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Inside Chrysler’s Trenton Engine North plant

Trenton Engine North

The Trenton Engine plant made its last 3.8 liter engine on May 20, 2011, wrapping up around six decades of production; in its first year, it made water pumps and air raid sirens, but engines were not far behind. Trenton (a distance southwest of Detroit) produced some of the most legendary Chrysler V8 engines, as well as four-cylinder engines for K-cars and Neons. In its last years, the plant made V6 engines; the last engine made was a 3.8, which itself wrapped up two decades of production. Photos were provided by a source within Trenton Engine North. (Next door, the Trenton Engine South plant was pumping out Pentastar V6 engines.)

1966 trenton engine

Trenton Engine North has 2.1 million square feet of floor space, and covers 136 acres. In 2010, the plant also made the 4-liter V6 used in minivans and the Dodge Nitro. 579 people worked there on two shifts. The plant was built in 1952, and expanded in 1969; it built over 38 million engines.

cold test

At one point, Trenton Michigan held not just the engine plant, but also a factory for Amplex, another for Chemical, and one for Friction Materials.

Trenton plant gained new life in June 2011

On June 13, Allpar posted a story, courtesy of "superduckie," on the City of Trenton's approval of tax breaks for Chrysler to keep the Trenton North plant open for parts production. Chrysler is using the rest of the plant to add another Pentastar V6 / Tiger Shark flex-line.  

1959 slant six line at Trenton Engine

There are two block lines for the 3.3 liter engines, Department 621 and 521. They can also make the 3.8 liter engine.

Department 621 was installed as a combination 3.8 and 3.3 line. It had a number of upgrades, with machines that had major rebuilds or replaced. It was given a new final hone (for better bores to help meet emissions requirements), a new or upgraded final bore, major rebuild rought bore, and a new OP 40 (the first transfer machine in the line), all in its last four to five years. The line makes 3.8 liter engines because it can outproduce Department 521, which only makes 3.3 liter engines.

doghouse gauge

Department 521 started life as the 3.5 liter block line; it was converted to the 3.8 liter engines when the iron-block 3.5 was ended, and was later converted to the 3.3. It has been upgraded with many of the same items as 621.

A new 3.8 liter crank line was installed around 1996; the old one got new final lappers (for better microfinish) and a number of rebuilds and upgrades. Two nice Landis finish main bearing grinders which were about one and a half years old were taken from the old 2.0 Neon line and reworked for the 3.3 / 3.8’s old crank line, in 2007. The cam line had the lobe mills rebuilt in-house, which helped cam quality a lot.

final 3.8 engine

Department 638 (the 3.3 / 3.8 liter assembly line) had extensive work before the RT minivan and Jeep Wrangler Unlimited came out; the 4.0 liter aluminum engine is now made on the old, rebuilt 3.5 liter aluminum engine tooling and assembly line. They put in a new finish crank line and re-used the “old new” final lapper. (Someone else can tell the story about the train wreck. No-one got hurt in that event, thank God.)

gauge station

... [December 12, 2010:] The end of an era has arrived, with both 3.3 and 4.0 liter V6 production at Trenton Engine officially over, and the assembly lines are shut down. A single line continues, with the 3.8 liter engines in production until late Spring to power Jeep Wranglers. After that, the "old" Trenton Engine will be closed down, after 21 years.

Department 524 made the cylinder heads for both iron and aluminum block 3.5 liter engines, and the 4-liter aluminum-block engines. Department 624 made the heads for the 3.3 and 3.8 liter V6 engines. Department 724 is still making new cylinder heads.

The Trenton Engine Plant (North)
200 Van Horn Road, Trenton, MI
In 2010, this plant had 2.1 million square feet of floor space, with 825 hourly and 100 salaried employees on two shifts. The plant started production in 1952 and was expanded in 1969.

I was at Trenton Engine from 1976 to 1978. When Chrysler dropped the large V8s in the late seventies, a lot of younger workers were laid off. Some were recalled to work several years later and are now ready to retire. I was not one of them; but twenty years later, I was lured back to Chrysler by the big money, iron clad contract and the fact that I could add to the time I already had there and work on another pension.

When I arrived back at Trenton Engine in December 1999, the place was full of life and machines for making parts. I don't think there was any floor space left in the 2.1 million square foot building to add anything else. At that time they were making the 3.2L and 3.5L aluminum block V6 engines, the 3.3L and 3.8L V6 engines for the minivans, and the 1.8L (for export) and 2.0L Neon motors. They made all of the pistons, connecting rods, crankshafts, camshafts, blocks, cylinder heads, intake manifolds, exhaust manifolds and water pumps for each of these motors plus some parts for the 318 and the 3.9L V6 that were assembled at Mound Road engine plant.

last blocks

The process of outsourcing began around the beginning of 2000 [two years after the Daimler takeover]. The parts made in-house were held to a much higher quality standard then the ones they bought from the outside. One department after another was shut down and the machines were torn out and scrapped. There were new machines being unloaded from trucks for departments that were to be shut down within two weeks of their arrival. I guess once the ball got rolling to outsource there wasn't time to stop new equipment from being built and delivered. I think the new machinery ended up in the boneyard along with the rest of the scrap as Chrysler wasn't going to be making these parts at any of their other plants either. Some of the parts like connecting rods were going to be changed over to powdered metal so even the suppliers couldn't use the machines.

last engine

After a while, DCX decided that Kenosha would be a good place to build the 3.5L V6 and now we were shutting down assembly lines. In late 2000, we had just finished putting in a new assembly line to add production for the 3.8L V6, which was started up and run for about one year. It could never hit its production numbers due to its size and design.

last head

In 2001, we put in another assembly line for a version of the 3.5L V6 to go into the minivans. Chrysler even advertised that the 3.5 was going to be available in 2003 in the sales brochures. Unfortunately the transaxles for the minivans couldn't handle the torque from the high revving 3.5 and the Pacifica transmission would not be ready for another year. I doubt that fifty engines made it off that assembly line before it was shut down, ripped out, and sent to Mexico.

last TEP engine

The World Engine project meant the 2.0L was doomed. When is a joint venture not really a joint venture? When two of the three partners announce a year before the plant opens that they have no plans of using any of the engines produced there. So now DCX is hiring new workers off the street for this venture while 25 miles away the workers who should be allowed to follow the work being transferred out of their plant are going into the job bank. The employment level has gone from about 3500 workers in the year 2000 to less than 1600 in 2006. I have a lot of friends with me in the job bank now. The plant is getting to more and more like it was in 1955 when it opened and all it made was water pumps and air raid sirens.

See the water tower coming down... or see the 7 millionth engine (a V8) being built...


pallet of heads


trenton powerplant

trenton waste treatment plant

Trenton Panorama

See the water tower coming down... or see the 7 millionth engine (a V8) being built...

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