4 Spd Truck Trans Differences ?

[55 Fargo]

Hey all, I have a 4spd trans in the 55 fargo, behind a 251 engine.

Even with 3.23 gears, 1st gear is still pretty "bull low".

I am looking to acquire a trans from around a 1952 Dodge 1 ton 4 speed.

Would the 1 ton 4 speed, have different gear ratios than a 1/2 ton, or would it be 1 in the same, employing suspension and rear diff gears to accomodate the heavier 1 ton trucks?

Does anyone know if there were different type 4 spd synchro trans, for the late 40s and 50s Dodge trucks?....thanx

[Plymouthy Adams]

Fred..the truck 1st gears are usually never used in an unloaded truck or at least this is how we drove them back in the day...but...I can see the possible need of first with your higher 3.23 with light load or low elevated highway/ramps and driveways......as for the later/larger model trucks and actual gear ratio..I do not have that information..but usually only the close ratio had the better street gearing...a wide ratio truck tranny of even modern times have a lower first and second gear

[55 Fargo]

Fred..the truck 1st gears are usually never used in an unloaded truck or at least this is how we drove them back in the day...but...I can see the possible need of first with your higher 3.23 with light load or low elevated highway/ramps and driveways......as for the later/larger model trucks and actual gear ratio..I do not have that information..but usually only the close ratio had the better street gearing...a wide ratio truck tranny of even modern times have a lower first and second gear

Thanx Tim, i do not need to use 1st at all, even with 3.23 gears, takes off in 2nd like nothing. Can even take off in 3rd, not well but it can.

I am hoping to possibly get another 4spd, and use it, as mine has some chewed gears.I have no idea when I might try a 5 speed trans plant, the need is not as great with a 3.23 diff.

[P15-D24]

FIrst is a compound low, used to get things rolling when you are loaded up.

Never use empty.

When you are loaded up 1st will save your clutch a lot of wear.  

[55 Fargo]

FIrst is a compound low, used to get things rolling when you are loaded up.

Never use empty.

When you are loaded up 1st will save your clutch a lot of wear.  

thanx, yes i understand this, and even with 3.23 gears, 1st is still for a load, and not everyday driving.

My question is more of a are there other 4 spd transmissions, that have even lower 2nd and 3rd gear ratios, cuz what I have now, is tolerable..

[ggdad1951]

my one ton 4 speed has the 4.3....47mph TOP speed w/o making the engine scream.

[Merle Coggins]

I believe all of the light truck 4 speed trannys are the same ratios. 1st is only used for very heavy loads, as mentioned, or for low speed off road work. Also good for parades. Just drive it like a 3 speed unless that low gear is required.

 

How bad are the gears? Do they howl or whine? Is there a lot of metal flakes in the oil?

 

Merle

[55 Fargo]

I believe all of the light truck 4 speed trannys are the same ratios. 1st is only used for very heavy loads, as mentioned, or for low speed off road work. Also good for parades. Just drive it like a 3 speed unless that low gear is required.

 

How bad are the gears? Do they howl or whine? Is there a lot of metal flakes in the oil?

 

Merle

Hey Merle, no howling, a little whining in 1st and reverse. There is all fresh oil in it, no metal shavings were ever found by me. There was a gear with teeth missing. It shifts well, no problem

 with downshifting either.

 

Just too truck to General Store, no noises from trans,shifted well also. it is only 8 above, the truck with no insulation is cold on the highway, heater box is throwing heat, but has a 160 t/stat, would be much better with a 180.....

Edited February 14, 2013 by C38Spitfire6

[Merle Coggins]

First and Reverse are probably still straight cut gears and the rest are helical cut gears. That would account for the whine in those two gears. That's fairly common on this style trans. My truck has the earlier version 4 speed where all of the gears are straight cut, and no syncros. It whines in every gear except 4th, which is direct drive.

 

Your broken teeth must not be bad enough for the gears to loose constant mesh, otherwise it would skip and cause more damage. If there are just small chips missing from a few teeth it may not hurt to continue to use it. You're typically not in 2nd and 3rd very long anyway, and once you're in 4th the gears are out of play and have no load on them. If you were pulling heavy loads in the lower gears with the damaged teeth, that might cause more damage. But with light loads you can probably run it for quite some time without issues.

 

Merle

[55 Fargo]

First and Reverse are probably still straight cut gears and the rest are helical cut gears. That would account for the whine in those two gears. That's fairly common on this style trans. My truck has the earlier version 4 speed where all of the gears are straight cut, and no syncros. It whines in every gear except 4th, which is direct drive.

 

Your broken teeth must not be bad enough for the gears to loose constant mesh, otherwise it would skip and cause more damage. If there are just small chips missing from a few teeth it may not hurt to continue to use it. You're typically not in 2nd and 3rd very long anyway, and once you're in 4th the gears are out of play and have no load on them. If you were pulling heavy loads in the lower gears with the damaged teeth, that might cause more damage. But with light loads you can probably run it for quite some time without issues.

 

Merle

Hi Merle your correct, and 2nd and 3rd don,t skip or jump out of gear, no issues  you downshift into those gears while moving too. Like the rest of Mopar engineering probably built tough as nails. i love drivin this old truck short wheel base just the feel of it. I actually enjoy it more than my 47 Chrysler...

[ggdad1951]

in FEF the 1st, 2nd and reverse gears are straight

[55 Fargo]

My 2nd gear must be helical cut, you can downshift into 2nd gear from 3rd while moving

[ggdad1951]

Lucky dog....

[Dave72dt]

I remember the whine of the gears in my Dad's truck he had when I was small.  Don't recall clearly anything else about it.  Didn't recall the sound until I did a road test on a '51 F3 I'd just finished.  Good memories.  Just now thinking about it, I recall the sound of the truck he replaced it with too.

Edited February 15, 2013 by Dave72dt

[Dodgeb4ya]

Here is the transmission and rear end ratio chart for the 1951 and up for both 3 and 4 speed transmissions installed in the Dodge 1/2 through 1 ton models. Syncro and Spur gear 4 speed transmissions had all the same forward gear ratio's. Reverse gear was a bit lower on the spur gear 4 speeds. In 1951 or 52 the 4 speed synco trans was a nice option update over the earlier spur gear 4 speeds.. Some extra juicy data shown too!

        

Edited February 15, 2013 by Dodgeb4ya

[Looznutz]

I wish I could find the 5 speed with overdrive. That would be cool. Straight swap for my straight cut 4 speed trans. Oh well keep on dreaming.

[Young Ed]

Mark what size tires are you running? According to that chart with your 4.3 you should be able to get to atleast 55 without the engine screaming too much.

[ggdad1951]

Mark what size tires are you running? According to that chart with your 4.3 you should be able to get to atleast 55 without the engine screaming too much.

BIG ones, R16 if I'm remembering right  .....we'll go for a ride this spring and you can tell me if I've been overly cautious, or maybe a misidentified gear ratio?  Gonna have to go digging thru my pics for my ring gear.

Edited February 15, 2013 by ggdad1951

[Young Ed]

BIG ones, R16 if I'm remembering right  .....we'll go for a ride this spring and you can tell me if I've been overly cautious, or maybe a misidentified gear ratio?  Gonna have to go digging thru my pics for my ring gear.

 

That will be fun. I don't think I've ridden in it put together. The best thing to do it hook up a temp tach and really see where things are at.

[ggdad1951]

That will be fun. I don't think I've ridden in it put together. The best thing to do it hook up a temp tach and really see where things are at.

you got one?  I've thought about hooking one up I could hide when showing and swing out from under the dash when driving...  but how to hide it on the engine and firewall....

Edited February 15, 2013 by ggdad1951

[Young Ed]

you got one?  I've thought about hooking one up I could hide when showing and swing out from under the dash when driving...  but how to hide it on the engine and firewall....

 

Ya Dad has a tach/dwell meter I'm sure we could use. As far as hiding a permanent one the under hood would be easy just have to get some more cloth covered wire.

[ggdad1951]

Ya Dad has a tach/dwell meter I'm sure we could use. As far as hiding a permanent one the under hood would be easy just have to get some more cloth covered wire.

your dads could be rigged up for use while driving?  I've got pleny of cloth covered wire from RIWire, or I could order more. Would it not be obvious still tho?  Extra wires around that area?

Edited February 15, 2013 by ggdad1951

[Young Ed]

your dads could be rigged up for use while driving?  I've got pleny of cloth covered wire from RIWire, or I could order more. Would it not be obvious still tho?  Extra wires around that area?

 

Yes we were able to do it in my plymouth. I think the wires were long enough to connect under the hood and then come into the car through an open window. If not you could always rig an extension of some sort. For the tach I think you only need to hide a wire on the dist to the interior.

[Plymouthy Adams]

so the tranny gears in the Spd. is:      Rev..7.8; 1st 6.4; 2nd 3.09; 3rd. 1.69 and of course 1.0 in 4th 

 

slight difference in the 3 speed:  Rev 4.3; 1st 3.3; 2nd 1.78 and 3rd is 1.0

 

for you folks that have or entertaining modern rear gears....

[Reg Evans]

C38spitfire6,

I also have a 251 Chrysler in my 52 1/2 ton with a 4 speed syncro.  My rear end ration is 3.0 and I still never need to use 1st gear. I have tried it a few times starting out on steep hills but by the time I can get the trans into 2nd gear the truck has just about lost all it's forward momentum. It's still a stump puller even with the 3.0 !