48RE problems when warm

[MRobinette]

My trans seems to skip 1st gear when it gets hot. I have a bd x monitor and

the temp reads between 210 & 230, when the temp gets to about 220 it seems to skip 1st. I know these temps are not correct because it reads this high all the time. If i manually shift to first it acts normal, I have 24,000 miles and changed the fluid last month. Has anyone had this problem or herd of it, any insite will help. Thanks

 

[Dieselnerd]

I also have the X monitor and my temps never go above 170-175. You either have a bad X monitor or a bad thermistor in the transmission since that's where the X monitor gets it's reading from. Turn on your ignition without starting the engine when it's cold and hasn't been run. Your trans temp, pyro and your overhead temp should all read pretty close to the same which will be the outside temp. Since you say it doesn't shift normal you may have a bad thermistor.

 

[oldcrow]

I have a 2004 Dodge Diesel and have the same readings with the X-Monitor. I will need to check mine out too. Maybe it is just the model year.

 

[Caveman]

It skips first?



What gear makes it go forward?... . I mean do you shift into 2nd and roll or does it slip a lot defore going into 2nd?

 

[MRobinette]

It seems to slip, but I really cant tell if it slips or actually skips 1st. 1st works

fine if I manually shift to first. I disconnected the batteries for 45 min. to see if it would reset, If that dosent work I will take it to the dealer and post what I find out.

 

[MRobinette]

I got my truck back from the dealer, the problem was a bad valve body. They had it back the next day and it shifts like new.