USMC205

Try the fan clutch.  I have a 460 and when I was loaded climbing hills it would want to overheat.  Got tired of messing with it so I changed the water pump, thermostat and fan clutch.  Mine has a viscous fan clutch and I didn't realize how loud it would get until I put a new one on it.  Just as you said, my old one only kicked in when it was already getting warm.  I can hear my new one kick in just at or about 180.  But like I said, its a viscous, not sure what kind you have.

Well I had a feeling the fan clutch wasn’t turning as hard as it should, so I went ahead and replaced the water pump and fan clutch.  Made a world of difference.  I can’t get it to overheat if I tried now.  I thought the clutch was turning just fine until I heard what it’s SUPPOSED to sound like.  Also replaced the thermostat while I was at it.  Taking the fan shroud off also gave me a new view into how dirty the radiator actually was.  The old dog stays cooler than the underside of a pillow now.

13 hours ago, Mackpro said:

If you have the last 6 of the VIN I can do some digging for ya and see if there were any bulletins on the issue 

It’s got a viscous fan and yeah I noticed a little seepage before.  From what I can gather it came with the his clutch.  I can hear the fan roaring at higher rpm’s but not so much at lower, it kind of seems like the fan kicks in fully later than it should.  Might try a new one and see.  How hard would it be to convert to an air clutch?  I’d like to have a switch to flip before a big hill.  060231 is the last 6.  01 RD688.  Thanks guys for the replys.

2 hours ago, alex g said:

If your putting more fuel to it your problem may me overfueling as compared to radiator problems. Is your pyrometer running hot? Sounds like you've already checked cooling system

It gets up to 900 when pulling a hill.  I didn’t turn up the fuel, I was just assuming the 460 puts more fuel and air into the engine.

2001 RD688 Dump- I’ve been battling overheating when pulling a good hill for a year or so now,  I’ve just learned to take it easy but even then it still comes close.  From what I can tell, the radiators are about the same in most of the RD’s regardless of the engine.  I would think there would be a larger or upgraded one for the 460 since I’m putting more fuel and air to it.  I’m going to pull it soon and have it flow tested.  Any suggestions on an aftermarket or better one?  Radiator is clean, no boost leaks, thermostat changed, viscous fan seems to be working and water pump is pumping (from what I can tell).  Anybody have any suggestions?

1 hour ago, Mack Technician said:

Nail down exactly where the leak is coming from. If its the pinion housing in the center of the picture that's a pretty easy fix. Most likely, usually, it is coming from the mounting surface of axle banjo-to-differential. The best thing to do is pull the top breather and hook up an air pressure regulator. Add 3-4PSI to the diff and spray (soapy water) the suspicious areas.

Yes sir it looks like it’s coming from the part that has the extra holes to pull it apart?  What’s it called and is it as simple as pulling it apart and sealing it or is there more to it?  

I’ve got a leaking rear end and I’m not sure exactly what the leaking part is called.  I’ve attached a picture.  It’s not coming from the pinion seal but behind that.  Is this the carrier or is the carrier the whole top assembly that drops down into the housing? Where it’s leaking looks relatively simple, drop drive shaft undo bolts and it should pull forward. It seems those two empty holes are to out a bolt in to separate the parts?  Also when I had it cleaned it looked like a drop of oil came out of the hole on the bottom.  Is this possible?  I’ve had a tech tell me that since I have 4.44 gears it will not pull all the way out, just an inch or two and just enough room to clean and reseal.  I’ve also read that I need to take the inspection plate off the side in order to get to two bolts.  I think I may have a little bit of both repairs mixed up in my head.  If anyone has experience I this I would welcome a text or even a phone call if you have time.  It’s an 01 RD688 Dump.  Thanks.

My tach stops at 2400, lower than all other trucks I’ve driven.  I usually shift around 16-1700.  I never let it get over 1900.  I’ve heard that the 460 was better suited for over the road, but it seems to do just fine in my dump.  Whats the sweet spot for pulling hills?  What’s the danger RPMs for this engine?  It’s an 01’ and is paired with an Eaton 8LL.  Thanks fellas.

On 9/5/2019 at 7:28 AM, j hancock said:

Sounds like you are gaining on it.

Balancing the drives may help a little.  Your tire guy probably told you that a balanced tire/wheel combo doesn't mean that it is round.  No balancing will ever solve a bent wheel.

My tire guy told me one time that he could balance a square block but I wouldn't like the ride!

What did you find out on the hub damage mentioned in your first post?

Everything is still true and balanced with. No wobble from steers.

Thanks for the replies all.  Had to get a tire replaced so I had them jack it up.  There’s more than one rim bent in the drives.  The vibration was more coming from the rear, no bump or anything in the steering wheel at all.  With the whole rear off the ground my very old and wise suspension/alignment/tire guy put a wheel spinner on and got them up to all speeds.  Once up to speed both axles were vibrating so bad it almost jumped off the stands.  He it was so bad he couldn’t tell which rims may be bent.  I’m having 2 tires put on next week and gonna balance all the drives and go from there.

Yes it did, Paul.  Sorry I should have clarified that.

I've got an 01' RD688S dump.  I'm getting a side to side wobble it seems like from 40-45 mph and again from 60-65 mph.  It doesn't seem like a death wobble I'd say but it is enough for concern.  I have brand new balanced steer tires on and it still does it.  When they changed the steers they noticed one of the dog ears on the driver's hub was broken off and they said this could be the problem and I would need a new hub.  It makes sense, but I don't want to take a tire mans word to make a 1K dollar repair.  What do y'all think?  Within the last year I have had the kingpins and tie-rod ends replaced.  I have all but two drives replaced in the last two months.  Any ideas?

23 hours ago, Mack Technician said:

Make sure you get the correct pedestal gasket for the oil manifold base. I believe there are two variations that can be easily swapped after Mack did the left hand revision for the flipped centrimax and cluster plate cooler. 

Any idea of the torque specs for the manifold bolts?  The gasket is a metal type manifold gasket so it might be a little more than I’m thinking.

Ill check more into it tomorrow, hopefully I can just unbolt the oil filter housing from the block and replace the gasket and be done.  I already have that gasket, it might be a pain in the ass to do it without touching the oil cooler, but we'll see.

I've got an '01 E7 460 that has the double spin on with centrifugal filter on top.  It seems like the oil filter housing is leaking down the side of the block.  It seems to be getting worse over time so it's time to get at it.  I'm new to working on this engine but it seems like the oil cooler is right there with it.  I'm thinking drain down coolant, unhook lines going to the cooler, unbold housing at block, replace gasket or whatever it has and bolt everything back up.  Does this seem about right and is there anything I should know or any extra parts I will need?  I tried searching and couldn't find a topic on it.  Thanks for the help.

26 minutes ago, mrsmackpaul said:

There was a fella on here some time ago that had the same issue and it turned out his elephant ears were some neoprene that didnt have enough flex in them and didn't allow the axles to track properly 

He replaced them with the correct rubber and the problem was gone 

Maybe worth looking into 

 

Paul 

It’s been close to a year since they were replaced and I did use neoprene but they have been fine.  It’s been going on for a couple weeks.  Im gonna get a buddy to drive it in a circle while I walk beside it. I’ll also check everything everyone has suggested.  

1 hour ago, JoeH said:

We rarely have drive tires all the same size, never have. Never had problems with our Auto or manual power dividers.

Is it Camelback or air ride? If Camelback, did you replace the trunion bar bushings or the elephant pads? 

Spoke hubs or bud wheels?

Is this a recent problem or has it been doing it for a while? 

Camelback, the elephant pads were replaced, bud wheels.

3 hours ago, mrsmackpaul said:

Im guessing a Mack back end

If so, all drive tyres need to be fairly close to the same size as the power divider on a Mack bogie isnt really a power divider

However I would check and make sure the power divider isnt locked first 

Paul 

All tires are the same, how can I manually check to make sure it’s not locked in?

6 hours ago, 41chevy said:

Both directions or only one?

Both.

1 hour ago, Lmackattack said:

is it a the power divider kicking in?

I wouldn’t think so.  Shouldn’t the power divider only engage when the switch is flipped?

Thanks Joe.

13 hours ago, JoeH said:

Oil pan to cyl block (8mm screw) 23 lb-ft

Oil pan to cyl block shoulder 15 lb-ft

By shoulder your talking about the front and rear of the pan or the sides?  

Does anyone know the torque specs for the oil pan bolts on an ‘01 E7 460?  Thanks.

Is dynamat the best for soundproofing?