bigragu

What is the "feel" in shift like as compared to how it drove before the kit? The reasons I ask is, like you see in my sig, I have a DTT tranny. The PO told me at the time of the sale in 2005 that he had a new tranny put in 3 years prior. He handed me receipts and I don't think he realized what he had, as he never elaborated on it. Even though he had owned a diesel, he wasn't in the know with diesels. When I got home with my new to me truck and inspected the receipts, that's when I read that the shop had installed a DTT. so far it's been a great tranny, knock on wood, and shifts pretty good, as far as I know. So, back in the day I heard that DTT was the cats meow. Were shift kits standard on those? What made the DTT tranny so popular anyway? Anyway, I'm looking to hear your seat of the pants comments on your shift kit mods, so that I can have a base to go by, or to see if these are the types of shifts I'm feeling based on your comments. On another note, lately my temps have risen to above 195. It always creeps up while at a stop, idling in this Bay Area freeway cluster. My temps have always hung around 180 on a hot day, same stopped, idling situation. I normally change out my valvoline ATF +4 every 12,000 miles, and I also filter my ATF with an external spin on. Right now I'm at 15,000, so I went past my maintenance mark. Fluid still looks good, and smells like new. Been reading on here a lot on the different ATF fluids some of you use. I personally can't afford Royal Purple or Amsoil. Have you all been having good success with +4?

j_martin

ATF+4 is the required fluid. I thnk it is a full synthetic fluid, so temp extremes shouldn't bother it much. If your fluid stays pretty, you aren't hurting it. It will turn dark if overheated. I'm thinking it could stand 300 degrees short term.

I run amziol, and my tranny will go over 200 a little bit in extreme use, ie mountain pull double in hot weather. Fluid is pretty as a peach after 30,000 miles.

bigragu

Hey, J, I've read some of your past original posts that were regarding your transmission rebuild. If I recall, did you not have a shift kit installed in your rig, along with the low stall goerend converter?

ChrisLib

Comparing different companies shift kits/valve bodies is sort of apples and oranges as there are so many variables in how to get the desired result. DTT if I`m not mistaken never used any kit but built their valve bodies using proprietary springs/valves etc. I have a transgo tfod kit in mine and I`d be willing to bet its prob quite different in the ways it changes the shift quality/timing from a DTT valve body. All that mumbo jumbo aside, the work I did made a night/day difference from what it was stock, but I also did the entire trans at the same time. Where before it had the normal stock Dodge driving thru a wet rag feeling (read, you couldnt feel a single shift) it now shifts pretty darned firm meaning when it changes gears you can feel it and def hear the change in engine load. I also run hydraulic oil instead of ATF as it is a fairly aggressive fluid meaning iow it has much less "slip" (friction modifiers) than any ATF and I`m sure that accounts for a good amount of the firmness in my trans operation, if I was running ATF+4 it would likely be a much smoother/softer shifting unit.

Trans fluid temps of 195 are nothing to worry about, the crtical range is somewhere around 230 deg F for atf so youve got a good ways to go before fluid breakdown becomes a problem. This chart is good/accepted range of when things start to go bad

Philip

DTT was the first company to make an upgraded converter for our trucks. They have been around a long time.

A trans company will tailor the valve body upgrades to what the owner wants/ needs. If the truck is just a DD with very little or no towing and the owner makes no comments on a shift style preference. They might leave the valve body with the TV (throttle valve) controlling the upshift harshness. If towing a lot. The company would make the it shift a little harder to lower the gear change over lap time. The longer the shift time. The more heat a trans builds. For performance they would set the shifts for hard and fast. On a Dodge they have two options for that. Leave the TV in use or reverse the shift pattern and take the TV valve out of the circuit. That means manual shifts only.

j_martin

I have a transgo kit in mine, installed wrong at first. NATCO took out the TQ pressure mod, and also found the loose parts in the OD mod.

That said, with this shift kit, high quality clutches, a few hard parts for reliability, but nothing big like a billet front shaft, Amzoil, and good cooling, this thing is a beast.

My son had a 2000 with a 5 speed. He wore that out, sold it, and bought a 93 W250 with an A 518 transmission in it. He then brought it out to MN and had NATCO do his for him.

What sold him was when I picked up 3 tons of gravel, pulled out on the highway, floored it, and had to back out for overspeed in short order. While he would have been waiting for things to spool down and up when shifting, mine just pulled like a mule.

On shift quality, there's a compromise between smooth and hot. It needs to shift firm enough so the clutches aren't heating and wearing excessively, but if it's too firm, you can break things.

Speaking of breaking, don't even think of turning up engine and transmission without putting a decent flex plate in. Both my son and I sheared ours in short order.

diesel402004

I'm still struggling with the pros and cons of my shift kit--it's a year and a half. I understand that the harder shifts and engine speed drops mean a longer lasting tranny and less extreme temps, but I miss the spooled turbo staying in the peak during the shifts. I still have the stock setup and the "lag master" turbo takes soo long to get boosted and my 2>3 shift is too early and leaves the boost flat during that critical acceleration. I now have to fool with springs in the body because the tv cable adjustment doesn't affect the shift times like it used to. I could do what everybody else is doing with different turbos/injectors etc. but I don't tow that much so sub 250hp is not really that bothersome. Maybe I'll try the "green" spring next time I drop the pan and see if that helps the 2>3 shift. I still feel like the shop (which I WILL NOT be going back to) did something incorrect in there

ChrisLib

It might simply be a matter of someone upping the line pressure via the adjuster on the v/b and not adjusting the throttle pressure adjustment at the same time. These two pressures in the unit must work in harmony/together to have the shift points where you want them. I learned this the hard way early on in my ownership of my heap. I did a Trans service and figured while I had the pan down I'd up the line pressure...all good right?....wrong, b/c when I upped the line pressure ONLY it threw off the balance/relationship with throttle pressure and the result was firmer but early shifts I could not adjust out with only tv cable adjustments. If you look on the web and find install instructions for a trans go tfod kit it will explain the throttle pressure adjustment a little more clearly but suffice to say if you mess with one you have to compensate on the other.
This pic shows the adjusters I'm talkin about

diesel402004

Good thoughts chris except I've tried the line pressure and it didnt help. Im nervous about the early shift one because your not supposed to go in more than .0800 and thats where it is now.

BC847

The best and least expensive thing you can do is call the shift-kit builder tech-line and explain what you do with the truck, and they'll steer you to the best Kit, and how best to set it up.

. . . . . The first time.