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StanleyRubrik 09-16-2021 05:10 AM

4600 T444E - need advice
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Hey Skoolie fam! I’m new to the world of Skoolies and I may be picking one up this week to start this adventure.

Just looked at a 3800 T444E that I need some advice on. I have a moderate amount of mechanical knowledge and do all my own work on my 4Runner and motorcycles. But I’ve never touched a Diesel engine before.

I’ve attached some photos of the bus I’m looking to buy, and I wanted to see if any experts in here can see any known issues.

The turbo looks a bit old and worn, but I’m not an expert in eyeballing them so I could be wrong. Piping all looks solid and it spins up fine.

Belts look good, I couldn’t find this anywhere, but Are the T444E’s interference engines?

I’m a bit concerned about the splines visible on the drive shaft near the U-Joint connector. You can see in my photo. Is this normal for these busses?

Also I haven’t been able to find any info about the braking systems. This one is hydraulic and the pump seems okay, distributor seems okay but the wheel wells have definitely seen better days. Any advice to share there would be appreciated.

Thanks for the thoughts everyone!

cadillackid 09-16-2021 07:09 AM

the T444E is the parent engine of the 7.3 ford powerstroke (international made the 7.3 for ford).. turno looks pretty normal to me.. as do the splines. the driveshaft moves in and out as the bus suspension flexes.. thats normal mount of splines visible.

ISAF2009 09-16-2021 10:14 AM

Splines are in a slip yoke. Thats normal. No way to tell about a turbo by looking besides the most obvious defects. That is my favorite light/medium duty engine.

magnakansas 09-16-2021 12:38 PM

I don't see any screaming red flags in any of the pictures you posted. Looks normal/average.

Yes I believe the 444e is a valve bender - an interference engine.


Power Hungry 09-16-2021 01:06 PM


Originally Posted by magnakansas (Post 453113)
I don't see any screaming red flags in any of the pictures you posted. Looks normal/average.

Yes I believe the 444e is a valve bender - an interference engine.


The nice thing about the 7.3L / 444 engine is that it is gear driven on the camshaft, so no chain stretch or anything like that. They'll go 500,000+ miles without any concern. Also, on the Ford versions of these engines, we've run them well over 4000 RPM without any valve issues.

The only real concern is exhaust valve seat pressure. Navistar versions are a bit light to begin with, and with age the valve springs get weaker. This could cause potential problems, especially when using any sort of an exhaust brake. However, if you keep things under 3000 RPM, you should be fine for quite a long time.

ISAF2009 09-16-2021 01:32 PM

Almost all diesel engines are interference.

HamSkoolie 09-16-2021 08:01 PM

I'm a military diesel mechanic and here's my advice:
Pay a qualified heavy diesel mechanic to conduct a THOROUGH inspection of the entire vehicle, not just the drive train.
I spent 4 1/2 hours performing the inspection and drive test before we purchased our bus. I knew about the age and condition of the tires, the checked rubber air line between the frame rails, the amount of blow by, the serviceability of the air conditioners as well as the heaters, defroster, etc., the condition and adjustment of the brake pads and the air system in general, and yes, a lot of time looking over the engine bay.
Our bus has the DT444E engine as well. So does our F350 Power Stroke (called the 7.3) and the engine is a heck of a work horse. The DT444E is rated for medium heavy equipment up to 75,000 GVWR so in our 40' bus at 31,800 gross it's having a nice day.
The "B10" on the engine is 200,000 miles (meaning 10% of engines will need major maintenance which includes anything that requires dropping the oil pan, pulling a head, etc. not necessarily a rebuild. The "B50" on the engine is 350,000 miles meaning 50% of engines require major maintenance before 350,000 which ALSO MEANS that HALF of all the engines go MORE than 350,000 before needing major maintenance.
That's pretty darn good considering this engine is installed in equipment up to 75,000 GROSS.
Properly maintained the DT444E is considered a "million mile engine".
Now, is the one your looking at? Pay a mechanic to check it out.

StanleyRubrik 09-17-2021 11:46 AM

Thank you everyone! Really helpful feedback about this setup!

Iím going to take the bus for test drive next week. What are some common issues I should be looking out for?

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