I have owned and towed with older gas trucks that have non overdrive 3 speed auto trans in them. I have never owned a 1st gen cummins auto truck w/4 speed overdrive trans. I have been looking for quite a while to buy a 2wd first gen truck and have prefered the 5 speeds. Always preferred manuals. However, in my looking over several months across several states, I have found them to be almost non existent. So on to my question. I am looking seriously at a 92 LE 2wd auto with 3.54 gears that has approx 100 miles on it. With the exception of the manual 5speed, the truck is a perfect configuration for me. I have read up a bit on the OD operation of the auto trans for this generation and the relationship between the VSS, PCM, TPS and internal trans electric seleniod for OD shift. It is also my understanding that year is a non-lockup converter. I have read other posts from some that have had at length issues diagnosing OD shift issues (not working or not consistent). I tow a 5K pound camper during the summer and nothing heavier. Are the 4 speed autos of this year generally rock solid and reliable when maintained correctly? Is the OD operation a big weak spot on these trucks. I was a bit suprised to find there is a PCM in these trucks which controls grid heater, alt charging, trans OD shift. Are the PCM units in this year truck generally solid or prone to failure due to age of electronics? Are they even available anymore? Need to decide if I really should be holding out for a 5speed truck. Thanks for reading!

 

When I researched these trucks I found out that the A518 transmission is pretty darn burly. Mine shifts well and the non-lockup torque convertor really doesn't make a difference. Just do a pan drop and filter change when you get it. The best part about an auto is that if you ever need to replace it you can buy one with 3 year 36K warranty for under 2K, which is just about the same price as a South Bend clutch, throw out bearing, and hydraulics. I would get the automatic and enjoy.

 

Thanks for the feedback. Just curious, on the A518, does it have a drainable torque converter for complete drain and fill? Ever any issue with the OD/shift function or associated components such as the PCM, TPS, VSS etc?

 

I'm not sure of the torque convertor drain but you can always do as I do on automatics and just drain the pan, put it back on without a new seal/gasket just to hold it in place, fill trans, start engine and go through gears without moving it for about 2 minutes, then drain pan again. After 3 or 4 of these pan drops then I replace the filter and install the pan with a new gasket/seal.

My transmission shifts through all the gears as it should. If your PCM ever goes bad you can just get it rebuilt for around $250. Like I said I've had no problems with my truck (KNOCK ON LOCUST).

 

In a stock configuration the autos are fine but when you start bumping up the power the flexplate and converter don't like it. The main thing with the OD is the TPS going bad and most fix that with a POT meter from DNR Customs or build their own POT meter ($12ish homemad-$40ish DNR) These trucks are fairly easy to do a 5spd swap or a 2nd gen auto swap. At 5k for a trailer weight I'd think you'd be fine on the auto just keep up the maintenance.

 

The 518 will laugh at 5k. I would recomend a basic convertor, Goerand, Suncoast, Spec-Rite make some great ones. Also Hughes for a lower budget type. If you have OD issues and can't fix them with simple TPS adjustments I would just pop in the kit from DNR and be done.