All Activity

without knowing which switch does what im not sure but there is one to the far left by itself and the the brake light switchs on the manifold behind the brake pedal and the parking brake switch. i ordered on from my mack dealer that was supposed to be the low pressure switch.

We sure can! Let me dig up some info and a quote and I'll PM you shortly!

Single counter-shaft transmission are not built the same way, and this is not a "theory". Single countershaft have no opposing force so the main shaft carries the side thrust. The gears on those run bushing in the gears that ride on the main shaft

You do realize that based on that theory, tens of thousands of single countershaft transmissions have nothing "centering" mainshaft gears. Like for instance in an M Drive

Best number I could find for the LH steering gear is 8148-M100PPJ3R, Mack has them in stock. It's a reman Sheppard.

Steering arm but not Pitman arm, I would assume it would be one of these below: No87 is 5QH3281B, superseded to 25119672. No105 is 5QH3245B, superseded to 25115926. Both are available to order from Mack.

dont know how i missed alot of this tread,,,,,i was still on nights,,,when it started ,lol,not sure,,bob

I think I’ll have to take your word for it ha ha a little too long for me

yes sir, but my re-building knowledge of eatons an meritors is weak, with the exception of 10 speed back boxes. However, Mack transmissions where one of my many skills when I worked in the Mack Dealerships. Thats all i got..

Joey, that sounds just like Spicer and Fuller, The spacers and lock rings just keep the gear located fore and aft, the countershaft gears keep the gear centered but not riding on the main shaft.

in the Mack transmissions, the speed gears have 2 thrust washers in the middle of them, held in with a snap ring. one washer has splines on the inside diameter, that engage the main shaft splines, the other washer has large teeth on the outside diameter that engage the clutching splines inside the speed gear. that thrust washer is to keep the sliding clutch at the proper depth during gear selection. The speed gears that are back to back of each other on the main shaft have a ground surface on the back sides. these gears are thrust against each other. snap rings on the main shaft keep these gears from sliding up and down the main shaft. the sliding clutches are splined in the inside diameter, and are slid over the splines on the main shaft. when this is assembled, as GW said earlier. the countershaft gears keep the speed gear centered. the main shaft is centered by bearings on the ends. the front one being a spigot bear engaged into the input shaft. the speed gear from front to back are as follows. 4th-5th-3rd-2nd-1st-rev... my post is from my head and not my books, so there's a chance I left something out.

Then there's another bushing like that in the auxilury after the auxilury drive.

I'm pretty sure the gears on the mainshaft are splined inside and ride the mainshaft. It's all pretty tight. Floats, yet tight. Not a clearance that can be adjusted like the limit washers for fore and aft. More like good or bad. The mainshaft shares a common centerline that also isn't adjustable. Good or bad. Bearing on the input, bushing between (input) rest of the shaft and bearing where it goes into the auxilury drive. All floats, but it's tight. Doesn't rely on countershafts to give support in any way.

Not if you look at the 1st picture I posted from the manual, that gear is going over the splines at quite and angle. Also there is no listing for the clearance of the gears on the shaft. The only listed clearance is for fore and aft float which is .005-.012 adjusted with spacer thickness. If Glenn Akers was still with us he could settle this quickly. The main is held by a bearing at one end and bushing in the input shaft pocket. the gears are held located by the countershaft gears they mate with. They don't ride on the main shaft when the trans is assembled.

I'm going to do it over a little neater like my dump truck

Those splined gears on the main shaft are a very close fit to the splined part. Like enough for oil and that's it. Perhaps I should have used the word "bushing" as opposed to adding an (S) Point is none of the mainshaft assembly relies on countershafts for support. It's a delicate balance in there of floating and not. If anything on a mainshaft does more than float as intended ??? you have problems.

20-30# less rotating mass(one less CS) will more then likely make it quicker to shift.

I've seen that 20+ yrs ago at local track. Likely a newer version driven by Bill.

Better picture of the main shaft, showing splines and grooves for spacers and lock ring to locate the gear fore and aft. this is from a different manual that better shows the shaft.

hell i forgot about that thing,,,,i built the model as a teen...bob

yup this will be a tough one Pai has the mounting brackets and thats it ! There used to be a kit for these but not anymore you could try droping some big flat washers behind the ball socket incert

Not the main shaft itself, but the gears that are on it are floating, the countershaft keeps them centered over the shaft. Being "pretty sure" doesn't cut it. That is why I posted a picture from the Fuller Roadranger manual. I have no idea on a Mack triple counter shaft trans, how they do it, Jo-Jo could chime in on that. The main shaft except the nose (where there is a bushing between it and the input shaft, is splined the whole length with grooves tangentially for snap rings to hold the fore and aft position of the gears, The clearance between the gears and main shaft are maintained by the gears on the two countershafts. If the counter shaft or its key gets a twist, the gear on the main shaft gets out of line and it can be difficult or impossible to get into that gear. It is one of the 1st things to check on overhaul. A bushing riding on a splined shaft would have an extremely short life.

I like the look of the pintle area,gives a finished look,and is different from the usual treatment.

Mainshaft gears in a Fuller have the round part on the other side of the clutching teeth that ride on the shaft or just the inner teeth that are against the mainshaft (yes they float on there and are shimed into position front to back) . The input shaft ??? I'm pretty sure there's a bushing in there where it goes into the mainshaft. Which is where it makes the mainshaft assembly able to turn as per gear selection. None of the mainshaft assemble relies on countershafts to support it's centerline.

Nice going bud thanks for the updates and I have shit sitting around here. I bought for mine way longer than seven years ha ha let’s keep it up very hard to do anything on these things when you’re still working…. Bob