doubleclutchinweasel

I'll give them a shout. Thanks.As far as I can tell, these are 1-1/8" - 12 on both ends (LH thread on one end, and RH thread on the other).

Yeah, that looks a lot like mine! I hope that, when I get in there, mine is serviceable, too. I figured it would take longer to disassemble the hubs/brakes/linkages than it would to do the actual knuckles! I've already cleaned the surrounding areas the best I could, and have soaked everything down with penetrant. Hopefully, the backing plates will un-bolt fairly easily. Looks like I will be delayed a bit due to the weather turning colder and the days getting shorter. It's freakin' dark when I get home...and the time hasn't even changed yet. This truck has the oil-filled Stemco hubs on it, too. So, i figure I'll do a little work in there while I'm at it. I hope the pressed-on seal rings aren't too badly worn, as new ones cost WAY more than the seals themselves. According to my Mack service manual, the bearings are retained by the nut/lockwasher/locknut system, rather then the pinch-type nut. I have no idea what size spindle nut wrench that takes. Got any ideas?

Hi, Everybody! Well, as soon as I identify definite sources for all the bits and pieces on the front end of the old R600, I will start pulling the front end apart so I can replace the kingpins and bushings. I am working on a "dolly" right now, which should help me to pull the tire/wheel/hub assembly off. Of course, I probably won't have the correct spindle nut wrench (I never do!). Then, I guess I get to fight those ancient bolts/nuts holding the backing plate on. Yea! More rusty fasteners! Thank God for PB-Blaster. Then, maybe I can get to the knuckles themselves. As far as I can tell, this axle (FA-535) uses the "bushing on the bottom / needle bearing on the top / thrust bearing underneath" setup with tapered pins (301 SQ 46B kit - see image below). The kits now appear to come with the "drive plug" to close off the top, like the later models. Mine actually uses the bolt-on cap. But, as near as I can tell, the new "B" kit will work for either configuration. I plan to replace the tie rod (it's bent on the end), the tie rod ends, the drag link end, the kinpins/bushings, and all the oils seals and such on the spindles. I have (hopefully) good part numbers on everything, and am currently confirming availability of some of the smaller parts from multiple sources. I am hoping that the needles in the bearings have not worn through the races, and started digging into the bore in the knuckle itself. If they have, then a new needle bearing won't live long in that bore! If the knuckle bores are damaged, then a whole new game plan might be needed. Anybody ever seen one wear that far? Or, is most of the wear concentrated on the pins, as it should be? Kent

Hey, Anybody got a good, straight tie rod tube (center link) for an FA-535 front axle? The tube is about 2" diameter in the middle, and steps down at the ends. The ends of the tube are internally threaded 1-1/8" (12 threads per inch). The overall length is right at 60". I THINK the Mack part number may be 7 QH 243. Mine is bent right through the threaded portion. The tie rod end is bent there as well. So, a curved tie rod end in a curved hole! That's not coming out! I have a guy looking for one, but don't know when he will be able to concentrate on it enough to do me any good. So, I thought I'd ask the brain trust! This is posted in both the "parts wanted" and "suspension" forums. Kent

Hey, Anybody got a good, straight tie rod tube (center link) for an FA-535 front axle? The tube is about 2" diameter in the middle, and steps down at the ends. The ends of the tube are internally threaded 1-1/8" (12 threads per inch). The overall length is right at 60". I THINK the Mack part number may be 7 QH 243. Mine is bent right through the threaded portion. The tie rod end is bent there as well. So, a curved tie rod end in a curved hole! That's not coming out! I have a guy looking for one, but don't know when he will be able to concentrate on it enough to do me any good. So, I thought I'd ask the brain trust! This is posted in both the "parts wanted" and "suspension" forums. Kent

Yeah, different clutch. Cable-operated, twin-disc, pull-style. Has noisy t/o bearing, which only comes with the pressure plate.Kent

This one does not have the spacers. It is a cable-operated two-disc pull-style clutch. The only reason I need to change it is because the t/o bearing is pretty noisy. Discs have life left in them, but the t/o bearing only comes with the pressure plate. Bummer, huh? Besides, I'd hate to tear it down that far and NOT replace everything in there!Kent

Thanks, Ron.Stops like a new one, too! And, leaks a lot less! You know, everything I'm doing on this truck turns into an "education". Nothing is simple! Everything reqires research, study, planning, and (finally) execution. And, the big parts are not usually the problem. Usually it's the little 1/4" bolts that hold the wires up out of the way that cause all the sweatin' and cussin'. Makes me feel old! I was out there last night, with the flashlight in my mouth (again) finishing up a couple of more air lines. Ten minutes to run the air lines, but two hours to get the old ones off. Wait a minute... That's what we love about workin' on these old trucks, isn't it?!!! More to come... Kent

The manual states that "additional" gages could be mounted in this panel, or that the standard gages could be moved there, if there was a tachograph (or tachographs) installed in the conventional location in the main dash. Apparently, if there was one or two recording instruments installed in the main dash, there was no room left for anything else.The angled gages do look really cool, don't they?! Kent

In this book, they just call it "auxiliary" (see pic). Not sure what else they may have called it through the years...we are talkin' about Mack here!

Nice job. I just did some similar work on my R600, which originally had DD3 chambers. Looks like we may have used the same brand of chambers. Looks like the ones from Ranger Brake in Tennessee. I got mine from CarQuest. Talked to the son of the founder of the company. Pretty cool little family business. They made components for other brake folks for years, and then started selling their own. They still sell to the other guys from time to time, And, I liked the price! I didn't notice how you handled the anti-compounding function (sorry). My truck had a PP-2 control valve instead of a PP-1. This valve has built-in anti-compounding capability, via a line tee'd off the service brake line. It is the one attached to the lower part of the valve. Of course, you may have handled this a dozen different way. If so, sorry for the distraction. I used a Haldex-Midland-remanufactured Bendix QR-1 as a quick release valve, as well as a convenient place to tee the lines. I still have LOTS of lines to upgrade! Keep up the good work. Kent

Just a couple of shots of the new slack adjusters and spring brakes on the old Dog. Notice the bolt-on retention instead of snap rings...

A few shots of the new spring brake chambers, new tubing, and new slack adjusters. Gonna do a little more "detailing" on it this weekend, and maybe do the next axle.

As promised, here are a couple of pictures of the DD3 system. Let me know if anybody is interested. Oh, and we CAN do trades! I have a long list of little, piddly parts I need. Somebody out there might have them just laying around... Kent

Okay, got the DD3s replaced on the rear-most axle this week. Put in 2424s and new slack adjusters. 2424s fit well. Of course, I thought they would, once I determined that the front drive axle actually DID have 24s on it! Sometimes it's hard to determine exactly what you have when the parts are this old! Have to find old product information to be able to accurately identify this stuff. The finished axle looks very neat. I was able to use another QR valve in the new spring brake release circuit as both a release valve and a convenient tee location. I mounted it back-to-back on the existing QR valve, so it looks really clean. I'll get a picture or three on here in a day or two. Might give somebody else some ideas. The Gates air brake tubing sure looks better than 43-year-old hose. I went with G32 (compression) fittings instead of push-to-lock fittings. I like the PtL, but the compression fittings just make me feel better. Managed to keep the isolated air tank at the rear, originally connected to the DD3 system, as an emergency brake release reservoir. Still got a lot to do. But, I can now start moving forward, replacing a little air system at a time. Plan to do the front drive axle, and a few feet of air line, this weekend...wife permitting! Who knows; some day I might actually get through the whole air system! Brakes...brakes are cool...m'kay? Much more to come... Kent

Hi, everybody! I have a pair of DD3 chambers (24 sq in service / 17 sq in parking) I just removed from my '70 R600. The bellows on them need replaced, but the cans worked correctly when I removed them (08/23/12). I took the entire "octopus" of hoses off the rear axle as a complete unit when I removed it. So, the mounting brackets, tees, inversion valve, etc... are all there and intact. Pictues and pricing will be forthcoming. I need to research pricing a bit before I commit to anything. Actually, I have a post out there entitled "Spring Brake Upgrade" which has a few pictures of the system on it, if anybody's interested. I don't need them, and would prefer to sell the whole thing to avoid starting a pile of "junk" in the garage! So, the pricing will be reasonable, but not free! I mean, they're not "junk" by any means. But, they're not new either. I do not think these are '70 vintage, but rather have been rebuilt and replaced at some point in time between then and now. I understand these can be somewhat difficult to come by, and rebuilt ones can be pricey. Maybe these can help somebody get something going without having to fork out the dough for a new set. In the meantime, feel free to make offers or suggestions (be nice, Rob)! More to come... Kent

More on the brakes...One of the DD3s failed to release this weekend. Turns out, at some previous service, somebody swapped the service and parking lines. So, there was no way for the smaller (17 sq in) chamber to advance the rod far enough to allow the roller locks to disengage. Even when I swapped them back, I had to loosen the bracket slightly to get them to release. Works better now. And, it stops a lot better on the larger (24 sq in) diaphragm. Have some 2424s located locally, and am waiting on a few more air brake tubing fittings from same source. Should have everything here this week. Going to remove DD3s and replace with the 2424s (after verifying clearance...but it looks okay). Will remove "inversion valve", and other DD3-related plumbing. probably put in a QR valve on the parking brake line. DD3 setup didn't have one. Probably couldn't use one, what with the inversion valve and such. Good time to put on a new pair of slack adjusters (they finally arrived). Found a schematic using standard spring brakes that allows me to keep the remote reservoir and emergency release circuit intact, so I'm going to do that. I like having the isolated emergency release reservoir. Beats the heck out of caging the parking brake spring to move a dead truck off the railroad tracks! So, hopefully I'll have the rear drive axle converted to current brakes and new brake line tubing soon. Then, I can move to the front drive axle and replace the cans and lines there, as well. The tees and junctions along the frame allow for a fairly small section of air line to be replaced at a time, starting from the rear. So, I can do that in stages and not get over-stressed by taking everything off at once. More to come... Kent

New spring leaves are in. The guys in Knoxville, TN, at Suspensions Unlimited (aka Knoxville Spring Service) got me in and out in about an hour. Did 3 new leaves at $50/per, and 2 new U-bolts. Total cost: $211. They were planning to have to cut the spring bands off, but, like everything else under this truck, they came off with no problem. Sometimes it's good being covered in oil! They reminded me to re-torque the new U-bolts after a little driving. Will also re-chech the screws in the bands. So, this piece (1 of 10,000) is done. Now, back to brakes, lights, etc... Thanks for all the comments. More to come... Kent

The slack adjusters have now arrived at the parts house. They should ship out on Monday, and be here by Thursday or Friday. I should have the front spring back in by then, so I can put these on next weekend, maybe.

Found a guy a couple of hours away who can make me a couple of replacement leaves fo $50 each. He's another old 40-year veteran spring maker, and was recommended by the Mack dealer there. So, I pulled the spring out this morning. Use a cut-up cross tie for blocks. Jacked up against the middle of the front crossmember. After spring was removed, put another block on the axle, and let it down until the frame rested on it. Also have a block under the front crossmember. Front pin wouldn't quite go out from the outside-in, because of a slightly tweaked bumper mount. So, I pushed it back in and went out the other way. Of course, the spring got out of kilter, and had to be weaseled into position before the pin would go in. Pictures of the hanger cap soaking, the truck blocked up, the spring cleaned up and resting comfortably in the back of the Tahoe (FUN by yourself!), and a close-up of the broken leaves. U-bolts came out with a little torque, so I didn't have to torch them. Should make it easier to duplicate them, having them in one piece!

Holy crap. This is funny!I had stumbled across St. Louis Spring earlier, and had sent them a message from work. When I checked my work email, they had already responded. His price is about 1/3 that of Stengel brothers. I'll be talking to them soon... Thanks again, Kent

Thanks, Dude.

You ain't right!I was lookin' at new springs for my old R. And, the more I learn, the less I like the prospect of diggin' two more 40-year-old springs out of the junk yard. I mean, they're the same age as my worn out and broken things. I checked with Stengel Bros. They can hook you up, but that's almost as much as I paid for the truck! Know of any other reputable spring shops (preferrable in the SouthEast...so shipping doesn't cost more than the springs)?

Ya know... Some of the old U-model sales brochures point out that the left-side spring had more leaves than the right-hand one (like 12 vs. 10). For what it's worth...

Thanks, Ron.When you mention the rear spring hangers, I assume you're talking about the entire bracket which bolts to the frame. And, I also assume you re-used your original axle. Did yours have threaded front pins or straight front pins? Kent