LMM is mechanically same as LBZ, which is widely regarded as one of the best/most reliable built so far. Likely problems you would face would probably be electrical stuff or the emissions crap (DPF).

 

Biggest issues running stock are with the DPF/regen, and fuel related issues with loosing prime or throwing a P0087 low rail code. Maybe a few with blown inter cooler boots due to the PCV and the occasional glow plug problem.
Once you start bumping power the LBZ/LMM trucks seem to like to crack pistons.
All in all, they are built to go 300,000+ miles if you take care of them.

 

Bumping power at all above stock or how much?

 

^ What he said but go 600,000 miles.

 

Approaching 140K miles on my '07 NBS LMM. Had one glow plug go bad around 120K. Replaced the 'always cry wolf' WIF sensor with a billet plug a while back. That's been it. Can't complain.

 

115,000 miles only problems with mine has been one tran's line leak, and one power steering line leak. On my 3rd set of batteries, and have replaced the belt and belt tensioner. Still have the original brakes with a ton of pad life left. Best Chevy I've own to date.

 

Only problems iv had, were EGR, & DPF troubles. I took care of those problems, by eliminating the problems. Ctrl-alt-delete + tuning. :thumb:

 

Awesome ! Thanks guys seems like most are having good luck unless they start putting a bunch of power to them . But you know the say fast or reliable lol

 

I had to replace one glow plug. Now it looks like an alternator (another post). I've had the truck since new, and maintain it myself. It's all stock. It pulls my 5th wheel fine. Other than that glow plug and (presumably) the alternator, it has been very reliable.

 

All stock and very reliable. Keep the fuel filter changed regularly with the stock ac delco or equivilent Parker racor. Keep the oil changed and on top of other fluids. I've moved to transynd in the Allison and happy with that for the mountain towing I do. Mine is a keeper for sure.

 

We have one running now pulling trailers with about 775,000 on it.

 

That's awesome . Seems like keeping it close to stock is the way to keep it !

 

My brother's 09 has low miles but worked hard, 66,000 km's, its had an alternator, filters changes, rear u-joint, front pads and rear pads/rotors. Had to replace a rear wheel stud as tightening it, it went snap????????? I could spin the nut off the stud, lol.

 

key cam and crank! I bought stock truck with crank already busted with 190k I believe due to vibration dampner breaking dowel and getting out of balance. probably not all that common but not unheard of either.

 

lmao you guys who don't even own LMM

2007.5 - i tranny line, rear joint and i gloplug - 96k

 

yeah I just don't know how to update my ancient sig

 

User CP at the top of the page.

 

I have replace 2 glow plugs, the crank sensor, and one trans line. 85,000 miles on my 2007.5.

 

140k towing big in hot weather through some serious inclines.

Had to do: all fuel line rubbers, transmission lines, busted CP3, 4 injectors, reprogram the OEM trailer brake, marker lights

Wanted to do: AD 165, EFI Live with Idaho Rob tunes, BD remote tranny cooler with fan, Nictane filter adapter with CAT filter, PS cooler, Transgo Jr kit, Cognito upper control arms with keys, 85 gal RDS aux tank

 

reprogram the OEM trailer brake, marker lights

Can I ask why you had to do this?
I'm having trouble with my trailer brakes...


96k on my '09 and I've had 2 glow plugs go and my steering wheel sensor has gone out.
Great truck so far.

MOD

 

Tranny lines at 15K, Pitman and Idler Arm at 35K, Rear output seal at 55K, Rear axle seal 110K. Truck has 122K on it know.