hutchwilco

So I've had a trans mechanic look at it - good sort came and looked at it on the weekend to give his advice. We drove it round till it warmed up and as expected the shuddering started above 70k and especially when on a slight incline. He said it's definitely not missing as the frequency is much lower than expected for that. He checked the trans fluid and said it didn't smell burnt. The other main observation he had was that it shuddered equally as bad out of OD, which implied to him that it's not the lock-up plate, as that only comes on when you're in OD and cruising. He did say you can't drive them in 2wd as no matter what you do, the clutches will always get worn after anything more than a short trip. Not getting any fault codes, and nothing else indicating coil packs. I'm thinking of running car at night and spraying water-mist on to see if they are arcing? Sound sensible? Another source is suggesting drive shaft, but it's just so regular on-off and consistent it really seems like something in the auto trans...

So my stutter/shudder occurs after driving for about 20mins. Seems like the trans has to warm up first. It only happens when I'm sitting tight at a steady cruise, a bump (roads are riddled with them here in earthquake central - Christchurch) seems to be able to set it off, then its a forward back shudder which seems to feed on itself and grow more severe if I let it continue. Usually I can stop it by slowing or accelerating but it will always start again eventually. Occurs in both OD and not, over 60km/hr. I can induce it by gently accelerating from a cruise. I've just spoken to a trans mechanic who thinks that because the lock up clutch/plate only comes in when in OD that my problem must be something else, since it occurs at 100km/hr out of OD. He reckons something like engine misfire, saying that under a load/ instantaneous surge, like a bump, the engine could be misfiring. The car had been owned by a backpacker who may have been putting low octane 91 in it - I'm not sure. I know I put a tank of 91 in before I learned I should be using 95 at least. If it is mismatched wheels causing the ATESSA to do this, would there be a warning light, or diagnostic code? I think the tires could have slightly different wear but as I understood it, ATESSA is designed to accomodate wear in tires - it would be pretty silly for it not like it. Wondering if rear diff/4wd fluids need checking?

just bought a 4wd 97 rb25de with lock up stutter above 60km/hr and most often when in OD. most pronounced at 100km/hr. was quoted about nz1k to remove and service torque converter based on my verbal description. might look at the over drive button myself, but pretty sure its the lockup plate worn since I can induce it by gently accelerating from cruise. keen to hear what you find out...