• Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!

Spicer 5+4 Trans Set Up / 13 or 18 speed swap?

Chopper95

Well-Known Member
Joined
Jan 27, 2014
Messages
195
Location
Colorado
I know quite a few of you may be familiar with or have experience wrenching on twin stick transmission set ups - I don't any old timers or shops locally that specialize with older gear.

But I recently picked up an 84 KW C500 that has a Big Cam 3, Spcier 5+4 twin stick and 5.38 Rockwell Meritor SSHD rear ends

The main trans is a 5 speed 1452A and the Aux is a 1241C. Looking for dimensions, especially length, on the Main trans in regards to swapping it to a conventional 13 or 18 speed. That would be very helpful.

But also curious about how much power I can put through that Aux 1241C as it is only rated for 1200 ft lb I believe before it grenades. Saving the aux would mean not having to put a new driveline into the truck entirely.

I would like to put a 3406B Cat into the truck, but not sure if its too much power for everything to stay together. the Cummins is only rated 300hp I believe as is.

If it is easier for me to find new diffs for the Rockwells and remove the aux box for a proper road speed, and avoid problems down the road with the aux, then perhaps that is the best route.

Thanks for any advice or input! Happy New Year to everyone and their families, hope the holidays have treated everyone right in this time of lunacy.
 

crane operator

Senior Member
Joined
Mar 27, 2009
Messages
8,275
Location
sw missouri
what do you want to use the truck for? and how much do you want to spend?

If you're just building a toy hauler and the money doesn't matter- do whatever you want. Drop the cummins and both transmissions, put in the cat and a 13 speed and a new driveline. Find a rear cutoff and bolt it in.

If you're making a working truck for pulling heavy loads, there's probably not a lot that it won't pull set up just like it is, it just won't do it super fast. With the main and aux, that big cam and the gears would walk about whatever you hooked it to.

If you really want 3406, 13 or 18 speed and 3.70 rears and air ride, I think it would be a lot easier to just find a daycab 900 or pete 359/379 that has that stuff, as to tear apart the c500. All you would save out of the c500 would be the cab and frame rails.


Looking for dimensions, especially length, on the Main trans in regards to swapping it to a conventional 13 or 18 speed.
If you have the truck, why don't you just go measure it? It really doesn't matter how long it is if you're pulling and swapping trans and engine.

Set the engine and transmission you want in the truck, measure yoke to yoke from the new transmission to the new rears you want, and where the hangar bearing is, and go to the driveline shop. New drivelines aren't expensive compared to all the other stuff you're looking at doing.
 

Truck Shop

Senior Member
Joined
Dec 7, 2015
Messages
16,556
Location
WWW.
A lot of work-Keep everything as is, remove the 5 speed main and install a RT 14609 nine speed. For most
driving you would leave the aux 4 speed in direct and and only split the top four gears. Direct to over each
gear change 5th through 8th. On the low side you will have plenty of low gears. 9 speeds are cheap and
easy to change. I knew several loggers that ran 9 and 4 setup, worked well.

Below you can look up eaton gear boxes, at the end of each column is weight and length.

http://www.roadranger.com/rr/ProductsServices/ProductsbyCategory/Transmissions/PCT_486870
 

Chopper95

Well-Known Member
Joined
Jan 27, 2014
Messages
195
Location
Colorado
Appreciate the replies Truck Shop and crane operator.

Truck is about an hour away in a buddy's yard, otherwise I would go crawl under the thing and call it a day.
The length would just be nice to know when looking at charts like the Eaton one above or shopping for parts.

If I could get away with dropping a new trans in and keeping the Big Cam for now, I would probably head that route for money reasons. If I was sitting in it everyday, Cat and modern trans would be going in just for service and parts reasons.

The truck is currently set up as a tri axle dump truck with a 16ft half round box.
Was owned by a concrete company in AZ and hauled out of the pit to the plant for almost its whole life.
Title has a construction company on it, so I think it was used for off road use or site work for a few years. Would pass a DOT with a little work, but a ways from me sitting in it everyday.

Plan on keeping it a dump truck, but tractor potential is also there I suppose. Heaviest thing to be hauled would be a 55k machine on a pintle tag trailer. So maybe 65k-70k gross depending on the set up. Nothing heavy duty compared to what a lot of guys move on here.
Thats why I am willing to trade the road speed, especially empty, versus the gearing for towing heavy.

Hate to cut the truck up, it is VERY very clean besides a fender and hood hole. But a roller rear end would be the easiest way to go I reckon if you want to update everything and get lockers etc.
Frame on it looks brand new for being 40 years old. Thank the desert.

We'll see, just was hunting for twin stick ideas. Will look into running a 9 and the 4
 

49pacific

Active Member
Joined
Jan 18, 2013
Messages
38
Location
port alberni
I just put a 3406E model in my 67 Hayes. I put a 18 speed behind it with the original 4 speed(can’t think off hand what the number is). We pull are lowbed with it. It’s nice when in the bush we put the A box in second and in the highway we put it in 3rd still haven’t gotten a long enough straight stretch to get her maxed out yet
 

crane operator

Senior Member
Joined
Mar 27, 2009
Messages
8,275
Location
sw missouri
Plan on keeping it a dump truck, but tractor potential is also there I suppose. Heaviest thing to be hauled would be a 55k machine on a pintle tag trailer. So maybe 65k-70k gross depending on the set up.

That's got to be a 20,000lbs plus truck, I don't think you're getting down to 65k gross with a 55k machine on the trailer. :)

I know hallback spent quite a while looking for a c500, it seems odd to me to split it all up. Surely someone out there wants the heavy thing, and you could find something closer to what you want.

Cut off, trans. and 3406B are all going to cost $$$, I doubt you can get all that for much under $8-9,000 right now as used parts. Would that $10,000 and all the labor, and selling the c500, get you closer to what you want, because to me the c500 doesn't sound like what you want at all in a truck.

And I guess it makes a big difference if this is all work you can do yourself, and if you have a place to do it at. If you have to pay someone else to do it all, its going to be really hard on a budget.

I don't mind buying things that are mostly what I want- i.e. if the dump just had a little too tall gears, or not plumbed for pintle, or you want a 15 speed instead of the 9 speed. But you're really not wanting anything much driveline related out of the old truck.

If I was sitting in it everyday, Cat and modern trans would be going in just for service and parts reasons.

In my area, you'll find just as many guys that will work on a big cam, as will work on a B model, and they are becoming fewer all the time.
 

Truck Shop

Senior Member
Joined
Dec 7, 2015
Messages
16,556
Location
WWW.
All parts used or new, aftermarket or oem are getting very expensive. If it's Cummins you just about can't
afford oem replacement parts. Cummins has priced themselves out of the market. Transmission parts have
climbed also. Wrecking/salvage yards are getting stupid prices for used.
For instance I have a Big Cam IV 400 that I'm converting to full flow cooling and have completely tore down
down and rebuilt everything needed or replaced everything needed just to put it up for sale. It will probably
be priced somewhere around $ 11,500 to $ 12,500. The days of $ 8,000 rebuilt big cams are long gone.
I have seen prices as high as $ 18,000 for a big cam.
 

Chopper95

Well-Known Member
Joined
Jan 27, 2014
Messages
195
Location
Colorado
Sorry, should had specified 65k-70k gross behind the truck maximum.
Tare weight is 25k on it empty.

Totally understand it doesn't make much sense turning an orange into a banana in terms of completely swapping all sorts of things around powertrain wise just for personal taste.

Im still very happy to own the truck how it sits and fortunately (or unfortunately for my sanity) have the space and ability to do most the work myself with the help from some good friends, the problem is just finding the time to get it all done.

Hate to already call it a hobby truck, but some people build Model Ts or drag cars for fun, I just happened to pick a C500.

A lot of truth though in the fact that finding somebody to turn wrenches on the older mechanical stuff is a rarity, not like hooking a laptop up for a diagnostic by any means.
 

crane operator

Senior Member
Joined
Mar 27, 2009
Messages
8,275
Location
sw missouri
I just happened to pick a C500.

Its okay, I've got a c500 in the back yard that I haven't decided what I'm doing with either. Mine is 13 speed ahead of a 4 speed, triple framed to the cab, double framed to front bumper. Its a oilfield truck with big winches and a flatbed.

Doing the work yourself saves a lot of the expense. Then there's the choice that if you start using it, you can't fix it all how you want it.
 

Chopper95

Well-Known Member
Joined
Jan 27, 2014
Messages
195
Location
Colorado
Update: had a brand new, literally brand new, 1650tq 8LL with PTO fall in my lap the other day for criminally cheap. $1650 cheap

couldn’t pass on it. Not a 13 or 18, but oh well will work great for the time being
 

Truck Shop

Senior Member
Joined
Dec 7, 2015
Messages
16,556
Location
WWW.
Not doubting your word or info Chopper95 but---------Both of those 500's have A model cabs. There were no
A model cabs used in production after 1982. 1983 was the first year of B model cab. Odd.
 

dieseldog5.9

Senior Member
Joined
Aug 11, 2014
Messages
614
Location
New Hampshire
In an attempt to learn the nuances of kenworth how do you tell the difference between an A model cab and a B model cab. Unfortunately all I notice difference in kenworth is the change between round headlights and square headlights.
 
Top