hi, im sorta new here. here are a couple of questions i have, if its in the wrong place please move it to where its meant to be. i realize it should be fairly obvious but i havent dont it before and just wondering how it would be done? also have some other questions too
a) just wondering how hard it would be to service your own gearbox?
b) do you need a many tools to do it?
c) are gearbox parts cheap?
d) also, how can you tell what sort of gearbox you have? is there a c# stamped on a box or a tag somewhere on the gear box?
when my gearbox changes gear often its noticeable, like there will be a thump or thud that kind of noise, usually when selecting reverse when the gearbox is cold, and when driving around the gear changes will be noticeable too, thats why the questions.

There should be an id tag on the box
I have the tag numbers for XR to XY C4 auto box,Borg Warner 35 6cyl auto and FMX auto tag numbers, I'm not sure about the larger C sieries auto boxes or the later models if they use the same id numbers. What i do know is it seems that the last set of numbers or letters define the year model and engine size but I'm not 100% sure.
Basically if the tags have any of these numbers as follows thats the type of box you'll have.

Borg Warner 35 6CYL box will have a ford number and a Borg Warner number. The ford numbers are 72DA-7000-** or 76DA-7000-** the last 2 letters (*) define the engine size and model.
The Borg Warner numbers all start with 0546-******

(*) are the same as above and below.

C4 auto box Id numbers start with PEE-** and PEF-**

FMX auto box Id numbers start with PHB-*

Sevicing these boxes is easily done if you are mechanicaly minded and not a complete dumb s**t. Once youv'e worked out which box you have you need to buy a filter and oil pan gasket kit to suit usually no more than $40 the last one i bought for my C4 was $25. While your there buy 10 litres of the right trans fluid to suit your auto trans. Then is pretty much as simple as draining all the fluid from the box and torque converter ,the easiest way I have found to drain it as much as possible without removing the entire box and converter is to dissconect the trans cooler lines from the front of the car at the trans cooler or radiator and put them in a bucket to catch the trans fluid, then dissconect the coil lead from the motor and wind the motor over untill no more fluid comes out the cooler lines , this should pump out allmost all of the trans fluid from the box and the converter, it will pump the trans fluid out of the torque converter back into the box then through the cooler lines (some people i know of actually start the engine and let it idle untill they see air bubbles coming from the cooler pipes) its up to you but if you just remove the oil pan from the gear box you will only drain the box its self and not the torque converter again it is up to you, . Then get under the car remove the oil pan from the gear box and give it a thorough clean remove all the old pan gasket , remove the trans fluid filter from inside the gear box you will see it as soon as the oil pan is removed and remove the old Oring,you'll see the O-ring in the hole the filter came from, then replace with the new Oring and filter ,glue the new oil pan gasket to the oil pan with a VERY SMALL amount of gasket glue refit the oil pan and screw the oil pan bolts up finger tight then torque the oil pan bolts up to 16 to 22 Nm using a torque wrench and fill with the trans fluid.
If you want to adjust the bands you really need to know what box you have,
the C4 band adjustment is all externally done by first loosening the locking screw on the left hand side of the box then tightening it back up to 14Nm then backing it off 1 3/4 turns then on the right hand side is the same process but back the locking screw off 3 full tuns.
Borg Warner 35 and FMX have an internal adjustment which you need to use a feeler guage and will need to be done befor the oil pan is bolted back in place and external band adjustment done last once the filter and pan are back in place and the box is full of trans fluid . Both are done the same way but have different tollerences if you have one of these boxes msg me and i'll e mail the process to you as its a little more involved but very easy to do.

If your talking about your NA F'lane....is it a 3sp or a 4sp????
3sp will be a Borg-Warner 51......the other will be a BTR LE85 or something like that.
They both take different fluid.......the 51 takes either DEXII or DEXIII.....and the BTR will take Castrol TQ95 or Valvoline LE95, or Pentrite LE95.
They are both adjustable as mentioned before.

cool, thanks heaps for all that info. i will have to check/look at tags tomorrow in my pj's now. the guy that owned it before me replaced the original gearbox with a four speed, not sure what it is right now though. when i got it serviced (left all my tools in adelaide) the mechanic said it looked like it has been steam cleaned or something. is it a rebuild then whenyou start changing things like solenoids and other things like that? i will get under it tomorrow. post back tomorrow when i know more about it. thanks

If it's been steam cleaned, then the Gear Position Switch ( found on Pass. side of box ) will be fvcked.....it would have forced water inside it.
Replace that first, and go from there.
There is an oil seal under it, and they ( the Switch ) are usually rusted onto the shaft too.
Check the play of the Slip Yoke Bush too.....known for wearing out.
Check for oil leaks at the Servo plates ( 2 of....front & rear ). the rear one is bolted on, and the front one is held in with a circlip.

didnt get a chance to look at it today, when i get my tools back which should be soon i will have to post back then, i will definately look at the things you mentioned though. thanks heaps for the info.