Engine/Transmission (1998.5 - 2002) DTT questions

[BWooldridge]

I just got my new DTT transmission installed in my ‘01’ and couldn’t wait to see how it drove. I merged onto the freeway and to my dismay; I had lost the acceleration I had once had. I got on the phone with Bill at DTT and discussed the issues I was having and we ran through some tests and everything checked out. He explained some things to me and I thought well it just works differently than the stock piece of crap (47RE) I had in it before. This morning I hooked up my Wilton utility dump trailer and went to the dump with only about 1000 lbs in the trailer. I merged onto the freeway and it took me forever to get up to 55 mph. What is going on?

I plan on calling Bill K. on monday to find out what's going on but I know you guys in TDR land will have some advice for me. Thanks

 

[Bob Wagner]

do you have any power modifications?

 

[SnoKing]

Did Bill have you check the voltage at the transmission voltage regulator at the passenger side near the hood hinge. Sounds like maybe you are in limp mode. Look at page 4 and 5 of the of the manual he provided, regarding checking voltage and the adjustment if you are in limp mode. This the stappled document that says Diesel Transmission Technology - 94 & Later - Valve Body Installtion Instructions on the front page. SNOKING

 

[Fred Swanson]

Is it shifting through all of the gears?, could be in limp mode. Who installed it?

Is it slower from a dead stop? You say it took forever to get to 55?



Lots of questions to determine the actual issue.

 

[BWooldridge]

I was on the phone with Vinnie @ DTT and he had me check the voltage. 4. 6 volts. all the line pressures were ok as well. I do have 60 additional HP in the edge EZ. It shifts through all of the gears nicely but it seems like it's lugging and spool-up time is slow. A local shop installed it for me.

 

[AndrewKing]

Just a thought but perhaps the converter is too tight and not allowing the turbo to spool up properly... . When I got my DTT converter, Stefan at DTT said I needed the DTT 89TC for just that reason... . Too tight a converter (they also

make a 91 and a 93 which are tighter than mine) will hinder performance unless the engine has the power (for the most part I am near stock levels) to use the tighter converter... . Hope this helps.

Andrew

 

[Ramafid]

I have the 89 TC and with no power modifications the truck was a dog. I promptly added a DDTTPM and it made a big difference. If you already have more power you should be ok. Did you get a 93 TC by mistake? Keep talking to Bill and I'm sure you will get it figured out.

 

[Snow man]

Even with a 93 tc it should be fine once above 20mph. I run the DTT93 % daily with no trouble even with no box and 2. 5 injectors. I yank over 9500 lbs all summer with no issues. One thing thats going to take some getting used to is the fact that the engine doesnt rev to 2800 anymore before it starts moving. Maybe your so used to it winding out then slowly accelerating til it hits lockup. I know when i drive a stock trans i totally hate it,every truck in our family,and all my friends all have DTT transmissions,its rare that i drive a stocker,but when i do i cannot believe how poor they transfer power in fluid coupling. When you drive it next,from a deadstop in drive apply light throttle,and see if you feel it shift at about 1600-1900,to 2nd,then 3rd about 1600-1900 by 33 mph it should be in 3rd. If it is defaulted ,you wont feel a shift,just VERY slow initial acceleration,until about 30mph,then its pretty decent. If its defaulting get it back to the installer asap.

 

[fox]

What is the FUEL pressure? Lift pump may be out.

 

[Fred Swanson]

Okay, it's shifting through all the gears. What RPM is it shifting at? It could be shifting too quick, thus lugging the motor. How much throttle are you using to get up to speed? You have gauges?

 

[Snow man]

an 01 with an HY35 and EZ should not be lugging,it should spool almost instantly. Do you have any exhaust leaks,any chance the wastegate isnt fully shutting. With a warm engine a stock truck with an hy35 should make at least 10-12psi of boost in neutral,at hi idle. See what your boost is with your foot to the floor,hold it there about 5 seconds (3500 RPM)and see if you get 10-12 psi. If its low I'd look for boost leaks or wastegate problems. On the Edge EZ is the jumper in the 3rd spot? ,that setting is what you want with stock injectors for instant power and response. As Fred said the trans my be shifting a touch too soon,you may be able to have it fine tuned with just the TV cable,but if its already on the tight side,valve body mods will need to be done by the DTT installer.

 

[BWooldridge]

Unfortunately, I don't have any gauges yet so I can't measure Boost. I will document the RPM shift points and report back. I don't know what TC I have but I'm sure Bill will inform me on Monday. I think the TC may be too tight or I just need some adjustment.

 

[BWooldridge]

Ok, the first run:

Idle 800 rpm

Normal throttle:

1st to 2nd @ 2100 RPM and dropped to 1800 RPM

2nd to 3rd @ 2100 RPM



2nd run:

Full Throttle

1st 2900 RPM

2nd 2800 RPM

3rd 2200 RPM

4th 3000 RPM @ 80 MPH

 

[BWooldridge]

Ok, I found the problem. The communication connector on the EZ had a loose wire. Now I feel this transmission working. Awesome!! I still think it need some more miles on it then some adjustment. Thanks for your help.