EastTex Cartage

On 5/27/2022 at 9:11 PM, GulfMack said:

I’m relatively new to macks, I bought a 2001 rd688 with the em7 300/Allison ht740. I was wanting to swap that’s trans out for a 4560 to be able to run interstate speeds and not be turning 2100rpm the whole way. I’ve called a couple shops and they act like it isn’t something easily done?

I have researched installing the Allison HD4560 in various different chassis, mostly to improve driver comfort on long days. 

As I understand it, the Allison HT740 is a 'mechanical' automatic trans with a non-locking convertor and the HT4560 is computer controlled with a locking convertor.

I know (I have seen) a Mack Rd688 with an E7 and Allison HD4560 from Mack, so I know its possible. To convert? Probably need to get the VIN off a factory automatic Mack and do a dealer parts change list -or- you would need a stand-alone controller for the Ally - which I have never found. Also need another program for the engine, I am sure they are completely different.

I know of a company in my area that converted a Freightshaker from manual to automatic and they spent something on the order of $20-25k.

I am looking for the factory shop manual(s) covering the removal, rebuild and installation of the mechanical injection pump on Mack E7 & EM7 engines. Also a E7/EM7 factory engine manual covering the rebuilding process.

Any help is appreciated.

On 4/11/2014 at 7:00 PM, 90plow said:

What does pai mean? The handles are fine I just wish the interior were beefier really hard to crank the windows on this truck. Even after spraying the gears and tracks any advice on that?

One reason the windows get sticky is the weatherstripping in the window runs located inside the door swells and gets misshapen with age. Replace it and it gets a bunch easier to roll up and down.

I am looking for a R series wiring diagram, specifically for a 1994 RD-690S.

On 7/25/2013 at 11:06 PM, jakebrake86 said:

I think it depends on what size floats you're running. I may be wrong, but I think a 315 float will go on the same rim as an 11r22.5, but I know a 425 or 445 needs a wider wheel. As for there being any difference in the hub, no, there shouldn't be.

A 315 tire needs a specific 9" wide rim, the 11R (8.25") rim is not the right width and isn't made for the pressure. They will fit on a 8.25" rim, but if you run up on a very, um, 'by the book' trooper or CMV officer, it could be a problem. Plus, your tire guy will hate you, lol.

One thing about the EM-7, the torque (1425 lb. ft.) comes in at like 1000 RPM. It might work well just like it is, especially with that Allison. I have heard nothing but good things about the pair. The thing about Mack RD/MR/RM trucks, they will never be race cars, but the don't get stuck (Unless it just sinks completely) and are very reliable if you service it regularly. I have a 1994 RD690S (as a dump truck) with the EM-7 @ 300hp and an Eaton 10spd an it is a VERY reliable truck. It routinely hauls 17-19 tons, daily. It's actually my most profitable truck, lol.

Does anyone know or have a chart that shows the various chassis measurements for the RD/DM chassis? I'm looking for specifically the BBC (Bumper to Back of Cab) measurement and a few others.

I had the same issue and I was under the truck greasing and inspecting and found that the ride height valve had failed - that is the little white plastic tube had broken in two.

Yes, its the one on the top.

I am looking for the cowl door vent on a 1994 RD690S Mack, as mine got bashed.

Mack R series kinda wrote the book on vocational trucks. The E7 was designed as a low RPM engine. They are not race cars. They will haul dirt/sand/aggregate/whatever through things other dumps just will not. Most R series do not have a 'diff-lock' per say, but they have a centrifugally activated 'peanut' setup that really works. They will last forever. I also have an International, which started life as a dump and the rear diff housing has been welded many times. Asking the rearend guy why? He replies 'It's not a Mack'

Is there  a reinforcement that the pull pin/pull ring mounts to behind the front bumper?

Its a 1999 RD688