So check this out, Ive got a 88 4wd auto wagon in the shop at the moment. Theres no drive in FWD, but it moves fine in 4wd.
Axles are fine, the front diff is fine from what Ive been told. I looked through my book and the only place I can think of is right here.....the splines where the trans mates with the bellhousing.
The pinion gear is permamently attached to the shaft, correct? I know it is on the manual trans.
that is fairly normal build up from the drain plug magnet, there are internal clutches that slowly wear on an auto trans (like the brakes or a clutch on a manual trans, it is how it works and eventually wears out), this is normal and on a car as light as a Tercel the auto trans clutches (and most of the rest of the internal mechanism) lasts a very long time if the ATF is serviced at regular intervals per the manual (30,000 mile change interval as I recall).
The most likely issue with the FWD is unfortunately not unusual, on the auto trans only there is a coupling from the front out put shaft of the trans to the front differential that sometimes fails. There have been several threads on this topic with pictures, do a search of the archives. It is actually an easy fix once the trans is pulled, front diff/bell housing is separated from the main gearbox housing and it is all exposed. You need to find the replacement parts however.
As I recall the parts to fix it are no longer available new from the dealer, but this part is the same on all 2wd and 4wd Tercels, so any autotrans from any of the 2nd generation Tercels will have the parts you need (perhaps even any autotrans first gen Tercel '80-82). That is from '83 to '86 sedans and hatch back Tercels, and '83 to '88 wagons only. If it has an auto trans in it, it has the part you need to repair this.
I think this part fails when in 2wd and someone back the car up and while it is still rolling backwards, they put it into drive and stomp on the gas. This puts a lot of strain on the drive train and unfortunately this coupling is the weak link in the system (perhaps intentionally designed to fail first so you do not damage the transmission internal parts).
meanwhile it will not harm anything at all for you to drive it as a RWD wagon if you want to wait, though you will want to change the fluids from both front diff and trans to make sure no fine broken metal bits get circulated throughout the trans. If it is in the shop now, best to have it fixed if you can locate the parts. One of the best things about this otherwise simple econo-box cars from the '80s is the 4wd feature, and you will need to have it fixed eventually anyway, so best to just fix it now.
Good news then Petros! I have a donor 4wd auto trans right beside me. However Im unsure of the condition of the clutches and bands so it appears Ill be swapping that part over. I DO know, the front coupling is good. It doesnt want to roll when in park like the trans in the car does.
Thanks xirdneh, I figured the governor was behind it, but if its the same, hey, thats awesome.
Ill scour the forum archives and double check on all this.
you might save time by just swamping out the whole trans assembly. it would be a good idea to put in new seals while it is out. Of course if the replacement trans has issues, than you will have to pull it out and swap out the part. but I have found these old toyota auto trans are remarkably durable, other than these troublesome governor couplings. I suspect it is a sacrificial part, Toyota should have kept an inventory of them for those of us that keep their old Toyotas running.
whenever I change out the ATF on an old car, I also include some quality additives to help clean out the valve body and improve wear and the life of the trans. One time on an old Honda auto trans for my daughter, it was getting slow to shift (the engine would wind up very high before it would finally shift), the transmission valves were sticking. I put in a can of valve body cleaner and the problem went away, put another 100k miles on it and sold it still working well. The trans "experts" advise against additives, but these same experts recommend a $2000 trans overhaul for this problem. Ha! Some expert.
Well thats the thing. The donor was in the junkyard with no visible damage. It did have a brand new radiator though. (snagged that) No coolant in the oil or vice-versa.
I drained and pulled the pan on the donor a few minutes ago, its got some sparkly pieces in the pan that were large enough to bother me so Im def gonna just pull em apart and swap out the piece. Id love to just swap trannys, but Id rather not put it in just to find out it wont shift right.
Good info on the additives, Ill run a bottle through it when I get it back together and toss it in. How long did you drive around with the additive?
I fixed a slipping cressida trans by flushing it with toyota trans fluid ($8 a quart!) and and adding a larger tranny cooler. It worked good enough I ended up buying the car back after I sold it.
That happened on my automatic as well. It was that splined coupling you were talking about. It's called a governor because it's also a centrifugal valve that adjusts fluid pressure based on rpm. The splines gradually wear out over the years and then they suddenly shear. I drove around in 4wd (which was rwd) for a few weeks. If the trans still shifts fine in 4wd, the governor is still rotating on the shaft and it's the splines on the output side of it (to the diff) that have sheared. I doubt you'll ever find a new one. I bought an 2wd old core transmission from a local transmission shop for $75 if I remember right. I opened it up and took the governor out and installed it on my 4wd. It was a bit risky buying that old trans from the shop since I had no idea what the condition of the governor was. It turned out to be fine. The splines were slightly worn, but I guessed that was normal. So far I've been driving around with it for a few years without a problem. Another cause of no power to the front wheels (other than the front diff, which you said was fine) is the splines on the drive axles.
rather than a conventional trans fluid change (which leaves several quarts inside the trans/torque converter), if you use the cooler lines to pump the fluid out, while adding new fluid into the input line or filler neck while idling it, it will clean out all of the old fluid. You keep it up until you see fresh pink ATF coming out of the output cooler line. Be very careful you never allow the ATF to pump out of it. There are youtube tutorials on doing this.
Once you have all fresh AT fluid, you put in the additives and drive it until the next fluid change.
