Inliners International Forums General Discussion Drive Train 49 Fastback go back together

Greetings . . .

I can’t believe that it has been over six years since the car went up on caster jack stands:
Inliners Post circa '10

I had thrown a cover over the driveline (on the bench) as I thought that piece was done after I swapped the 3.55 gears.

But alas less than a year later I was presented with the opportunity to acquire an uber-rare Truckstell mechanical overdrive.

So I disassembled the third member and cut it down to fit the Truckstell flange:

A guy in western Ohio with a large lathe cut down the torque tube to fit (-20”):

The unit was purported to have low miles so I simply flushed the insides – cleaned and refinished the outer surfaces. Bench testing has been promising and these units are said to be stout and bullet proof. I even have the tip-toe circuit which can be driven off the clutch as well the accelerator. I used heat shrink wrap to replace the leather sheath on the original cables. What remained of the original leather sheaths turned to dust at every touch:


In ’14 the project was really feeling heavy. There seemed to be so much to do and it was hard to prioritize. Moreover, some of the grunt work was really un-rewarding. So I decided to cut the project in two and to make a push on getting the engine back in between the frame rails. This meant refurbishing the front end and the firewall. This created a tale of two projects – with the front end (fire wall forward) under assembly while the rear two thirds and floors were yet to be stripped and finished:

This was necessary because the underside was a real drag. Someone had ‘undercoated’ everything with road tar. The stuff came off by the pound:

In some areas it was dry and broke off like peanut brittle – in other places it was gooey and required heat to let go. Underneath the tar was a mixture of clean metal, surface rust and some rot. I treated everything with POR15 + Eastwood’s Rust Encapsulator + top coat:


Having the project divided in two was the only way to stay sane. I would spend hours scraping underneath and get so bummed I didn’t want to do anymore work. But I would then wake the next day and work on clean under hood detail items out front.

The driveline is now back in the car. The same dolly that pulled the original was used to position the restored item:


I could not install the driveline with the overdrive attached. It was just too unwieldy. I had to bolt the Truckstell on after the rear-end was attached to the leaf springs and the frame. This meant splitting the universal joint to marry it with the transmission.

I have been collecting parts for this project for over 15 years now. Pulling boxes down from the attic is like Christmas day:


I hated to have to split the factory assembled u-joint but that’s what it took to get the Truckstell mated with transmission at the ball housing:


Regards,
Stock49

Seems there’s a limit on the number of images in a single post – so I need to reply to finish my posting

The attic treasure trove included NOS shocks from Houdaille – the so called Golden Glides:


With the driveline back in the car I have now moved on to plumbing the brake lines:


Progress feels good – but there is still tons to do before this car goes back on the road.

Regards,
Stock49

Stock 49, the patience and craftsmanship that you have shown on this project is almost beyond my ability to imanigne!! 15 years rounding up parts! I have a question. What is the overdrive ratio? With the overdrive would going back to 4.11 gears be a possibility?please if possible post more pictures. jay

I helped a friend here bring home a '52 Chevy pickup with a Truckstill OD from his in-law's. It was complete with all the linkage. They were all bent on all "modern" running gear and said I could have all the "old junk" if I'd haul it away. Then came the nasty divorce. The pickup is still in the area in pieces and I'm sure the "old junk" is scattered around. It's been a while maybe I can ask now.

Yours is looking really nice. Thanks for the update.

The Truckstell is a 72% planetary overdrive gear set. This translates as follows with the stock 4.11 ring and pinion:
1st gear 12.08 - 8.70 OD
2nd gear 6.9 - 4.97 OD
3rd gear 4.11 - 2.96 OD
with the tip-toe semi-automatic one can run all six forward speeds.

Substituting the 3.55 changes the landscape dramatically:
1st gear 10.43 - 7.51 OD
2nd gear 5.96 - 4.29 OD
3rd gear 3.55 - 2.56 OD

There's no reason to go back. Look at the ratios. I don't need an initial 12.08 for hole shots. Moreover, with the 3.55 the 1st OD ratio is close to second gear in the stock setup. And second OD is close to 3rd in the stock setup. I expect the car to cruise around town in 2nd and 2nd OD . . . leaving the top two ratios for the freeway . . .

One man's junk is another man's treasure . . .

Very true about "Junk". Stock 49, how far up the RPM scale do you think the power range has been moved up on your engine compared stock? Just curious about which gear would do best on the freeway, 3.55 in third direct or third in O.D. Jay

With the added duration on the camshaft the power band has definitely moved to the right. Till I get it on the road it remains to be seen if it will cruise on most grades in 3rd OD. If not it's just clutch pedal tap to downshift to 1:1.

Depending on how tall the tires are that you are going to run, it's at least possible that a highest top speed would be in third direct with a 3.55 ratio. How tall of tires are planned and more importantly how soon will it be on the road? Jay

In every old engine powered OD equipped vehicle I have owned there are times when you have to take it out of OD especially on hills. My son's Stude Wagon originally had 4.27 rear gears and A BW 30% OD. With 28-29" tires 3rd gear direct was 3,000 + rpm at 55mph. We did that from Vegas to Kingman once. In OD the same rpm was around 70. Having a supercharged Stude 289 it rarely ran out of power even loaded and pulling a trailer. My '53 Chevy pickup with a 270 GMC 3.55 rear end, 30" tires, and a T-5 is about 60 mph at 2,700 in 4th direct and 90mph at 3,000 in 5th OD. Rarely have to down shift. (the 90 mph numbers came from averaging several 4-5 mile tests using mile markers and a stop watch on the way home from Bonneville) The engine will turn 6,000 but maybe not in OD. There is serious air at around 100 mph in those trucks.

That's kinda what I am saying about Stock 49's Chevy. 2.56 gears which what he will have in overdrive are pretty tall especially with tall tires in the 30 inch range. The fact that he has a fastback will help some, but I would imanigne that a 49 Chevy has a lot of wind restistance. 3.55 gears, however with those same tall tires would unload his engine enough to let it wind out to max power in high gear. 100 mph in overdrive with 30 inch tires would be 2867rpm. Put it in direct and the rpm becomes 3976, much closer to the max power RPM of his engine. Don't worry Stock 49, we haven't raced your Chevy too much! Ha ha. Jay

I think he'll be fine. He'll only need OD on the highway or the very handy 2nd OD around town. I am very interested to see how the Truckstell works out in this application. The well and carefully built 216 is as classic inline as it gets.

I have another piece of marketing literature that contains a cool diagram showing the impact of the Truckstell on RPM as various speeds. I did some arithmetic and some art-work over coffee to add in the PG+OD RPM figues:

again if you right-click on the pic and choose View Image it is much easier to read.

At 70mph the figures in the diagram suggest and RPM of 2227 . . . so I think I will likely be stepping down to 1:1 on grades . . .inline with Beater's experience . . .

Stock 49, that is acool chart, to look at. The one variable that is left out of the equation is tire diameter. What size tires are stock? What size do you plan to use? Here are the numbers that I come up with for the 2.56 ratio that would be third gear in OD.with 3.55 gears at 70mph.
With 30 inch tires:2007
With29 inch tires:2076
With 28 inch tires:2150
With 27 inch tires:2230
With 26 inch tires:2315
That's using the formula of: speed x gear ratio x 336 divided by tire diameter. In my experience the published tire diameter works ok at the kind of speeds that are run on the street. Basically tire growth and slippage cancel each other out. (not like the rear slicks on a top fuel car). But I have to agree with you and Beater that even with 26 inch tires that dropping to 1:1 on hills will probably have to happen with the cam duration that you are running. Jay

I don't know what tire was OEM - but the car came with BF Goodrich Silver town bias ply wide whites. ~27 inches in diameter. The spare still has a sticker:

IMHO the fastback looks a lot better than the regular sedan. In my case we got rid of the OEM wheels, (one wasn't right for the car anyway I still have them) in the rear we have 215/65/R15 tires (26 inch ) on 15x7 Montie Carlo SS wheels and 215/70/R14 tires on 14X6 S10 wheels. (both wheels look the same style wise) sand blasted by me and painted by my 11year old grandson. On the 75-79 novas the front track is wider than the rear by 1 inch. Both wheels fit in the center of the wheel well and the front and rear are closer to having the same track. The rest of the drivetrain is a 8.50 open axle with a 2.73 ratio and a stock (for now) TH 350. Wasn't the 3.55 gears that you put in for Powerglide cars? Jay

That's odd the rear track would be narrower than the front. One would expect wider in the rear if not the same. Differing size wheels/tires is more common today - as are directional tires. Back in the day the OEMs preferred same size tires with a full size spare allowing for a circular 5 tire rotation regimen.

Yes. The 3.55 ratio was created for the Power Glide transmission which was introduced in '50 along with Bendix brakes. The third members are completely indistinguishable so the PG units carried a ratio tag:

In the factory they placed them on the drivers side bearing carrier bolt. I placed it on a banjo bolt at 2 o'clock (to telegraph the swap to the detailed eye). The is where GM placed these later on when many ratios where offered:

During assembly it was important to know this detail because the correct speedo gear had to be fitted to the transmission during assembly.

Chevy also offered a 3.73 ratio starting in '40. But these are rare. I once saw business coupe at a show that claimed to have be so equipped - (for efficient long distance travel of a Salesman).

My moms 73 dodge dart was the same way, wider in the front track than the rear. I have no idea why it was done. In the case of my nova it actually hurt interchange of drum to drum rear axle assembly's with second generation Camaros made at the same time. Hard to believe today that 3.73 was a "economy " ratio used on a car without overdrive. To your knowledge when did Chevy quit using those tags? Jay

These engineering decisions need to be kept in context. A traveler on Route 66 in the 1940's would have found speed limits in the 35 to 50 range (and slower in towns). And I am told that the limits were reduced to 35 during WWII to save fuel (which was rationed).

Ike didn't authorize/fund the interstate system until '56. Most of the freeways here in Ohio date from the 1960s - with the 4xx bypasses and loops going in in 1980s.

These old cars were not designed with 70mph in mind - because there wasn't anyplace to go that fast.

I don't know when those ratio tags went out of use on the GM factory floor. I suspect there were others ways to ID different assemblies.

By the time I was 12 in 1957 I had traveled Route 66 from Santa Monica to Chicago though not all the way in one trip. It continues to this day. As a child when Dad was driving it was mostly done in MOPARS built from '40 to '57. on our many trips from Texas to California and back the maximum speed limit was mostly 60 except in Arizona where it was 55. Nevada didn't have a maximum speed until the mid to late '70s but it didn't have 66 either. On the trips I remember it was Dad's goal to average 50 mph. That was a tough goal to meet because of lower posted speeds, gas and food stops (the box of fried chicken and boiled eggs eventually ran out) and the fact that you went through every town. The leading industry in many rural areas was traffic tickets so speed limits were obeyed. Sneaky cops were very good at hiding in very remote areas. Dad usually drove straight through with only a little sleep when Mom would drive. None of us slept well when she was driving. I only remember going 70 once when Mom was driving the '57 Dodge. One trip was in a 1950 International farm truck. We did not average 50 mph. It was great because all of those towns were alive back then. The neon lights alone were worth the trip.

Another engineering/safety concern at least on the old Chevys is the caged ball bearings in the front wheels. They were fine for the day but not good for today's higher sustained speeds and wide tires and wheels that create more of a side load.

Beater, because of the ball bearings on the front axle, does this mean that we have to quit top end racing Stock 49's Chevy? We were just getting the engine broke in! LOL
I grew up in Columbus, Ohio but my mom was from Louisville, KY. We made a trip down there about every 5 or 6 weeks before I71 was built rolling down 3C highway which went right by our house. 60 was thetop speed limit between towns but one semi truck could cut that down quick. In towns the limit dropped to 35 then to 25. I agree about those towns being worth it to go through. Jay

They make a tapered roller conversion. The outer is a standard bearing but the body of the inner is thicker. You probably could machine a spacer and use a standard bearing. I've never had one totally fail but but I've seen some awfully loose wheels.

I hope that Stock 49 has done/ will consider the conversion. I remember in 1976 when in mechanics school we did the front brakes on a 56 Chevy that one of the students had. When I pulled out the wheel bearings I was shocked to see a ball Bering unit instead of the tapered roller bearings that I was used to. That was the only car that I ever seen those types of bearings on. Everything else that I worked on was too new. Jay

They were always in the plan - and already in hand:

thanks to CPP in Anaheim. Kit includes the seals and all.

It is one heck of a plan! I really like what you are doing. I can't wait to see how it goes down the road. It will be at home on any kind of highway. A 216 and a Truckstell ? One of a kind!

This will make things a lot safer when Stock49 outruns the Ohio Highway Patrol and quickly swerves into the right lane to blend in inconspicuously with traffic. Due to overbore aren't you closer to 230-235 cubic inches? I remember that the pistons that were installed gave a compression boost to 8.5- 9 to one which will help a lot compared to the stock 6.6 ratio. Compared to when new, this car has at least twice th power. Jay

Technically now a 230. Bored .030 over. Stroked 3/16 using a 235 Hi-torque crank.

Don't know how one is not conspicuous in a late 40's era car. But in my case the car is blue - making it invisible to the Staties here in Ohio . . . versus Red which can earn a ticket for 60 in 55.

Right, tap it into third overdrive to quiet the exhaust down, pull in the right lane and disappear into a sea of Masda Nissan, Honda, and Toyoda, sedans LOL. The only giveaway will be having too much class. I have an "Arrest Me Red" truck so I have to watch out for thr highway patrol. Something I noticed in the pictures, it looked like the leaves for the rear springs have some sort of cover on them. Do they? Please forgive me for asking so many questions, ts just that I don't know much about cars of this era. Jay

Indeed the springs are wrapped in canvas and then clad with sheet metal:
Old Car Manual Project 49-54 Chevrolet Service Manual
The dealer service bay had a special c-clamp tool to inject grease under the canvas. I used aerosol white grease with the little red straw to get grease into the existing holes from previous dealer service.

Ok, I get it. This must have been done to quiet the spring leaves. I have had leaf spring cars and trucks over the years but this is the first time I have seen this. Thanks for showing me how it works. Jay

My '48 ford front spring was originally wrapped with strips of sheet lead and had grease fittings installed. Back in the day, they traveled down a lot of dirt and gravel roads and those old springs would screech and chatter incessantly!!

Hi Blackwater ... I've never seen leaf springs with zerks - interesting. What I do find fascinating are the apparent myths and legends around the demise of wrapped and lubricated springs:
FAQ Eaton Detroit Spring
Engineering Forums (TIPS) circa '12
I am baffled by the idea that lubrication could somehow break down steel. But I have indeed driven vehicles with 'dry' leaves for decades - so was lubrication ever needed in the first place? Never gave it much thought until I started working on a forties era car.

regards,
stock49

That was interesting. I guess I can blame my spring failures on my oil leaks and not overloading the truck on my rough road.

If you look at many modern leaf spring assemblies, you'll find a small anti-friction pad at the ends of each leaf. I spotted this on the rear leaves on my rat rod when I re-did the rear suspension. The springs are out of a Nissan 100 pickup. Others I've dissected are similar.

I've also found factory spring assemblies with non-metallic strips between the leaves.

I seriously doubt the claims of lubricants degrading spring steel of ANY alloy!! I'd want to see documentation of those claims.

As I said before, the wrap and lube was for noise reduction more than anything. I got that information from an old Ford engineer years ago at an antique car event back in the early early '70s!!

If I think about it when I'm at the shop, I'll drag that old spring out, take a picture of it, and post it here!!