transmission swap

[Chiro]

Okay, my boys and I are really getting into it now. We have begun work on the truck ('55 first). Using the '58 235 and one of two transmissions. Here is the question.

The motor is going into a truck that already has a column shift 3 speed in it. This is the junker truck ('54) that has the bad sheet metal. I am putting the good sheet metal from the other truck on this truck (yeah, that's right. I'm making one good truck out of two not-so-good trucks). However, I also have a '54 four speed trans (floor shift).

What I want to know is can I simply bolt up the four speed to the torque tube that has the three speed attached to it now? Or are the tranny's different lengths and setups requiring modifications to the torque tube?

Somebody please tell me that these farmer's trucks were made so that all tranny's were interchangable so as to make repairs in the field easier. I really don't want to hassle with modifying the torque tube. I could go get the rear that the 4-speed was attached to which came out of a hot rodders truck, but I don't want to drive 4 hours away and move that large and heavy rear/torque tube assembly. My suburban is big, but I don't think it's THAT big.

Also, I have two flywheels and two clutch assemblies of different diameters. Does it matter which diameter clutch assembly I use with the four speed.

Andy

 

[brit 50]

Nate? your on!
________
SILVERADO

 

[vwnate1]

Sorry ; missed this post .

yes , it should be a bolt up deal as I swapped several back and forth back in the day . input shaft splnes and bolt pattern is exactly the same .

The u-joint is different between the 3 speed and 4 speed tranny IIRC so you'll be wise to have all the spare parts on hand before you begin...

Don't forget to shim the ball _before_ you install the u-joint so it'll follow correctly and lot leak like a sieve .

Take a couple spare tranny to bellhousing bols and cut the heads off them , screw into the bell housing and use as guide pins when you install the tranny as it's heavy , this avoids the common bending of the clutch disc....

Once the other two bolts are in , remove the guide pins and replace with the correct bolts .

 

[Chiro]

Thanks for the reply Nate. Couple of more questions if you don't mind. Was writing this reply when it disappeared so here it goes again.

What is "IIRC"? I figured out "SWMBO" and "FLAPS", but "IIRC" eludes me!!! I read the procedure in the shop manual (they finally came) about shimming the ball. Where do I get the shims? Also, catalogs I have do not specify a difference in u-joints. Where might I get the four speed u-joint? Have been unable to locate exploded view of the ball and seal. Are the shims involved just a matter of how many gaskets to use where the ball mounts to the trans? If that is the case, then Classic Parts I think has what is needed in their "U-Joint ball gasket and seal" set Part # 92-111. Please let me know if this part is what you are taling about as far as shims are concerned, but where do I get the 4-speed u-joint?

Thanks,

Andy

 

[vwnate1]

Acronyms & Shorthand Ball Shimming Etc.

LOL

It means :

If

I

Recall

Correctly .

It seems to me it matters what years as I've used the same U-joint on both three and four speed top loader trannies but the catalog shows different u-joints for three speed and four speed trannies in 1/2 ton trucks during the AD run .

Just hand fit it all before installing the ball , either the splines and offset etc. will be the same , or not .

If one has loose trunions on the cross , look to see if you can mix 'N match to make one good one out of two .

New replacements are made in Argentina , yet another coutry who makes machine parts without any apparent quality control so look hard at it before you accept it as I've got one that was machined off center , leaving it not good for use .

I'd get the U-joint off the truck you took the 4 speed Muncie SM420 tranny out of , it should have been dangling off the back of the tranny as junkyard tend to simply unbolt the tranny and pull it off the Torque Tube (lazy ya know ) .

The ball is dead simple and one of you all hipped me to the easy way to do it:

Clean the back of the tranny cavity and the ball's face , test fit and move it around , if it's silky smooth (doubtful) skip on down to the shimming part , if it's rough as they normally are , get some 1,000 grit or _finer_ wet/dry sand paper and sand down the ridges you'll see there untill it moves smoothly in it's seat .

Clean it all up _hospital_ clean as a tiny bit of SWARF or abrasive grit residue will gring up the tranny etc. .

Now , test install the ball (sans U-joint & O-ring , dig) and it's retainer and gently install the bolts , the idea is : the balll should be able to move with a gentle tug on the sleeve end but _not_ drop and fall down of it's own weight .

Add the paper shims from the ball seal kit untill it as this point of smooth movement but not loose nor binding , DO NOT bend the living crap out of the retainer ring by fully tightening it in the initial test fit .

TIP : there's a large perimiter seal inside the retainer ring , if you're lucky and still have the leather one , soak it in a pan of clean oil whilst you're fooling with the rest of it . the new synthetic O-rings don't seal as well and don't last 65 years either....

Your local leather shop (Cobbler) should be able to make you a new one for $25.00 or so..

The threaded collar at the rear of the ball where it fits to the driveshaft proper , also has some leather rings in it , tighten only enough to stop the drip .

Loosens up every 10 miles does it ? lightly smack it with your dead blow mallet _after_ the next time you tighten it to stop the drip , this will make it ever so slightly egg - shaped and hold it's place but also makes it difficult to
" feel " the proper torque .

I hope this helps , print out a couple copies and drag under the truck with you and it should all be clear , if not ask again and I'll try to write a better note .

 

[Chiro]

Thanks for the detailed and timely reply. Seems pretty straightforward. I only have ONE u-joint. Have to call the hot-rodder I got the 4-speed from to see if he still has the other. don't expect to hear back from him though. I been there, done that and paid him so I am out of HIS mind. Tried to get another part from him after I saw him, but no good. Will work with what I have a make it go and get other parts as needed. all in a days fun trying to build a work truck with my kids. You're right Nate. This project has brought us all closer already.

Andy