automatic reliability?

[redneckaggie]

Been wantin a 12 valve for a while and found one, price is decent and milage is ok (~150k). But it has an auto in it. I am no stranger to cummins as my bro has owned three 12 valves, I have wrenched on a few 24 valves, and my grandpa has owned about 5 12 valves. out of all of those three of the 12 valves and 1 of the 24 valves have been autos and we have had royal hell with them. The 12 valves would always drop od or have a bad tps which burnt the torque converter up in one of them. Are these common problems for the automatics or have we just had some strange beasts. I could swap a standard into it but that would add up to a little more cash than I would wanna spend

 

[marblecrusher]

I know they hold up alright if you just drive them around and tow a few things every now and then, but if you tow alot of weight alot, or throw alot of power behind them they dont hold up and need to be built well.
heres a cool easy fix for the TPS- http://www.dieseltruckresource.com/dev/super-cool-and-cheap-tps-fix-dial-t42003.html?t=42003

-Jordan-

 

[argve]

Dodge automatics.... RUN don't walk.... When I was looking for my first Cummins I researched and dug through tons of data... what I found was the auto they strapped behind the 12v was rated for less hp and tq than the engine produced.... can we say planned failure.... either swap it for a manual or plan on doing a rebuild on the tranny.

 

[marblecrusher]

agreed unless i was using it for putting around town or for a daily leaving it stock which what is the fun in that lol, It would have to be a pretty good price to make up for that tranny build!

-Jordan-

 

[redneckaggie]

awesome thanks guys I actually went ahead and passed on the truck and bought a horse trailer, but now my gf the 99 12v that I have been trying to buy from her grandma for at least 4 months given to her. Only one condition to her getting it and that is that I leave it stock(exhaust mods ok but no injectors, fuel pins or anything else). That absolutely SUCKS

 

[argve]

but a free truck is a free truck. plus in stock form it will last eons....

 

[redneckaggie]

Yes but the only reason I have ever wanted a cummins was to rod it around but you are right about it lasting eons, I know a guy down the road from my parents that has a 1st gen cummins with 580,000. You couldnt hardly hold it on the road because the front end was so shot and it already had two complete front end rebuilds at 200k and 400k

 

[billdoodle]

WASN'T AWARE THEY put a 12 v in a 99???

 

[linkfarms]

there is no factory 99 12v
last 12v was 98.5

 

[jbuck]

Change the fluid to a good Synthetic like Amsoil and keep the bands adjusted. This is a very simple process, two bolts with lock nuts, one for the front band and one for the rear. Rear requires you drop the pan and adjust. Losen lock nut tighten to specific torque, (sorry can't rember of top of my head) and secure lock nut. Heat kills the tranny. Free 12 valve, man be happy and enjoy.