DTT Valve Body issues or not?

[jthorpe]

I had a DTT valve body installed a while back and had my transmission rebuilt recently. I was having 2-3 shift problems before the rebuild but it seems to be better now. However, I am still having a funky 2-3 shift when under light throttle, hot or cold. Under light throttle, 2-3 seems to be a bit sluggish and very slow. WOT or normal throttle, shifts very quick and firm, it only does this under light throttle. When I'm towing, it will do this and hunt on light to medium throttle, especially up hills. Again, when I hammer it, quick and firm.

I also have an issue when forcing into 2nd, when I hit the gas around 30mph, it still wants to go into third then hunts.

I know my second issue has something to do with the computer reading a high governer pressure, at least I think so. The first issue though concerns me. I am taking it back to the rebuilder tonight to see if they can see anything.

Have you guys seen this before?

Jack

 

[Hawk22]

Just left the dealership because of that. They suggested for me to but a valve body kit in it and let them know the difference. They put the computer on it and said everything ws fine... ... ..... ? I am one to let it idle though, not no more or until I put a valve body kit in.

Slow idle, sluggish shifting
Hammered, tight and firm. Dealer said normal... ... ..... ?

Thats been my expierence so for.

------------------
1999 3500 QC Auto,SLT loaded. 2000 34'Terry Triple Slide 5th Wheel. 1999 350 Big Bear and plenty other toys.

 

[jthorpe]

Just to give you an idea, when I first bought this truck, I never had problems like this. The shifting was smooth and slow but it never was this slow, and it never hunted for a **** gear to be in. This is really starting to get on my nerves. I just want a transmission that is right. So far I have put a total of 2200 bucks into this thing. I wonder how much it's going to take to make it right again. Everybody tells me all of this stuff is normal, I just don't believe it. Oh well. I know the boat you're in.

Jack

 

[K_Arts]

Jack. . did you happen to talk to Bill K about this problem you are having?

 

[jthorpe]

Wow! I like Bills customer service! HE called ME this evening to discuss the issue. I have the truck at the shop tonight and the builder happen to be there late. We talked for a few minutes and he is going to call Bill tomorrow. Basically, it looks like I do a bit too much light throttle driving in traffic for the current setting of the VB. Once the builder calls Bill and they work out the details, I'll let you all know.

Jack

 

[K_Arts]

Jthorpe... now you know why I have so much faith in Bill, He has great customer service and really knows what he is talking about.


Way to go BILL!!!!!


Kev

[This message has been edited by K_Arts (edited 01-04-2001). ]

 

[jthorpe]

Bill has been great to me so far. Helped me through this problem and is continuing to work with me after the sale. I also feel good about my builder. Maybe they can get together for some kind of resell agreement. I would love that since they're only a few blocks away from me.

 

[Fred Swanson]

That's the nice thing about Bill K's setup, you tune it to your specific driving habits. Not everyone drives the same.

------------------
Fred Swanson
Co-Owner
Canyon State Components, LLC
www.canyonstatecomponents.com

'00 QC,SB,4x4,Auto,3. 54 w/LSD,Trailer Package, Tow Package, DTT's VB & TC

 

[Bill Kondolay]

For those of you that are following this thread and are trying to figure out what is going on, this is not a transmission problem.
What is happening here is that eventhough we take a detailed customer profile sheet on each truck, we still have to guage the customers driving habits and program the valve body accordingly.

What Jack is describing is commonly known to a transmission rebuilder as hunting. What this means is that the transmission does not know what gear it should be in. This situation manifests itself primarily under 2 situations.
1)Extrememly light driving conditions.
2)Under full throttle conditions.

The challenge we face when custom calibrating valve bodies is knowing exactly how an individual drives. While most of the time the calibration is compatable with the customers driving habits sometimes like in Jack's case we need to tweak the vb to assure optimum performance.

In Jacks particlular case the vehicle is hunting under light throttle.

What is happening inside the valve body, is that there is a battle going on, between the throttle pressure circuit and the governor pressure.

Throttle pressure is resisting the upshift.

The governor pressure is trying to force upshifts. When these two pressure equalize on each side of the valve the transmission starts to hunt. There is not enough governor pressure to force the upshift and there is not throttle pressure to maintain 2nd gear. So by doing a pressure adjustment on the throttle valve circuit we can either increase the throttle pressure to force the transmission to stay in 2nd gear longer or lower the throttle pressure to allow an earlier shift into third.

Thats what i mean by tweaking the valve body.

So what Jack is going to have done is have an adjustment to make the transmission shift either earlier or later depending on his driving needs.

Jack is fortunate to be dealing with a reputable transmission shop, i mean that they follow the same proceedures for testing that i do. They check the transmission out after a couple weeks for any leaks,they do any necessary adjustments and service as required. I look forward to working with them to ensure Jack is completely satisfied.

Sorry for the sermon guys but this kind of vb tweaking is the most challenging and satisfying part of being a transmission technician. Hopefully didnt bore you to sleep.

Bill
Diesel Transmission Technology

 

[jthorpe]

Didn't bore me. I think this is good info for those guys to have when they're ordering the VB from you. I drive my truck in traffic quite frequently meaning I have a lot of light throttle driving. I also tow quite frequently so I do some agressive throttle driving as well. I guess making it shift earlier under light throttle would probably be appropriate. The only concern I would have then is my WOT shift points. I am hoping that those would NOT change.

Jack

 

[Bill Kondolay]

Jack,
Dont worry this adjustment does not affect wide open throttle shift points. That is a whole different story. If anyone is wanting wide open throttle adjustment info. i will post it, as this adjustment is for all valve bodys not just stock or DTT valve bodys. While our valve bodies give you a much broader range of adjustment options this proceedure is the same for all valve bodys.

Bill
Diesel Transmission Technology

 

[BigCarl64]

Bill,

Please post the information. I'm sure there are others that would like the info as well.

THanks!!

 

[TKilgore]

TTT
Yes, please post. The more info we have, the better.

Thanks

 

[jthorpe]

Bill and the builder had their conversation and the consensus is to back off the Throttle Valve stop. If I am wrong in my terminology, it's the blue lock tight that Bill explained to me last night. This should give better performance under light throttle. I won't have the truck back until next week so that's all I have for now.

Jack

 

[jthorpe]

Nothing significant to report yet. The builder is getting ready to put it on the lift. He is also going to call Bill sometime soon so I'll let you all know how that goes.

 

[Bill Kondolay]

I just have to take some photos and hopefully Kevin Arts will put them on the tdr site for me so you see the actual cable adjustments.

The wide open shift points are adjustable in 2 different manners.

When i have the photos i will post it,
Bill
Diesel Transmission Technology

 

[K_Arts]

Bill, just send me those photos when you get them and I would be glad to post them... I'll just add it to your tab. . LOL (Just Joking).

Kev

 

[jthorpe]

Well, transmission shop checked the thing again, didn't find anything wrong with it. They also adjusted the VB to make an earlier 2-3 shift. Feels solid under decent throttle but still delays under light, medium-light throttle. I'm going to call Bill on Monday.

 

[Mopar-muscle]

jack i think you want to delay the shift more , not make it happen earlier , i have the same problem , i drive it right around 25 mph on the first and last 2 miles of my commute , i just hold it manually in 2nd . bill told me to put a couple of turns in to make it happen later .

 

[Bill Kondolay]

Mopar,

Your suggestion for your application is 100% correct as you are trying to achieve later shifts.
As I recall your quarter mile time is now in the 14 second range. #ad
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Jack is wanting earlier sifts similar to factory to suit his daily driving habits. All of our valve bodies are designed to have later than factory shifts under light throttle to increase the durability of the transmission and that is why we set our valve bodies to hold 1st and 2nd gear longer.

Jack I will call you on Monday.

Bill Kondolay
Diesel Transmission Technology