98 12V DTT transmission glitch?

[tgrfan2]

I tried to search for this but running out of time. My truck has 327K on it with 150K on the DTT with no problems until Tuesday. I haven't towed with it since getting my 2018 in January.
Tuesday I was coming back from a trip pulling a 9K equipment trailer. I was midway up a moderate hill when I felt a slight "bump". A second later I felt it again. This time I was watching the tach and it didn't move. I still suspected it was dropping out of OD lockup but in 60 more miles not a blip.
Friday I was coming back from another 290 mile trip same trailer and cruising (65-70mph) on a slight incline it dropped to drive? and rpms went to about 2400. I let off and it shifted back to OD and into lockup normally. A little while later on a downhill run I was gaining on a vehicle so I backed off the throttle slightly and it happened again.
I am thinking something electrical or TPS but I am debating taking it back to the shop that built my DTT and let them check it first for pressures. We are passing by it tomorrow on a camping trip and I could drop it off.
Except for these three "blips" the truck worked flawlessly this week in 800 miles of towing 9 to 14K. transmission temp stayed normal throughout.
Any thoughts would be appreciated.

 

[Turbo Terry]

No codes ?

 

[tgrfan2]

No codes ?

Still waiting to hear from transmission shop. Talked to a friend that works at a Chrysler dealership and has two CTDs himself. He said it sounded to be electrical and could even be a ground. I guess I will give the transmission shop a couple more days unless the 2018 starts acting up.

 

[SAndreasen]

Full of oil ? Mine acts strange when it gets a quart low

 

[Turbo Terry]

Could be many things I guess Fluid level. Maybe. My brain is telling alternator noise affecting the transmission. Do you a have a noise filter on it. I had a DDT one behind the control module small rectangler bot. Says DTT on it. It went bad. Same symptoms. No codes. Sloppy shifting. Poor mans test is wrap the big alternator wire in aluminum foil electrical tape. See if it helps or goes away. Call BD Diesel for a replacement. Very easy install

 

[Turbo Terry]

Thoroughbred diesel has a video Apps noise isolator BD Diesel

 

[Turbo Terry]

Low fluid level shows up by when you first start up and try to drive away but truck doesn’t move right away. Not going down the road so much warmed up etc.

 

[tgrfan2]

Could be many things I guess Fluid level. Maybe. My brain is telling alternator noise affecting the transmission. Do you a have a noise filter on it. I had a DDT one behind the control module small rectangler bot. Says DTT on it. It went bad. Same symptoms. No codes. Sloppy shifting. Poor mans test is wrap the big alternator wire in aluminum foil electrical tape. See if it helps or goes away. Call BD Diesel for a replacement. Very easy install

Thanks. I just got it back from the shop. He couldn't get it to act up and neither could I on 30 mile drive back home. I think I remember reading about the "noise" problem. I bought some Dollar General foil my wife won't use. I guess I will wrap it on thick and try another long haul soon.
Also a friend that works at a Chrysler dealership but has late model CTDs just told me he thought he remembered a ground problem on some of these trucks. I will check with him after trying the wrap if it doesn't help.
Thanks.

 

[Turbo Terry]

Yes wrap it up Do as much as you can couple layers and use electrical tape to help hold it on. I left mine on and replaced the noise isolator also. Mine was very hard to feel I could tell it but after sitting behind the steering wheel for 170 k and some 20 plus years I know when somethings up. The average person might not really notice it at all. please let us know ur it stops or keeps doing it Good luck

 

[tgrfan2]

Could be many things I guess Fluid level. Maybe. My brain is telling alternator noise affecting the transmission. Do you a have a noise filter on it. I had a DDT one behind the control module small rectangler bot. Says DTT on it. It went bad. Same symptoms. No codes. Sloppy shifting. Poor mans test is wrap the big alternator wire in aluminum foil electrical tape. See if it helps or goes away. Call BD Diesel for a replacement. Very easy install

I think you might have hit it with the TST "box". I let the truck sit for several days this week and was planning to wrap the cable today. Yesterday I started it and pulling off it felt weird. I first thought it was just the soft lawn but in pretty much a decades old response I pulled the shifter down into low. The truck took off normally. I am now thinking it is the TST resistor. I remember the transmission shop telling me this resistor might need to be adjusted if it ever tried to start off in a higher gear but I don't remember the procedure. I feel sure I have it somewhere in my 3 folders of 12V info but if anyone has had to adjust this resistor please let me know. Meantime I am going to wrap that cable. Thanks.

 

[Turbo Terry]

Not sure what a TST box is. Does it connect to the ecm for alternator noise etc ?.

 

[tgrfan2]

Not sure what a TST box is. Does it connect to the ecm for alternator noise etc ?.

Sorry for the brain fart. I meant DTT box. It is a resistor, I think. It is a white box smaller than a pack of Camels with a couple of DTT stickers on it and I think only a red and a black wire coming out of it. I seem to remember the young fellow at the transmission shop who actually built the transmission for me saying you could adjust it if the transmission started in a higher gear. I can't find any notes I made on that though. I probably thought I would just take it back to them if it acted up.
I had a 2008 Aspen do something similar years ago and I think it was called the low/reverse solenoid. This same shop replaced that part and now at 276K it still shifts good.
It may have done this before and I didn't notice it driving off concrete to gravel on a long driveway. I am going to try to check it out more today.
Thanks for helping me out.

 

[Turbo Terry]

I have a brand new spare DTT controller with adjustment screw if you really need one. In and out now on road trip in Pacific Northwest. Let me know Not available anymore. It was my spare

 

[tgrfan2]

I have a brand new spare DTT controller with adjustment screw if you really need one. In and out now on road trip in Pacific Northwest. Let me know Not available anymore. It was my spare

Thanks. I am almost afraid to try to adjust this one since it has been in a great deal of dust and moisture under the hood. I have driven it on several short trips this week without a problem but who knows when it could act up.
Let me know when it is convenient for you and we will make the deal. We are going camping for two weeks beginning Sunday but hopefully will still have some access to the TDR.

 

[Turbo Terry]

Ok back after October 25

 

[tgrfan2]

Thoroughbred diesel has a video Apps noise isolator BD Diesel

I finally got around to watching that video. Really good info source. I went ahead and ordered The BD isolator. The first two glitches felt like dropping lockup to me. I hope I can get the wire pierced without releasing the harness. I can picture the connector crumbling in my hand.
Thanks for that info too.

 

[Turbo Terry]

Will not be a hard hook up. Remove the air filter box use a good light and hook it up simple

 

[tgrfan2]

Will not be a hard hook up. Remove the air filter box use a good light and hook it up simple

My air box is long gone. I am going to check those other grounds shown on the video while I am in there. I am not sure when the isolator will get here but we won't be back home until the 21st so "Little Red" will get a long rest before surgery! Thanks for keeping up with my troubles.