Joey Mack

Its a CH, still has an acc. relay in the dash, probably a cube style plugged in by the fuse panels, left side.. JoeH, i'm pretty sure that on the firewall celenoid there is a large power wire that goes the the cab, then through the cab relay as you have stated.. With respect, Jojo and yes, My bet is its an E-Tech... V-Mac III like you say.. I forgot to add the on the firewall next to the starter relay there is a black one.. that is a ground breaker.. If it fails, it will cause the issue you have. you can jump the terminals for a minute to see if she lights back up..

you been away for a while MarkT, but you came back with a vengeance.. It's good to see you again.... Jojo

Uhhh,,, I dont remember that... well, i am away from them in the dealership for a while now.. We would just hook up PTT and make adjustments.. Or am I full of SH!T??

the starter celenoid on the firewall is a main power source to the truck.. check the terminals and cable ends..

is it coming on hard or is it just coming in slow and then going out slow??

I know one thing.... if this is his first big truck clutch job,,, He picked a 'Doozy'

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If you have to replace the rear main seal, I have a tool that is still available and it works great. I can post pictures and part numbers for the tool.. Jojo

assuming you have a Mack transmission, it is very heavy, I think around 700 pounds.. I have a transmission jack from harbor frieght that is decent and strong enough. it is the biggest one they offer in the store, around $300.00 (4 years ago), dont know the prices in your area.. I have a few suggestions... when i do a clutch in a DM, i remove the right side door.. it may take a half hour or so but you will gain a ton of room to get it there and pull the seat and floor pan.., also, when you have the floor out, this is the time to decide whether you want to replace the treadle valve and brake pedal base. next, there are no rear engine mounts, so the engine will need to be supported before pulling the transmission back. now on the plus side, you can pull the doghouse and get even more room. next,,, if you have to do any work on or under the rear valve cover this is a great time to do that as well, because you will have room and you can lower the engine after the transmission is out, and easily remove the valve cover.. I am adding work to this job, but trust me, if you do it during the clutch job, you will thank me later.. Just imagine having to do those other repairs individually, and the work to get in there to fix it. You may want to inspect the throttle pedal base too. they corrode the heel plate and nutserts (for the brake pedal) are still available. the rest is just 'good ole' hard work.. Jojo

I believe you have a 14'' dog dish clutch.. I have replaced that setup with a 15 1/2'' clutch on an E-7 flywheel... I wish I knew the part number for the flywheel.. I have seen posts that say you can still get the clutch and flywheel that you have. I lean towards the larger one because it is readily available and you can get a 9 spring HD clutch whether you need it or not and you can get an Eaton ''Easy pedal'' clutch that is.... easy on your left leg.. take a minute to search out these posts here... Jojo

i'm just happy that someone brought back an older Mack logo, instead of the chiseled looking Volvo crap...

There is a plug, 4 actually, 2 on the front and JoeH is right, one is behind the timing cover.. every time I have the front cover off I check them, and I have found the hidden one leaking.. it isnt very common, but its possible...

Have you done any work in the EUP's? When the lower o-ring goes bad, it will put fuel in the crankcase.. If you are not familiar with how to remove and install the EUP'S, come back here and we will guide you.. Jojo

Yes sir. Always interested in Mack Manual's. P.M. me as needed.. Jojo

Here is a code list.. the code sequence is down the middle of the pages.. V-MAC_Fault_Assignments.pdf

Yeah, I really can't stay away... Especially for an E-7/E-Tech issue... I just don't want to stack too many things on at one time for someone who is not familiar with this setup... Jojo

all good,, just going to see the results of his diag.. I tend to post post too much.. im training myself to ''chill''

It may be best for me to leave this thread. Good luck sir.. Jojo

Your engine is an E-Tech.. flywheel sensor is behind the starter in the side of the flywheel housing. The plug and wires can be seen running along where the clutch cable is.... The cam sensor is at the right front corner of the engine near the over board breather.. the cam sensor is called the engine position sensor. The one in the flywheel housing is called RPM/TDC sensor.. do you know where the fuse box is under the hood? Did you check the ground wires on the block yet? All this is easy and free to do.

I forgot to add, to check the large ground bolt on the engine, in front of the starter.. the 2 thin eyelets are for the engine harness..

I doubt ECM... Check the condition of the fuse box under the center of the windshield. Fuse 40 is the ECM. Looks like you have an RD 688S... Also, when it's running, unplug the cam sensor, if it shuts off the flywheel sensor or wires are bad, if it stays running, plug it back in and unplug the flywheel sensor. If it shuts off, the cam sensor is bad... 2 simple steps that are FREE to do. If you would like, you can go to flywheel sensor wires and peel back the loom to see if the wires are damaged.. I have seen that a lot. Jojo

I have never seen that kind of damage before.. Holy Crap..

I wish I could drive that rig.. Sounds like a bunch of skill... I guess today, the driver just pushes his right foot closer to the floor...

Ok, I thought we were talking about 4 valve engines... Sorry....

if you have the old gray rubber gaskets or the black ones that are attached at the business end, , you can re-use them.. you will see how the crush on them makes them just a tick wider at the mating side.. You can flip them over, they will fit snug in the valve cover groove.. the cover bolts are shouldered so they will only go down so far before they stop... to me this is not a crappy way to do this, its just using both sides of them.. of course, you have to determine if they are to far gone for re-use...