CUCV M1008 Build

[adf5565]

I've owned my M1008 for a little over a month now so i figured it was about time I started documenting the project. I found the truck for sale from a few states away, overall in pretty good condition and rust free which was the main thing i was looking for. From stickers on the truck it was previously owned by the West Virginia Forest Service and then a Fire Department prior to the last owner who only had it for a year. Getting it shipped to me was a royal pain but it worked out eventually so now i can get into the enjoyable part of rebuilding it.

A few things I've done so far:
- Cleaned up unused/aftermarket added wiring and removed the FD light bar. Nothing I've found so far was a hack job thankfully.
- Had a bad glow plug relay so i replaced that and glow plugs, starts very easy now.
- Flush and replace antifreeze, radiator/heater hoses, and thermostat.
- The truck already had the factory fuel filter bypassed with filter I wasn't impressed with so changed that to a Parker system with WIF and heater system that I integrated with the factory setup.
- Installed new Energy Suspension body mounts
- Straightened out some of dented/misaligned body panels and started some of the body work

Items are deck include:
- I ordered new kingpins, steering tie rods, steering box, damper, front-rearward shackle/bushings, front wheel bearings and axle shaft U-joints. I only drove the truck a mile so far but noticed a clunk in the front end. The greaseable components seem extremely dry so I'm proactively changing all of these components.
- Redo the braking system including master cylinder, brake booster, power steering pump, hoses, brakes themselves, etc. Being able to stop is pretty important and there are some minor leaks on these parts anyways.
- Bowtie Overdrives level two 700R4 tranmission, I'm in the process of gathering parts for this now. I need to be able to comfortable drive at least 65 on the highway.
- Rear driveshaft u-joints
- The engine leaks a little bit of oil so I will be replacing the oil pan gasket and rear main seal while the tranny is out as well.
- Install some oil pressure and water temp gauges.
- Also in the interior add a modern radio/speakers, hopefully find some nice bucket seats with a counsel that won't break the bank, sound mating, etc.
- Finish body work and paint truck back to a dark flat green.

I'm sure there will be plenty more to do but this is enough to get me started!

 

[cucvrus]

I drove an M1028A1 for 174K miles on it in stock form and sold it to a member on this site. I was coast to coast 2 times and up and down the east coast for 18 years. Towed and used it. It had 2500 miles on it when I bought it from SECO in 1995. &0 -75 MPH was the sweet speed range, and I never had any issues other than a rear main seal early on. And the new owner also agrees that is the best speed at highway. That old OEM rope seal was leaking the day it left the factory. So, my advice is the TH400 fits the bill. I can't figure it out. Back in the 1995 / 2000 era I was selling every TH400 transmission to everyone that came to me, and I was taking the 700R transmissions as cores and scrapping them. My M1028A1 was a bit rough when I sold it, but I never lost a dime on it after 18 years. I called it Dude because I found rolling papers and a pair of hemostats in the glove box when I bought it. But last I knew it was in Connecticut running strong. Good Luck. Do as you wish. IMHO the TH400 is bulletproof.

 

[adf5565]

I drove an M1028A1 for 174K miles on it in stock form and sold it to a member on this site. I was coast to coast 2 times and up and down the east coast for 18 years. Towed and used it. It had 2500 miles on it when I bought it from SECO in 1995. &0 -75 MPH was the sweet speed range, and I never had any issues other than a rear main seal early on. And the new owner also agrees that is the best speed at highway. That old OEM rope seal was leaking the day it left the factory. So, my advice is the TH400 fits the bill. I can't figure it out. Back in the 1995 / 2000 era I was selling every TH400 transmission to everyone that came to me, and I was taking the 700R transmissions as cores and scrapping them. My M1028A1 was a bit rough when I sold it, but I never lost a dime on it after 18 years. I called it Dude because I found rolling papers and a pair of hemostats in the glove box when I bought it. But last I knew it was in Connecticut running strong. Good Luck. Do as you wish. IMHO the TH400 is bulletproof. View attachment 855875View attachment 855876

What would the RPM be going that fast with the TH400? I thought from what I read on here from other members and from a standard gear ratio calculator the motor would be close to redline at that speed. I’m not saying the TH400 isn’t a good transmission and I wouldn’t consider a 700R4 in stock form, I was just figuring I needed something with overdrive.

 

[cucvrus]

I have no idea of what the RPM is. I never thought about it. It was revving and I heard katydids at top speed. But after several thousand miles I never took notice anymore. And I heard others drive them that fast also. My Sons both had them for years and beat them like stolen horses and they held up relatively well. I am just saying save the coin the end result is not worth the effort or the savings. It is a CUCV and will NEVER be nothing more. And it held up this well and is over 30 years old. Why change it now. Once the change is made it just continues to be a money pit. I loved and still do love CUCV's but after over 25 years of private ownership the novelty and charm has worn off and I no longer want one as a daily driver. They are cool reliable vehicles in stock form. after that I don't see it. Great off road and HD snowplow rigs. Never really designed for comfort or everyday use. They are utilitarian military Heavy Duty commercial trucks. They are supposed to make noise and be uncomfortable. That is what makes them a CUCV. Good Luck. Enjoy the CUCV. Do as you wish. Never mind me. I am wired different.

 

[WWRD99]

What would the RPM be going that fast with the TH400? I thought from what I read on here from other members and from a standard gear ratio calculator the motor would be close to redline at that speed. I’m not saying the TH400 isn’t a good transmission and I wouldn’t consider a 700R4 in stock form, I was just figuring I needed something with overdrive.

You certainly can go with a built 700...the parts they have now actually make them work and not self grenade every other week...there's a reason these didn't come with them and being they really were an absolute design and parts nightmare is just a small one...the 2 parts I think I have heard that is tough to get is the kick down cable and mount as the truck doesn't really have an easy way to hook that up, which that trans does need, but I do think there are threads on here or web that solve that. If you want the 0.73 overdrive it may help some on rpm but the cost might not be worth it...I think that is what cucvrus is getting at giving the example of driving one all over the country with 174k miles with no real issues at 75 mph...you can probably get more with less money out of bigger tires...I got new rims and tires for just at 800$...looks like you have the stock gm rims which are 6.5 inches wide...that could be a limiting factor in tire selection since tire width usually comes with height...you can use ford rims that are 7 inch and that puts you closer to being able to use a taller tire without to much doughnut...I have seen these trucks with larger tires with the stock rims though but I would have them checked to make sure they are not bent as all mine were hence the search for ford rims and got a set after I found all of mine were bent and mounted the tires anyhow...yes...I did it 2x which was not fun...I would check the tire date codes either way as they may be a decade or so old which isn't the best thing to have on a heavy truck...one of mine didn't have a date code which made it older than 2000...I had a brand new tire on it that was 12 years old too...for me replacing the tires had to happen so bigger it was...food for thought on that if needed. As far as the 400 trans in it now they really are the base point all 3 speed autos are compared to...in the small truck ally, it really is the best....I think there is some type of overdrive out there that goes in between the trans and transfer case or after it that does work without the cable on the throttle or changing much but driveshaft length...again cost might not be worth it there as well...but at least you can keep the 400 and get the overdrive you're thinking of.

 

[adf5565]

I was able to get a few things done recently between clearing out snow and the last few days of flintlock season. Changed out the door pins and lock striker, they were pretty bad and one of the pins wore all the way through the bushing. Removed and cleaned up the old FD stickers on the doors and front fenders, getting rid of that old glue was a project in itself. I also pulled out the power steering pump to get sent out for rebuild, the hoses were pretty stiff and leaking so I’m glad I’m changing those out too. And finally got the parts I’ve been waiting for so I’ll be able to start on the front axle next!

 

[adf5565]

Next up is the axle rebuild. Starting on the driver side I pulled the hub off, removed the spindle, axle shaft, and got the upper kingpin cap off before running out of time tonight. I noticed some chop on the outer axle shaft from the spindle bearing. I have new spindle bearings but do you guys think the shaft going to be a problem?

 

[ehuppert]

At a minimum I would clean up the stub with crocus cloth till smooth. If it was mine I would replace the stub .

In my younger, poorer and six kids days I would have just cleaned it up with the crocus..... In my old age I try to do things right so I don't have to do it again (ever!)

 

[adf5565]

At a minimum I would clean up the stub with crocus cloth till smooth. If it was mine I would replace the stub .

In my younger, poorer and six kids days I would have just cleaned it up with the crocus..... In my old age I try to do things right so I don't have to do it again (ever!)

Yeah i ended up ordering a new stub shaft for it. Like you said, might as well suck it up and replace it now instead of running into problems down the road (literally). As the saying goes buy once-cry once!

 

[WWRD99]

Next up is the axle rebuild. Starting on the driver side I pulled the hub off, removed the spindle, axle shaft, and got the upper kingpin cap off before running out of time tonight. I noticed some chop on the outer axle shaft from the spindle bearing. I have new spindle bearings but do you guys think the shaft going to be a problem?

If you can clean it up and can't feel it in the bearing rolling it over it that should be ok...hard to tell how hammered it is...can you feel it with the fingernail?...if you end up replacing it I saw a few online for around 120$ so it isn't that expensive...probably check the other side as well to see if it is needed there to save on shipping and time...are the ujoints being replaced as well? Have you thought of pulling the gearset and replacing the inner seals? This is one of those since I have it apart thoughts.

 

[adf5565]

If you can clean it up and can't feel it in the bearing rolling it over it that should be ok...hard to tell how hammered it is...can you feel it with the fingernail?...if you end up replacing it I saw a few online for around 120$ so it isn't that expensive...probably check the other side as well to see if it is needed there to save on shipping and time...are the ujoints being replaced as well? Have you thought of pulling the gearset and replacing the inner seals? This is one of those since I have it apart thoughts.

I haven't tried cleaning it up but i can feel the roughness on the shaft so I'll just replace it. And yep i am replacing the u-joints as well.

With regards to the inner seals, not to open a can of worms but would I have to adjust any shims/backlash from just removing it to access the seals? I also don't currently own a case spreader which I think I would need, correct? I agree it would be best to change them if I am able to.

 

[WWRD99]

I haven't tried cleaning it up but i can feel the roughness on the shaft so I'll just replace it. And yep i am replacing the u-joints as well.

With regards to the inner seals, not to open a can of worms but would I have to adjust any shims/backlash from just removing it to access the seals? I also don't currently own a case spreader which I think I would need, correct? I agree it would be best to change them if I am able to.

The case spreader will make it easier to get out but most use those to set up new gear sets to make sure there is enough preload on the bearings when new...it will be tight but will come out without it...as far as setting it back up after you remove it no not really since it is going back in the way you took it apart...if you replace bearings or gears then yes you'd have to set up the diff again...I always check backlash before I take it apart either way just to make sure it's the same once back together...there is a cheap tool you can buy or make to get the new seals in that you will need though...simple search will find that. What you are doing I have planned for a warmer month this spring!

 

[adf5565]

The case spreader will make it easier to get out but most use those to set up new gear sets to make sure there is enough preload on the bearings when new...it will be tight but will come out without it...as far as setting it back up after you remove it no not really since it is going back in the way you took it apart...if you replace bearings or gears then yes you'd have to set up the diff again...I always check backlash before I take it apart either way just to make sure it's the same once back together...there is a cheap tool you can buy or make to get the new seals in that you will need though...simple search will find that. What you are doing I have planned for a warmer month this spring!

Makes sense, thanks for the info! I will keep posting updates as I make progress. Yeah working in the cold isn't the best but I wanted to get a head start on everything.

 

[adf5565]

I was able to get the kingpin assemblies pulled apart, cleaned up, replaced, and put back together on the steering knuckles. There was definitely some wear on the old pins so I’m glad they’re getting changed out. Overall wasn’t bad to do, just make sure you have a nice big extension for the 7/8 Allen wrench and they pop free pretty easily.

The new stub axle shafts and inner seals came in yesterday so I’ll get those installed soon so I can get the axle put back together.

 

[adf5565]

Anyone else have issues with new kingpin bushings? On one of them the bushing is moving slightly within the steering knuckle instead of just on the kingpin. From comparing the new vs old bushing, the “ridge” which fits into a groove in the knuckle is much smaller on the new bushing, causing it to have some play. Not sure it’s a huge issue but I ended up having to put some epoxy on the new bushing to build the ridge up a little to take up the extra space. I ordered another bushing and looked online at others and they all seem to be this way now.

 

[DIVE DIVE]

Anyone else have issues with new kingpin bushings? On one of them the bushing is moving slightly within the steering knuckle instead of just on the kingpin. From comparing the new vs old bushing, the “ridge” which fits into a groove in the knuckle is much smaller on the new bushing, causing it to have some play. Not sure it’s a huge issue but I ended up having to put some epoxy on the new bushing to build the ridge up a little to take up the extra space. I ordered another bushing and looked online at others and they all seem to be this way now.View attachment 857987

Hmmm. I’ve never seen a bushing like the one pictured on the top. I looked around the shop and all 6 bushings I found look like the one on the bottom. I have two Dana 60s and both steering knuckles on both axles look like the one pictured below so it’s almost like the top bushing wouldn’t even work correctly because the channel in the knuckle only goes half way down. Either way, once the weight is on her and that Teflon is lubricated it’s not going to move in there so I wouldn’t put too much more effort into it. Good luck

 

[adf5565]

Hmmm. I’ve never seen a bushing like the one pictured on the top. I looked around the shop and all 6 bushings I found look like the one on the bottom. I have two Dana 60s and both steering knuckles on both axles look like the one pictured below so it’s almost like the top bushing wouldn’t even work correctly because the channel in the knuckle only goes half way down. Either way, once the weight is on her and that Teflon is lubricated it’s not going to move in there so I wouldn’t put too much more effort into it. Good luck

That would make sense then why the new bushings have only half a ridge. I didn’t take a picture of my knuckle but from what I recall it had the slot through the entire way. Prior to me building up the ridge a little it did move when fully installed with the spring compressed (however without the tire or vehicle weight) but now it works the way it supposed to.

 

[adf5565]

Just about finished up the front axle. Pulled the front diff out and put new seals since everything else was apart and cleaned out a little crap in there. Got new u joints and stub shafts and got those reassembled and installed into the spindles with new bearings.
Only one minor screw up is I installed the u-joints with the grease fitting angled towards the wheel which turns out is the direction with less clearance so now in order to grease I have to turn the wheels to the side. Not a big deal and not worth pulling it back apart.
Also added new wheel bearings and races, new brake pads and brake hoses and reinstalled everything back onto the axle.
Only thing left on the axle is to clean it up and coat with some POR15 when it gets a little warmer.

 

[adf5565]

Also made progress on the power steering/brake booster system. Got my power steering pump back from rebuild so I got that installed. Also pulled out the master cylinder and brake booster. I have new units so I’ll get those installed here soon.
One thing I noticed when trying to figure out what brake fluid is in there is that someone must’ve added a small amount of the wrong fluid at some point. Looks like it’s separated/cloudy in the master cylinder. I haven’t noticed anything cloudy coming out of the master cylinder when the lines were disconnected or at the calipers so I think it was just a small amount of incorrect fluid that was added. I plan on replacing with DOT5 once all the new brake components are installed.

 

[WWRD99]

Just about finished up the front axle. Pulled the front diff out and put new seals since everything else was apart and cleaned out a little crap in there. Got new u joints and stub shafts and got those reassembled and installed into the spindles with new bearings.
Only one minor screw up is I installed the u-joints with the grease fitting angled towards the wheel which turns out is the direction with less clearance so now in order to grease I have to turn the wheels to the side. Not a big deal and not worth pulling it back apart.
Also added new wheel bearings and races, new brake pads and brake hoses and reinstalled everything back onto the axle.
Only thing left on the axle is to clean it up and coat with some POR15 when it gets a little warmer.

That's a great rebuild of the front axle...that center come out easy enough I hope. Should be good for a long time now.