i have noticed under heavy acceleration my car has started to lag between gears seems to be getting worse,shift points dont feel right,feels like fuel is being cut off for a second between gears under hard acceleration,checked trany fluid seemed ok.do i need trany service?,would bad spark plugs cause this.
need some help before i take her in.thanks
99 gs400 65000 miles.

 

Time for a tranny flush. I would also consider changing the timing belt, differential fluid, motor oil (Mobil Synth 5W-30), possibly the plugs too, etc...... At 65K miles and under heavy driving....it makes sense.

Pete

 

had trany serviced,appears rmm tc is slipping,i can hear a short sqeal when car shifts from first to second,has this happened to any one else?,i bought the car used with rmm tc installed already.does rmm warranty there tc.and how much will a stock tc cost me.

 

lexo, I think Im having the same problem with my RMM tc. Same deal, I bought the car with it on already, has low miles on it though. At first I thought it was the tranny slipping, but Im really leaning towards it being the TC. If my tranny was slipping like it did a few days ago, then it would still be slipping. It has been acting fine on and off, the tranny wouldnt just fix itself spuratically. I really think its the TC, but Im not sure how a shop would go about determining this. Does anyone know how to tell if a TC is slipping?

There are times when I first drive the car after sitting that it slips real bad for a the first 20 feet or so then its fine. Almost like its not getting fluid to it immediately, or something like that.

 

Ok I have the exact same thing 2 weeks ago I went to Matt at Under Pressure. He drove the car and thought it was the Tranny. Maybe the T/C , either way I have 375 HP to the wheels w/o NOS so I am having a tranny built. It should be done in 5-7 days now. They are going to pull the RMM T/C and check before reinstalling in the new tranny.

I will let you guys know. This question with the RMM T/C has come up before.

My slipping is hard excelleration between shifts, more so in "D" rather than the triptronic. It has also made a high pitch noise between shifts 2-3rd gear. I change the tranny fluid every 3000 miles along with Mobil One 5/30 and rear diff fluid. $$$

 

Hmm.... How many miles do you have since installing the TC?

roenick7: Every 3K miles you flush the tranny? I follow a slightly *ahem* less rigorous schedule though still more so than usual. Every year or 10K miles I'll do those services. I've got almost 20K on the car with TC and a touch more RWHP. No problems yet. "Knock on wood".

I'm curious to hear what the outcome of the inspection is. BTW: Who's doing the rebuild and what's involved?

 

This is pretty much what mine does also, I havent noticed it when using the triptronic, yet!!

 

well it turns out i had a bad maf sensor,car feels like new again,transmission lag is gone.i would of bet my life it was the rmm tc,who knew.if they could only fix the low idle, i would be a happy camper.