Engine/Transmission (1998.5 - 2002) transmission slipping

[GreggNoble]

hi, guys. when i hit a bump on the highway my transmission slipps and engine revs up for a few seconds,i had thought it was the torque converter but it also happens with the overdrive cancelled so could it be the transmission clutches slipping? how can i be sure? thanks

 

[Bill Stockard]

Use your left foot to hold up under the brake pedal to prevent it from shaking when traveling over the bumps. If there is no "slipping", it could be the brake light switch out of adjustment. When the brake light circuit is energized, the torque converter will unlock and when the the brake lights are off, it will re-lock.



IIRC, the 47RE locks the torque converter in 3rd gear when Overdrive is turned off.



Bill

 

[GreggNoble]

Thanks bill, someone told me about the brake switch and i tried that but it still slipps.

so until i find out whats wrong am i damaging my torque or transmission?

so if i`m gettin slipping with the od off it must be the transmission? thanks

 

[THoltz]

I am not a transmission mechanic but I would think if the TC is in lockup and it slips you would have severe TC wear and damage. If it is not in lockup and there was slip or a difference in speed between the TC drive element and the driven element there would be heat generation, the magnitude dependent on the % slip and duration.



It sounds like the slip you notice might be the 3rd gear band. Have you tried removing the pan and adjusting the band? I think I have seen instructions in more than one post on TDR on how to adjust. Is your fluid discolored which might indicate clutch wear material?



You might clean your battery terminals also.



Hope this gives you some ideas.

 

[GreggNoble]

Thanks guys,this doesnt see to be a common problem with these trucks,usually when there is transmission trouble,it shows its self as shifting irregularities,but i defenatly got a slip in overdrive and in third gear,strangely it only happens when i hit a bump in the road while goin up hill,there are no error codes so it doesn`t seem to be electrical! dunno !!!

 

[Joe Mc]

I'd drop the pan and inspect for material in the bottom, if it looks pretty clean - adj bands, new filter and fluid. Then give it a try. This is a cheap way to give it a "shad-tree" inspection. If the pan has little piles of black material in 2 - 3 spots and allot of brass/metal-flake laying on the bottom then start saving for an after-market trans about 3500 +/-.



Just noticed the mileage in your signature is 178000 klm, that's like 116000 miles, as a reference my trans started slipping on the 2-3 shift at around 136000 miles. I saw the little piles and metal-flake - adjusted the bands, new fluid/filter and drove for a week - still slipping took down the pan on the very next weekend - same deal. So I DTT'ed it - happy camper ever since.

 

[GreggNoble]

Thanks Joe, thats the best diagnosis i thing i`ve gotten,i`ll do that soon...

so should i just get a stock transmission or can i get a improved one for a little more?

i got a few mods like Banks ram intake, Bank power elbo with 4" exhast,and i use a superchips module on the lowest setting and i drive like a 70 year old lady ,my truck gets an easy ride, i use 265/75 r16 tires i have 355 ratio.

i`d like to have a transmission that will lock the torque in 3 & 4th gear

thanks so much. ps my truck now has 270000klms ,i love the engine,hate everything else ha ha ha ha

 

[Joe Mc]

should i just get a stock transmission or can i get a improved one for a little more?



I went w/DTT DTT Performance Diesel Transmission and Power Accessories Call and tell them what's going on now. Tell them what you have power mods, if you tow and what and how often, and if you plan to make any more power. They'll tell you what to look at with the present problems and give an idea of what they think you should do if you decide/need a rebuild later on. I had the complete rebuild done at one of their facilities (Tim Barber of TRE Diesel Performance, VA Beach, Va) for $3500 - I already had the Mag Hy-Tech double deep pan so there was a little knocked off the typical price. Of course prices may have changed since I had mine done back 4 - 5 years ago. Great Customer Service and Great folks.

 

[B.G. Smith]

The torque converter will/can be locked in OD or third lockout above 45 mph depending on acceleration. Maybe you could try holding your foot on the brake just enough to unlock the converter and see what happens at the bump. Sounds like a bad connection or something to me. Also the band that you have to pull the pan to access is low/reverse and I believe the third gear would be a clutch rarher than a band. 117,000 is not too high if the transmission hasn't subjected to higher horsepower or a lot of heavy towing. I drove a 99 a litle over 100,000 with no transmission problem and most of that was towing a 31' fifth wheel. bg