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Detroit Series 40 350 HP Engine

Yahoo Message Number: 55913
Hello all,

I'm the new guy here and have just about purchased a 1997 CC Magna 40'. The unit was a repo and shows neglect but has the potential of becoming a beautiful coach.
I am interested in any comments people might have about the Detroit engine. I haven't seen many of these in motorhomes and wonder what the up's and down's are.
I am not familiar with the newer fuel management systems.
Also, what service should be done to the Allison trans since I have no records of service. Any and all recommendations would be appreciated.
I am a retired boat builder and might be able to answer fiberglass questions and finish problems.
Thanks in advance, Don

Re: Detroit Series 40 350 HP Engine

Reply #1 –
Yahoo Message Number: 55914
Hi Don,

There are a couple of us who have the DD series 40 on this forum. I think you will find it is a 330 HP. All that good information is on top of the valve cover. We have a 97 40' serial #5418. By my book the 330 HP was the biggest engine installed. With that said, so far I like the engine. Had a fuel lift pump fail, pump not expensive and easy to replace. Other then a repo, what history, if any, do you have on it? Makes a big difference on how one approaches service. Our unit had been sitting for several years, which led to lots of maintenance issues to get up to date. Suspect with your background you can do most of what needs done.

As for the Allison, change the filters and change over to synethic oil. I installed Amsoil in mine. Depends on what you know of history will determine what else I will suggest. Not need to make a long list now.

Very nice running road machine. One hand, set back and relax.

Leonard

97 Magna 5418

What state are you in? We are in Oregon.

Re: Detroit Series 40 350 HP Engine

Reply #2 –
Yahoo Message Number: 55915
Quote from: Leonard Kerns
Hi Don,
> There are a couple of us who have the DD series 40 on this forum. I think you will find it is a 330 HP. All that good information is on top of the valve cover. We have a 97 40' serial #5418. By my book the 330 HP was the biggest engine installed. With that said, so far I like the engine. Had a fuel lift pump fail, pump not expensive and easy to replace. Other then a repo, what history, if any, do you have on it? Makes a big difference on how one approaches service. Our unit had been sitting for several years, which led to lots of maintenance issues to get up to date. Suspect with your background you can do most of what needs done.
> As for the Allison, change the filters and change over to synethic oil. I installed Amsoil in mine. Depends on what you know of history will determine what else I will suggest. Not need to make a long list now.

Very nice running road machine. One hand, set back and relax.

Leonard

97 Magna 5418

What state are you in? We are in Oregon.

Re: Detroit Series 40 350 HP Engine

Reply #3 –
Yahoo Message Number: 55917
We pull a 22' enclosed trailer and the only long trip we got 6.5 at 70 mph through Idaho. Next time out will travel slower and see what we get. No ideal on roof panels. Think it maybe hard to do. There are those on this forum that would know. How many miles on the coach? We have less then 50,000 so the engine is not broken in yet.

Leonard

Re: Detroit Series 40 350 HP Engine

Reply #4 –
Yahoo Message Number: 55924
Hello Leonard,

This coach has 107K on it. Wanted one with less but....I was planing on a 22' trailer so that really helps. 6.5 is kinda scarry though. My present coach is gas and it gets only 6GPM. It would probably be better at 55. I won't be in a hurry when we hit the road for good. I would like to see 10...its easier to figure!I know a guy should have the valves adjusted and check injectors for the best fuel mileage. A series 60 at 100K gross will get 9.MPG. I have a friend with a fleet of series 60's.
If and when we get to travel time I will keep you informed on mileage.
I had Jimmies in several comm. boats and knew them inside and out. Those were the 2cycle engines. I had to change filters and set rack and injectors or the fuel bill would double. Those engines were bullet proof and you didn't worry about a circuit board going out like these newer engines with the fuel management computer.
It sounds like these DD engines have a good track record. Not many installed in MH though. Kinda like a Cat...they must cost more.
Has your steering kept tight? I hate a coach that wonders around. I haven't even driven this coach but have committed to buying it.
Thanks for the info, Don

Re: Detroit Series 40 350 HP Engine

Reply #5 –
Yahoo Message Number: 55926
Don

The best we have had is about 7.5, but think things will improve with more run time, engine is still not broken in. I ran the rack and checked the timing. Someone had advanced it to 20 degrees, suppose to be 13 as stated on the valve cover. As for steering, it is great, handles extremely well. You probably will want to adjust the shocks. They should be Koni and are adjustable. Check there website. The biggest problem you will have is not having the Country Coach manuel with the wiring etc, information. It has been worth it's weight in gold to me. Much more important the the Gillig manuel for trouble shooting. This is our first diesel. We had our hitch beefed up for the trailer. We really like our coach. Has a slide and is very comfortable to drive and live in. When you get it and start checking things out, let us know if we can help. Spent all summer fixing things. Had to replace the brake treadle valve. Seems they are know for not working when a rig spends time setting. I really have learned the coach and still really like it and am impressed with the way they are built.

Leonard

Re: Detroit Series 40 350 HP Engine

Reply #6 –
Yahoo Message Number: 55931
Mmmm.. think when I get title I will try to contact previous owner. They probably have a bad taste with the repo etc. I can get the gillig manual etc but like you said get the CC manual. Heck, they can't use it and might want to make a quick 1oo bucks. The 50amp cord is missing and two chairs.I would really like to have elec. prints.
Someone put a BBQ in the wall for access outside. Lousy install.and looks like heck. One of the first jobs when the weather turns warm up here. They then installed a ugly cabinet to cover inside of BBQ looks like a vanity from a bathroom. Some people don't have a clue. It is 6' long and I might leave it on site before I leave the lot.
I have heard 9MPG towing a car and 10 without with this engine. I will shoot for those numbers.
Is your coach inside? In a perfect world...I would have a shop large enough to put it inside.
Is there a screw jack to power out the generator? I also noticed that the Magna has larger brakes and running gear. I like that! Thanks again for the info, Don

Re: Detroit Series 40 350 HP Engine

Reply #7 –
Yahoo Message Number: 55933
Right on with contacting the previous owners. Worse case, might be able to help out and get ours copied for you, just pay copy and shipping. We have an RV cover to keep it dry in the winter. The 50 amp cord is not cheap to replace. Good luck on it. For the gen, open the compartment door on the drivers corner. There is a switch that trips the gen release, then it slides out the front. Very easy to get to and service. Will have to deal with the shield, if it still has one. I took our off as it looked very bad. Glad to have it out of the way. Suspect the 9 to10 is a doable figure. The transmission does not go into 6th until almost 60 mph.

One thing I was told, the rear wheel seals dry out and get hard with setting and then leak on the brakes etc. Very expensive repair. Might be cheaper to just have the rear seals replaced if in doubt.

You will really enjoy it.

Leonard

Re: Detroit Series 40 330 HP Engine

Reply #8 –
Yahoo Message Number: 55943
Thanks a bunch on the copy of the manual. I did it once for some people on my HMC and took the manual to a copy store and they even printed the front and rear of the page. I will keep this in mind. It would be nice to get the service records from prev. owners. There are some records with expenses on board now but haven't sorted them out.
I did the wheel seals on mine last year. The hardest part was lifting the brakes and wheels....my son was here for a week and we did both in a day. We are talking some heavy parts but the service was easy.
Good advice.

I will plan on a DD manual also. The first thing I would install is a good block heater if there isn't one.
How the heck do you get in the engine comp. to work on it? Looks tight down there...lol

Thanks again Leonard, where are you guys? Don

Re: Detroit Series 40 330 HP Engine

Reply #9 –
Yahoo Message Number: 55944
Under the bed is the engine compartment cover. Really opens it up for much easier access. It should have a block heater, look for the switch on the panel to the left of the driver. One should say block heater.

We are in the Eugene, Ore area.

Leonard