f1jsb79

We brought one of the horses back from the trainer this morning. At almost 50 mph, the transmission goes into high (I guess that's 4th?) and feels like it's lugging (over-geared for the amount of power available) and there is a low freq. vibration. It seems to go away once the speed is increased, It does not seem to do it as bad when not towing the trailer... does seem a little worse with the horse in the trailer.

What are the possible options? Do shops service transmissions or just send them off to be rebuilt? Is it so bad that I dare not trust it? We don't use it often, but the wife wanted to start taking one of the horse a few miles away to ride in a lighted ring in the evenings.

Thanks for any ideas you can give me.

-Steve

dozer12216

Could you have a restricted filter???? You did not say the tranny was not shifting properlly. Could be a injector gone bad.

DMcPherson

thats the speed the torque converter locks up, it could be starting to slip untill you get out of the torque band. this is also why it lugs

f1jsb79

Dozier- Correct- it still seems to shift fine... maybe a tad late into 4th

Mcpherson- I know jack about trannys- I going try and put my limited understanding to what you said. The tranny shifts when the torque converter locks up, then goes to the next gear? And the TC slipping means it's trying to shift early?

Is there still anything to cause me to stop driving and get to the shop tomorrow?

Thanks for the guidance folks!!

RowJ

When towing, just lock out your OD till you are around 60 mph. I agree there is just too much of a difference between 3rd and OD, but I think you are just lugging the engine. If you have oversized tires or any added fueling... the lurching problem will be even worst.
Keep it above 1700 rpm (after the shift) when towing and all will be well. No engine concerns here...the Cummins can run at 2500+ rpm all day long.

RJ

f1jsb79

Oddly enough, we never take it out of overdrive... wierd things happen when we do. I read some posts here that said not to even worry about that- the Cummins had plenty of torque to spare.

Mike D

Let see if this will help. The transmission shifts 1-2-3 and the converter locks this is with the O/D button in the off position. With the O/D button on the transmission shifts, 1-2-3 locks the converter then unlock and shifts to 4 then locks again. Some trucks, the converter will stay locked during the 3-4 shift depending on the programming of the PCM.

When you're towing turn the O/D button off as RowJ said, it should go through the gears to third and then lockup the converter, once up to speed on the highway say 55-60 mph then hit the O/D button, the converter should unlock and shift to 4th and then lockup again. Otherwise the you can be in 4th gear with the converter locked and you're lugging the engine and it will tend to buck. Lugging the engine is worse than letting it rev out in gear.

Think of it like a straight drive, you're trying to do things in 5 gear when you should probably be in 3rd.

f1jsb79

Any idea why it would suddenly start doing it? We've had "The Beast" 3 years- I think we've put almost 10k on it, about a quarter with the horses. Before yesterday, it rarely even noticed the trailer was behind, unless we were going uphill from a dead stop.

Thanks.

-Steve

Mike D

Maybe the lock up clutch in the torque converter is giving up the ghost.

93beater

my buddys truck is a 99 and when his convertor locks is lugg's till the turbo can spool back up??? what could cause that?? could it be just a junk 24v

Mike D

No more than a junk 1st Gen.

RowJ

First time you mentioned that things were different. Seems strange. If anything should be easier in the older weather to get away with low rpm in OD.
Boost readings same as always?
No more smoke than usual?
Tq Converter staying locked ...like before?
Any change in mileage?

Sounds like it's not a real heavy trailer? I don't know why things are different now but.........
I do know the Cummins is much happier when cruising with decent rpm (1700+).

RJ

omlambu

My 02, does what you are describing without a trailer. when my TC locks up the truck will sort of vibrate until i get going a little faster, or if I am cruising around 45-50 and just ease on the gas it will vibrate/moan. I don't know how long the truck has been doing this as I just bought it in October. I does not feel like anything is slipping so I just figured drive and keep an eye on my fluid for discoloration, smells, and particles

f1jsb79

Is there an easy way to check/refill the level on the TC?

dozer12216

Go back to page one and my question on fuel filter and fuel pressure to IP!!!
Yes you can drive home in OD lockout....