Hi all. I'm looking at a 94 Dodge 2500 diesel with 268K miles on it and the 47rh auto tranny in it. I've never driven a Dodge auto before (only a five speed) and so I'm not sure what I should be expecting out of it. I test drove it yesterday and when I put the pedel on the floor it doesn't accelerate anywhere near as fast as I expected it to. It will spin tires at the git go, but after about 20-25 mph it just slowly but steadily accelerates, and it wont do like all the gas autos I've driven that will downshift for more gettup when you mash the pedal. I think its downshifting when you need more power, the revs just don't come up very far and there doesn't seem to be alot of power there. It has no trouble getting up to 80 +, it just takes time getting there, much more than my buddy's five speed (which I kinda expected, but not quite this sluggish).

Is this just the way a 268K miles cummins and 47rh would be? Or could there possibly be a problem with the engine or tranny? By the way the motor and undercarriage are very clean...the truck has not been abused, off roaded, or used for heavy towing whatsoever...

Thanks in advance!

Ed

 

Sounds kind of normal for a stock 12 valve. When I bought mine not too long ago, I wrote this forum a letter very much like yours. For what ever reason, Dodge decided to limit the stock Cummings performance to a minimal amount. The good news it is easy to fix. Just a 3000 RPM governor kit and a fuel plate modification will change the truck dramatically; into to what you'd expect. Easy modifications (maybe 2-3hrs of your labor) and not very expensive (maybe $150, if you grind your own plate.)
Do a search on this site and you will find hundreds of posts, pictures, sources and everything else you need to know to do these mods. You will be amazed how well the mods work.
The 268k isn't that big of a problem. From what I hear, that is just middle aged for this engine.
Cougsfan

 

Roger that thanks for the reply...sorry I didn't search I'm at work and won't have time to search afterwards, probably gonna pick up the truck.

Thanks again!

Ed

 

THe biggest problem is the transmission. I had a auto in mine and it was a dog, had no acceleration no matter how far u pushed the pedal. U can spend about $1200 and drastically improve the trans (a nice Single disc Torque converter, and High pressure valve body). The truck also is a 94 auto which has the smallest hp pump, but u can improve that pretty easily with free mods like fuel plate, gsk, and pump tweaks.

A good test to see if the Torque converter isn't efficient is to drive normal and check the rpms drops between shift, if the rpms don't drop very much during the first 3 shifts, but drops alot when it locks up into overdrive then the TC is whats making u loose all the power.

 

Cool I'll do that this evening. I'm figuring that when the auto starts to go bad (or I get sick of it) i'm gonna swap a manual in there...

I see in your signiture that you swapped a five speed in yours...how did that go for you? Would you say its worth the money to buy the 5 spd and do that swap, or just build up the auto?

 

Well, if the truck ur getting has 3.5 gears in the axles then i'd say a 5spd swap would be great. The more I drive it the more I like the 5spd, at first when I switched from the auto to the 5spd I almost regretted it because of the shifting in traffic and all that. But I added some power since then and it makes it so much better, and I plan to swap in 3.5 gears to really help gearing.

The swap was pretty straight forward and someone like me who didn't have much wrenching experience did it alone, so that says something, lol. People say a TC and VB are just a bandaid for the trans, and if u add any good amount of power u will need a full rebuild and upgrade which cost 3k+ usually. U can do the 5spd swap for under 2k depending what parts u go with. I've enjoyed the 5spd, a built auto would be really nice at times, so more than anything i'd say do what u would prefer. If u like shifting a manual, a 5spd is alot of fun behind the cummins, but a auto is easy to drive and u can just relax more, so take that into consideration.

 

Sounds pretty normal, the 94-95 autos have a 160pump my truck struggled to get out of its way also when it downshifts the stock gov springs aren't letting the engine get fuel. I also think a tc/vb would be a baindaid for a trans w/268k on it. Its not hard to spend 3k on a nice auto, I also looked into doing a 5speed swap and I would say Box 5 did a good job of finding all his parts for under 2k counting clutch? I hate to say it but I wish I would of waited to find a 96-98 with a five speed but finding one is easier said than done around here at least.

 

Thanks for the advice I'm figuring on running it easy (i don't mind the slower vehicle) until the tranny's beyond then swapping the 5 spd. I actually like shifting manuals on highway and city.

 

yea I found everything in one truck that I needed at the junkyard so that was nice. It gets harder and more expensive if u have to piece every part together from somewhere else. I also was set on a 96-98 5spd, and just missed a 97 the day it sold, or else I would have that one for $7500!! It just goes like that sometimes, i looked forever everyday and finally found mine and have been really happy.