Transmission Fluid Changing Methods... some questions

[Jon '92 325ic]

Hello,

I have a '92 325ic (e30) with an automatic tranmission. If I replace the transmission fluid myself (and the filter) using the instructions in Bentley or elsewhere, I'll only be replacing about 2 quarts of the transmission fluid (from the pan). Any tranny fluid in the transmission, torque converter, transmission cooler and transmission cooler lines (a total of about 5 additional quarts I believe) will stay in place and mix in with the 2 new quarts of fluid once I start driving. However, at EZ-Lube (just for example) they offer a service (for $90) that will replace 99% of your transmission fluid, not just the 2 quarts in the pan. This method replaces the fluid in the pan, the cooler, the cooler lines, the torque converter....

1. Is this latter method, where 99% of the tranny fluid is changed a better option?(Espicially since I currently have non-synthetic fluid and want to switch to Redline.)

2. Besides EZ-Lube, do most other places perform this type of service? I've called EZ-Lube and AAMCO and both will do the job with the Redline Fluid (which I would have to provide) and just charge me for labor. However, neither would provide a warranty against any future damage/failure to the tranmission (except leaking) since they are not supplying or recommending the Redline fluid.

Any feedback is appreciated.

Thanks

Jon

[DaN]

I would definitely have the system flushed. It wouldn't be a good idea to just replace the 2 quarts in the pan. Old burnt fluid doesn't mix well with new fluid.

Have a shop do it for you, just make sure you provide enough fluid. Look up the capacity in your manual.