Lockup at 42 mph? Where's the Power?

[Skyjacked Ram]

I have a 98 24v 4x4 with 33x12. 5x16. 5.

My problem is that I hate getting on the freeway and with lockup at 42mph my rpms drop to 1100. This absolutely drives me nuts! I do have the 4. 10 with an auto. Will the DTT Valve body etc really help with slippage or should I start considering a higher gear say 4. 56 etc. Even at 75mph I am only turning 1900rpm.

I know others with larger tires have faced this problem all help is greatly appreciated. Thanks

 

[work2muchplay2little]

With the DTT valve body, as long as I'm accelerating, it does not go into overdrive. When I'm anticipating the need to accelerate at a moment's notice, I turn off the overdrive on the gear selector. Give Bill Kondolay a call. I like my transmission set-up.

 

[Todd G]

With my 33" tires, at 75 mph I'm turning 2400 rpm. You've got some major slippage dude!

 

[chuck3]

Slippage

Does not sound like slippage if hes only turning 1900rpm and doing 75 mph to me!

 

[LSMITH]

75 @ 1900 RPM with 33" tires sounds like 3. 5 gearing to me. That is really close to what I turn at that speed with my 285's. I also lock up the TC at 45 MPH which is about 1250 RPM if the throttle is light. If I have my foot in it beyond half throttle it will not lock up until I let out a little or hit 80 MPH. It locks up at 80-85 regardless of throttle position.

 

[K_Arts]

Originally posted by Skyjacked Ram

My problem is that I hate getting on the freeway and with lockup at 42mph my rpms drop to 1100.

I was having somewhat the same problem before I upgraded my transmission to the DTT setup. Bill K had some good advice that helped out my stock transmission from locking up so early.



His exact words were "Drive around town with OD locked out, Do not turn on OD until you are above 55mph!"



He was not joking. After I started my truck and locked out OD, problem fixed. My truck then wouldn't lockup until around 50 - 55 mph, pending on how much throttle I was giving my truck.



Just my $. 02



Kev

 

[Ramafid]

I think you have 3. 54's also. I turn 2000 rpm at 75 mph with 32" tires. Call Bill K. and see what he can do for you.

 

[KatDiesel]

Re: Re: Lockup at 42 mph? Where's the Power?

Originally posted by K_Arts

His exact words were "Drive around town with OD locked out, Do not turn on OD until you are above 55mph!"

You sure you heard that the first time from Bill? Thought someone else mentioned that to ya?



I keep my overdrive locked out unless I am above 60mph, and thats with 4. 10 ratio.

 

[Ray J]

Re: Re: Re: Lockup at 42 mph? Where's the Power?

Originally posted by KatDiesel





I keep my overdrive locked out unless I am above 60mph, and thats with 4. 10 ratio.

Kat, that's just about the guideline I use also (55-60) and it seems to work out fine... . no muss, no fuss.

 

[K_Arts]

Re: Re: Re: Lockup at 42 mph? Where's the Power?

Originally posted by KatDiesel

You sure you heard that the first time from Bill? Thought someone else mentioned that to ya?

KAT, Actually no, I didn't "First" hear it from Bill, that's why I didn't say that in my post. I first heard about it on the TDR, then when you came here to CO, you and I discussed it.



But Bill was the only one who explained to me how the trans works and why to lock OD out.



Kev

 

[TXRam]

I have 4. 10's with 305/70 16's (almost exactly a 33X12. 50) and I turn about 2250rpm's at 75mph - ratio'ing that to 3. 54 gives ~1950rpm's.



I'd check my gear ratio if I were you.

 

[Dennis Garrett]

My 97 was like that when I first got it. I took it to a dealer who had a mechanic that knew about diesel pickups, he made some adjustments in or around the TPS switch, and when he got done, it shifted and locked up at a higher RPM. I later added a 3 pos. lockup switch, mounted an inch below the turn signal lever, & almost never let it lock up on it's own anymore. I have total control over lock up, and drive it with the switch almost 100% of the time. Even with 5 years, 135k & turned up HP, I have a happy, stock, original transmission & lockup clutch as a result.

 

[Dennis Garrett]

One more thing in addition to my above post. If you drop the pan, there is an adjustment in there on the driver's side that will increase line pressure, and increase the speed & RPM for the shift points. About a year ago, there was a photo of the adjustments here but can't remember how to find it. I did both, and have a much firmer shifting, snappier feeling truck now.

 

[JBlock]

The Transmission VC is on DTT sie

Originally posted by Dennis Garrett

One more thing in addition to my above post. If you drop the pan, there is an adjustment in there on the driver's side that will increase line pressure, and increase the speed & RPM for the shift points. About a year ago, there was a photo of the adjustments here but can't remember how to find it. I did both, and have a much firmer shifting, snappier feeling truck now.

check DTT, that Bill Web page joe

 

[Snow man]

You definetely have 3. 54's. I have 4. 10's and 33" tires,I am turning 22-2300 at 75 mph. As to where is the power,Ive got an EZ edge sitting on my bench,it will fix your weak low end.

 

[Skyjacked Ram]

Snow Man--You definetely have 3. 54's. I have 4. 10's and 33" tires,I am turning 22-2300 at 75 mph.

That is what I would have thought however on the tag on the underside of my hood it says that I have option... .

DMF... 4. 10 ratio

DSA... anti spin



At 2300rpm I am doing closer to 95mph... . I once (out of frustration because of the lack of umph due to transmission downshifting so soon) held the throttle wide open to get the rpm up to the 3000 mark, and although it took me what seemed like minutes I did reach 112mph in the truck. I am seriously thinking about going to 4. 56 gears and DTT upgrades.....



Thanks Guys... . I really appreciate the advise and help.

Derek

 

[KatDiesel]

Originally posted by Skyjacked Ram





That is what I would have thought however on the tag on the underside of my hood it says that I have option... .

DMF... 4. 10 ratio

DSA... anti spin



At 2300rpm I am doing closer to 95mph... . I once (out of frustration because of the lack of umph due to transmission downshifting so soon) held the throttle wide open to get the rpm up to the 3000 mark, and although it took me what seemed like minutes I did reach 112mph in the truck. I am seriously thinking about going to 4. 56 gears and DTT upgrades.....

Something is off I have 285/75/16 tires (32. 8" tall) with 4. 10 ratio, around 2400 is 80mph in my truck. Have you owned the truck since new? That label is wrong, or someone swapped the gears on you. My truck gets upto speed pretty quick, I get on the highway and look down and I am at 90mph (or higher) I think Floor It can vouch for this? Hehe Can't get much over 100mph tho due to the govnor, speedo has not been corrected for the tire change yet. Not the best for fuel economy tho but its fun. I would do investingating on which ratio you actually have.

 

[Snow man]

Skyjacked Ram,I had a 96 with 3. 54's,it did eaxctly 102 mph at 2500RPM's,it was defueling at that point. It had 285/75/16's too. The 2000 is about 85-87 mph at 2500. Either the speedo is off,or the gears have been changed,get someone to follow you on the highway,and pace you,to check your speedo,if its right on,someone changed your gears. When i first got my 2000,I was upset that it had 4. 10's. but ive grown to love them,since i rarley travel over 75 anyway.