 degrees castor. I added 3 degrees and seemed to help (couldn't add any more, it was pulling center bolt out too far). Then replaced spacer between axle and spring with one that I machined 5 degrees into it. This seemed to help a little more. I could add 2-3 degrees more. I am slowly sneaking up on the cure - hard to check out seat covers when it won't stay where I put it (the truck that is!). Any suggestions - I'm all ears Quote Link to comment Share on other sites More sharing options...
Rob Posted February 24, 2020 Share Posted February 24, 2020 (edited) need to ensure the rubber isolators in the spring perches at the front of the truck are there and holding the spring ends stable. This is a very often overlooked item. Get a pry and work the axle with both weight on, and weight off the front wheels looking for movement. Spring pins in their mounts at the rear is another place to look closely. The rear spring eyes have bronze bushings in them and they could be worn out. I've seen these spring pins worn elliptical in the housing and any movement in these area really makes for erratic steering habits. Typically positive caster is introduced to assist in return to center at the completion of a turn and to the help the wheels steer to centerline. Steering axis inclination has a lot to do with this also but is built into the steering geometry and normally not adjustable. Increasing caster angles tends to increase steering effort required and is a bit harder on parts, (king pins/bearings) due to the increase from pin rotation centerline. Caster angles should be even but slightly more positive on the rt. side tends to correct for road crown. Can be perceptible to the driver but most times not with hydraulic power assist. Sheppard steering is always "mushy" feeling in comparison to Vickers/Ross, (IMO) although just as good or bad dependent upon your perception. Where is toe set at? Edited February 24, 2020 by 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...
j hancock Posted February 26, 2020 Share Posted February 26, 2020 A good truck mechanic, who has since passed away, told me one time that if everything is tight in the front, take a look for worn rear suspension pieces. The rear end can give some "steer" to a vehicle. When radial tires came along, it seemed like a little less toe in worked better than the original bias tire toe in specifications. 1 Quote JimIt doesn't cost anything to pay attention. Link to comment Share on other sites More sharing options...
Rob Posted February 26, 2020 Share Posted February 26, 2020 I would suggest you not start chasing your tail moving to another area till one area is proven sound. Far too many variables still remained unsolved for to interject another area of concern. The mechanic was/is very correct with analogy and the same path I would pursue. 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...
fuzzy buzzard Posted February 27, 2020 Author Share Posted February 27, 2020 Toe was set by alignment shop last trip. Lord only knows what it was set at, - there is a different crew in there every time I stop in with other trucks. Number one son spent number of years with Thomas Bus dealership, always bunch of steering recalls. He built set of trammel points for toe so my next move is get on smooth level surface (which ain't anywhere on Ignorant Ridge) and set toe. May different ideas on toe-in with radial tires. I'm inclined to set at zero unless someone here changes my mind so let's hear your ideas !! Thanks, FuzzyBuzzard said that 5-5-2-2 (that's a WV 10-4) Quote Link to comment Share on other sites More sharing options...
Rob Posted February 27, 2020 Share Posted February 27, 2020 You will need some toe in or return to center will suffer. 1/8" is usually adequate but setting it without turntables is a best guess scenario. Chasing the steering wheel is usually loose parts and your pins/bushings are really suspect in the leaf springs of everything else is proven tight. Have you checked over center torque of the steering gear? One of the most overlooked sources of erratic steering there is. 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...
mrsmackpaul Posted February 27, 2020 Share Posted February 27, 2020 (edited) In Australia before the days of luxurious power steering and the like trucks had either a lesser or greater castor angle which caused you to chase the wheel at speed down the high Often this is referred to as taching, like sailing a yacht This is easily correct by returning the caster to the correct angle with wedges between the axle and the springs The purpose of the incorrect castor angle was it made it much easier to steer at low speed as in parking ot tight manoeuvring Im guessing this was a common practice back in tbe day across the world Im also guessing the castor angle was decreased but a proper wheel alignment place should be able to give you correct castor or no doubt google can help Then off to your local hardware store and buy a spirit level doodah that can measure angles and see what you come up with Paul Edited February 27, 2020 by mrsmackpaul 1 Quote Link to comment Share on other sites More sharing options...
fuzzy buzzard Posted March 8, 2020 Author Share Posted March 8, 2020 Steer axle update - remember I made new spacers to go between front axle and springs. They were made with 5 degree taper between top and bottom. This modification seemed to help steering a bunch as I didn't have to chase it so much. Today me and son sat down with trammel points to check toe-in. Turns out it was toed in 3/8", a might too much. We set it 0-1/16" toed in. Man what a difference this made - I can look out the side window now - I'll be taking pictures just like Other Dog does! Twenty years of chasing this old thing and it just needed more caster and good alignment. Think I might put 2 degrees more in it sometime just to see how it acts. But for now, the next hot topic is installing A/C. I have a new Red Dot Back Wall Unit to set between the seats. Thinking about putting condenser under bunk like Freightrain. Hoping to get ice cubes spewing out on 95 degree days. Quote Link to comment Share on other sites More sharing options...
Rob Posted March 8, 2020 Share Posted March 8, 2020 That is why I wanted to know your settings before going very far. Very easy to overlook the trees in the forest when chasing one's tail. Back that caster angle down to about 3 degrees positive and you will be real happy. Too much positive caster will be hard on the king pins over time. 1/8" toe in is about as much as needed or wanted to not see "cupping" of the outer edge, and "feathering" of the inner edge of the steer tires from pavement skid. 1 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...
j hancock Posted March 8, 2020 Share Posted March 8, 2020 Fuzzy, glad you are gaining on it. Here are the alignment specs out of a B maintenance book from back in the bias ply tire days. 1 Quote JimIt doesn't cost anything to pay attention. Link to comment Share on other sites More sharing options...
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