[mechanic17]

I'm seriously considering buying a used type I or III ambulance soon for a camper conversion. Mid-late 90s vintage is about what I can afford. The most common seems to be the ford f350/450 chassis with a 7.3 TD powerstroke. There are some Dodge 5.9 TD Cummins out there, and a few GMCs.

I do intend to load the thing up with my junk, but won't be towing a big boat or anything, so I'm more interested in powertrain reliability/economy than ultimate power, and I don't forsee modifying it.

I'm sold on a diesel for the mileage and reliability--problem is I know nothing about them. Never owned one. I read a lot of tranny replacement stories. SO, given that I'm starting from square-one, can anyone give their recommendation for best combo?

I'm assuming that any heavy chassis by the big three will do, but if someone wants to warn me about weak frames, rear-ends, electrical issues, consider me a welcoming blank slate. I do plan on buying down south to avoid something rusty underneath. Thanks in advance.

[David Holmberg]

The 7.3 Ford is probably the way to go. Excellent motor and reliability, good chassis to work with as well. The only weak point is the E4OD transmission, but once rebuilt (100K miles) it should be good to go.

You don't want a 90's GM diesel, they're ok, but not in the league with the PowerStroke.

[74gtoguy]

a 95-98 12 valve cummins is the way 2 go. better mileage than a ford, less problems.
i have one for 15 years and 280k miles. trans was replaced at 270k
avoid the powerstroke to many problems!!

[mechanickeith]

Both are good as stated. You will pay a premium for the Cummins. 7.3 mechanical engine fords are lower power than the electronic ones but are bullit proof. If you get a Cummins, get a manual trans one.

[455Grandville]

Originally Posted by 74gtoguy

a 95-98 12 valve cummins is the way 2 go. better mileage than a ford, less problems.
i have one for 15 years and 280k miles. trans was replaced at 270k
avoid the powerstroke to many problems!!

You're very wrong if you mean the 7.3 P -Stroke.

Cummins had some bad blocks that would crack and

they had that dreaded dowel pin that would drop and cause problems.

Seen plenty of 7.3 P- Strokes (and Cummins) surpass 500K. 280K is nothin'.

[password taken]

Go down to a local diesel shop and ask them, they will tell ya!!! Ive worked on tons of these trucks and will only suggest you buy a cummins.

[74gtoguy]

never any bad cummins 5.9 blocks, the dowel pin is a minor problem easy and cheap to fix before it happens
cummins have easily done a million miles with only valve adjustments and pms

[The Boss]

Just speaking from my own experience, my 97 F-350 7.3 spun the guts of it's automatic transmission at 74,000 miles and then promptly ate it's 3rd cam position sensor. My 2000 F-350 7.3 is still pushing hard on it's original automatic transmission with 214,000 miles and has only munched one cam position sensor - about 1000 miles ago.

I can tell you I ask a lot from my trucks and they have NEVER let me down. I have pulled many a lumber truck out of the mud (including a cummins powered boom truck) and have given several cement & tri-axle dump trucks the extra umph they needed to get out of each of their predicaments.

Although I'm no longer looking to test my current transmission I'm sure if needed it would be up to the task.

[455Grandville]

Originally Posted by The Boss

Just speaking from my own experience, my 97 F-350 7.3 spun the guts of it's automatic transmission at 74,000 miles and then promptly ate it's 3rd cam position sensor. My 2000 F-350 7.3 is still pushing hard on it's original automatic transmission with 214,000 miles and has only munched one cam position sensor - about 1000 miles ago.

I can tell you I ask a lot from my trucks and they have NEVER let me down. I have pulled many a lumber truck out of the mud (including a cummins powered boom truck) and have given several cement & tri-axle dump trucks the extra umph they needed to get out of each of their predicaments.

Although I'm no longer looking to test my current transmission I'm sure if needed it would be up to the task.

Seems damn near every auto behind any diesel pickup is junk, 'cept the D-Maxx

Originally Posted by 74gtoguy

never any bad cummins 5.9 blocks, the dowel pin is a minor problem easy and cheap to fix before it happens
cummins have easily done a million miles with only valve adjustments and pms

Certain years had cracking issues (the blocks cast in Brazil I believe)

http://www.locknstitch.com/1999_to_2...lock_crack.htm

We put one in a nice Dodge that cracked out of the blue for no reason, owner didn't abuse it.

I worked on a 6.9 IDI that had a pushrod go through the rocker arm just a few hundred

miles short of a 1,000,000 miles.

[Ben M.]

The 6.2-6.5 Detroit Diesels (1982-1997 GM) are perfectly fine engines for driving around and towing, but don't expect to do any redneck modifications to belch black smoke or win races. The TH400 behind them is bulletproof unless someone was stupid about maintenance, the TH700-4R\4L60E is something I am not comfortable running due to how many I hear about needing to be rebuilt, and the 4L80E that came in some after 1991 is the one to have.

If you can afford it, the 7.3 is also a very nice engine. I've never been a Dodge fan, so I don't know too much about the Cummins.

[mechanic17]

Is there any auto trans (stock) that came behind either the Powerstroke OR the Cummins that can be trusted? Remember, we're talking '90s vintage.

BTW, I am working my way through the other diesel threads and have read the "tow vehicle" one twice already.

[Sirrotica]

Originally Posted by Ben M.

The 6.2-6.5 Detroit Diesels (1982-1997 GM) are perfectly fine engines for driving around and towing, but don't expect to do any redneck modifications to belch black smoke or win races. The TH400 behind them is bulletproof unless someone was stupid about maintenance, the TH700-4R\4L60E is something I am not comfortable running due to how many I hear about needing to be rebuilt, and the 4L80E that came in some after 1991 is the one to have.

If you can afford it, the 7.3 is also a very nice engine. I've never been a Dodge fan, so I don't know too much about the Cummins.

I agree, the 6.5 turbo in my 93 K3500 has close to 230,000 miles and the 4L80E is just a T400 with an OD electrically shifted. The engine and the transmission both work fine in my truck.

One other thing about the 6.5 is parts are usually much cheaper and many sources of used parts are available.

That being said I also have a IH with the N/A 7.3 in it that is about the same mileage as the 6.5. Both of mine are mechanically injected so the parts in the injection systems are relatively cheap and easy to work on. They all have advantages and disadvantages, most important thing is how the former owners maintained them, they'll all run good with proper maintenance.

[mechanic17]

Hmm, I'll look more into the GMC option--I'm taking my time, trying to get educated.

I see that the Freightliner medium duties give you a Cummins AND an Allison tranny--though I don't see many in my price range without 300k on 'em. Anybody have any experience with something like those?

[salem1912]

Would you consider the Dodge Sprinter?

[Ben M.]

Originally Posted by Sirrotica

They all have advantages and disadvantages, most important thing is how the former owners maintained them, they'll all run good with proper maintenance.

This is ultimately the biggest point. Unless it's a Ford 6.0 or an Olds 5.7, there really is very little in the way of terrible problems if they've been maintained and taken care of. And if they haven't you can take care of that and improve it to get them back into service.

[455Grandville]

Originally Posted by Ben M.

The 6.2-6.5 Detroit Diesels (1982-1997 GM) are perfectly fine engines for driving around and towing, but don't expect to do any redneck modifications to belch black smoke or win races. The TH400 behind them is bulletproof unless someone was stupid about maintenance, the TH700-4R\4L60E is something I am not comfortable running due to how many I hear about needing to be rebuilt, and the 4L80E that came in some after 1991 is the one to have.

If you can afford it, the 7.3 is also a very nice engine. I've never been a Dodge fan, so I don't know too much about the Cummins.

6.9 & 7.3 IDI's are common and you can buy em for about the same price as a 6.2 GM from those years (usually pretty cheap)

However, a 6.2 will beat a 6.9 IDI on fuel economy easily.

[Ben M.]

Originally Posted by 455Grandville

6.9 & 7.3 IDI's are common and you can buy em for about the same price as a 6.2 GM from those years (usually pretty cheap)

Depends on where you live. Where I live, the 6.2 is rare but goes for peanuts. The 7.3 is more common, but the also costs a few grand more just because it's the 7.3. The 6.9 is a bit cheaper, but most of those trucks of that era have had the snot beat out of them.

[Sirrotica]

Hmm, I'll look more into the GMC option--I'm taking my time, trying to get educated.

Look here for GM diesel information, I got a ton of information on my 6.5 turbo on these forums: http://www.dieselplace.com/forum/?

BTW, I paid $1800 for my Ext cab K3500 dually 4X4 so the chevy /GMC can be bought pretty reasonably. Needed some TLC but it does everything I need in a truck, haul, plow, and it surely ain't pretty but I don't need a pretty truck.

[V-Ped]

I have a 6.5 TD/4L80E truck that has 180k on the clock. It has been very reliable for me...once I learned about the PMD problem. the Pump Mounted Driver is a pair of high current transistors that control the electronic fuel injection pump. When it starts to go, the truck will stall repeatedly or not run at all. The trouble codes indicate thet the injector pump need to be replaced which is very high dollar and that solves the problem because the PMD is replaced at the same time. However, with the help of forums on these trucks, you learn to only replace the PMD and relocate it to a cooler place. Relatively cheap and easy to do. My favorite forum for these is http://www.sixfiveturbodiesel.com/ .

I frequently haul an overhead camper and tow a boat or cars some distance without issues. The truck just loves to pull stuff at about 65 mph. Go faster and mileage drops off. I do alot of trailing with friends, sometimes involving 80 to 100 vehicles. Some of these guys nicknamed my truck "The Savior" because it doesn't fail and freqently is required to help them along.

This is the same engine/tranny in huge numbers of H1's serving in Iraq/Afganistan, hauling around the heft of up-armor. That indicates a relatively good track record and provides huge stockpiles of spare parts. The 6.2's were in military blazers and trucks before the H1's.

I think any of the options you are considering will require familiarizing yourself with the shortcomings of the drivetrain and being prepared to deal with them up front.

BTY a friend picked up a wrecked Penske truck at auction. He paid a little over 3K for a truck with a Cat engine (25k miles) and Allison auto tranny. He wound up removing the box and installing a 5th wheel for towing his toyhauler. He has less than $10K in it including all repairs, paint, etc.

[mzbk2l]

Originally Posted by V-Ped

This is the same engine/tranny in huge numbers of H1's serving in Iraq/Afganistan, hauling around the heft of up-armor. That indicates a relatively good track record and provides huge stockpiles of spare parts.

One trick I learned my first summer over here is that Humvee's love to not start (or die while running) when it gets hot out. Didn't take long to figure out that dumping a bottle of cold water over the injector pump will get it to fire right back up. Can't tell you how many soldiers I amazed with that trick.