upside to trimatics?

[Paiste402]

sorry about another thread, im just a bit new to these old commodores and how they work.

is there an upside to the trimatic gearbox? i read some pages on a site and apparently the tri was an upgrade for the SL and SL/E.

Also why the heck r they only 3 gears?

thanks blokes.

[SL/ENUT]

Well, trimatics were used on all of the 6 cylinders and 253 V8s since the trimatics were built.
They are only 3 forward gears cause, that was basically worldwide for any auto, although in America they was starting to play with 4 speed autos. Remember, trimatic are built in Australia.

Also, with the trimatic equipped cars, they have a taller diff, usually 2.78:1 in 202/253 powered commodores, 2.60:1 on 308 powered commodores. Thats why some cars fill like a slug.

[tigervh]

sorry about another thread, im just a bit new to these old commodores and how they work.

is there an upside to the trimatic gearbox? i read some pages on a site and apparently the tri was an upgrade for the SL and SL/E.

Also why the heck r they only 3 gears?

thanks blokes.

The trimatic was always the bread and butter auto trans in the early Commodores. The TH400 was the heavy duty option.

4 speed autos didn't come out until the VL's in the Commodores and the Late EA's in the Falcons.

At that period of time 3 speed auto's and 4 speed manuals were considered normal, where as 4 speed auto's and 5 speed manuals were considered technologically advanced. Now days 4 speed autos and 5 speed manuals are run off the mill, while 6 speed manuals and autos are the higher spec options.

The Trimatic's can be built to be quite strong, though personally I'd rather ditch the auto for a Supra 5 speed.

[Huitzi]

Just my 2 cents worth on this one,the trimatics can be build quite strong at a reasonable cost say about $2000 including a stally and trans cooler....mine has had a fair bit of work and is built to take quite a punch,3000 stall,8 clutches per forward gear (instead of the normal 3 ,dont quote me i could be wrong)stage 2 shift kit,billet servo piston,pump upgrade,wb bell housing (they have got the extra internal webbing to make it stronger) just ask around cos the trimatics have been worked out nicely these days to do the job quite well combined with a good diff ratio 3,45:1 or better then you wont be disappointed.

[immortality]

the good thing about the trimatic is that they are lighter then the th350. less internal mass etc. it means you loose less power through the driveline so you get more power at the wheels. these box's can be made to handle in excess of 500hp although it does require some work.

the 2.6 diffs with the trimatic 308's were a little slow of the mark but great for cruising. you could break every speed limit in the country in 1st. even so, you were still doing 2200rpm when cruising at 100km/h which is still a little high for a V8

[Clutchy]

There is no up side to them if ya ask me have had nothing but truble with them.

[Reaper]

Stock they were a real slusher but do a bit of work and they were great for any stock/mild mill. As others have said, they are light and efficient whilst still relatively cheap.

Reaper

[Paiste402]

what kind of work can you do to them? i cant imagine really, not like an engine where u can change the timing and filters and fuel mixture etc....

[Huitzi]

Just my 2 cents worth on this one,the trimatics can be build quite strong at a reasonable cost say about $2000 including a stally and trans cooler....mine has had a fair bit of work and is built to take quite a punch,3000 stall,8 clutches per forward gear (instead of the normal 3 ,dont quote me i could be wrong)stage 2 shift kit,billet servo piston,pump upgrade,wb bell housing (they have got the extra internal webbing to make it stronger) just ask around cos the trimatics have been worked out nicely these days to do the job quite well combined with a good diff ratio 3,45:1 or better then you wont be disappointed.

this setup will take a mild 308 and a 150 shot of nos comfortably.