there may be a slight miss. but I cant realy tell.I changed the trans fluid last week it was very dirty. I might make note that it sometimes sudders real bad and sometimes it sudders just a little bit. I am not getting any pcm codes. do you think I should take it to a tranny shop for diagnostic.

 

take it to an auto transx shop only if you personally totally trust and have previous trade knowledge of the business.

did the new ATF improve the shudder and high speed shifting problems? if you did a pan change only, only about 1/3 of the tranny fluid was changed. torque converter and vavle body were still full of the old goop.
overdrive clutch pack and torque converter lockup clutch probably coated in failed ATF goop varnish.

do not do a flush at auto tranny shop, pushes goop and friction particles into valve body small openings and puts more junk in than removes if they don't clean machine after every flush.
do a gentle flush and save a bundle.
replace all the fluid using this technique. use a top quality ATF such as Chevron with ISO SYN, Valvoline MaxLife or if cost is not an object and long ATF life is use Mobil 1 ATF, Amsoil or Redline. TallPaul has had good success with Redline D4 and I use Mobil 1.
warm engine to operating temp on the road. park on level.
pull the bottom steel transmission cooler line out of the radiator side cooler or if you have an aux tranny cooler in front of the radiator, pull off the rubber return line back to the tranny. put on extension neoprene hose into drain bucket, start engine, drain out 3 quarts ATFwhile shifting thru the gears with parking brake set and wheel chocks, stop engine, put in 3 quarts new ATF, repeat drain and fill until you've ran 10 quarts thru.
add one bottle of LubeGuard "Red" auto transmission protectant, an ester synthetic oil product that cleans failed ATF varnish and deposits gently from valve body and other controlling parts in tranny.
available from Volvo, Audi, Mercedes and some Ford dealers and auto tranny shops.
best web price
http://www.transmissionpartsusa.com/Transmission_Fluids_s/3.htm

top off with ATF to crosshatch area, do NOT overfill.
should be another 50k left in that old tranny. put a large aux cooler on it.
check ATF condition every 200-300 miles, if diry again, new fluid and LubeGuard did their job, cleaned the old goop, change ATF again with new LubeGuard.
new rebuilt on web $1900, full master rebuild here is $2500 installed.

 

I just did a drain an fill about three 1/2 qts and I did not notice a differance so this weekend I will do a flush like you instructed and see where that leads me. I did not state in my last post that the second I take my foot off the gas peddle the shutter go's away when I put my foot back into it and it starts to pull the shutter comes back. just to confirm it sounds like the torque converter?

 

yes, sounds like lockup direct drive clutch in torque converter is slipping, tranny goes into torque converter lockup when 3rd or 4th and under light to moderate engine load at cruising when torque fluid multiplication is not needed for extra pulling power.
far more efficient when in lockup. no torque converter slippage when working correctly.
almost like another overdrive gear

 

well! I did a complete fluid change and added a tranny conditioner. it was not the lubeguard but it was labeled as treatment for tranny shudders. and it made a big differance although I still get a shudder it is nothing like it was. I will drive it for a couple weeks and flush again .I will keep you posted.
Thanks to all
Gary

 

LubeGuard and SmartBlend are the only two that I would use, both use proprietary designed ester oils and friction modifiers, the rest are cheap seal conditioner/swellers.
Both will gentle clean the varish/goop buildup in auto trannys-clutchs, bands, and valve assemblies

A $2000 transmission is worth a $10 bottle of ATF treatment that works, also use a top grade ATF like Chevron IsoSyn or one of the full synthetics for long life.

 

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I have used Chevron's ATF for fluid changes in my '87 Aerostar w/ A4LD trans. No leaks, No Problems, Trans upshifts normal and downshifts normal when coming to a stop sign or redlight. Freeway onramp, the stud-like 3.0 little V6 accelerates, transmission upshifts into "OD" @ 45-50 mph, in which 65-70 mph cruising speed is effortless, and quiet. All from Chevron's ATF, van @ 139K miles, P215 75 R14 tires (4). I will always run Chevron ATF in my Aerostar... Ed

 

I agree Ed, Chevron ATF is "the right stuff". Have used it myself for years when I finally quit using the cheapest stuff on the shelf. Chevron has IsoSyn which is their version of a Group II synthetic hydrocracked from dino oil.
Since I tow a trailer with the Aero, I now use Mobil 1 full synthetic ATF after I found it on sale, has a higher temp breakdown than the Chevron.
non towing apps unless in desert SW or Middle East do not need full synthetic ATF if they have a good large tranny cooler installed.