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That's what they'd all like to say! :) Posted this last night in the new to forum section and was told to bring it up here.... Thanks!

Hey all,
Been mildly watching out for an old truck and stumbled on this great site. Today I bought a local '52 - 2 ton dump 4600 that's actually in pretty good shape. Will have to do some light restoration. The truck is not original...used to be a fire pump truck for Brentwood, New Hampshire, converted to dump, but the engine sounds great, drives fine, and there's no rust - which is hard to find up here in Maine.

I'll post pics when it's actually in my drive. Have to finalize tomorrow.

Two questions:
Two speed axle: what's the proper way to shift and what should I be listening for? Tried it today on the test drive by simply putting clutch in while for example cruising in low 2 - swapping the lever over to high - pulling clutch out and it seemed to shift into the higher ratio fine - bit of a jerk - but... But are there no, no's? and is this the correct way to do it? Haven't had a two speed axle before.

Second:
Brakes seems funny. Have to pump it once or twice for it to feel as if it's building up enough pressure to actually give some stopping force. First push is mush to the floor - pump it again and third time there's pressure enough and the truck stops fine. But it doesn't seem right. Is there something tell tale I should look for or replace here? Master Cylinder or Hydrovac?

Thanks and looking forward to a great project...

Pinch

Hy Pinch, it sounds like you have some air trapped in your brake system, see if bleeding the brakes will take care of the problem. We usually advise everyone to do a complete overhaul of the brake system, for everyones safety, but try bleeding the system first to see if you can eliminate the problem, hope that helps.

Hey 3B (Hello, By the way) we had that same problem with the '49 4400. Complete new brake system (everything new) with DOT5 fluid, even. Bled the brakes multiple times and then bled them several more times -- couldn't get away from the same mushiness as Pinch. Turned out we hadn't adjusted the brake shoes out enough and it was taking multiple pumps to get them to travel far enough to make contact with the drums. So we took more slack out and the brakes were perfect.

If he's bled the brakes correctly and still having that issue, he might try checking that the adjustment is correct on all the shoes.

Just my limited experience, FWIW.

just remember there are 2 adjusters on each corner, top and bottom

Thanks - will begin looking into it. Meanwhile, here she is...

http://s1002.photobucket.com/user/Pinchy22/media/IMG_0265_zps72a81197.jpg.html

http://i1002.photobucket.com/albums/af143/Pinchy22/IMG_0265_zps72a81197.jpg

photobucket...

That is a great find.

Looking good and ready to run. You can enjoy it right away and only have to do one fix/project at a time.

Good luck

Pinch,

Welcome looks great...nice find!

The 4600 would be a 1-1/2 ton rated truck, not 2-ton.

I agree with John, jack the wheels up off the ground (one at a time) and adjust the brakes for heavy drag while spinning the wheel by hand. that may be all you need to do. After adjusting check the fluid level.

Mike B

Sorry....dyslexic. Meant 6500..with the longer wheel base.
Had 4600 in my head for some reason.

Thanks for the brake tips. Will have a look into it.

2 Speed axle?? Is it simply let off gas and shift it over - or put in clutch and shift it over? When shifting say from 3rd low to 2nd high - is it, put in clutch - put in second and shift to high on the axle all at once?? Don't want to blow anything out...

Thanks and indeed it's a good solid rig right now. Will have fun over the winter picking away at the smaller details.


Pinch

I drive my 2-speeds like the Hi range is like overdrive. I start in 2nd low and just shift the trans up to 4th low (or 5th if it's a 5-speed), then flip it into Hi range...that's it. Unless your loaded there is no need to split shift.

Down shifting the rear from 4 Hi to 4 low is easy as long as you are pulling a load going up hill. As you feel the truck slowing down, flip it into low range, let off the gas for a few seconds and mash back down on the gas. After you get back up to speed shift it back into Hi...no clutch needed. It's hard to down shift the rear if you're just rolling along on flat ground...the gears don't want to go and everything starts grinding.

Mike B

That's a great looking truck! Congratulations!

Regarding the 2 speed--like Mike says, unless you're loaded there's usually no need to even use it. You can probably leave it in high. Otherwise drive it like Mike said.

Nice truck.

It is often easier and less brain damage to just get new wheel cylinders, rather than fool with honing and replacing innards on used ones, especially in the the rust belt where corrosion is rampant. Brake fluid is hygroscopic.

Thanks - just able to take it for a spin this evening. After things heated up and cleaned out a bit - she was fine. Got the hang of the High/low as well.... and did pretty much just what you described, Mike.

Cheers, Pinch

Any idea where to get them?? I see them up to a 1 ton on the Classic Parts site.... but not sure that would be the one....

Thanks,
Pinch

If you end up driving the truck in High rear all the time, put it in Low rear when parked. The shift linkage can fall out of high gear due to gravity and the rear can end up in neutral allowing the truck to roll free.

Mike B

Sharp truck!

There should be a decal on the dash that instructs you how to shift the rear axle. Obviously yours is missing. If you want to P/U a new one go to http://mongosgarage.com/catalog/2Speed.htm
That's where I got mine, it was so faded I could hardly see it. They also have VIN plates for the Big Bolts.


My '49

i thought i read that the wheel cylinders are the same as the smaller huck type. if so the oreilly auto parts number is wc3677 for the rear and wc3406. i may have mixed those up but you will know which is which when you see them.

Awesome...thanks, Pinch

Can you explain that a little further. This is my first vacuum 2 speed and I haven't even driven it yet so I don't know what I'm talking about...

My understanding is - no vacuum no go. It takes vacuum to hold it into gear whether it's in Hi or Lo.

So, doesn't the rear end go to neutral no matter where you put the selector switch, without vacuum?

Thanks,
Greg

Most units don't need the vacuum to hold it in a range. There is no neutral.
On a double reduction the slide shaft has detents that holds the gear in one position or the other, the vacuum is required to pull the gear over the detents from one position to the other.

Imagine if you had a vacuum leak or broke a hose while you were driving.

Goob,The "Hi/Lo" shaft,below the "Pancake",is in an almost vertical position. when the "pancake"/shaft loses vacuum,(holding it up),it may "drop" out of gear,which could result in catastrophe! Another thing that you NEVER want to trust is a "Hydro-lock" brake switch! Check-out Jeff Bradshaw's'55 G.M.C. 350 dump truck,after the Hydro-lock" bled-off! Same thing could happen,if you leave your 2-speed on the "Hi"-side! These things are designed to be shifted under vacuum.And,yes,if you accidentally switch the selector with the engine off,you may have to manually engage the shaft,("Lo"-side). I tried to engage it,(like a dummy),on the "Hi"-side,but by the time I got the bolts tightened back up,the shaft would drop. The shaft as a notch forged in it,at the same angle as the tang,on the selector switch,in the rear-end. Make sure you "Permatex" the housing,or it will leak. If you're on the "Hi"-side,with the button "Down",switch your hoses at the "pancake".Hope this helps.

OK thanks guys. That makes more sense.

another Old wives' tale I can scratch off the list

Greg

My 1956 Chevy vacuum Shift rear works as Willy described...in Hi rear the acutation shaft attached to the shift lever for the rear is pulled UP. With the truck OFF there is no vacuum holding the actuation shaft up. Over time with the truck parked gravity could allow the shaft to slide back down (remember these parts are 50 years old and broke in well) and right at the moment it drops from Hi and just before it goes into LO it will be in between gears. At this point you should still be OK as there will be pressure on the rear gears holding them from shifting, but if someone bumps the truck or slams the door it could allow the shift process to start, putting the truck in a freewheel condition...remember your hand brake is attached to the drive shaft ahead of the rear, so that won't help.

I was taught by the old timers to always park in LO and chock your wheels...

Mike B

Great find, be proud owner...

I drive my big truck with the rear axle in high all the time, only split gears when carrying heavy loads. Trans is a Clark 205V five speed. Rear axle is Eaton 2 speed.

There is a page here on Stovebolt that demonstrates how to shift a 2 speed axle. I believe there is also a video on YouTube.

GMCPic