1983 tercel transmission rebuild or swap?

[vermont]

Hello,
I'm trying to determine if i should pay for a tranny rebuild or swap. Here's the situation: i was trying to change my tranny fluid for the first time and i messed up and pulled the wrong bolt- i think it's called a b-10, and it sticks out the side of the tranny like the filler bolts, but holds the reversor into place. so i'm stuck, altho i did drive the car a half-mile to the mechanic, who explained what was wrong. no major weird noises along the way. now i have found a used tranny from a 1985 4wd tercel for 200, or every tranny mechanic i've talked to say they can rebuild it. my questions are: are the 1985 transmissions compatible with my 1983? one problem is that the mechanic i would buy the 1985 transmission off says it's 5-speed, and my transmission is 6. but i don't think they made 5-speed transmissions for the 4wd tercels (correct me if i'm wrong) and he assures me that it is a 1985 4wd tercel. i called the junkyard and they said that they look compatible according to their book. the 85 transmission has already been rebuilt, and has sat at this guy's shop for years.
any thoughts? has anyone seen this problem before? is there a way to fix it without taking the transmission apart?
Thanks,
Jeremiah

[xirdneh]

the differetials (built into the transmission) between '83 and "85 are different.
they are interchangable but you will need to change the rear differential to match it.
you could get by without changing it but would have to be very careful about running it in 4wd
i did it for one winter, only using it when road was very slippery.
the gears will bind up if there is not enough slippage.
i ended up switching the rear differential (got one for 60.00) at wreck yard

the trannys in these cars are 5 speeds with an extra gear for low range 4wd
so some refer to them as 6 speed

[vermont]

Thanks for the reply. At this point it seems reasonably clear that I won't be taking the used tranny, sweet deal though it is. In that case, I have another question: for a newbie with some mechanical experience, how long might it take me to take my transmission out? are tercels relatively easy or more difficult? are there shortcuts from the service manual that i should be aware of? are their any specialized tools involved? I'm just trying to decide if i should shell out the 4 or 5 hundred to have the pros do it, or do it myself.
THanks,
Jeremiah

[Petros]

If that was a rebuilt trans, that is an exceptional purchase. I would buy it. but as noted the '83-'84 diff ratios are different from the '85 and later ones. They have to match gear ratios in the diff front and rear. You might consider swapping out your old front diff ring and pinion on the new trans so you will have the old final drive ratio. The trans are interchangeable but you either have to swap out the front ring and pinon gear in the new transaxle (requires adjusting the lash with shims), or you have to change the third member diff in the rear axle so they match (not that hard to do, but it is messy). The later one is 4.1:1 ratio which is better for off road, performance and low end power, but it makes the engine noisy at fwy speeds (higher RPMs). So it will be a bit quieter with the higher gearing, but not as good off road, or on steep roads. Oddly there does not seem to be much effect on economy, usually the higher gearing (lower fwy RPMs) you get better economy.

good luck