1955 Chevy 3100 1st series 5 window
 

I recently bought this 55 1st series and decided to fix her up. I am needing quite a few parts for it. Including new floor panels, hood, bed boards, just to name a few. It has a later year 235 with a 3 speed and I am hoping to put in a 4 speed w/ a floor shifter. Does anyone know if this would just bolt straight up to the 235? Thanks. I'll

Re: 1955 Chevy 3100 1st series 5 window
 

That is the original 55 engine in the bed.

Re: 1955 Chevy 3100 1st series 5 window
 

a four speed from the same era as the 3 speed or with same input shaft should bolt right up. If the 3 speed has an open drive line you might get lucky but I would plan on some drivelive work too. Floor shifters are available, you want to get one with a longer lever or plan on shifting hunched over, which gets old, I had a T-10 in my 57/235 pick up in the late 60's. The granny four speeds (SM465??) will bolt up to if that is what you want.

Re: 1955 Chevy 3100 1st series 5 window
 

Alright, thanks. I found a 4 speed from a 53, it has been sitting outside for 6 months but ran before sitting. Any ideas on how to clean it out?

Re: 1955 Chevy 3100 1st series 5 window
 

Should be sealed up pretty tight unless it was partially disassembled. I'd drain the fluid and if no water comes out and its not milky refill it. Steel wool and WD40 will clean up the input shaft if its rusty. While its out is a good time to look at the front and rear seals too.

Re: 1955 Chevy 3100 1st series 5 window
 

Well, it was taken off of a truck and laid on its side and just has set there.

Re: 1955 Chevy 3100 1st series 5 window
 

Man I love those 54 & 55's!! :metal: Cant wait to see what you do to it.

Re: 1955 Chevy 3100 1st series 5 window
 

Can't wait to get done:burnout::truck:

Re: 1955 Chevy 3100 1st series 5 window
 

Unless it had something wrong with it when pulled it should be ok, I'd drain and refill it and call it good unless the seals were obviously leaking before.

Re: 1955 Chevy 3100 1st series 5 window
 

Alright will do probably Thursday. Let you know how it goes. Thank you fir all your help thus far! :alc:

Re: 1955 Chevy 3100 1st series 5 window
 

It will not bolt up to the 4 speed. You will need to get a new bell housing if it orginally had the three speed. I did the same thing on my pickup, and was unpleasantly surprised when I tried to bolt them up. One of the many lessons I learned. Also you will have to modify the length on the clutch throw, no big deal but it took me an afternoon to figure it all out.

Re: 1955 Chevy 3100 1st series 5 window
 

Maybe later is different I bolted a SM465 that was in a 56 to my 59 three speed bellhousing. Input shaft fit fine and did not have to change the clutch. Are the AD three speeds different than TF years?

Re: 1955 Chevy 3100 1st series 5 window
 

Orrie knows a hell of a lot more about these things than do I. I am not sure what year the 4 speed came out of, only know it was from a one ton truck, and the bell housing was a lot beefier than the three speed bell housing. The shaft was not a problem, and the throwout lever was just enough different (maybe it was bent) that I had to modify the clutch throw distance to make it all work. I LOVE the 4 speed on the floor. It just sounds and feels right.

Re: 1955 Chevy 3100 1st series 5 window
 

Sound like I was just lucky and someone before me had done all the adjusting on the 56 donar, and it was 28 years ago! Best to measure and compare the input shafts and bolt patterns between the 3speed and 4speed, then if it looks right jack it up and see if it fits ok. Clutch is an easy fix, just basic geometry problem to solve. I can't remember if I had to swap out the zeebar or not...

Re: 1955 Chevy 3100 1st series 5 window
 

Didn't they change the bolt pattern on the bell housing in '55? I'm thinking that an earlier model xmision might not bolt up. Or was the change made for the TF later in '55?

Re: 1955 Chevy 3100 1st series 5 window
 

Bells changed in '54 to accomodate the change to the cross member that also accepted the Hydramatic trans. Never heard of it being an issue to swap 3 and 4 speeds, though, and only see 1 bell for the two groups (pre and post 54). I want T5 and open rear end for my '54...someday.

Re: 1955 Chevy 3100 1st series 5 window
 

Hate to resurrect a dead thread, but it's better than making a new one (I think?)
I've got a 57 with a three speed, wanting to go to a SM565.
It looks like I may or may not have throwout bearing travel adjustments to make.
Do the later-model SM465 transmissions use the same 4-bolt bellhousing pattern as the earlier 3 speeds?
Also - I'm told by previous owner that the existing trans is a 3 speed with a granny low that came out of an old school bus. It is shifted off the floor, looks to have a 10 spline output (I didn't count, though. D'oh) and is bolted to the 235 currently. I also have a 90 degree V8 / 3rd gen I-6 bell housing for this mystery trans. Any ideas what it is, so I can start figuring out compatibility?

Re: 1955 Chevy 3100 1st series 5 window
 

Nevermind. Confirmed w/ previous owner it is a 4 speed w/ granny low.