Dana Spicer 3153B 5 Speed Usability in a 66K20

[Joe P]

My truck is a 66 K20 with 4.79 gears. It's more of a mountain goat than a highway cruiser. I want to keep the original axles and the 17.5 inch wheels but the low ratio gears keep me under 50 MPH. Anyone have experience with Dana Spicer 3153B 5 speed and can it be used in the K-20? Any other suggestions that will give me another 10 MPH but still keep the truck period correct? Thanks! Joe P...

[factorystock]

Any truck trans that wasn't originally installed in a pickup will need some modifications ( drive shaft shortening and parking brake drum removed possible trans hump enlarging ) to make it work, but the 3153 was optional in Chevy medium duty truck during this era, doesn't show 3151B. If it is indeed an overdrive unit like the 3153, it would be a nice upgrade. .8 overdrive works better for working trucks compared to the .7 overdrive found in most all modern pickup overdrive transmissions. Since the '66 transfer case does not mount directly to the trans, it should work with minor modifications.

[Joe P]

Originally Posted by factorystock

Any truck trans that wasn't originally installed in a pickup will need some modifications ( drive shaft shortening and parking brake drum removed possible trans hump enlarging ) to make it work, but the 3153 was optional in Chevy medium duty truck during this era, doesn't show 3151B. If it is indeed an overdrive unit like the 3153, it would be a nice upgrade. .8 overdrive works better for working trucks compared to the .7 overdrive found in most all modern pickup overdrive transmissions. Since the '66 transfer case does not mount directly to the trans, it should work with minor modifications.

Thanks for the info! The unit I am looking at is actually a 3153B. I went shopping for one precisely for the .8 fifth gear. I also like the uniqueness of the Spicer 5 Speed shift pattern. It will put a big grin on my face if I can actually get it and make it work. Thanks again!

[raylube]

Double check your axle gear ratio. Someone correct me if wrong I think they should be 4.57 or 4.56 gears. Would like to see pictures of your truck.

[weim55]

Originally Posted by factorystock

Any truck trans that wasn't originally installed in a pickup will need some modifications ( drive shaft shortening and parking brake drum removed possible trans hump enlarging ) to make it work, but the 3153 was optional in Chevy medium duty truck during this era, doesn't show 3151B. If it is indeed an overdrive unit like the 3153, it would be a nice upgrade. .8 overdrive works better for working trucks compared to the .7 overdrive found in most all modern pickup overdrive transmissions. Since the '66 transfer case does not mount directly to the trans, it should work with minor modifications.

Stunned to see this transmission even exists! Tought I had seen it all, even the 2 ton stuff. Guessing this is one rare bird. Anyone know the original application?? Picture of one??

Steve weim55 Colorado

[WorkinLonghorn]

Originally Posted by weim55

Stunned to see this transmission even exists! Tought I had seen it all, even the 2 ton stuff. Guessing this is one rare bird. Anyone know the original application?? Picture of one??

Steve weim55 Colorado

This is what I have;

[Joe P]

Originally Posted by WorkinLonghorn

This is what I have;

Wow, thanks for posting this info. What is the publication it came from?

[WorkinLonghorn]

Deleted (Info on the Dana).

[Joe P]

Originally Posted by weim55

Stunned to see this transmission even exists! Tought I had seen it all, even the 2 ton stuff. Guessing this is one rare bird. Anyone know the original application?? Picture of one??

Steve weim55 Colorado

There's a guy on E-Bay selling four of them, supposed rebuilt. Search E-Bay for "3153B Spicer" and you will see the posting with a few photos. I have contacted the seller for details, but he has been slow to respond. I will post more info when he get's back to me.

[jocko]

4.79 was not a thing. Another option that allows you to maintain your original trans and rear end is to add a gear vendors over/underdrive behind the t-case (and only use it in 2WD of course). Allows gear splitting of each gear as well, if you choose to use it that way, but most just use it as an overdrive. Very heavy duty also.

[Classic v6 GMC's]

That sounds like a good swap for a k20 and should not take much to put it in. A k20 would have 4.56/4.57 gears

['63GENIII]

That transmission looks mammoth! Very cool that it has the OD.

The '57 Napco truck that I had ran a Clark 5 speed in it that was fun to drive. I had heard a rumor that they had put an OD in a select few of the Clarks but they were like hens teeth supposedly. I spent most of the time up until I sold that truck trying to find one and never did.

Good luck with the Spicer! Having OD in these trucks just makes you want to drive them even more!

[Joe P]

Here are a couple of photos of my truck for those who requested. These are from when I got it in July 2018. Working on making it safe. It's currently disassembled inside waiting for warmer weather. I don't like working in the cold (I'm old). Also posted is a photo of the numbers on the Eaton rear differential. I think this is an H072 - And of course, the HZ code indicates a 4.57 ratio. Thanks to all who posted replies.

[jdl71]

following

[Joe P]

Here's some photos that the seller sent me just this afternoon. Sadly the input shaft has no machined area for a pilot bearing....

[Joe P]

So I found a Clark from a C60 and decided to buy it. Should be here in a week. It does not have the unconventional shift pattern that I was after but apparently does have the overdrive 5th gear.

[jdl71]

Originally Posted by Joe P

So I found a Clark from a C60 and decided to buy it. Should be here in a week. It does not have the unconventional shift pattern that I was after but apparently does have the overdrive 5th gear.

Is that synchro’d?

[Joe P]

Originally Posted by jdl71

Is that synchro’d?

Yes, all gears except first.

[jdl71]

I don't know how those compare to an sm420 as far as weight, are you looking at making some kind of mount for it or going to let it hang off the bell housing?

[Joe P]

Originally Posted by jdl71

I don't know how those compare to an sm420 as far as weight, are you looking at making some kind of mount for it or going to let it hang off the bell housing?

Plan is to change as few things as possible. The C60 this came off used the bell housing as the rear support, same as the K20. For sure, the bell housing off the C 60 was larger in order to accommodate a larger clutch, and is more robust, likely to handle heavier loading. I have the General Motors part number for it it may end up having to get one. We will see how many things bolt up and also those other things that must be changed. One example of this is the pilot bearing as the input shaft is larger in diameter in this area. I’m also not sure if the input shaft splines will mate with the K 20 clutch disk. I will keep y’all posted as this effort progresses.

[jdl71]

Please do. I'd love to have overdrive myself but don't want all the hassle of swapping to a modern trans so I am very interested in this.

[jdl71]

I'm also curious how you are getting these shipped and still making it worthwhile. Seems like it would cost a fortune to send one somewhere.

[Joe P]

Originally Posted by jdl71

I'm also curious how you are getting these shipped and still making it worthwhile. Seems like it would cost a fortune to send one somewhere.

Transmission is coming to CT from Ohio - See the photos for the carrier. I don't have a bill yet or a manifest, but I don't think the cost will be prohibitive. I will let you know when the bill comes.

On the other hand, I budgeted a total of $1000 for this 5th gear segment of my project. Hope I don't blow through that, but I'll let you know when done. I still have to figure out a bunch of technical unknowns (read: $$).

[jdl71]

Originally Posted by Joe P

Transmission is coming to CT from Ohio - See the photos for the carrier. I don't have a bill yet or a manifest, but I don't think the cost will be prohibitive. I will let you know when the bill comes.

On the other hand, I budgeted a total of $1000 for this 5th gear segment of my project. Hope I don't blow through that, but I'll let you know when done. I still have to figure out a bunch of technical unknowns (read: $$).

If you can get it done for a grand, that would be a very good investment.

[Joe P]

Does anyone know the inside diameter of the bore in the butt end of a 292 crankshaft where the pilot bearing sits? I don't have one loose to look at. The 327 crank I have is 1.70 inches.