Transmissions and torque

[Eveahlers]

Hello I'm wondering if there is any info on strength of transmissions. I'm looking at lowering a tercel for peppy windy road car. Not a ton of power but more than stock

[teranfirbt]

I've been running a 4AFE in my car for a couple of years now without any trouble, and I don't drive it easy.
Someone's got a 20 valve 4AGE (~160hp) running on a T4WD transmission. Haven't heard anything specific about problems.
If the T4WD trans is built anything like Toyota's other transmissions, it'll handle a fair bit over stock power. The limits are more about how you drive it. I imagine you could get up to the 180 hp range without too much trouble, as long as you avoid the smokey burnouts and other shenanigans. The differential is probably the weakest link, they aren't exactly big in these cars.

[Eveahlers]

I'm looking at a highly tuned 4ac, so it sounds like the tranny should handle it. Is there a better year for a differential?

[teranfirbt]

I believe the '85+ years got aluminum shift forks that are more reliable. Otherwise it's probably more down to miles than specific years.

[Petros]

the trans should handle a 4ac no problem, just make sure you keep the gear lube topped up and you change it at the recommended interval (and keep after leaks, which will cause to run low on gear lube). the '83-84 diffs use 3.73 final drive ratio which is a bit more quiet at fwy speeds, but not as good for steep hills and off road, the '85 and newer diff use 4.1:1 final drive ratio and better for steep terrain and low speed/rough road driving, at the expense of more noise at fwy speeds because of the higher speed the engine runs at. economy is about the same with either, I have run both gear ratios for many miles on different Tercel4wd I have owned, I have come to like the 3.73 for daily driving on normal roads, particularly with the little bit of extra power you get from the 4ac, so pulling away from a stop will not as easily stall the engine. For good off road performance the lower 4.1:1 is a better choice.

I do not know if one is more durable than the other, but either should serve you well if you take care of it and not drive like an adolescent.

[splatterdog]

Generally the lower the gearing, less stress is put on the driveline, but a bit more on the diff(s).