5 ton test bed.

[acme66]

I run the truck the exact same way everyday and keep meticulous mileage and maintenance records. It would be a perfect test bed for ideas you might have. For instance I can tell you that switching to 90wt in the axles and transfer case will give you a .2mpg fuel economy boost. Making the air cleaner mod gives you another .2mpg when the original is about half of service life. I can say definitely that running 40-45psi in the rear and 60psi in the front will cost you about .2mpg over running 80-90psi all around. I can also precisely describe the effect switching to a real transmission fluid over motor oil has on day to day operations. Additionally I have my oil tested and can post those results with the spin on oil filter versus the original cartridge.

My hope next year is to change to a 5 inch exhaust and do the duel fuel line modifications and see if that helps. Also switch it over to wet hubs in the rear.

The truck is a 83 M925A1 so not everything will translate but what we do is so uniquely repetitive I can provide useful info.

Let me know some ideas.

Ken

 

[gringeltaube]

Running @ +/- 55mph with head rack + sides installed, vs. plain bed? Cargo area cover on- vs. -off?




G.

 

[acme66]

The cargo cover and sides are extra tall on mine for the passengers and can't be removed easily. That on I am not going to be able to give you.

Ken

 

[gringeltaube]

No problem, just curious.
Guessing that makes more than 0.2% difference. Maybe up to 5-10% ???

 

[rumplecat]

What difference did you see switching from 10wt. to ATF?

 

[acme66]

Crap. On all my numbers I mean .2 more mpg not %. Brain fart. I will have to fix that when I get home.

 

[JohnnyBM931A2]

Crap. On all my numbers I mean .2 more mpg not %. Brain fart. I will have to fix that when I get home.

lol How are the tours going? I always enjoy watching your videos.

 

[acme66]

Tours are up this year. It has been really wet so the road isn't holding up as well and it can be very cold up above 7000 feet when the clouds are low.

I switched this truck to trans fluid on this truck because I was tired of the drive lines ringing and banging when it shifted. I only changed mine once so it is a mix of motor oil and fluid. I will get it flushed again at the end of the season. Even with a single flush you will feel a substantial improvement. Shifts are softer, when the converter locks it isn't big lump anymore. Sometimes you only realize how rough it actually is after you do it. It will also stop doing that strange hunting for a gear thing.

It is because of the friction modifiers in the proper trans fluid. The oil lacks them so it shifts/locks up when the pressure climes high enough to force them together. With the friction fluids the clutches start to lock up and lower pressure and speed so it isn't as an abrupt event. Yes your truck will work fine with the motor oil but changing to the actual modern fluids is still one of the first things I would do to one of my trucks.

Ken

 

[JohnnyBM931A2]

^^^ What he said. I decided to swap out the oil for trans fluid after watching his video a while back, and I am glad that I did. Results were immediately noticeable

Glad to hear that the tours are going ok

 

[tbar123]

Is that a turbo or non turbo engine? I have a 84' M923 that is non turbo and have been seriously thinking about adding a turbo. The main reason is to add horsepower for any kind of incline. My truck is done at 55. I would like to go at least 60. Any thoughts?

 

[acme66]

You can search on it here and see the conversions guys have done. One of the venders was going to offer a kit on it. I hate to say it but you might just learn to live with it, they are sort of dogs and nothing sort of lots of $$$$$ is going to make a lot of difference. I know that isn't what you want to hear.

 

[OilfieldRoughneck]

Is that a turbo or non turbo engine? I have a 84' M923 that is non turbo and have been seriously thinking about adding a turbo. The main reason is to add horsepower for any kind of incline. My truck is done at 55. I would like to go at least 60. Any thoughts?

These are big slugs no matter what. Save the money for another MV

 

[Gunzy]

Is that a turbo or non turbo engine? I have a 84' M923 that is non turbo and have been seriously thinking about adding a turbo. The main reason is to add horsepower for any kind of incline. My truck is done at 55. I would like to go at least 60. Any thoughts?

If you want to do 60mph switch to super single 14.00R20s, but remember that they are speed rated to 55mph.