M880 truck

[msgjd]

Another thing that kills mileage on these is the full-time 4WD. Mile marker used to make a kit to deactivate that into manual mode. No way to put locking hubs on it without a lot of parts changeout. That kit did markedly inprove the MPG.

The front wheel bearing (yes, just one) can fail and put you out of service fast. There is no maint on it other than changing the unit bearing out.

I drove one for many miles as a work-provided ride.

You are usually 110% correct with info on so many things, thus it is difficult for me to say you are mistaken about the front bearings .. I realize you were driving one for work and not owning/maintaining one yourself, thus what I am saying next is not at all directed at you, so here goes .. The front bearings are part of the scheduled maintenance requirement right in the manual,, aka, GREASE ... Each of those bearing packs has a zerk fitting... The "problem" with those bearings is not the bearings themselves, but their owners who are too ignorant or too lazy to remove the front tires at the required mileage/time intervals to grease the bearings .. There is a hole in the rotor hub plain as day to access the grease fitting.. I have owned 1970s AWD dodge/plymouths since 1983 and only replaced one front AWD hub bearing because PO failed to grease it . All who have changed out the 1970s AWD front hub bearing packs can agree they are a pain to replace and expensive to buy.. .. Worse yet, if the bearing gets to a point it spins the race(s), it hollows out the bearing hub and that means the new bearing will not be a press fit as it's supposed to be, thus the damaged side will have abnormal tire wear in the form of toe-in/toe out/camber inconsistencies..

As for the full-time-four, it is agreed it affected fuel economy a bit , however, one does not need to buy any "kit" to convert it to 2wd , there are two other options and neither cost a penny.. . Simply removing either of the driveshafts helps mileage.. They can be run as a front-wheel-drive or as a rear wheel peel, it doesn't matter.. The xfer case has to be shifted to "Loc" for it to work with either shaft removed.. They handle and corner wonderfully as a front-wheel-drive, I must say.. Ran one particular truck "shaft-less" for more than a decade, exclusively on-road 100 miles every day .. But as one can imagine, doing it as "front wheel drive only" puts a higher amount of stress on the front driveshaft joints as well as the axle u-joints.. I only did it as an experiment for a few days, and went back to running it rear-wheel-peel for many years

 

[gringeltaube]

The "problem" with those bearings is not the bearings themselves, but their owners who are too ignorant or too lazy to remove the front tires at the required mileage/time intervals to grease the bearings ..

Exactly, you hit the nail on the head...!

 

[G744]

The wrench that took care of that M880 knew about the bearing grease zerk. Since the truck was ex-mil with lots of miles, the left front bearing started growling so he went to have it replaced. It required a press to do it, so it was sent out for that job.

Apparently, the press operator got it a little cocked and it developed a hairline crack that caused it to fail on an off-road mountain trail. All that kept it from sending me over the side was the brake caliper. Needless to say, the recovery and correct fix was free.

Pulling driveshafts wasn't an option for me, as multiple mountain radio sites required 4WD to get to some of them. All in all, the old 880 did it's job till the engine failed it's smog tests and away it went.

 

[msgjd]

Apparently, the press operator got it a little cocked and it developed a hairline crack that caused it to fail on an off-road mountain trail. All that kept it from sending me over the side was the brake caliper. Needless to say, the recovery and correct fix was free.

scary stuff ! .. those bulky bearing packs can be a difficult press fit, even with the hub heated a bit

 

[NDT]

Another thing that kills mileage on these is the full-time 4WD. Mile marker used to make a kit to deactivate that into manual mode. No way to put locking hubs on it without a lot of parts changeout. That kit did markedly inprove the MPG.

The front wheel bearing (yes, just one) can fail and put you out of service fast. There is no maint on it other than changing the unit bearing out.

I drove one for many miles as a work-provided ride.

When I got my 884 from (then) Ft Hood, all the auction trucks from cann point were missing the transfer case. I installed a 2WD transmission and driveshaft and drove it like that for years, getting around 15 mpg. When I finally got a transfer case and installed it, I was not pleased that fuel economy basically dropped in half.

 

[GopherHill]

Some data points: Once you work the bugs out of them, 880s are awesome capable trucks. Mine has carried 2 yards of crushed concrete, pulled around a D3 dozer on a 3 axle trailer, transported nearly anything imaginable all over the state of Texas for me a 70 mph. Plan on 8-10 mpg. What kills them is rust, like all 70's Mopars, the steel has no pretreatment or galvanizing. They rust from the inside out. I had my cab sandblasted and zinc primed, still rusted out from the inside. Unless you live in Arizona, plan on keeping yours in a shed.

Our Volunteer Fire Department had one for 2 or so years. It was rust proofed in the ZBart style with the plastic plugs in the usual places. It came from one of the defense reutilization yards. No rust on the truck.