alawode

Thank you guys for all the responses, i appreciate the answers

Does anyone know why the DM Macks have the hood shifting to the right hand side? Is there a reason why these truck were designed this way? Thanks in advance!

In general, if you're going to use the tractor for heavy hauling, such as moving equipment on a lowboy or pulling a dump trailer, then the DM688s will be what you want because it's heavy spec'd.

For normal on road trailer truckin', then the R688st would be more appropriate.

This is just a broad generalization, as it depends on the exact specs of each unit.

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Thanks for the response, the DM is actually a DM690S but i think it was converted to a tractor. Does anyone know if the low gear can be a drawback if using to haul heavy containers?

Hi Guys,

I have to choose between two tractors: a DM688S and a R688ST. The R688ST is a 1988 model and the DM688S is a 1991 model. Can you please advise me on the advantages/disadvantages of either model, and what the difference between the two is? Thanks in advance!!

Any help please???

Can you see if it's just a valve cover or worse(head gasket)? I assume you haven't started it to see if it "leaks" while running.

From your description("where the top of the engine can be removed"), does that mean the head gasket area(between block and head)?

Yes Larry, its the head gasket area between the block and the head, and i didn't see it leak while running. I did start it, but i didn't observe a leak when it was running

Hi Guys,

The picture below is for a 1991 Ch613 Mack that i'm planning on buying. The problem is that on inspecting the engine i saw that there was an oil leak near the top of the engine near the back [the side that nearly touches the dashboard/cabin]. The truck has not been moved for awhile so i also spotted some oil stains on the floor directly under the leak.

I was wondering if this discovery was a big enough red flag not to buy the truck, or is it something to expect due to its age? Please advise, your input is highly appreciated!!

N.B> the leak comes between where the top of the engine can be removed [near the back]

I've seen the clutch setups as low as 359.99, up to better that $700.00, (exchange). It depends on what setup you have. Call your Mack dealer with the vin of the truck to ascertain what components you have to research parts.

Rob

Thanks Rob!

If you are doing the work yourself don't rule out your Mack dealer. I've bought several Mack branded clutch setups that were priced competitively with the aftermarket parts houses.

A new clutch set will come with the friction disc(s), the intermediate plate, and pressure plate, (clutch cover) and throw out bearing. A machine shop will need to resurface the flywheel face and install the disc driving "dogs" if a 14 inch clutch. Be sure to replace both the crankshaft pilot bearing, and clutch brake while it is apart. Also look at the bushings in the flywheel housing and inspect the pivot shaft that operates the release, or throw out bearing for wear.

Ensure everything is properly greased upon reassembly.

I also like to use new bolts and hardware for everything upon reassembly, but it is not entirely necessary.

Rob

How much do you think all these parts will cost me?

The clutch on my 1988 R688st has gone , does anyone know where i can buy a new one, and what parts to buy? Thanks!!

That's an electronic E7.

No throttle shaft or linkage hooked to the governor, and it has that big electrical connector right next to the inj. pump.

.

Thanks!!

Hi Guys,

I'm trying to buy a mack truck with a mechanical engine and not the electrical one. I have a 1991 CH613 in mind and i have attached the pics of the engine to this post. Can anyone please tell me if this engine is mechanical or electrical? Thanks in advance

Thank you all for your input!

Thank you all for your input, it was very insightful. Can you please explain the Phrase "unless volvo fcuks that up'?

Hi Guys,

I am split between buying a 1988 R688ST [350hp] or a 1980 Mack superliner [350hp]. I was wondering if anyone could tell me what the difference is between the two of them engine wise and what the pros and cons of each could be? Thanks in advance