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Discussion Starter · #1 ·
Okay, my truck has a very odd problem that has come up.

Sometimes, when I crank it up to go somewhere, it doesn't want to go in reverse. I can shift it into gear, but I have to tap the throttle once or twice before it will fully gear in. I am getting no codes from it at all.

It will do it cold or hot, most often cold though.

The truck has 95k miles on it. When i bought it, ALL of the maintenance records were in it, and it had a servicing done at about 55k miles on the tranny.

I am going to change the fluid and filter next week when my money comes in, however, if that doesn't solve the problem, I will swap the tranny more than likely.

Now, if I DO swap the tranny, I was thinking of swapping a four speed in instead of another three speed. I have a shop with all the tools I need, but what am I looking at for doing this job? Here's what I know I will need:

Tranny
Tranny computer
Gauge cluster
Shifter assembly

Is there anything else I am missing?

The reason is I was offered a four speed for $350 with a six month warranty from a rebuilder, or a three speed for $550. The other parts I can get from a U-Pull-It for around $150, so it would be close to the same cost, with a few more hours of labor.

I was also thinking of regearing the rear end, and putting in a spider gear since it's open differential right now, and doing it at the same time. Can anyone link me to a good retailer for new gear kits for the rear? I've found a few sites, but they seem a bit sketchy to me. Not enough information on the different kits to make a good decision.
 

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First off, your truck has a 5-speed (545RFE) trans now. This is the same (hardware-wise) as the 4-speed 45RFE that was used in prior model year Jeeps and Dakotas / Durangos. The software is different so it enables all 5 gears in your truck.

Does this problem ever happen in Drive, or only in Reverse? What exactly does it feel like in Reverse? Just a very long, delayed engagement, where you finally feel it "thump" into gear? Or does it start to move very slowly, and then kind of "oozes" slowly into gear?

Does it ever slip at all in Reverse (once it gets engaged)? Do you ever have any problems starting the engine in Park or Neutral (where you have to wiggle the shift lever to get it to crank)?
 

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Discussion Starter · #3 ·
It slowly oozes into gear.

And...a five speed? gah, they need to update the gauges then. I'm used to D,2,1 being a three speed tranny. Shows you how old the stuff I normally work on is.

No problems cranking, fires up every time nice and solid.

Though now I have a suspicion that the right tranny is going to cost me more...joy of joys. At least I won't be doing anything too crazy.

I'm not sure, but I think it did the oozing thing once in drive when I was facing away from where I was parked, and could just drive off.
 

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If it's "oozing" into gear, then you most likely (99% chance) have converter drainback, where part of the fluid in the torque converter is draining back into the trans when the engine is shut off. Then when you start the engine, the converter is half full of air (instead of oil). Since air does not transmit torque very well, you basically get no torque (from the engine, into the trans) when you first shift it into gear. Then as the converter refills, the torque level slowly rises, until finally it's back to normal. That's why you get the "ooze into gear" feeling - you are actually feeling the trans input torque slowly building. Once you move the truck, everything's fine, so it works great from then on (until you park it again and it drains down).

The most common cause of drainback is changing the fluid and filters, and using an aftermarket spin-on (cooler return) filter. The spin-on filter has an internal diaphragm to prevent converter drainback, but on some aftermarket filters, the diaphragm doesn't work well enough, giving you converter drainback and a slow engagement after the truck's been sitting overnight or for several hours. So the fix would likely be a new spin-on filter. Use a Mopar filter (05179267AC) and you should be OK.

By the way, this is NOT something that will harm your transmission (or converter). As I noted, the problem is too little torque (not too much), and the trans is NOT slipping - it's all in the converter. So you don't have to get it fixed right away if it's not convenient - you can wait until your next fluid change if you want. Drainback is annoying but it will not harm anything. If you let the truck idle (in Park or Neutral) for a short period after you start it, the converter will refill and you'll be fine.
 
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