My truck ('97 1500 4x4 w/ 318ci.) seems to run fine in 1st, 2nd, 3rd, and even 4th gear, but when the torque converter locks up when i'm cruising at 45mph and faster the truck shakes and shudders. If I increase the throttle it gets worse until the torque converter unlocks allowing for the gears to work normally. The tranny fluid level is good so I don't know what it could be. Any ideas?

 

actually the tc locks up in 3rd at about 35-40, and then it shifts to OD at about 45. thats probably your shaking, shuddering. trying driving with your OD off to test this. if trans hasn't been serviced recently you could try a fluid/filter change with ATF+4 and see if it helps any. might, might not, but not too expensive as first step. if that doesn't help you probably need to go to your local transmission shop that has the best reputation. don't wait for it to explode or it will cost more.

 

yea i was just making assumptions as to when the tc locks up. i just think its wierd that it works fine otherwise except for when i'm cruising on a flat road. i want to change the oil and replace the filter, but i won't have a garage to do it in for another 2 weeks.

 

try driving with od off except for highway over 55-60. you can probably drive it like that for a long time.

nice diy help site. http://www.pavementsucks.com/tech/trans.php

if you don't have a trans pan drain plug it is a messy job. if you're going to keep the truck put in a drain plug kit avail from any local auto parts store for $5. it will make it easier in the future. tip. use a very large drain pan and loosen rear pan bolts first and let fluid level above pan run out the back. then put floor jack snug under heavy pan and remove all bolts. ease down the heavy full pan while balancing on jack, takes about 3-4 hands and dump fluid over into drain. otherwise its too heavy to handle.

a friend of mine recently bought a 99 ext cab 4x4 with about 105k and a hole in the bed where the prev owner had a gooseneck for SERIOUS TOWING (that should have been a red flag). my friend is real impatient and didn't look it over close or get any other opinions, he just saw it and bought it. after about a 10-15 minute drive it would get warmed up good and when you went up a hill in OD it would hammer like crazy. we changed the fluid a couple of times and it would do ok for about 4-5 days and then go back to hammering. it needed a few other repairs like IAC, rear axle seals, rear axle bearings (or maybe differential roaring), t-case seal, cracked dash, steering box. after about a month he traded it in on a new ford.

 

I don't know about the newer Rams but I am quite sure that my tranny goes from 3rd, to od, THEN it locks up.

If you have a bad shudder in lockup, more than likely the clutch is slipping from a raised hot spot, or the housing is warped. Or a few of the fins have let go and are restricting fluid flow. It's pretty common with the mid 90 Rams.