allfritz123

Yes, it is a spring loaded throttle linkage! Even though the linkage was wore, I made sure that the spring was compressed with the accelerator pedal and that it could be held there. The road test was done on the hi-way so it was fairly smooth. My top end was about 55 MPH with the gearing at 1550. We talked to a diesel shop and they figured a couple of hours and the RPM can be adjusted on the truck without removing the pump. Changing springs and maybe weights to increase the RPM.

Thanks for all the advice. I had checked and double checked again clearance of flywheel and wear ring distance when I had installed the wear ring and again when I took the flywheel off the second time. No contact there. I think I have a good .1 inch interface. I hole mic'd the wear ring and I am at .165 inches. I think flywheel was about .050 inches if I remember correctly. I actually used anaerobic sealer for the seal housing to block interface. It stays pliable but is resistant to oil! I used it as I mounted a dial indicator on the crank and was shifting the seal housing around to align it. I thought I was within .004 or .005 TIR. The Mack specs told me anything less than .007 was good. I will definitely push the wear ring on cold next time and with a sealant. Maybe there was damage on the crank but I certainly didn't see it. My eyes are getting a bit tired already though! Slipping on reading glasses and taking them off when I drop things out of my fingers and onto the floor! I thought I had a nice tight fit when I had put the ring on. I guess if there was a hollow spot anything can happen. I think as well I will rotate the crank with the adapter plate installed in order to seat the seal and avoid bounce back and might get an evener set. I might have been further ahead to use a teflon seal and avoid the wear ring altogether? They talk about using a guide sleeve with that type of install...... I have never put one of them on but it did say to install dry and use no lubricant. I don't follow those instructions! Isn't there always going to be oil on that interface and what you are trying to keep in the engine? How could oil or white grease hurt the install? It seems like contrarian thinking! The plate on the pump says 1725 rpm. I think my governor weights are holding it at 1550. I can get approx. 1700 when truck is stationary or in a low gear. It sure feels odd when compared to my E7s. I certainly think I will plug off the puff limiter to see the difference in response! Johnny law rarely sees this truck as it spends its life in soft fields and gravel back roads!

The engine I am working on actually has an aluminum housing with a separate cast iron seal housing. So the leak has to come from that separate seal housing as there is no contact between the crankcase oil and the bell housing I believe. As stated, you have to line up the bell housing to the crank and the seal housing to the crank. The old EM6 engine does have a cast housing and a somewhat different seal housing (maybe like an old lead seal??). I never removed the flywheel from that engine but when I peered up with the oil pan off, you can actually see the back side of the rubber seal. It also had a v-shaped profile (less material at the center) where the oil pan gasket contacted. This E6 engine you can not see the seal with the oil pan removed. We took the truck for a cruise today (even thought it has the parasitic oil leak). Initially, this engine was set to run at 1550 RPM maximum as far as I can see. I managed to get 1700 RPM out of the engine when stationary by allowing more free travel stroke on the pump lever by removing the forward limiting screw. However, it refuses to get past about 1550 RPM (governed) while doing a road test. So I gained nothing by giving the lever more stroke. I can get a top end out of this truck at about 55 MPH and 1550 RPM! We talked to a local diesel shop. They said the RPM can be adjusted with the fuel pump (Robert Bosch) in place but they said you likely can't increase it enough without changing the weights on the governor. They are not sure if they would be able to source the weights required to do that mod. It sounds like they can do this all while the fuel pump is on the engine. The engine runs good but it certainly doesn't have the power the old maxidyne EM6-285 did. Maybe it is due to the puff limiter valve being bypassed on that one and possibly the pump being set up a bit? Apparently that was easy to do on an American Bosch pump. I pulled some hills with this truck (empty) and I only saw about 700 F or so on the pyrometer. Very nice and quiet engine. I did notice the hesitation going up the hill likely caused by the puff limiter response when I stepped on it. There was a noticeable delay in the spooling but no smoke! The old gal used to respond quicker but lots of smoke and a quicker more rapid pyrometer increase as well!

I still have problems....I didn't realize the wear ring could leak oil! We actually bought a good tool I thought!! It worked good. https://monacotool.com/collections/mack/products/rear-crankshaft-seal-wear-sleeve-installer-mack-e6-e7-engines I didn't suspect the wear ring. I heated it and pushed it in and it went in tight. I could feel it move and took some force. I wouldn't have suspected the shrink fit leaking! It landed nice and square at about .165 from end. I did mic the old ring that was well used and it was about .050 around it. The one I put in was almost perfect when I mic'd it. We bought another seal and wear ring so we could examine it (National seal and wear ring combo from PAI). I put the new seal and wear ring on the pusher and then removed to see where the seal was landing. it looked like I was 1/32 inch past the chamfer and was visible on the flat of the ring. That was NOT the case when I actually used the tool on the crankshaft. That puzzles me. I noticed that the seal was right at the edge of the interface and I thought everything was good since I used a quality tool and never question - only eyeballed. When I pulled out the engine a second time, I confirmed what I saw. The only thing I thought was that I had seal "push back" after releasing the tool and caused it not to remain in place. Maybe a guy should rotate the crank after landing the seal in place!!? So I machined a washer and pushed the seal in a little further until I definitely could see the edge beyond the chamfer with the naked eye. I went in a good .040 or .050 beyond I then used a hole micrometer and squared the seal up to about .007 from crankshaft end. The housing and crankshaft actually mic'd perfectly and close to 0! After pushing the seal in a little deeper, I had a variance of about .025 around the seal. So I tapped the seal with a punch until it was closer to square! I still have a leak. Very frustrating. I think the tool was good enough to push in cold but I followed the Mack Manual and used heat! I get a drop every 2 to 4 seconds and I have already seen where it stopped for a while! I used the Parker formula and have decided to run it until fall. I may use 2 or 3 gallons in the 200 hours we put on the engine every year. A good little app! https://divapps.parker.com/divapps/tfd/oil-loss-calculator/ We made a decision to see the how the rest of the engine is working for a while and maybe in fall give it another go. I am getting tired of working on this engine - although it is a good learning experience! The truck doesn't seem to want to leave the warmth of the shop! Obviously if the wear ring is the problem, I am kind of screwed. Someone suggested putting blue devil in the oil to swell a seal?! I have never heard of that product before! I wonder if there is anything out there that could seal up a wear ring - rather than replacing it!!!!! Likely not or everybody would be using it!

Not quite yet. Another learning experience. It appears the rear seal was sitting on the chamfer edge of wear ring just ever so slightly. Removed engine after changing thrust washers thinking that might help! Gained .002 with that move. Still leaked a drop every 2 seconds although it quit for 30 seconds once! Mack specs say wear ring to be at .162 and seal at .198. My seal was already at .24 and looked like about the spot I pulled the old one came out from the housing. Mack said to heat wear ring to 400 F and push in place. That is what I did. It was nice and even at about .165. However on second look my seal is just at the chamfer interface. I hate to have a learning experiences like this but I can now take engine out in less than a day! Common sense should have told me to push seal in a little further and make sure it was on the flat! Know better next time!

Yes it is. I had to make a bracket to adjust the idle rpm. It was so low against the stop it was was way below 625. I made an adjustment screw to bring it up to about 650 but I can adjust it if necessary. Also, the high end in this engine's last application was set to 1550 RPM. So I had to remove the stop screw and allow it to come fully forward against the housing. Then I got 1700 RPM which is what is on the plate. I want a little more RPM as the old truck had the EM6 which allowed you to get to 2100 RPM. So I will be a little bit slower ground speed at the top end with this engine. We are not really concerned as it is used off road. I thought I would post a video with the old motor (EM6 rolling coal). Going to miss that!

The engine is running really good and has no blowby. Starts really well. One thing I have noted is the engine RPM is only 1700 on the plate and that is all I get out of the Robert Bosch pump. We put the hood back on and it fits! I might tilt the radiator back a little bit at the top. Our aftercooler has some metal tabs on it which just contact the hood at the top. I could remove them too but I don't see any issue with shortening my top turnbuckles to gain the clearance. Lots of room between fan and rad at the fan shroud. I would only move it back 1/4 inch so not a big deal. We are thinking of adding a rad screen for grasshoppers and chaff onto those mounts. We are also looking at adding diamond mesh to the hood opening to protect the rad. We have an issue with a rear engine seal leak. I used the installer to put the seal and the wear sleeve in. I did this in 2 operations. I heated the ring to 400F and put it in. It turned out very nice and even. I then put the seal into the cover with the same pusher and it also went in good. I had checked the aluminum cover it pushed into and got it to within .005 in rotation with a dial indicator. I am getting a drip every 2 seconds. Before I starte I checked the endplay on the crank it was .010. The Mack specs say it can be up to .011. I thought the seal went in perfectly with the installing tool. Trying to figure out why? Is the large endplay causing this leak? It is definitely coming from the centerline of the oil pan and is not the oil pan itself. Always issues! I noted in an E7 manual that the maximum endplay was changed from .005 to .007. I am over that with this E6!

No they kept using the dynatard camshaft in the 4vh engine. I am not sure at what point they stopped that production. My 4VH service manual has an entire section devoted to the dynatard engine brake so that option was still being sold and the same camshaft was therefore being used. I don't know at what point you could no longer get the Mack dynatard brake? Maybe when the E7 came out??? The flywheel is still marked to check valve lash on 3 different spots over 2 complete rotations. Somewhere along the line they no longer used the dynatard camshaft as it didn't end with the 2vh. I replaced the bent lifter and rocker arm on #6 and everything runs good now! I talked to a technician from Edmonton and asked where the problem could have been. He said he has saw stuck valves that can cause this in a cold winter start. If a valve gets frozen. It won't open. I am wondering in the cold weather in Canada if that didn't happen before we got it. I removed at least 2 US quarts of sludge from the oil pan. If this truck had very dirty oil in it and then added cold winter temperatures - perhaps high visocity/stuck valve resulted in a bent pushrod? Maybe someone "ethered" the engine and that gave it a sharp blow and sticking valve caused the bend! That is a couple of scenarios.

I did check the bridge fjh and I used your guideline of 60 degree turn of screw after contact. (Another one of your appreciated posts and also your mention of dynatard camshaft!). They were all very close. I had to do the exhaust bridges anew because the bridge was replaced to accommodate the jake brake and a wider anvil. I have the 4vh manual and never really understand their instructions. I didn't have a narrow enough feeler gauge to read the .010 reading anyway! Your instructions made perfect sense and logical! Contact +1 flat to insure being just slightly up. When I removed the bent rod, it was seated in its socket as I could feel the suction when I lifted the rod out. The engine was running very smoothly and running like a top. After getting primed, it starts instantly and runs beautiful! My above measurements I made were before we ever removed anything in putting on the jake assembly. It never had one before and the bridge looked good on all. Those measurements listed were made when this engine was new to me and came out of storage. Unusual to me was that #6 intake was bang on! I did think it was unusual to have large variations on gaps. I thought it may have possibly been poorly set and that perhaps someone didn't know it was a dynatard camshaft and that you have to set individual cylinders in sequence. I read some instruction on youtube videos where on later non-dynatard camshaft engines you can set all the valves in two full turns of crankshaft. I was thinking someone may have set it on that basis and so that was why it was wrong! I made settings based on the intake opening, then closing and very next lining up the timing mark appropriately for it. Once I moved into position for #1 I followed the 1/3 turn pattern to set each set in succession. So #6 became one full turn after seeing #1 pattern. We only ran this engine for about 20 minutes. I didn't see anything on the bung when we had the oil pan out. We are thinking of cutting the old oil filters apart. There was an absolute huge amount of sludge at the bottom of the pan that did not run out and had to be scraped out. This engine sat for at least 15 years as we bought it with the truck at an auction sale and never used until now! Who knows how long before we got it that it sat. We took an old propane tank, modified and primed the oil galley before starting. We never heard nothing when we cranked the engine over and oil pressure was up before it ever fired. I also squirted oil on the entire top as well and made sure bridges were oiled. Could you please explain the lifter problem and how it could interchange? I assume the lifter is under the push rod and sits on the cam. As I had mentioned above. I could feel the suction as I removed the bent rod and the lifter moved up with it. We have found another pushrod and rocker from Northwest Trucks in Edmonton. As it is the most rear intake (6), I am not sure if I can peer down the hole without a snake. Should I be pulling the side panel off the engine and is that a possible way to inspect this lifter? Your thoughts are greatly appreciated and respected! When I removed the bent rod, I put it into setting position. The engine was still hot but I did have enough clearance on the bridge that I could rotate it.

We have finally got to the bottom or top of the problem with the donor engine. It seems it has a bent lifter on #6 intake and that is why the rocker was dancing back and forward on the rocker tube. We are wondering why this could have occurred? Any thoughts? The engine ran real nice and starts immediately even with a bent push rod! We measured the gaps before adding the jake brake and that particularly one came in correct at .016.

We finally got the donor engine running. It sounds good. The number 6 intake rocker at the rear of the engine is wandering on the tube against the spring pressure holding it against the support. That is disturbing! Anyone see something like that? The rest of the rockers seem to be good. When it walks it releases some oil spray from its edge. I am guessing we need to do some work on the bushings or put in a whole new rocker assembly? Old manuals talk about honing bushings for rockers. It seems tight tolerances ( .0005 to .0015). Could a push rod be bent and cause the wandering. It sure looks like the rocker has a lot of slop and more than it should when twisting it. We put on a new turbo on because they other donor turbo was using v-band clamps and we were having trouble finding a connector on the intake turbo side to go to 3.5 inch "barb". So just decided to update with a new one. It is a Borg Warner and the old one was a Garrett and new turbo is bigger in size than the old one. Inlet still is 3" but meant for 3.5 inch barb hose to attach. The Garret had a 3 inch v-band type connection system. We found an air to air (new) and had the horns turned out like Josh had done by a machine shop. We found some piping from NW Trucking in Edmonton and so that was a relief. A driver's side pipe and used intake manifold! We also found a jake brake for it (new and made by etech!) from another supplier. It was old stock! The jake is working nicely when I manually engage it at the tappet top when I purged air out. The kit came with a clutch pedal switch and a normal switch for the back of the Robert Bosch pump. It has a diode in it and I really don't know why that switch has that in it? I assume our truck is a negative ground setup and not a positive ground setup which apparently requires reversing the diode on the switch if it does. Taking the foot off the gas didn't engage the jake with the 2 cylinder switches turned on so I have to figure out the electric issues there. Maybe my switch at the pump isn't contacting? I didn't bother with hooking up the clutch pedal switch as we never had it there with the Dynatard system in the old engine and I don't think it is necessary or important. It looked like the wiring harness was intact and in order to install you would have to cut the wire in the harness and put the clutch switch into the system. I think it is unnecessary? The low idle needs to be set up and it looks like the max RPM against the pin is 1550. So I am hoping we can adjust that up to 1800 by turning the screw to allow the lever to go forward a little more. We put in a brand new clutch and it appears that the clutch brake is not engaging. We have an optional clutch brake fiber disk shim that came with the clutch. We hope that putting that in will rectify that. We still have to fit the hood. I hope it has enough room like in Josh's truck!

I will keep you posted when we get it going! We are pretty much in the same boat. There are very few Mack trucks in our area and definitely very few RD Macks. We have a variety of the E7 4 valve with the electronic modules. This our oldest one. It is nicknamed Bucky and okay to shift when you are used to it - hence the name!

Thanks Josh! I have it figured out. I removed the roll pin and flipped the lever up at the firewall. This allowed for directional reversal. I used the same linkage. The only thing I had to do was bend the air compressor cooling tube out of the way as it was contacting the linkage. It is the copper line going from the blue compressor back to the block! It actually works good. I was fearful that the linkage was at such a horrible obtuse angle to the injection pump arm that it would bind or be difficult. It works smoother than I anticipated and so far it looks like the mid-hole is a good fit on the Robert Bosch pump. I don't need any of the other linkages used in the cab over scenario which go to the front. I am very much relieved that it turned out simple as it did. I envisioned having to put in an additional fulcrum! It certainly is hard to find these old trucks around anymore to learn from!

I was progressing slowly but steadily and finally got the donor engine into the truck. It actually went in really well. I am now facing a new problem and I hope someone can shed some light on it. This donor engine has a Robert Bosch pump while my original engine has an American Bosch pump. I have all the mechanical linkages for the American Bosch fuel pump in my truck. The donor engine was out of a cabover I believe and I have some linkages but my problem is the fuel racks in the opposite direction from what my old engine did. So my linkage is reversed! Can anyone tell me if there is a kit or have pictures of what my linkage should look look like in a Mack RD with the different fuel pump? I would have to reverse the fulcrum to make my accelerator pedal work correctly. If I flip my oscillating lever, I will be changing geometry and maybe only get half my throttle. I am wondering what my solution is! I have shown the linkage hooked up from the cabover donor engine. I put it on just for visual and looking for solution. I have the rod that links from my old design but it is not in the picture. I may have to move the lever on the fuel pump so I get more of a right angle to the fulcrum. Looking for suggestions~ I have modified a charge air cooler like Josh did and so I have that done already! I had to buy a new one!

Yeah Joey I think I should just buy it. I am doing the work myself and if I needed it again I will have it. Ruining a seal or having one leak after a bad install is not worth it!