O4 2500 Cummins 4x4. 286,000 miles. Time for another Trans. 175 out of new then 110 on the rebuild. As I get pricing and warranty info for the rebuild nobody is giving a decent warranty. Disappointed.
Truck is used for highway driving with no heavy towing. Is the 100,000 miles I got on the first rebuild reasonable? I did two servicings on the rebuild. Any suggestions to greatly improve the next?? Thanks

 

Basically, service it when the owners manual says you should, make sure you are in tow/haul if you are towing/hauling, and maybe install an aux cooler? External filter? Don't know what's available for 'upgrades' on the newer transmissions though.

 

I deal with a lot of Cummins at my shop and we have a trans guy at a speed shop who rebuilds…pretty much to have a strong tranny you got to dump about $6-7k…but they put in all billet shafts etc…

One he rebuilt for us and truck on dyno was pulling 750hp+, the guy beats the ever living hell out that truck, has a lot of miles on it (high mileage rebuild with beefy parts) , no trans issues since the build a few years ago

 

95Ram's comments about a trans guy is right on, find yourself a good rebuilder. Ask around at some local garages and 4wd specialty stores to find out who they recommend. You'll know you found your guy when you hear the same name several times. Of course you want a good rebuild, but you may also be faced with a replace decision, and you want to be talking to someone who knows trannies.
After you get your trans installed, it's important to keep the fluid cool and clean. Also, the firmer the shift the longer the life. Install a trans temp gauge if you don't have one already. On my 1500, I make sure my my trans temp stays under 200 degrees when towing. Riding around the temp is about 170. If you see your temp going over 200 then consider adding another cooler to your existing setup. I've never heard of a tranny cooler getting clogged, but it couldn't hurt to drain the cooler and blow it out with air.
I hook my scanner to my truck when towing so I can monitor temps.
100K is decent mileage on a rebuild. How do you use your truck? If you are running heavy or towing then 100K is good. Keep your fluid cool and clean on this rebuild and you will get the most life out of it.