DTT Questions

[PPeters]

Looks like the transmission is toast, so getting ready to replace. Read lots of posts, convinced that to do it right I need the DTT. So, all you DTT users please give me the benefit of your acquired wisdom before I part with my cash



I use the truck like a truck, haul horses and 20' loaded goose (~16K). I am in the process of HP upgrades (gauges, 16cm, injectors, intake and exhaust). Looking to get to 225-250HP, nothing wild.



Spoke with Bill K directly about 3 mo ago, he recommended a 2nd gen case with their 89H converter. Thought while I'm at it, might as well add additional cooling capability while work is being done. I've got to travel about 600 miles to nearest dealer (Mass Diesel) , so I really want the details worked out in advance. Bring it on guys!



Pat

 

[WyoJim]

Pat, I had my truck DTT'd in April with the works including an 89% TC. Drove all the way to Arizona for Fred Swanson to do the work. I have had zero glitches and couldn't be happier.



But what if I would have had problems. A thousand miles is a long ways to go back. And what if you have a glitch, 600 miles is a long return. Isn't Smokin Diesel down by Pittsburgh in business still? http://www.smokindiesel.com/.

 

[fox]

I have their 89, front clutch upgrade, billet servo's and shafts.

I did the valve body myself but as I look back it would be faster/better/and possibly cheaper to buy the valvebody and do it once .

This will be the FIRST upgrade next time!!

I could almost pay for it if I was charging for test runs!!!

 

[RGT]

What is the advantage to the 2nd Gen transmission case?

 

[cerberusiam]

The 47RH transmission is a heavier unit and stiffened up a bit to handle the torque. The interior parts are heavier with steel planetaries and more clutches. The overdrive was beefed up with more clutches (I think) and better cooling and the lockup converter was added. Talking to several builders the 47RH is about the best trans out there right now for upgrades.



Good luck Pat and get ready to open up the wallet. There is no cheap way to upgrade to the later trans and do it right. Trying to find a core is a pain since even the junk ones go out as soon as they come in. Big competition from the parts houses for rebuildable pieces. About all the builders want a core charge if don't have the same trans so the choise is buy a working one and upgrade it or just pay the core and go from there. You will need to change the starter, engine adapter, and while your at it the flex plate to the later model pieces. I have the

Cummins part #'s for the 95 pieces if you want them. With the 4x4 you won't have to worry about adapting the speed sensor. You will have relocate the tcase as the later trans is a couple of inches longer. You can reposition the cross member and drill new holes or do like most do and build a plate to use the original mount. Drilling more holes in a frame that is probably borderline heavy enough could have some adverse effects or not. Depends on driving, use, etc. Since the tcase has moved you will have to modify both drive shaft lengths. Some have not lengthened the front shaft but pulling better than an inch out of the splines looks like a problem waiting to happen. You will need to relocate the frame side mount of the shift linkage to get it lined up correctly again. Once it has been suggested not drilling new holes but building a plate to move it. The cooler lines can be made to fit by loosening the clamps and pulling the extra length you need back. To run the lock you should really get a programmable controller so you don't have to worry about lock\unlock if somebody else is driving. You can use a mystery switch if you so desire.



I checked with three different builders about prices then went to a local guy and started doing comparisons. Its pretty much a wash between all four. The one thing it did convince me to do was go to the 47RH and do it right. The 518 trans is all right but it has some serious deficiencies when you go much beyond the stock configuration. Following are what I found for costs:



Good transmission build $1800

Good TC $1300

Core charge $800



Cummins parts $500

Install\machine work\fab $1500





You can save yourself some money by installing it and making plates yourself if thats what you like to do. I am buying parts and pieces and used trans when I get to it then start building from there. Good luck.

 

[BushWakr - RIP]

I should qualify my comments with the following... ...



I do not have any special or secret inside information. I paid for it all. I am not working for or related to DTT in any way... . I'm literally just an end user...

You'll likely think I'm pretty enthusiastic and I am, but I'm also being honest too...



If I had to pick one modification that has more than been worth while for the $$$, it would be the upgrade to the DTT system.

I can only guess but I'd think that roughly 35% of the $$ I spent on power mods was literally going missing on the way to the road.

For example if I spend $600. 00 on injectors then loose 30% +or- on the way to the wheels then my "cost per HP" has just gone up, and it is the same rationale for all the other $$$ under the hood.

In the end I am getting one heck of a value for my $$$ in the process of making a great, fun to drive 7,000 Lb monster.

Not only do I have a great fluid connection, but it has allowed me to actually SEE/Feel the other mods I've done.

For the 1st Gen guys you will actually have to do a bit of re- thinking when it comes to your engine tuning... . why??? because your engine will actually have to work for living after this.



I was treated EXACTLY like I'd want my family treated if it were them walking in off the street. I was not sold what THEY needed to sell, it was what I needed and wanted.

My compliments to Bill, Vinnie, Lalita, Stephan, Shanti, Darrin, Krystal and the entire crew...



end of sermon...



bob.

 

[cguthrie]

I think we talked about this not too long ago, but the second gen case has a lockup t/c and the first gen has a non lockup t/c. I talked to ATS about having them put a second gen transmission in and they wanted around $6000 for it. I think for that amount of money i'm gonna go with a DTT. Right now i'm on a budget and from what i've heard about DTT has been all good. I'm not saying i haven't heard good things about ATS but i really can't see myself spending that much money on a transmission right now.



Chris

 

[PPeters]

Hey everyone, thanks for the replys. I wondered about the 2nd gen case being lockup. Scott (at Mass Diesel) tells me that in this application I am still going to be fluid (non-lock). Essentially they use a sleeve in the case for the electronic connector and the 1st gen valve body and front pump. He also uses the OD from my truck (rebuilds to DTT spec), to avoid the over length issue. So you get the 2nd gen case, DTT goodies, and retain fluid connection.



Price is a little steep, my quote out the door is a little over $4400 US. Been looking for quite some time, and the price from Sun Coast is almost identical. Still cheaper than new truck though.



Pat

 

[PPeters]

Talked with Bill K directly about a couple issues. First, Smokindiesel is not an authorized dealer for DTT. Right from Bill, he says they have not attended training at his facility. He does know them, likes them, has purchased from them, but they are only interested in selling complete units, not doing the build work. So Mass Diesel is it.



Bushy, question for you:



Bill told me my best bet setup is a 14cm housing with a 91 TC. He mentioned your name when talking about guys chasing HP and swapping TC's out. I see by your sig that you are still running the 16cm, I asked Bill about EGT's when going to smaller housings, he said that it's almost a non issue. If I were to stay at a 16cm housing, he would recommend a 89H, but if I drop to a 14 its a 91. Apparently there is a balancing issue which has a zero net effect on the EGT's Straighten me out (as if that's possible )



Pat

 

[jbolt]

Pat FYI-



Had mine done early this year. Complete DTT upgrade/rebuild with all the latest improvements available plus new input & output shafts, new steel planetaries all around, replace OD output bearing and Mag-tech pan was $3800



I looked at upgrading the case but we (me and my installer) felt it was not necessary with my driving style which is mostly unloaded. He did feel if I was going to push the HP I should consider the 91%. I chose the 89% becuase it was faster off the line where as the 91% takes a little more juice to get it going.



Either way you'll be impressed by how much more HP is making it to the ground.



Jay

 

[BushWakr - RIP]

Pat,



Ok here's were I gotta "come clean"... .



When I had my system done I was absolutely positive I would NOT chase any more HP.

I was at about 225 RWHP.

To his credit Bill said "... ... ya ya ya... ... you all say that..... "



Well I went with the 91% initially and found that it was too tight for my HP. (Wish I had strapped on a 14cm then cause I had a 16 on)

I had some noticable " pull down" or hold down, on the engine when loaded with weight and on, say, soft soil. It would take a bit to get it rolling because of the tight connection.

Once it was moving you darn better get out of the way... .



Ok, since I "wasn't going after more HP"... . I changed over to the 89% TC. Same VB etc, just a slightly looser TC.

Well... ... . ok, I'm at 325. 9 RWHP and I darn well better go get the

91% put back in cause NOW I can turn it...

If you are in the 250 HP range and run a 14cm gated or nongated you can run the 91%..... I would do it tomorrow.

Bill was right, I was wrong... or just fooling myself I guess. .



This is why I mentioned "rethinking" your truck tuning/setup.

If you do the mods right, and configure them right, you'll have so much fun you'll never park the truck... .

Just as an example, when I had the 91% in, I tried a baby brake stand/launch. .

I built up about 8-10psi with brakes on, let loose, hammered the throttle and I finally gave up after about 200' of smoke and rubber... and that was all the way up to, and into OD.....

On the highway, I found the 91 to be a really "pull out and go by" system. The 89 is just a tad softer at the upper end but allows for a bit more RPM to get you launched...

Keep in mind when I hit 285 HP I thought "ok that's it now... . "

Ahhhh hell, I'm going for no less than 400 RWHP before I even consider taking a break... I just may need the 93%



Just take Bill's advice... . and if you talk to him again. . tell him I said "I hate it when he's always right"...



Bob.

 

[PPeters]

Thanks for the reply Bob, now I'm thinking 14cm and 91. I've got the 16 from PDR, just have not installed yet, and pump is stock except for timing (same with injectors). Am I correct in thinking that I should get the housing changed over and tweek pump before installing DTT? I would assume that this makes sense.

Gotta call Piers and see if I can exchange for the 14.



Pull Down? You mean like lag between pressing the go pedal and motion? Already have that



I assume you are still running the 16, or have you swapped?



Pat

 

[BushWakr - RIP]

I have been running the PDRHX35/16 for a while now and I like it alot... . if you stay with the stock H1C then put a 14cm on it and go with the 91. You can always tweak and tune a bit on the pump later.



I don't have the HX35 on right now,,, I got one on that sucked the liscence plate off the guy in front of me last night though... .



I think it was originally used to power a Zephlin or sumthin... .



Pastor Bob.