What would a M1028 RPM's be with 410 gears and stock tire?I

[tim292stro]

Non-lockup converter would add 200-300 rpm at speed...

And a ton of heat - there is a benefit to the lockup converter, the normal torque conveter multiplies the torque by having transmission fluid shear between two finned discs. This shearing action puts a lot of heat into the fluid. In a lockup converter when the two discs get to nearly the same speed, the lockup clutch locks the two discs together, and there is no extra heat put into the tranny fluid.

The stock gears on a M1009 should be 3.08, that model CUCV is better suited to Highway driving as configured from GM.

You asked a simple question at the start of this thread, I'm going to suggest that you follow up with info about your use case before you just pick parts, we can give you better information that way.

 

[clinto]

If you wanna' go fast, even with 4.10's, an NV4500 or 700R4 swap is in your future.

Doghead, that crawlpedia link is the one I was about to post!

 

[the skull]

If I want to go fast (60 mph or more) I'll drive one of my cars.
If I want to hold up traffic, I drive the M1008. I usually allow
10-20 extra minutes of travel time, whenever I drive it. If you
don't like it go around. I wouldn't follow one of these things,
what if something fell off???? Holy crap, you could skid on
an oil slick or diesel spill!

 

[huggy]

Ok, So tim292stro, your saying that I should of had a locking torque converter in the trans. when it was just rebuilt? That will help keep the heat down??? Is this why when I run my M1009's at highway speeds, before I installed the transmision coolers they would spit fluid out when driving over 55 mph. Well now I know! Isn't it good though that I put the trans cooler on the things?

 

[huggy]

Thanks to all you guys for your help and advice... Doghead, I am just going by the fact that my speedometer is 20 off in the truck that I say I was doing 100 in it. When I am doing 15 mph it is 35 mph, and at 65 it actually is going over 20 mph faster. I was doing 80 ta 90 on that trip home that time. I had to drive home in 1 night from West Virginia to Davenport Ia. And, it was already late when Igot the truck and realized it had problems that I needed my tools to work on it. I didn't want to get stuck in that state and be at the mercy of another mech. I was passing cars "LIKE THEY WERE STANDING STILL"... That one has Flow Master exhaust on it and it sounds like a monsterrr. I use a GPS in the thing cuz of the speedonmeter problem, and it is like 90 or so when I am doing 65 mph. Whatever, all I know is it is a great truck it is painted a Honda gun metal blue with a black top n black bumpers n wheels. It is like a show truck. I don't drive it like that, or haven't ever since. I try to take care of my machines and this is why I am going through and asking the questions as to what I am doing and need to do withthe M1028. Thanks, again to you all for the help!!!!!

 

[tim292stro]

Ok, So tim292stro, your saying that I should of had a locking torque converter in the trans. when it was just rebuilt? That will help keep the heat down??? Is this why when I run my M1009's at highway speeds, before I installed the transmision coolers they would spit fluid out when driving over 55 mph. Well now I know! Isn't it good though that I put the trans cooler on the things?

Yes, a lockup conveter will lock typically at the top end of city speeds, the most power is demanded when the truck has to go fast. The square square body trucks are like a brick with respect to aerodynamics, and the faster you go the harder it has to push through the air. The wide tires these trucks have (relative to say a Prius or a bicycle), have a high rolling resistance - that resistance doesn't go down at speed, since the rotation is happening faster you will have more total resistance overcome in a given time.

Work in drivetrain losses (also increase with rotation speed) and you will start to get the picture. Since the most power will be demanded at high speed from both the engine and the drivetrain in general, you will put a lot of heat out - a transmission cooler will get the heat out of the transmission fluid, but if it's in front of the radiator, now you're making the cooling air or the radiator hotter so the engine will appear to run hotter (and since it's generating peak power, it probably already is running hotter). Putting in a lockup converter gets you around most of these issues since you aren't adding more heat when the system is working it's hardest - putting in a transmission cooler will help with those lower speeds still before you get to lockup, and is a good idea if you tow at all.

 

[VPed]

Yeah, lockup converters do reduce heat rejection but are not available with turbo hydramatic 400 (TH400) transmissions. That is what is in those stock CUCVs. When someone suggests a 700R4 as an alternative, you get a transmission with torque converter lockup capabilities as well as an overdrive gear. But you also get a much weaker transmission than the TH400. Additionally, a lockup TC will only return 200 to 300 rpm at a given highway speed.

 

[huggy]

Well, I just kept it under 65 around 60 to 63 still the most on the ride back the other day... I got a trans. Cooler to install and I wasn't going to put it on the radiator, like the others are on the Blazers! I didn't mind going slower, it seems ta a big help driving these trucks compared to my 65 Mustang with the 347 Stroker 500 horse motor, for not getting tickets! I went to one or a few sights to see what the Rome I am turning, and I also talked to the diesel tech who tuns the Dyno about the rpms. If I do what I did on the way home he says I will be fine. So, I am just not planning on driving it on the highway for long fast trips. Thanks to you all.....

 

[MarkM]

With the setup you have I would keep it between 55 and 58mph for a long cruise. Sure it will go faster but you will be beating the crap out of the motor to do it. My Pinzgauer will do 50mph on a preferred cruise of 3500rpms so that all she gets. I know it sucks but these military trucks were never designed for high speed.

Mark

 

[the skull]

Pinzgauer =