Flush a 1996 lexus Ls400 transmission with No previous problems but had 93,000 miles on the transmission fluid and filter (338,000 miles total on the transmission )after a total flush with No Filter change the car will not shift into gear. All gears act like Neutral, what's my problem? Thanks

SOURCE: Chevrolet Malibu 2001 Transmission Flush or not

75,000 miles isnt alot of miles,unless they were mostly city miles. If you aren't experiencing any transmission problems,i would drop the pan,change the filter and whatever fluid the pan holds,and hold off on flushing the entire sytem.The clutches and bands sometimes don't do well when shocked with ALL new fluid that contains a certain amount of detergent.The only real problems i have seen with the total flush is on Dodge trucks of the 90's up to even 2000 and some later models,the transmissions use a governor pressure sensor,and solenoid,and i have seen many of them set codes after the flush,and the components having to be replaced with new.Black fluid isn't a good indicator.Brown fluid,is better than black.And red fluid is the best.

Romy Kettlewell

• 154 Answers
• Posted on Aug 03, 2009

SOURCE: 1997 Mazda protege LX 1.5 automatic transmission

You are going to need a transmission shop. Mazdas do not always throw codes. You have an early OBD transmission, which do not send out many codes.

SOURCE: Change transmission fluide in 1999 Jeep Cherokee

Flush is Recomended Here as Changing Fluid can get Messy

SOURCE: 2002 Grand Am GT transmission problem.

Well, there could be several possible problems. It is not uncommon to have a little harder shifting after a fluid change for a period if the system was low prior to the change however, If you had the fluid changed using one of those reverse flush machines I see the problem getting worse. Most stations want to use the back flush system to do a fluid change now days. That is because the newer model vehicle have a metal filter screen which is re-usable and is designed at the factory to use Synthetic Fluid. In the older model vehicles, 2000 to 2005, manufacturers where still mixing the types of filters that were being used. This model has a standard filter that model uses the newer filter. If you went to Jiffy Lube and didn't specify you wanted a regular Fluid and Filter change they hooked it to the machine and charged $140+ for the job. A regular Filter and fluid change with regular fluid would have run about $50. Every time, and I mean Every time, I have had a fluid change using that back flush machine on a vehicle within 6 months I have had to have the Transmission repaired at a shop. If you didn't have the fluid changed using that backflush machine then your problem is just adjustment to the new fluid being at the proper level. If you did, start saving for a Transmission rebuild at a shop, it's not far away.

SOURCE: automatic transmission will only shift manually

This is a sensor issue. It can be from a couple of different sensors. The VSS, or vehicle speed sensor is the main one. Loose or faulty wiring can cause it, a faulty PCM can cause it, or the Throttle Position Sensor can cause it.