Dodge Cummins Diesel Forum banner
  • Hey everyone! Enter your ride HERE to be a part of this month's Ride of the Month Challenge!

1 - 15 of 15 Posts

·
Oregon Chapter President
Joined
·
3,673 Posts
Discussion Starter #1 (Edited)
47RE, strange shifting or just normal?

I recently rebuilt my tranny (47RE). Put in all the good stuff, and new TC, even went ahead and did a Transgo shift kit.

Anyhow, got it all back together according to specs. Drilled out my VB plate a little bigger in certain places in accordance with the instructions. Threw it back in the truck. Did everything right as far as I know. Even made sure the bands were spec, and adjusted the TV cable. So whats the problem?

Well... shifting from 1-2 the trans acts like there's not enough pressure to shift. Like it lugs halfway in between the two till my speed gets up a little more, then it grabs 2. From there, as I'm accelerating in 2, about midway speed before the proper shift point into 3, it kicks out into what I think is 1, then back into 2 with a really hard "ka-chunk". Then at the proper speed (I think), about 30-35 mph, it'll shift into 3, then on into OD as normal as I continue to accelerate.

The trans grabs good in all gears, no slip, firm shifts, runs at proper temp, hasn't thrown any codes, etc.

The only thing that concerns me is that small interval in 2 where it kicks out to 1 and back into 2. Is this normal? Should I not worry? I remember reading about the shift pattern on these things and it fits the pattern, and I remember it doing this before I rebuilt it, but it was so much more subtle, even under WOT. Is this all the shift kits making or am I just nuts and way to much of a perfectionist? :lol3:

Let me know!!! Thanks guys.
 

·
Tech Specialist
Joined
·
1,493 Posts
If I'm correct, if the shift timing isn't setup properly then 1-2 can bind when shifting. I THINK. I'm not sure though. Sounds like something in the valve body definitely isn't setup correctly though.
 

·
Oregon Chapter President
Joined
·
3,673 Posts
Discussion Starter #3
The only thing I could really think of is in the instructions for the Transgo they said not to put a certain spring in the rear servo for diesels... but then in fine print it said that if I was going to drill out my 1-2 and 2-3 holes for more pressure, then it was necessary for me to put it in. So I did, and I drilled out the holes within the specs they had, about .003 larger than the minimum they gave. Well short of the max.

As far as "bind" and shift timing for 1-2, are you referring to throttle valve cable adjustment, or perhaps front and rear band adjustment? I know I read somewhere that if the front band is too tight it affects 1-2 with bind, and if it's too loose I'll over rev going 2-3. But I don't seem to be experiencing the rev from 2-3 unless I'm manually shifting moderately heavy to wide open throttle.

I'm perplexed. :CRY:
 

·
Tech Specialist
Joined
·
1,493 Posts
Man I'm not intelligent enough with these tranny's to really help diagnose what's going on. I just know that something isn't right in the valve body. You might try checking the band tightness again just to make sure. You might also try calling up one of the tranny guys (HTS, DTT, Goerend, Suncoast, even transgo) and see what they have to say. They can probably give you a better idea.
 

·
Registered
Joined
·
180 Posts
my tranny was acting something like that, when you put it in gear and drove off it felt like the emergency brake was on, it pulled a few codes on the old key trick. i replaced the governer pressure switch and the transducer switch thanny is fine now. the parts cost me a little over 200 bucks. if you replace one of these switches you need to do both of them they need to read each other at the same voltage. you will need to pull the tranny pan it should onlt take about 45 minutes to get this done.

2001 2500 4x4 47RE 4" straight pipe, delete pipe, silencer ring mia tripple gauges
 

·
Tech Specialist
Joined
·
1,493 Posts
I just swapped the governor pressure solenoid and transducer on a buddy's truck this weekend. It was really easy. Drop the pan, there are 6 bolts holding them in (2 torx and 4 7/16" hex head), unbolt them, pop the little bracket off that's holding them in place and reinstall the new one's. I think it took me all of 20 minutes or so.
 
G

·
If I'm correct, if the shift timing isn't setup properly then 1-2 can bind when shifting. I THINK. I'm not sure though. Sounds like something in the valve body definitely isn't setup correctly though.
You are thinking of 2-3 shift. The 1-2 shift goes from having the rear clutch applied to rear clutch and front band applied. Thus, there shouldn't be an overlap there.

The 2-3 shift, (which I think you mean) uses hydraulic pressure to release the front band AND apply the front clutch. The band stops the front drum, the front clutch spins it. If these two overlap, that creates the bind you are speaking about.
 
G

·
There are a bunch of rebuilders that say a complete rebuild on the RE transmissions includes the governor solenoid and transducer.

As to the problem, I'd look at the front band adjustment. After that, I'd have to see exactly what was done to determine if the shift kit changed things or not. The spring in the rear servo versus the different hole sizes shouldn't have anything to do with forward gears, since the rear band is only used in reverse and manual low.

Another possible problem with the shift could be a broken seal ring, or a bad bushing on the pump support for the shafts. If you leave out a torrington bearing, this could allow the front drum to slide, causing the seal rings to be ineffective. That said, I'd stick with the front band and electronic inputs for now.
 

·
Oregon Chapter President
Joined
·
3,673 Posts
Discussion Starter #10
Awesome guys! Thanks for the input. I really hope it's something simple like the solenoid and transducer. It was a pain getting that tranny in and out with a makeshift tranny jack.

01BlueDevil, thats funny you mention the thing with the parking brake. Today I was letting the rig warm up for a second after work before my drive home. I usually kick it in neutral out of habit to get the fluids flowing in the tranny. Anyhow,when I went to put it in reverse, it was like my parking brake was still engaged even though I had already released it. I put it back into park, the into reverse again, and still it was stuck. So I gave it a little throttle, and it almost sounded like...umm... that sound you hear when you break a bolt loose thats been torqued and stuck for a longtime. Does that make sense? Anyways, it didn't sound good.

Then I noticed that when I applied the brakes, they grabbed extremely hard! I'm not even joking either. My rears were almost locking up, and the front end was diving into the stop. But then after a few minutes of stop and go, it was all normal again.

Well, I'll be looking for parts probably next week, then I'll throw it in, and let ya'all know whats going on. Thanks again guys. Oh by the way I did call Transgo, and the only advice they offered was to adjust my TV cable. And I already did that, so I just figured I'd post here and see what ideas popped up. I should call Goerend though huh?
 

·
Oregon Chapter President
Joined
·
3,673 Posts
Discussion Starter #11
There are a bunch of rebuilders that say a complete rebuild on the RE transmissions includes the governor solenoid and transducer.

As to the problem, I'd look at the front band adjustment. After that, I'd have to see exactly what was done to determine if the shift kit changed things or not. The spring in the rear servo versus the different hole sizes shouldn't have anything to do with forward gears, since the rear band is only used in reverse and manual low.

Another possible problem with the shift could be a broken seal ring, or a bad bushing on the pump support for the shafts. If you leave out a torrington bearing, this could allow the front drum to slide, causing the seal rings to be ineffective. That said, I'd stick with the front band and electronic inputs for now.
I did get a chance to remove the old bearing in the pump housing that supports the shafts. I also put on new seal rings. A couple stock ones, and a couple others that Transgo provided with their shift kit. So I guess I better hope I didn't damage them during the install or when I put the TC in. :lol3:
 

·
Registered
Joined
·
550 Posts
i recently had my tranny biult and had a few things put in the valve body but im not happy with how its shifting i want a firmer shift. i talked to the guys at ATS and they said there valve body was just what i needed i was wondering if anyone had any other ideas or if i need to go out and get a better valve body.
 

·
Registered
Joined
·
550 Posts
hey thanks for the info i'm not goin to ats, but regaurdless in need to get rid of my stock valve body any good prices, places, or suggestions.

by the way this is a great site!!!
 
G

·
I do my own work, so I'm not able to suggest any particular trans outfit. However, if you encounter info that you have questions about, feel free to ask here.

That said, you have two options on the VB, a shift kit that you do yourself, or buy one from one of hte builders. If you buy one, the builder may be able to tailor it to your specific application.
 
1 - 15 of 15 Posts
Top