The Stovebolt Site Forums The Parking Lot Big Bolts 1953 GMC, Detroit, Roadranger, disc brakes, and PS!

New project, not mine but helping out a friend.

In many ways it is like my 48 Chevy but hopefully learning from mine will allow this GMC to come together quicker and be as good or better in the end.

I'll start with a list of components:

53 GMC 2 ton frame, cab, front clip.
1978 Detroit Diesel 4-53T engine.
Roadranger RT-610 transmission, 10 speed
Front spindles and huge rotors from a Spicer axle, with 6 lug Budd stud centered bolt pattern.
Power steering gear box from an Isuzu cab over truck.
Rear axle from? It's a Dana 80 with 3.73 gears (might want 3.54 or even 3.31??), also has same disc brakes as the front and same bolt pattern.
Wheels are 6"x22.5 tubeless and will run 9-22.5 or 9R22.5 tires (have 4 good bias ply now)

My part of this project is to get the engine, transmission, axles, steering and so on complete so it's a running driving stopping truck with a cab that fits. Then when it leaves my shop it'll all come apart for the final cleanup paint and reassembly.

More to come, stay tuned!

Grigg

I would say you are already on your way to a quicker build you will have a hard time out doing your first though. How about the front axle will it need to be narrowed like yours???
Pretty good start though gathering the parts is a huge part in its' self.
Be looking forward to seeing more progress I have been deterred from my projects with one more my self I am building myself a powered portable screen plant that I will be able to tow from job site to job site.

I think 3.73 with a 10 sp direct is fast enough for a Detroit. Have you figured out how fast that thing will be going at 2500 in 10th gear?

What was the dana 80 out of originally?

Dave,

That axle has had an interesting history -- Rusty Rod picked it up from a guy in So. Calif (scrap yard) who had listed it on the LA Craig's List. Rusty took it over to ATHS Member Dennis Wells who had a truck going to the ATHS National in Huntsville, AL that year. Bolter Mike Roache loaded it in the back of his '52 for a ride back up to the Virginia/Maryland area and I took it from Maryland over to Grigg's this past fall. No one's really sure what it came out of but the best guess is an airport shuttle bus.

r,
John

In my search for axles and brakes for my 56 that has that same 6 bolt pattern I found it used by many Internationals. I believe that these same trucks also used disc brakes as well.

crenwelge 2500 would be awful tight to be spinning that 4-53 they do spin tighter than say a Cummins but cruse is still about 2100 at the most I could be wrong but last Detroit besides a 60 series that I was driving was a 8V92 and as I remember it was governed @ 2300.

The 453T is rated at 2500. If it has the new cross head pistons it could be rated at 2200. The 71 and 92 series were rated at 2100, but usually governed at 2300. Just as an example as to how times have changed, we now run our Cummins between 1200 and 1600 rpm. They are governed at 70 mph while turning 1450 in 10th gear and cosistently get 6 miles to the gallon where the old engines were lucky to get 4.

Here's a gear calculator
http://www.onlineconversion.com/bigger_tires.htm

This is not a silver engine, and is governed at 2,800 rpm (silver 53T engines are often governed at 2,500). However 2,400 is plenty fast enough for this one and all day driving, and 1,900 or there abouts will be more ideal for this truck when empty.

1,900 rpm with 38" tires and 3.31 gears gives 65 MPH, good for empty, on second thought might not be the ratio we want.
Or if the truck is often loaded a more reasonable ratio might be 3.54, that gives 65 MPH at 2,040.
Or figuring the current 3.73 ratio 65 mph is 2,150, which is close enough to run it for a while and then decide if it works or if it needs a faster gear or two.

Just for fun top speed of 85 MPH at 2,800 with 3.73 gears, or could hold 75 mph at 2,500 all day if you like to buy fuel.
3.31 gears bump those speeds up to 95 and 85 mph.

Nice thing about the Dana 80 is it has plenty of choices even up to 3.31, which will help in some cases when OD is not available, and has one faster gear available than a Dana 70 or 70HD.

Grigg

Very likely, All I have are the ends of a torched axle, new but missing most of the I-beam. It's a Spicer I-60 model if I remember, and I think it may have been form an IH.
Did the research a while ago and there never was a factory I-beam narrow enough from Spicer.
First on the list of choices is to narrow another P-30 axle beam and make thicker king pin bushings to adapt the Spicer outers.
But the GMC axle under it now looks pretty beefy, so I'll investigate adding the new stuff to that I-beam, would be simplest if it looks suitable.

Still not sure how it will all work out for the front.

Grigg

It sounds like you are going to try the 3.73 first. I think after you drive it for a while you will realize the Jimmie is happier at higher rpms than at lower rpms. I have always found a 13 speed and a slower rear to be ideal for a Detroit. You have the startability of a deep gear and it eliminates the 9th to 10th gear gap that really bogs a Detroit on an upshift.

Well, For comparson I had 6V53T in a 10,000 lb overgrown "1 ton" truck, and it had same tire size and same 3.73 axle gears, but it had the advantage of an overdrive 10 speed.
After several thousand miles of both loaded and empty from Virginia to Colorado to Washington state and back I'm sure it would have liked 3.54 gears, and would have them now if I'd kept the truck.

This GMC has less HP, ~170 not ~300, and is slower geared because no OD, those two factors should essentially cancel out and might be a perfect setup. But from my previous experience in a very similar truck I think it'll be close and if anything it might need a step higher.
I'm sure it'll be OK loaded, that overgrown F350 pulled and towed nicely in direct, which is the same setup as this GMC other than a little more HP. I fear when empty the GMC with 3.73 gears and no OD will feel gear bound and not be so comfortable on long trips on the highway, time will tell.

Grigg

That small HP difference may be the deciding factor that holds you to the slower gears though???
Hope that that is not the case for you this sounds like a really cool project which leads to the next question. You told us that it is not yours. Well whos' is it??? dose it belong to one of our Bolters and if not why have you not brought them aboard????

crenwelge: I wasn't real sure about the little Jimmies I think I drove a 6V71 once but driven a bunch of 8V71 & 92s' even a couple 12V71's
It is amazing that big truck power changed very little from the 50s to the late 90s but has change by leaps and bounds from the late 90 to present. I had a 2003 four axle T800 with a 550 HP C15 and an 18 speed that pulled a four axle pup trailer it could pull down 8GPM @ 105,500 lbs. This is pretty hilly territory here in Western Washington too

OK now, back on track with pictures and progress!

Edited August 2024 -- Grigg's Webshots, like so many others, can not be retrived. So, we've removed the link. This PDFs at the bottom of the post work.

Started on the front axle today, it needs disc brakes and a 6 lug Budd bolt pattern. First step was to remove all that including the spindles, but leave the I-beam axle.
The king pins drove out really easy (and not worn in the axle either) overall much easier than expected to get apart

Then if you remember I already have some pieces parts form a Spicer model I-60 axle...

Obviously the Spicer stuff is larger, but a few key things are the same as the old GMC stuff, king pin inclination angle (no camber problems), and the thickness of the I-beam where the king pin passes through.

The important to note differences are the king pin diameter and length.
Old king pin is 1.109" diameter and about 6-3/8" long
New king pin is 1.357" diameter and about 8" long

However it's not as bad as it sounds... check out these pictures of the Spicer spindle on the GMC axle (and really sloppy king pin bushings..)


But the axle thickness and space between the bores on the spindle works out nicely,

So the plan is to make thicker bushings for the new spindles.
Would like to find longer than original king pins, ideally 8"
Closest I've found on king pins other than custom making them is from a 73-78 Dodge truck of some sort with a 5,000 lb axle (NAPA kit # 262-1564). The dodge pins are 0.015" oversize (compared to GMC) and about 1" longer. Want to look some more and see what else I can find before deciding what to do.
Bushings I'll probably make thick bronze ones, or considering making steel adapter sleeves (about 1/8" wall thickness) and press them in place with some green loctite. Then an off the shelf GMC or Dodge king pin and bushing set would be easily available for a rebuild later on down the road.

Grigg

PS
For those that are curious, and for my future refference here are some links
Spicer Sales flier for the D-600 axle (newer version of I-60)
http://www2.dana.com/pdf/AXSL-0471.pdf
Application Guidelines for Spicer front axles
http://www2.dana.com/pdf/AXAG-0400.pdf
King pin kits and some other stuff http://www2.dana.com/pdf/HX500-QR.pdf
*** Complete axle parts list with choices and part numbers for different steering arms and tie-rod arms.

You might give these guys a call. http://www.stemcokaiser.com/Literature.aspx I have been using Kaiser king pins since the 80's and they are a one time fix. When Kaiser was still an independent company, they had good phone tech support. I would suppose they still do.

Thanks for the link,
However I had already remembered your fondness for their kits and literally just finished sending them an email asking if they offer custom kits and described my situation.

I'll let you know what I hear,

Grigg

Anyone know the factory rating on the stock GMC 2 ton front axle?

Grigg

GMC 350 series 2 ton, Factory F-045 front axle, is rated at 4500lbs.

Grigg,

Good progress! Isn't that truck a ton and a half? Also, there is a front axle from a Task Force two ton available, if needed (a fire truck that got parted out) -- just needs a replacement of some kind just to be able to roll the chassis around.

Nice wrench.


John

Thanks Spanky, 4,500 lb sounds good, so I shouldn't worry about that.
By keeping the original I-beam and king pins 4,500lb should still be the nominal rating, but it'll have wheel bearings and brakes that would handle 6,000 lb

Well, I figured it was a 2 ton because the front hub caps bolt on with 6 bolts. But then again I was quite surprised to find only a single speed rear axle. Guess I should look at the tag on the door and translate..

Thanks for the offer John, but I think I'll stick with the GMC axle, no narrowing necessary. This should be about the simplest and cheapest method for disc brakes, 22.5" wheels, and still fit under the fenders.

Grigg

And yep, I like the wrench too, have a couple dozen on order

Right on Grigg that is going to work out SWEET!!! With the Taskforce trucks I have found that the two tons come with 4000 to 6000 lbs front axles. My 57 parts truck has a 4000 lbs axle and my 56 has a 6000 lbs axle I see no visible difference in the I-beams or spindles. It appears the differences are the brakes,(one wheel cylinder or two) and the spring packs the 57 with the 4000 lbs axle has 9 leafs and the 56 with the 6000 lbs axle has 13 leafs.

Grigg, you never cease to amaze the crap out of me! I love watching your work.

They did not have anything that would help me with longer king pins or thicker bushings other than the standard kits they offer.

I'll try them again later when I'm dealing with bigger stuff.

Grigg

Hy Grigg, the 57 Chev 8100 with Eaton axle [485?] uses a kingpin which is 1.109" X 7.5". I had a heck of a time finding these 15 years ago, seems to be an omission in most parts books, mine needed to have two lock pin grooves, could only find one groove type. Sealed Power p/n 808-389 kit with shim type thrust bearing, may be the same as TRW K389, Sealed power p/n 808-439 kit with ball type thrust bearings. The part number for the pin alone is 2251845 = Eaton 32310, hope that helps.

Thanks, I'll definitely look into those pins, and no they aren't listed in the NAPA heavy duty chassis parts book I have here.

Grigg

Checked a few places and no luck at all on those 7.5" pins or even the part numbers.
Do have a lead on a 6.8something" long pin for an early 70's Chevy with a 5,500 lb axle. Next week I'll know if that kit is even available.

Grigg

Hy Grigg, The o.e.m. and Eaton numbers for those pins are,
two lock pin type 2251849 = Eaton 32427
single lock pin type 3740734 Eaton 44774
this part number is in the book as the pin for the largest tandem which is listed as also a 1.109" pin 3743886 Eaton 44599, I hope some of those help you find something.

Hy Grigg, I've been doing some searching for those pins I told you about. I came across this set, Napa NCP2621275 $114.00, these pins are 6.812" long, [not as long as the ones for the 57 Chev 8400 series], but longer than the 6.375" that I believe is the only other alternative that you have found, hope that helps.

Yep, I've been eyeballing those too, they are for a 41-46 Chevy 2 ton with the heavy axle as well as some Divcos and Studebakers.

The pins I've been considering as a default are NAPA # 262-1016, while I've been saying they are about 6-3/8" they actually are 6.344" according to the book..
The difference in those two pins is 0.468", and the 41-46 pins have a snap ring grove on one end, hard to tell the exact details from the picture but might be the effective length is less than the published length, making the difference negligible. The 41-46 pins are about $35 more than the others.

Also have my favorite parts place checking on some 6.9" long pins they show in the catalog, getting more details and pricing now.

Ideally I'd still like to find the 1.109" x 7.5" single keyway pins you mentioned earlier.

Thanks again,
Grigg

Investigated some power steering options today.
Click here and there are a few more similar pictures.
http://rides.webshots.com/photo/2464142410080251109hWGboA

A steering gear box from an Isuzu cab over truck, looks like a good choice but will probably wait till after engine and radiator are in place to decide exact placement, either forward of or behind the axle.

Grigg

Making progress on the front axle/disc brakes.

I'll try to get that side wrapped up this evening, waiting a day or two on a replacement bushing for the other side.

Soon I'll figure out the steering linkage and tierod.

Grigg

hub and rotor installed

Now I'm figuring out tie rod arms so the Ackermann geometry works out.
Old arms were not suitable and one was torched any how, and now that it's on a narrower axle beam and a different wheelbase if the old ones were correct any how it would have been pure luck.

Grigg

Grigg;

Nice work! You mentioned figuring out the Ackermann geometry. How do you do that in the shop? I think I know how the angles are suppose to work, but I can't see how a person can do it in a cramped shop. I'm curious to know your method. Strings, lasers or pure mathematics/plane geometry?

SimS

With these two links to start with
The first one on page 22 and 23 explains how Ackermann Geometry works.
The second link on page 19 gives the choices of steer arms that work with these spindles.
Using common medium duty axle is an advantage because there are lots of tie rod and steering arm choices available; these axles were used by many manufacturers in various length trucks. Which is not the case for say a pickup axle that only came in one width and one or three wheelbases, so only a few if any choices.

From studying the Ackermann Geometry:

In this case the wheelbase is 178.75" and the "King Pin Index" is 53.875"
Some trig reveals that the tie rod ends need to be set in at an angle of 8.57* so they point to the center of the rear axle, this is the "tie rod angle".
With that info I can do the math on the available tie rod arms and have determined that part numbers 080TR107 and 080TR108 are the most likely candidates.

I'm now going to call Spicer and see if they can confirm my findings.... Some of the measurements were tricky to make on the spindle to relate the center of the king pin to the reference point on the tie rod arms they give in the parts list. an 1/8" error is about a degree off on the angle so I need to get that right.
With luck they'll have more detailed info (than the parts book) readily available.

I am confidant on my KPI and wheelbase measurements, and even if I were off some it has little effect. For example a 2" mistake on KPI changes the angle by only about 0.3*, or a 2" wheelbase error makes only a 0.1* change.

Grigg

This makes my head hurt! I'll take Grigg's word for it. Great job on the build. I need to get down to your shop again soon.

Take care, George

Grigg;

Thanks for the links and explanation. Do you know if the Ackermann angles should be maintained throughout the full range of motion or just straight ahead and full lock?
I know we're not going for NASCAR sophistication, but steering and front end geometry have always been a research hobby for me. Keep up the good work and I look forward to your updates on this project.

SimS

The centerline of each spindle is (should be) radial to the center of the turn for small or large turns just the same. As I understand it's the whole advantage and principal behind the Ackerman Geometry.

For race cars they probably play with all sorts of things and may not use true/simple Ackermann Geometry, but for a truck seems like plain and simple will be just fine.

Grigg

Ordered tie rod arms that I'm reasonably sure will give the angle I need, I'll find out next week. The folks at Dana/Spicer were some help but not as much as I wanted. This axle was apparently made for International and has IH part numbers on stuff which didn't help things any.

Grigg

Fuel tanks came in today, they were on a smallish Freightliner.
If my math is right they are 50 gallons each, 4'9" long and bracket and all (no steps) puts the outside of the tank 22" outside the frame, which is a tad narrower than the wheels.

Grigg

Installed and reamed the bushings in the other spindle, then put that side back together.
Did a preliminary check on the camber and it looks to be within spec.

Outside of tire measurement is approximately 70" and a couple inches narrower at edge of tread, which should work just fine as the narrowest part of the fenders are 72".

Grigg