I was wondering if there is a way to look at the 904 and tell if it is a L/U or non L/U. I have an early 80's truck transmission laying on my floor and was wondering. Also do the truck 904's have any Heavy duty parts in them.

I am now towing my Valiant with my 85 D100 with a Lock/up transmission. It sounds like that may not be such a good idea long term. I may want to swap it out for a non L/U one in the near future.

Rick

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Early 80s 904 truck transmission will have the wide ratio gearset and will be a lockup transmission. A very few nonlockup 727 slant transmissions were installed in the 80s, but if you have an 80s era slant transmisison form a truck it will be a 904T wide ratio and lockup unit. Be absolutely sure about the year though.

You could also pull the trans ID number off the pan rail and look it up.

However, the easiest way to identify a lockup unit is to look at the splines on the input shaft:



Lockup on top, non-lockup on the bottom.

However, also be aware that as late as 1986 non-lockup 904s were being produced for trucks and vans sold in California. I used to have a 1986 Dodge van that was built for the California market and it had a non-lockup 904 transmission. The factory service manual even mentioned the fact that only California 904s were non-lockup.

So, check the input shaft to be sure, but it is highly likely that that transmission you have is a lockup and wide-ratio unit.

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Casually looking for a Clifford hyperpak intake for cheap.

Yeah, it is still bolted to the engine. I will see if I can pull a number off of it. Thanks Reed.

_________________
2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6