48RE Burp?

[4xquadrod]

48RE Burp? / Not a 48 but a 47

I was pulling a light load (4000lbs) up a grade, truck downshifted into drive and was pulling at 2900 rpms for 2 to 3 minutes, somewhere around 60 -65 ish. Then suddenly the truck seemed to downshift again and the rpms jumped up past 4000. I let off and it shifted back into drive but I lost alot of my speed.



Something similar happened driving with no load. I was at 95mph trying to see what it will do and traffic was ahead so I tapped the brakes and the truck down shifted to 2nd and rpms went up past 4000 for a brief amount of time 3 seconds roughly.



Both times I had the accelerator floored.

I talked to a service guy he said this truck wont let you red line.



I was in there for that transmission valve recall.



Now that this has happened again I am going to take it in. [

 

[ntenna]

$xquadrod-



Are you sure you have a 48RE/HO? Not any on this forum yet that I know of...



On my 47RE/SO '01 that is typical behavior on a hill if you have the stock transmission and peddle to the floor. At some point the transmission arbitrarily decides to downshift. Try going up a hill in cruise control and see what I mean!



Now on that second situation, well - never heard of it downshifting on a peddle lift..... scary!



JH

 

[4xquadrod]

When I bought the truck they told me the trans was of a new design by Chrysler. I assumed it was the 48 but the motor is not an HO. I can't get one in California.



A buddy of mine in Montana claims to have bought a HO auto recently. He said it was the first one in Bozeman (is that spelled right?). He is here in San Diego now so I am going to hunt him down and take a look.

 

[Vaughn MacKenzie]

Something's definitely not right. YES, it is possible for an engine to be forced past redline if the transmission erroneously downshifts at high speed. It's not too good for the engine although some guys take their 12 valve trucks to 4000 and beyond.



I would educate your dealer or find another one and get it resolved before this malfunction breaks your engine or transmission.



Vaughn

 

[4xquadrod]

Yep! :{

 

[kevincook]

I thought the HO were not available in California due to emissions?



KC

 

[4xquadrod]

Took truck to Dodge, talked to a different service rep. He said " :--) lets get this thing in and have a look right away! But we don't have an opening untill Monday. "



So Ill keep a load off of it till then.





No, this truck is not a HO.

:{

 

[Prairie Dog]

They will rev well past red-line. My truck exhibits the usual tendency that all the 3rd gens do, throttle has a mind of it's own. Once when shifting at about 3000, the engine speed flared and I saw the tach swing to 3500. I also witnessed my local dealers service manager routinely shift at more than 3500. I didn't say anything because he would have just argued it was good for it or something.

 

[MidwestMotorman]

4k kit

4000 rpm stock Cummins??? I would enjoy that for 36ooo miles at D-Cs expense!



But it should not downshift when letting off the throttle. Sounds like a sensor is faulty.

 

[4xquadrod]

I took the truck in today for the transmission problem. The truck pulled up a code which basically called out a dangerous crank speed. Their service manual or what ever they read from said to check for bent parts (Rods etc). I don't think at this point they are going to do that. They are stumped and will be contacting DC tomorrow.



This is a SO / 47RE I guess the sales rep didn't understand what the new trans was. And me either!