diesel/one-ton truck owners--advice needed
 

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.

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.

diesel
 

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!!

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.

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'.

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.

cummins
 

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

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) :D 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

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.

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.

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.

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.

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?

Would you consider the Dodge Sprinter?

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.

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.

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.

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.

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.

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. :)

You would think they would have figured that out early on & made the modification necessary to eliminate the problem.....:rolleyes:

Good scoop with the forum links, guys. I am reading them in between checking in here. Having talked myself into it, I'm like a kid in a candy store--unfortunately I only have enough coin to buy the one treat.

Some of the Ford guys swear the 6.9 gets better fuel economy. Problem with the 6.2s is if the glow plugs get swelled; you canot get them out and have to yank the heads. Keep that in mind if you're looking. Also it seems around 200K alot of the IDI Fords injection pumps like to retire. Not a hard job to do if you get the truck cheap enough. Also, I've picked up several IDIs for cheap where the glow plug relay went bad; seems commons and it's another easy fix.
Can't give you much sympathy on the area; rust there is nothing. Not bad here like up north, but still bad.

For all things Ford http://www.ford-trucks.com/forums/index.php

Dont allways have to pull the heads. Pull the injector & use a pair of angle needle nose pliers to pull the glow plug tip out through the injector hole. Have done this many many times with success. Dont have to worry about dropping the plug tip as it will stay in the combustion cup in the head. Magnet helps a lot also.

Have expanded my search to Step Vans-- alot more Chevys and GMCs there, but mostly gas engines. Would really like to score a Cummins 6 or Duramax 6.6/Allison in a reasonably sized (under 24 ft.) stand-up vehicle. Utility cabinets a big plus, and inverter/wiring and/or gennie desirable. Like an old Snap-On truck. Anyone knows of anything, I'm trying to stay under $8k.

There's quite a few for sale here on the local craigslist that meet most of your criteria, but it IS California and most people aren't interested in coming out here for cars.

I am willing to travel, but to go to California it would have to be THE ONE.

I've got a 94 Chevy K3500 6.5L 4x4. It had the PMD remote mounted on a heatsink already but was starting to show signs of failing injection pump, so I did the mechanical pump swap to it. Runs real well now, but sure wont win any diesel drags. Trans is the manual 5 speed, 3rd gear buzzes everytime but I can still get it in easily...heard it has carbon fiber synchros.
Body is going away to rust, though...anybody got a 8' Chevy dually bed they don't need?

I'd get something you can go from cab to rear in. The one pictured might just be a pass thru only.

Mike, where do you get cold water in the desert? I remember that picture of the pallet of bottled water stacked in the Sun. :)

My 1999 6.5L ran fine until I learned there was an 11 yr 110,000 mile warranty on the IP from GM. I had mine checked due to lots of soot and they replaced it due to codes ti tripped. It didn't take long until the PMD started going. Pooring water on the thing makes it fire right up. I bought a replacement PMD and a piece of heat sink material, but never had to install it after buying it. It hasn't failed to start and run since. It used to take me to work. By afternoon it wouldn't start to take me home. I always kept a bottle of water in the cab. Tepid water was all it needed--half a bottle.

Here's what I ended up with, for those interested. 1992 International 4000 ambulance body with a all-mechanical DTA360/Allison 545. Same combo as in a lot of Bluebird schoolbuses. Bought in Miami, rust free 110,000 miles.

Only got a disappointing 10 mpg on the 1500 mile ride home, but they were trouble-free. Runs great! Never saw temps over 180 for water or tranny. Oh, has 4-wheel disc brakes too!

I'm doing the PMs on it now. So far found 6 filters to change: two oil, two fuel, one coolant, one external tranny. The air has life left yet, and I'll get to the in-pan tranny filter when I can afford the 4 gallons of fluid.

Anyone think it's worthwhile to go synthetic oil and/or tranny with this beast? (I used Delo 15w/40 already). I'm new to diesel so any advice appreciated.

I have a 7.3 444 N/A 1988 with a Spicer 5 speed in it that I'm building a wrecker from (mine's a ex U Haul truck that I shortened the chassis about 8 feet) It has 4 wheel discs and air ride and in my opinion it's about the perfect chassis for a light/medium duty wrecker self leveling and 4 WD and a pretty much bullet proof driveline and engine. Mine got 12.5 MPG on the road about 250 mile trip.

Air and fuel filters are important and if your going to just going to use the factory style oil filters 3-4000 miles oil change intervals. Synthetic is usually a better choice for any lubricant if you can justify the expense. I use Shell Rotella 15-40W, but Delo is probably comparable.

I see you have lo-pro tires, hope they're in good shape because the 19.5s are about $2-300 per tire.

Should make a great camper...............:)

The 7.3s in those chassis usually do much better then the Dt466s , I would have thought the Dt360 would have done a little better, but it's a good little engine that should go many miles.

Not that you're still under any warranty on that thing, but Allison likes synthetic fluid enough that they used to offer double the warranty on a new transmission if it came equipped with their TranSynd synthetic fluid. They must find some benefit to it.

That said, there are millions of AT545s running around with whatever low-bid fluid the agencies purchased in bulk. You'll probably be fine either way.

What are guys getting for fuel mileage on the 7.3 Fords? My buddy says he gets 18mpg on his '99 Doge 2500 4x4 Cummins. It's a long bed.

I've recently been looking at 90s model Dodges, but I haven't ruled out the 7.3 either, but fuel mileage is a plus for me to make the move since my gas truck gets 9.5 unloaded. Never checked it pulling, but it has to be worse.

16 mpg combined around town & some highway - pulling an empty trailer on the highway it's close to the same, loaded I get around 12.

2000 F-350 Crew Cab, long bed, long wheel base, single rear wheel. 217,000 miles.

I have a 2wd '94 F150 5.0 that doesn't get that. Come to think of it my gas '85 Chevy with a 4.3 Vortec swap doesn't even get that.

I did 700 miles on Tuesday with it & left here with a full tank, filled up when we were close to empty and still had a 1/4 tank when we got home. :D

I'm really hoping that the fuel mileage will improve as I learn more and do better. The tire pressure may not have been optimal on the trip as one of the inner stems is not accessible. I need to pick up a 3/4" impact gun. I was trying to keep 85 psi in the front tires (the outer rears never needed any) but could not always get to air.

Also, the truck lived its whole life in one Florida town and did not run often. Probably saw very little highway use. I have not determined the gearing yet but was running about 2300 rpm at 60 mph (which I tried to stick to, as I sometimes had a vibration at 65). As someone pointed out, it has 19.5" tires. I believe the Allison is a 4-gear without overdrive.

I'll look for a K&N air filter. Also want to do the rear end fluid with the tranny. Am I missing anything?

BTW, I did find out when I changed the fuel filters that the manual primer pump does not screw down, and even though it worked fine it did leak alot on the floor during pumping. I never saw evidence of leaking fuel on the road--none in the oil, none on the ground during idling. I guess its possible it leaks at higher rpms, though I never saw anything underneath--and I checked quite often as the vehicle was new to me. Maybe that's part of the 10 mpgs?

Picked this one up today. '99 with 222k miles. Has a few issues that my guys can work through here at the shop in between customer cars.

A buddy tols me that he was getting 18mpg with a 7.3 with a power programmer.

I see there's a couple on craigslist for sale reasonablly - an Edge and a Superchip brand. Is one better than the other. Anybody have experience with them? I usually preach not putting anything on one, but if I can use economy mode and get more MPG I may be all for it...

Bullet proof engine and yours has the earlier rods which are more desirable and much more stronger.

Ive had several including 7.3 P-stroke duallie crew cab that did 18 mpg on occasion.

I've got the Superchips one & it does make a difference, but I'm only getting 16mpg on the highway unloaded with it.

Most of the time I'm running in performance-tow mode, not the full out performance mode.

It's a great truck - your going to love it.

I already love them. I worked at a Ford ealer for 6 years so I've driven literally hundreds of them. I was there when the 6.0 came out as well as the 6.4 and I never thought either one had the off the line torque of the 7.3

To be honest I was looking at Dodges due to what I percieve as less problems, but I couldn't find a comparable dodge for anywhere near the price range within a 200 mile radius on craigslist. The only comparable Dodge I found the people jacked me around and quit answering my calls. I believe there was something wrong with it and they were looking for an un-knowledgable person to buy it because once they found out I have a shop they quit answering my calls. after a couple days of that crap I called on my cel phone, got and wierd rambling reply, and then stopped answering my cel calls. I took it as a sign top stay away from it.

Difference in mileage or power?

The research I did shows that the ones with a 1/99 or newer production date like mine have larger intake runners as well as no catalytic converter. True?

When did they go to weaker rods?

Maybe in mileage but slightly less power and it is supposed to be easier on the transmission. Knock on wood, but I've still got the original trans in mine with 217,000 miles on it. ;)

Ok, went on my first decent trip in it this weekend. Had to go to Sacramento saturday and sunday, with a little running around here and there in town.

Got 17.5 MPG with the A/C on. Mostly freeway miles at 70 MPH

What year did they change the rods?