Getting my CUCV road worthy!

[Atrange07]

OK, I actually have a couple things here. I bought it of a guy in Arizona and he converted it to 12 volt as well as added a turbo and electric fuel pump. He also did a crappy/dangerous 6" lift and it was rolling on 38.5 swampers. Since I have taken posecession of it.
I put a smaller correct 4" lift from ORD on. My first question is what rims and backspacing are most people using to mount some 35" tires on their vehicles. Secondly when I have the vehicle at max speed it maxes out at 55mph and feels like the rpms are balls to the wall. I would like to re-gear the vehicle for 35" tires and be able to make highway speed of 70mph but not completely give up my towing capability. And my final question is there a way to mount up both alternators but only get the 14 volts?

 

[Chaski]

OK, I actually have a couple things here. I bought it of a guy in Arizona and he converted it to 12 volt as well as added a turbo and electric fuel pump. He also did a crappy/dangerous 6" lift and it was rolling on 38.5 swampers. Since I have taken posecession of it.
I put a smaller correct 4" lift from ORD on. My first question is what rims and backspacing are most people using to mount some 35" tires on their vehicles. Secondly when I have the vehicle at max speed it maxes out at 55mph and feels like the rpms are balls to the wall. I would like to re-gear the vehicle for 35" tires and be able to make highway speed of 70mph but not completely give up my towing capability. And my final question is there a way to mount up both alternators but only get the 14 volts?

Personally I would not mess with the gearing. 4.56:1 is about perfect for 35" tires in my opinion. If you want lower RPM freeway travel swap in an overdrive transmission. A bunch of folks on the form have put in a 700R4, and there are at least a few that have put in a 4L80E. On the subject of alternators, not knowing what the previous owner did to swap it to 12 volt my wild guess is yes... you could put both alternators in parallel instead of series. It would take some basic electrical knowledge and some time but I think it could be pulled off.

 

[rsh4364]

16x8 wheels 4.5 backspace. Yes to the 700r4. In od you would have 3.19 final drive ratio. At 70mph rpm would be 2150 rpms with out lock up convertor, 2-3 hundred less with lock up. Without od 456 gears at 70mph around 3050 rpm's. And with 700r4 and 456 gears you will have a kick but 13.95 1st gear, 7.38 2nd gear, 4.56 3rd gear. 4th is 3.19. With a th400 and 456 gears 1st is11.30,2nd is 6.74 and 3rd is 4.56. Just for a comparison a 1009 with th400 and 3.08 gears has a 1st gear of 7.6, 2nd is 4.55 and 3rd is 3.08. So if you have a stock 1009 and want to experience what it's like to drive a 1008 leave it in second gear and spin it up to 65mph.

 

[Chaski]

Go for wheels that are 5.25-4.5" backspacing. You'll need at least 16's to clear the brake calipers. If I was ever going to get rid of my HMMWV wheels I'd go with these... But wheels are like food... Everyone has different tastes.

 

[Drock]

Here's a cool RPM calculator...https://www.ringpinion.com/calculators/Calc_RPM.aspx

 

[olly hondro]

The conversion utilizing two alternators in a 12V configuration is straightforward. See the REC newsnote #10 published by Roscommon Equipment Center, Northeast Forest Fire Supervisors. It has pictures

Your challenge will be understanding, then undoing, the previous owner's handiwork.

 

[LT67]

Wheel Vintiques 82 series 16x8 with a neutral 4in backspace with 35's. Also a 4 leaf factory type springs in the front.... I can run 55-57 on the highway. Good enough for an old truck that's not meant for highway use.

 

[MarcusOReallyus]

If you want 70 MPH you bought the wrong truck.

 

[olly hondro]

If you want 70 MPH you bought the wrong truck.

Under special circumstances you can get abit more than 70 mph;

https://www.roadandtrack.com/car-cu...s-7-skydiving-car-scene-was-100-percent-real/

 

[Drock]

My M1028 lives on the highway at 70-80MPH. Banks turbo, Gear vendors overdrive, 31" tires, 4.56 gears

 

[rodent]

How does the gear vendors overdrive work with the tcase? Is it in front or behind it?

 

[cucvrus]

All my CUCV M1008/M1010/M1031/ M1028A1/M1028 trucks did 70MPH + always did and still do. Stock everything. Do they scream. Yes. Is it annoying. Worst then it was 20 years ago. I got older and less tolerant of the katydids sound at highway interstate speed. My Son and I travel a lot. We both enjoy and weather the trips much better in the newer trucks. And that is just a fact. I remember yelling at each other on trips and having the drone sound for a few hours after the trip. Now after 5 hours on the road we load and do the 5 hours back home. Walk in the house and relax. CUCV in 5 hours. Worn out. I went coast to coast in the M1028A1 twice. My Son drove M1028 The Dude up to Connecticut and it had 174 K on it still did the interstate speeds. The current owner said it still does 70MPH no problem. GPS says it is off by maybe 4 MPH at 75. I can hardly think. Been on I 78 to NJ many times to get heavy equipment that fits in the cargo bed. Flat out the whole way. Have a great day.

 

[rodent]

All my CUCV M1008/M1010/M1031/ M1028A1/M1028 trucks did 70MPH + always did and still do. Stock everything. Do they scream. Yes. Is it annoying. Worst then it was 20 years ago. I got older and less tolerant of the katydids sound at highway interstate speed. My Son and I travel a lot. We both enjoy and weather the trips much better in the newer trucks. And that is just a fact. I remember yelling at each other on trips and having the drone sound for a few hours after the trip. Now after 5 hours on the road we load and do the 5 hours back home. Walk in the house and relax. CUCV in 5 hours. Worn out. I went coast to coast in the M1028A1 twice. My Son drove M1028 The Dude up to Connecticut and it had 174 K on it still did the interstate speeds. The current owner said it still does 70MPH no problem. GPS says it is off by maybe 4 MPH at 75. I can hardly think. Been on I 78 to NJ many times to get heavy equipment that fits in the cargo bed. Flat out the whole way. Have a great day.

Well that makes me feel better when I looked down and I was accidentally doing 65mph. I keep reading do not go past 55mph with these engines and 4.56 gears but sounds like its ok. I installed some 37" tires which helps by 8mph but still sucks being in the slow lane the entire time.

 

[Drock]

How does the gear vendors overdrive work with the tcase? Is it in front or behind it?

It goes behind the transfer case, in place of the tail shaft. The only reason I went with the Gear vendors is it was faster & easier to install then adapting a whole AOD trans. My M1028 is my only transportation so I needed it up & running ASAP. 2 days total,..(1) day to install, and (1) day to have a driveshaft made. It works, but it's very clunky, you have to change the oil every 3000 miles, and you don't get the lock up torque converter like with an AOD.

 

[rodent]

Thats a pretty nice setup. I like the alum. shaft too!

 

[rsh4364]

My 86 1009 was regeared to 4.56 by the fire department before I bought it. I drive it at 65-70mph for hours at a time. I use GPS for speedometer and I have installed a tachometer, I try to keep rpm's at 3200 or less. But when aggravated with traffic I have spun up to 85mph. And I still get 15-16 mpg.

 

[MarcusOReallyus]

It works, but it's very clunky, you have to change the oil every 3000 miles

You have to change the oil in the GVO every 3,000 miles???

 

[rsh4364]

Gear vendors units are great if you own a 2wd vehicle.

 

[Drock]

You have to change the oil in the GVO every 3,000 miles???

Yeah it has no filter, just a magnet. So the oil has to be changed every 3000 miles per Gear Vendors. 1-1/2 bottles of Lucas synthetic 75W90 gear oil.

 

[BushEngineer]

Yeah it has no filter, just a magnet. So the oil has to be changed every 3000 miles per Gear Vendors. 1-1/2 bottles of Lucas synthetic 75W90 gear oil.

That's ridiculous.

My M1010 has 285/75/16 tires and hit 81mph the other day. Calculated rpms at this speed is about 3700rpm. The drone goes away at the higher engine speeds.
I was amazed at how smooth it was. I wouldn't cruise like this but she kept nudging me in the back trying to go faster. I think 37's will make 90mph possible and 70mph comfortable.