Digipixel

I just took my 91 Civic LX in for an oil change and tune-up. It has 128K miles on it. I also asked the mechanic to change the tranny fluid. However, when I picked up the car he said he preferred to NOT change the tranny fluid. He said when a transmission has that many miles on it, I could be asking for trouble to change the fluid. To be honest I can't recall the last time I had the xmission fluid changed, but it had to be a least 50K miles ago. Any opinions on whether it would be safe to change the fluid? Are there any fluid additives that might help prevent trouble in an old tranny after a change to new fluid?

gearbox

iTrader: (95)

he is right, just drive with whatever is in there til it dies. if you change now, more than likely the gears will start slipping and you will soon be buying a new one.

Digipixel

@ gearbox - thanks for the advice! Is it a bad idea to add an "extender" to the existing fluid? I was considering adding a little "Lucas Transmission Fix" (slip stop) to the existing fluid. The transmission is starting to "clunk" a little between gears.

gearbox

iTrader: (95)

no do not add anything to the fluid.

cb450sc

My son's Civic had 240,000 km on it when I changed the transmission fluid for the first time last summer. I changed it three times over a three week period while he was at home. I have to admit that for the first two months, the shifting was actually more stiff. Now it is smooth as butter and he has not had any problems with it. I say change it.

dtown101

It is good to change the fluid. you just dont change it like you do your oil. i mean think about it is a working gear system and it is going to wear over time just like anything else. Dont add anything to it because then you are mixing things and that isnt good. even if it is lucas. only add it if you are putting new oil in.

Digipixel

Thanks for all the input/feedback.

At this point I still have not changed the fluid. The fluid level is fine and it's not leaking anywhere so I am inclined to leave it alone. The ATF on the dipstick is clean and red with no burnt smell, but I am concerned about the clunky shifting which is showing up mainly between 2nd and 3rd gear.

I just don't want to make more trouble for myself if I don't have to.

gearbox

iTrader: (95)

well if its red, seems someone already changed it before you bought the car, probably with generic fluid. you could try switching slowly to valvoline maxlife dex/merc atf which is the only good atf rated for use in older honda trans that shouldnt cause problems. it will improve shift quality and work well. maybe do a single drain and fill first to see what happens, then a few weeks later a second drain and fill. you usually only change 1/2 the fluid capacity each time because a good amount stays inside the trans.

Digipixel

Thanks, GB. I bought the car new in 1991, so there are no former owners. Just me. However, since 1991 I have moved about 6 times (in and out of 4 different states), and to be honest I have lost most of my maintenance records. You are right, though. I may have had the ATF changed more than once or twice in the last 21 years! I just don't recall! I may take your advice though and try dropping the pan and changing the fluid.

Funny thing is, I just put a new set of Michelin tires on it, so now the tires are probably worth more than than car........

gearbox

iTrader: (95)

yeah drop the pan and see what it looks like. if things are mostly clean, do a drain and fill with new filter. im pretty sure those older civics have a removable filter. if there is lots of dirt and the fluid is gritty, i wouldnt do anything except maybe change the filter. new fluid may cause slipping.

palsana

those older civics have a removable filter, (Does 03 civic (7th Gen) have it?).
i wouldnt do anything except maybe change the filter. new fluid may cause slipping.
Dtown101 says: It is good to change the fluid. you just dont change it like you do your oil.
V/s
just drive with whatever is in there til it dies. if you change now, more than likely the gears will start slipping (Is that true for 7th Gen honda civics)
03 civic ex A/T transmission is starting to "clunk" a little between gears.I am concerned about the clunky shifting which is showing up mainly between 1st and 2nd gear. The gears just never fall in place a& you can drive upto 10mi without having a shift in gears just by pulling off and on your feet from the gas pedal. The car on the freeway will continue moving at a not to exceed 45mi/hr but never really still fall in gear from 1st to 2nd? is that really dangerous? what could be causing it? Are there any fluid additives that might help prevent trouble in an old tranny after a change to new fluid? the ATF on the dipstick is clean and red with no burnt smell, the fluid level is fine and it's not leaking anywhere

gearbox

iTrader: (95)

01-05 civic autos do not have any replaceable filter. there is one strainer inside the trans and once it clogs, youre finished. and yes i have quite a few other problems with mine aside from slipping. for example sometimes i get clunks during shifts, other times its so smooth it feels like something broke. other times when driving i randomly get single click sounds and when shifting into and out of R i hear even more noises. overall it drives okay once warmed up but i can tell there are too many noises. not to mention whining at lower rpms and idle. i use LC20 additive (just 1oz total) in the maxlife trans fluid but its more for keeping the fluid good longer rather than cleaning stuff inside. its a tricky game with these cars.

palsana

where do you get this LC20 with Valvoline MaxLife Trans Fluid? does it come already mixed into the transfluid or its a seperate item to be mixed with Valvoline Maxlife TransFluid (without Additive).
Can you mix this LC 20 with Honda Z1 Transfluid.

What you suggest is to drain but not flush out the existing TransFluid in the Transmission. Or do u mean just add this LC20 additive into your existing TransFluid and let it run a few 100 miles and wait on results.

gearbox

iTrader: (95)

lubecontrol.com has the oil additive. i use it in the engine too. yes you can use with z1 and it noticably improves shifting. not much difference when added to maxlife because its already a better fluid. i would do a single drain and fill to see what happens. never flush any trans. and use the maxlife atf without the stop leak additive. just get the regular trans fluid.

palsana

After having been through atleast 2 prior re-builds on my transmission. i do not believe the ATF fluid is Z1 inside at all. Most recently the re-build never really used Honda or other Valvoline MaxLife or anything like that!!!!!!
Wouldnt in that case, a full flush and drain along with the LC20 additive, make sense?
Drain down the whole previous ATF fluid from the Transmission and put in a Z1 fluid or Valvoline Max.
The last transmission re-built used a cheap cheap ATFluid in my transmission. I know so, for i believe the mechanic who worked on it did exactly that....better late than never.....

palsana

what say you gearbox. Flush or Exchange fluid? i know your answer i guess however, im not sure after re-builts

gearbox

iTrader: (95)

i would still not do a flush. several drain and fills is much safer. i would recommend 4x drain and fills so you would need around 12 qts of atf. that would leave just under 1/2 qt of old atf in there which is good enough (capacity is 6 qts). z1 is discontinued btw.