I have a 253 with a th180 I want to put in my 53 Chevy 3100.
I’m looking n the uk and can’t get any information on connecting the solenoid, where/how do I connect it to get a signal?rn

Please forgive my ignorance, but just to confirm, a button with a switched live from the ignition and connected to the solenoid? So when I mash the pedal it activates the solenoid, is that correct?

Hey Bacon,

Early trimatics (HT, HG and Early Hq) were cable kickdown. On these you will literally see a cable ( similar to a bicycle brake cable) coming out of the rear portion of the box and heading to the engine I presume connected with the acceleration linkages on the firewall.

If you don't have this but a solenoid instead it is a later trimatic triggered electronically as you stated off the pedal

Also, can anybody share a picture of where the check balls go please, or a site address where I can see a digram.

Basically yes. I cannot recall if the switch provides 12V or 0V like a horn. Pretty sure it’s 12V as from memory the solenoid only has one pin. I haven’t played with a Trimatic for over 20 years, I think it’s a little post sticking up on the RH side of the box. The TH180 has a cable in a similar spot.

Terry
Apart from bellhousing and similar fitment changes, what did GMH do to the TH180 to call it a Trimatic?
Did they add the internal crossover for right side shift?

I'm not sure where the US vehicles got them from but I have seen HOLDEN cast into bellhousings out of Brazil where they were used behind Chevy 6 design engines in Opala I think. Production on those began in 1968, released in November 1968 but whether they had a TH180/Trimatic/3L30 in them at that stage and if they did where were they made? Info online says the TH180 became optional in 1968 in the Opel Rekord and Commodore out of the Strasburg plant, but you know as well as I do that there is so much bullsh!t online about GMH stuff that people think is right that this too would need fact checking. Prior to the use of TH180 the Opels had a Powerglide - I wonder if that is where our HD-HT 6cyl and 253/308 Powerglides came from too? I did read that for 1969 model year (9/68 onwards) the Opel Commodore also used a TH180 and they call it "Opel's new 3 speed automatic transmission"
The North American references I have ever seen for the 1960's are for TH180 in Buick, specifically in Buick branded Opals like the GT. This is for 1969 model year again so September 1968 onwards.

Found thi stoo, Vauxhall seem to call it the GM 3speed automatic:
https://www.ebay.co.uk/itm/356424034821

Edited by user Thursday, 10 April 2025 12:02:39 PM(UTC)  | Reason: Not specified

We made the tail housings here too for 6cyl Powerglide I think. I always wondered if the cases used here (with removeable bellhousing) were made here too.

That’s the logical conclusion. Why I always wondered was the boxes used behind Aussie engines (161 up to 308) have a different gear set and removeable bellhousing, whereas those behind 307, 327 and 350 are a different gear set and have an integral bellhousing.

That’s what I meant, the lower ratio gear set and different case may have come from outside of the USA. Whether that be Canada, Mexico, Europe or even Australia. Or some combination. From what I've seen the lower ratio set is 4cyl and 6cyl (and GMH also used for 253 and 308). V8 used the gear set we got here behind SBC style engines.

Edited by user Friday, 11 April 2025 4:57:33 PM(UTC)  | Reason: Not specified