'05 3500 dually auto, manual downshift questions

[Motorhead]

A friend of mine has a cherry '05 Dually, automatic, 3. 73 2wd that he tows a huge 32ft 5th wheel. His truck has the "TOW" button not "TOW-HAUL" but it doesn't lock out 4th like my old 01. 5 did.

Question is, What is the way he needs to go to manually downshift from OD to third/direct for hills? He has tried pulling down the shifter under load but it won't drop. I had a built DTT in my '01. 5 and if I needed to go into second, I had to let off of the throttle to get it to go in.
Is his '05 tow button the same as the '01. 5 or does it just change the shift points???

I loaned him my Smarty jr set on 40hp with timing and soft torque to see if his EGT's would drop. I installed a Westach EGT and he was seeing 1400deg towing!!!

 

[AH64ID]

Not sure on the transmission, 6speed guy myself, but the Jr will certainly drop his EGT's. . 1400* is pretty normal for a stock 04. 5+ truck... but it still seems wrong. . I haven't broken 1250* since I put the Jr in.

 

[cerberusiam]

The 05 TH is just a shift point and lockup modifying program, it no longer locks out OD like the earlier trucks. Pulling the shifter down to second may or may not drop it into drive depending on speed and load. The transmission will protect itself from downshifts like that. Generally nothing will happen if the speed is over 50 mph.



To drop it to drive on hills with a load, just cycle the TH button and the trans will downshift to drive and lock the TC. If your pulling a good grade and have to keep throttle in it to keep speed up they generally won't upshift until you get onto flat rolling ground and you can lift off the throttle.



If that dosn't work as nicely as liked, BD makes and OD lockout kit that keeps the TH shift patter and lockup startegy and locks out OD.



FYI, Cummins has rated the 600 series engines for continuous duty at 1450 degrees. I would hesitate to advise that but they will take a lot of EGT's.

 

[Motorhead]

The 05 TH is just a shift point and lockup modifying program, it no longer locks out OD like the earlier trucks. Pulling the shifter down to second may or may not drop it into drive depending on speed and load. The transmission will protect itself from downshifts like that. Generally nothing will happen if the speed is over 50 mph.

To drop it to drive on hills with a load, just cycle the TH button and the trans will downshift to drive and lock the TC. If your pulling a good grade and have to keep throttle in it to keep speed up they generally won't upshift until you get onto flat rolling ground and you can lift off the throttle.

If that dosn't work as nicely as liked, BD makes and OD lockout kit that keeps the TH shift patter and lockup startegy and locks out OD.

FYI, Cummins has rated the 600 series engines for continuous duty at 1450 degrees. I would hesitate to advise that but they will take a lot of EGT's.

When you say "cycle the TH button", pull it out of tow or push it to tow?? He tells me he always runs in TOW but needs to go into third sometimes and doesn't like kicking it to the floor to downshift it.

 

[cerberusiam]

When you say "cycle the TH button", pull it out of tow or push it to tow?? He tells me he always runs in TOW but needs to go into third sometimes and doesn't like kicking it to the floor to downshift it.

Yeah, just a quick off and on again, hit the button twice, will drop the trans into drive. Under a hard pull it will generally stay there until you let off most of the throttle.

 

[Motorhead]

Yeah, just a quick off and on again, hit the button twice, will drop the trans into drive. Under a hard pull it will generally stay there until you let off most of the throttle.

Thanks! I'll let him know

 

[Jeepr]

Same thing for a down hill, hit it twice (assuming it is already in TH) and it will downshift to third and stay there until you get on the gas again. As an FYI, the dealer can change the function of the switch to an overdrive lockout, meaning when he hits it it WILL go down to 3rd, but that then replaces the tow/haul programming. It's either/or, but not both 2005 is the ONLY year of this restriction. -2004 and 2006+ both have both modes.

 

[rbeyer]

If your friend drives foothills, the stock transmission controls are a real pain. I have found the BD Overdrive Lock-out to be a very good solution. The only criticism I have is I regularly get a 1740 code since its install.

 

[wantabe351]

When I tow our 13,000# 5er the tow/haul works great in the change of its shift points. . but when on county roads I didn't want 4th gear. . so I got the BD od lock-out module. . works just like they said and have had it now for 3yrs.

 

[Motorhead]

When I tow our 13,000# 5er the tow/haul works great in the change of its shift points. . but when on county roads I didn't want 4th gear. . so I got the BD od lock-out module. . works just like they said and have had it now for 3yrs.

Good tip on the BD lock out module. I see on your signature you are running a 4. 10 gearing. His is 3. 73 and I suggested to him that a 4. 10 might help also.