This thing is really noisey and slow ??

[jason@snakeriver]

This is my first CUCV ( maintainence truck) and first 6.2. These things do not have an overdrive transmission and while it is cold it is really noisey. I can take it up to about 55 mph, and then when it warms up it will cruise up to about 65 mph.
You keep thinking it will shift into overdrive, but no such luck
Where there differant rear end gear ratios, or do all CUCV's drive about the same ? ? ?

 

[Stonepicker1]

All had GM TH400(no overdrive) that i've seen and 4.56 gears in the axles.
I changed the injector pump on mine(was leaking) and went from 70 mph to 82 mph with a lot more power.

 

[CARNAC]

The M1009 (blazer) has higher speed rear end and doesn;t sound like it is going to explode until you hit 65 or over but will doo 85.

 

[boomer]

I agree. When I got my first, it seemed it was "winding out" at 55. Then sometime after I got it up to 65. My second was a little faster. I found out #1 could use a new I P.
The way they sit, and look (especially the 1008's) is intimidating. Add the sound of the 6.2, along with those gears, and people will think twice about getting too close ( to you).

 

[hobie237]

All had GM TH400(no overdrive) that i've seen and 4.56 gears in the axles.
I changed the injector pump on mine(was leaking) and went from 70 mph to 82 mph with a lot more power.

Stock size tires? Lots of speedo error? Different axle ratios? I calculated the top speed to be limited to ~72mph (or was it ~75mph?) with everything stock- that's redline of the motor in top gear with the 4.56 rear and 235/85/16 tires. Either way, it was in the 70s, so if you were doing 82, something was changed or off on your truck- most likely speedo error, perhaps a governor that was allowing you to exceed the engine's redline RPM.

 

[gt1009]

I think stonepicker might have been talking about his 1009?

 

[hobie237]

Maybe, it was the 4.56 gears comment that made me assume he was talking about a 1008 (or variant thereof).

 

[Stonepicker1]

I do have a M1028(M1008 variant) with 4.56 gears, stock tires. I drive it every day(I put over 84,000 miles on it). The speedo does have a little error. Truck speedo will read 75 mph and my GPS says i'm going 72 mph. This is also confirmed by a radar unit on the turnpike(construction zone). It had to be the new pump that may it go 82 mph(i'll have to check it with my GPS for its top speed). And yes, my rear main is leaking again.

 

[hobie237]

I'd check that GPS for the top speed, it shouldn't be able to exceed 75-ish at redline with the rest of the driveline stock. Even if the truck will do it, I wouldn't, since you're spinning the motor faster than you should be.

 

[Dodgeman1941]

We had a m1008 on the FD I was on. We went from a m880 to the m1008 and everyone freeked out that it sounded like it was going to blow up at 55 compared to what the guys were used to with the m880. I found that my m1009 got much quiter running B20 or 2 gal of hyd oil per tank of fuel.

 

[kennyw]

This is my first CUCV ( maintainence truck) and first 6.2. These things do not have an overdrive transmission and while it is cold it is really noisey. I can take it up to about 55 mph, and then when it warms up it will cruise up to about 65 mph.
You keep thinking it will shift into overdrive, but no such luck
Where there differant rear end gear ratios, or do all CUCV's drive about the same ? ? ?

When it is cold, the timing is advanced and it makes a lot of racket. Larger tires or taller gearing will help it out alot on highway speeds. Even if you can get a M1008 up to 70mph your not going to be comfortable doing it and the mileage will suffer.

As was already mentioned the ratios were all 4.56 in the M1008/1028/1031. The addition of 37" HMMV tires can put you in the normal highway RPM range again though. With 2" lift and a little fender trimming they fit nicely.

 

[tsmall07]

And yes, my rear main is leaking again.

Probably because you are trying to run it at 80mph.

I keep mine at 55-60 and it stays happy. I just don't drive it when I'm in a hurry.

 

[AJMBLAZER]

Yeah, driving around at max RPM isn't good for these trucks in any way.

With the stock sized tires and drivetrain setup just keep it under 65 (preferably 60) and call it good. Remember the military considered the pickups to have a top speed of around 45 or so. Have to find my operator's manual and review that number but it was fairly low.

 

[ohfisherman]

what do you mean 2 gallons of hydraulic fluid per tank?

 

[scottc]

The 6.2 is not much of an engine . Luckly they used gears to make up for lack of horsepower. But it will last for ever with a little maintenance. If the injector pump has not been rebuilt, (probably has by now). You will eventually need to. Those pumps had a fiber gear in them that will deteriorate over time and clog the return check valve on the pump.

 

[Recovry4x4]

The 6.2 is not much of an engine .

I presume you are referring to the power dept. I've had a couple that went over 300,000 with little problems and a pump every 150,000 miles. My current pickup has a 6.5 with 190,000 on it and other than the POS DS-4 pump, good motor. My Burb has a 6.2 with 157,000 and runs fine.

 

[scottc]

I was referring to the power dept.

 

[AJMBLAZER]

Funny part is folks always bitch about their power...yet they're very similar in power to an early-mid 80's small block with a Quadrajet. That's what GM wanted them to be an alternative too, NOT the big block V8.

 

[dependable]

Wondering what anyone is using for sound insulation on floorboards and firewall, one that does not promote rust like the original floor pad. Have considered Cat cab insulation, but it is not a perfect or cheep solution. Any Ideas?

 

[hobie237]

Dynamat is the end all be all of sound insulation, but it can only do so much. If you want a quiet/smooth/compliant ride, you're barking up the wrong tree.