transmission flushing

[low99on22s]

took my friends truck, and went to the shop and was going to change filter in tranny but they told me it was better not to change filter,but should do a backflush on the system at dealership it works great and better for it , also they were going to fix his throttle surging problems ,when he driving down the road between 40 and 50 the engine surges and when he pushes down on the gas pedal to get up 50 or more it quits ,i think the throttle positioning switch is going bad,what do you think,what do you guys think about both ideas .,,,sorry about the spelling everyone,

[withac]

Here is the response I got from a Royal Purple rep when I emailed him a related question.

The pan drop is fine, our will over power what ever oil it mixes with as our film strength is 400 times stronger. With the mix we also recommend doing another pan drop at 5,000 miles to get a high concentrate of our oil in the tranny.


MY PERSONAL opinion-

A flush is like a empty glass with sugar in the bottom of it, then you pour tea into it. The sugar is stirred up and not is floating all around. What if the sugar was metal shavings in the pan and you flushed the transmission? Well the shavings will stir and go all over the transmission and could give you problems later. I know a lot of people who have never had a problem with flushes, but I myself would never have a flush done on my person car/truck. It is your call and this is my opinion not Royal Purple’s.

I had the TPS on my Durago start to go out. At first only when the cruise was on it would get mild surges, later it would get the mild surges with or without cruise. I replaced the TPS and cleaned the IAC, problem solved.

[low99on22s]

withac,thanks for the answer back, i fill the same way on the flushing also sounds great but leaves alot behindin the pan,and thought the throttle positioning switch was the problem but thanks for the answer on that,its nice for more than one opinion,thanks again

[withac]

withac,thanks for the answer back, i fill the same way on the flushing also sounds great but leaves alot behindin the pan,and thought the throttle positioning switch was the problem but thanks for the answer on that,its nice for more than one opinon,thanks again

No prob. but I'm pretty much a noob myself, I just happend to have a couple of incidents that related to where you're at. Before you buy a new tps you might want to wait and see if anyone else weighs in with thier opinions.

[Ydtrack]

I always do a fluid and filter change first, then use the T-tech to do a complete fluid exchange.

[txarkitekt]

Yeah, dropping the pan and replacing the filter will be fine for now.

As for the surging problem, it could be a number of things. First off, is there a CEL? If so, what are the codes? It seems logical to think the TPS is the culprit, but it could be several other things--and those would trip a CEL to come on. Even a problem with the TPS should cause the CEL to light up. Are you sure the guy's floor mat isn't bunched up under the gas pedal??? LOL...

[BossGMC]

The problem you have will not be solved by a trans flush, whats happening is that your torque converter lockup is surging in and out, at light throttle it disengages and locks back in when you get into the throttle, what happens is that all 4l60e fom 97-current have a torque converter regulator valve in the valvebody, it is pulsewidth for smooth lockup aplication, with time the valve wears out the bore in the valvebody it self and it looses pressure, to fix it there are to options, either you replace the valvebody assembly with the revised on sold by GM dealerships, cost about 600 dollars or you can replace the actual valve with on oversized one sold by trans-go, it comes with a new valve spring and installation procedure, only sold in there 4l60e shift kit, if you need any help on tech assistance let me know....