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Original tranny

6K views 27 replies 5 participants last post by  ImpalaJon 
#1 ·
Hello,

I'm new to the forum, and new to impala's. I'm an old gearhead and am quite familiar with chevelles and engine/tranny rebuilding. However I am new to restorations/body work as well as Impalas, and that's Why I'm here. I Bought a partially restored 1963 series 1800 impala with "THREE ON THE TREE". It came with a number "correct" 283 rebuilt motor, and an incorrect BW T-10 - the previous owner wanted to put this tranny in it. No problem. I, on the other hand, wish to restore it to more original specs and put an original "synchromesh" 3-speed back in it. I am not building a modrod or hot rod, and just want a near as I can get original Impala for my son to cruise in (he loves Impala's).

The build manual shows this as a part# 3820503 synchromesh transmission.

PROBLEM: I have no idea what this is or where to find one

I have looked everywhere and tried to call GM (no help there)

What is this transmission, and what are replaceable equivalents?

Muncie 318?
Muncie 319?
Warned Gear 3-speed?

Where can I find a "proper" replacement?

I'm sure this is not the first time this has come up for many of you, and probably even in these forums, but a quick search wasn't yielding.

Thanks for any help!

JD
 
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#2 ·
Welcome to the Team John!

Most if not all are scrap metal by this time. I had one in my 1961 three quarter ton Apache pick-up that I put a SBC 4000 and a SM465 four speed to make a tow truck for my race car (after my 1954 International R-160 Cab Over semi died for lack of replacement parts for it's brakes). I replaced the three speed with the Muncie four speed (with PTO) out of a dump truck because I was breaking a three speed every time I had to back up.

The tranny you are looking for was designed back in the early fifties and is a hold out from Chevrolet's extended love affair with the 235 stove bolt six cylinder. Because Chevy was the last marquee in GM's line up to get a V* none of the power train behind the six cylinder engines were updated when Chevy finally introduced the 265 V8 (not exactly a high torque engine). Your 283 is an eighth of an inch overbore of a 265 retaining the three inch stroke that allowed it to rev to 10,000 RPM with decent heads and a solid lifter cam.

I recommend using the Borg Warner T-16 transmission as it is indestructible (base transmission if you ordered a BBC in your 1965 Chevelle, with the Muncie four speed as an optional upgrade). Roundy round racers covet theses transmissions used in light trucks as they have a good gear spread and they have a high torque rating. Unlike the old "Synchromesh" which was GM's first fully synchronized gear transmission (prior three speeds where not synchronized on first gear).

Big Dave
 
#5 ·
To finish that thought,

It's so amazing to me to see that those original '63 impalas had an electronically switched overdrive.

Anyways, I found one BW T-5 transmission on eBay for $2500. May be the thing to have, but there's no way I'm dropping that much coin for one, heck, a brand new transmissions cost less, rock crushers cost less.....

Any other options for a compatible 3-speed? Would any of the older years 3-speed fit with out significant modifications?
Seems like any three speed from 1963 back should probably do it. Any thechnical issues I should be aware of?

Thanks again for your replies and help guys!

JD
 
#7 ·
That is an insane price for a T-5 tranny as it is worth about $14 because it is only good for scrap metal. The T-5 was purchased by Ford from Borg-Warner back in 1971 to use in their Pinto four cylinder economy car that weighed only 2,300 pounds. It was also used in the Pinto suspension and power train car that had new sheet metal hung on it called the Mustang II. This followed historical precedent as the original Mustang was new sheet metal hung on a Ford Falcon economy car with a 170 cube six or a 260 V8 engine.

The T-5 was discontinued in the 3300 pound Camaro because a 305 smog motor broke more than GM could afford to replace. If you have a 283 you can break it due to the weight of the 4200 pound Impala resisting the low torque of the 283 trying to accelerate the car.

The Saginaw synchromesh electric overdrive three speed was available as an option from 1955-64. It is longer than a usual three speed as the OD unit is in the tail shaft. It is also a rare option because the three speed synchromesh wasn't a strong tranny (low torque rating), so people threw them in the scrap metal pile when they replaced a broken one with a four speed or a cheaper three speed without OD that could be had for $25 to $50 back in the mid sixties (though a competent mechanic could transfer the OD over to the cheaper three speed by rebuilding it as it required installing a longer out put shaft).

Big Dave
 
#6 ·
That is Crack Price for a T5. You would be far better off with a used T56 six speed, it's twice as strong. For a three speed, they're out there. They were made by the tens of thousands. Later ones will work fine, as well, and they were used well into the 1970s. Later ones got stronger, with benefits like syncro first gear. My 65 C10 has the three speed column shift, I like it.
 
#8 ·
OK, now this is getting good as now it is getting more clear as to my options.

Thanks!

I'm sorry, I meant to say T-16, as that was what Big Dave had sugessteted not T-5: I found a T-16 for $2500.:surprise: I am finding all sorts of GM 3-speeds for several hundred dollars and this is what I am thinking will need to be done - with or without overdrive including several Muncie 318's (which is looking attractive to me right now....).

I guess that's my question now:

Would a 55-62 "Saginaw" 3-speed or Muncie 318 fit the stock driveline and frame (output tail assembly length aside for now), and would the shift pattern be the same (seems like it should, but finding documented support info of this is proving to be difficult at the point).

If I went to a four speed, it seems a floor shifter would be necessary and the column shifter would become useless, correct? Or is there some clever mod To allow 4-on-the-column (might be a consideration if this has been worked out)?

Thanks again!

JD
 
#9 ·
Sort of...

Olds had a four speed that was on the column along with a straight eight cylinder motor.

I thought the T-16 would be a popular tranny, just not that highly prized.

You don't have your home city in your profile so I don't know where you live without looking up your IP address. Reason I mention location is in the south there are a lot of good ole' boys that like to shoe up on Friday night with a case of beer and watch cars go round and round in the hopes of seeing a GOOD wreck (kind of hard to define as no one likes it when someone gets hurt). That is where you will find two or three of these trannies in every trailer that has the car and spare parts.

I dare say you could probably coax a tranny from someone for a fraction of that cost; if for no other reason than to help you out as southerns tend to like each other and people who like what they like (such as cars and roundy round racing).

Big Dave
 
#10 ·
Yes, I vote for the 3-speed with OD. Which model 3-speeds came with OD? Maybe we (members of impalas.net) can come up with a list if 3-speed transmissions model numbers, what applications they were installed into, physical measurements, spline count, etc.
 
#12 ·
More good information and a great idea for making a list - I'm sure they are out there but not easy to find. I'm learning a lot in these discussions and I have found out something as well elsewhere:

For the three speeds:

The 1st to 2nd gear synchronize trannys came about later (circa '66?) and appeared to be about 21 inches from bellhousing front to the rear seal (Jay's link)

The early non-synchronized trannys (1st to 2nd gear) WITH OD were roughly the same size and, splines aside, could be replaced easily with the later trannys (>'66) as this fit the drive shaft length (of course you would need correct yoke to match tranny output shaft and might need to modify tranny mount point and linkages)

The early non-synchro trannys WITHOUT OD were roughly 16 inches long in the x-frames and thus had a longer drive shaft to make the difference.

I can't be sure what length size tranny was originally in the car as this project was shipped with engine out, bellhousing off, and the 21.5" t-10. I tried to measure the distance from the drive shaft in the car to where the engine should dit and determined this would need a 21 inch tranny thus this vehicle probably had an OD originally (or the drive shaft switched) But right now I can't be sure about the measurement so this is a bit speculative.

What I must do now is make sure what I get will work with the column shifter (which appears to be in fairly good condition).

On another note, I'm going to have to find a transmission cross brace as this is missing...
 
#13 ·
The drive shaft is two piece. The 'rear' section is the same for all transmissions. The 'front' section varies in length depending on transmission. The length (between the centerline of the yoke bores) of the 'rear' section is 35". The length of the 'front' section of the 3 speed w/o OD is 30.1" and the length of the OD and 4 speed is 25".

Unless you are really enamored with the OD 3 speed, I'd opt for the non-OD and replace the front section of the drive shaft. Why? Mostly because I believe you will find the parts are cheaper and more readily available. I'm also rather simplistic in my philosophy regarding these old cars and believe 'less is more' in most common applications. I'm not 'dissing' the OD, I just think it is overkill and the cost is not commensurate with the gain.
 
#15 ·
True, but the highest gear ratio (lowest numerically) is only 3.08:1. So I think the OD option would still be useful and cool. And it does not complicate the car at all. This is my opinion.
 
#16 ·
Plagiarizing from the '61 shop manual:

The OD transission has an additional mechanical side (basically a two speed planetary transmission attached to the rear of a conventional 3 speed manual). It also has the electrical controls consisting of a solenoid, a speed sensitive governor switch, a relay and a kick down switch (and all the associated wiring).

A standard 3 speed does not have all that. I'm not suggesting that GM didn't make it work. It's an ingenious system. But, while I respect your opinion that 'it does not complicate the car at all', I disagree.

Please do NOT take what I said as being critical.
 
#17 ·
I kept all of my car magazines going back to 1959. I have all of the major titles and few specialty mags which today are not only sorted chronologically by title but placed in archival bags and plastic magazine storage bins.







Further I have even scanned a lot of them into my computer (about two terabytes worth so far). I have a couple of articles that out lined how to rebuild and maintain these trannys if I can figure out what it appeared in and when. So if you can figure out what it's in I can PM you a copy of the article (as I can not post here due to copy right infringement).

Big Dave
 
#21 ·
Boom!

I hadn't even noticed that while inspecting the undercarraige - just didn't even bother to look at the entire length of the drive shaft.

Upside is I'll have the ability to make more accurate measurements!

Thanks!

Btw, where did you find these diagrams?
 
#23 ·
The one I posted came from (first page is blank, scroll down):

https://www.gmheritagecenter.com/do...information-kits/Chevrolet/1963-Chevrolet.pdf

Big Dave's are much more elaborate and he'll have to respond.

Also, there is a yoke (that attaches to the 'front' drive shaft yoke via u joint, 5.555 in Big Dave's pic). That is a separate piece that needs to match your transmission out put shaft splines. I mention that because if you are willing to replace that yoke, you will expand your 3 speed Saginaw transmission choices.

Pete
 
#22 ·
Big Dave,

I just figured out your post was directed to me - 'doh

That is an awesome collection and would certainly be some useful references. I have no idea what to ask for at this moment and really wish I did. In all that do you have anything that talks about Muncie 318's or 319's? I'm still very curious about these transmissions and where they were originally used...

Thanks again!

JD
 
#25 · (Edited)
I already have two yokes for the "front" drive shaft, I presume you are referring to a 27 spline so a '64 tranny can be used? What else?

The truck transmissions may be viable. There was a reply to your post about that earlier.

Also, you may want to ID your bell housing. Some previous owner of my '63 used a truck bell housing and I had to get a larger bearing retainer for my 4 speed Muncie (I could have replaced the bell housing). Everything is just fine. Could have used a larger clutch disc (because the truck bell housing is larger than the car versions to accommodate the larger clutch) but chose not to.

You may also want to ID what size flywheel you have because that determines the size clutch to use. You may want to resurface your flywheel depending on its condition. Pilot bearing? Now's the best time to replace while everything is apart (they are not expensive but make sure you get a good non-ferrous one).

I had to replace every component of my clutch mechanism forward of the pedals (except for the frame mount and stud for the z bar) because a previous owner (those guys can be trouble) 'built' a mixed bag of parts contraption (that actually did mostly work) from parts foreign to my '63. The upper and lower push rods were wrong, the z bar was wrong, the clutch fork was wrong. Just something to look for before buying parts and putting everything back together.

I highly recommend acquiring the Shop Manuals (the '61 complete and the '63 supplement) and the Assembly manual. Tons of reliable useful info for very little investment. Wanna verify your parts/configurations are OEM? Those manuals will be a huge help.

Here's a couple of links to some info you may find helpful:

64... 4 speed conversion - ChevyTalk - FREE Restoration and Repair Help for your Chevrolet

4 speed bellhousing - ChevyTalk - FREE Restoration and Repair Help for your Chevrolet

There is some repetition and the topics are not specifically concerning your questions, but the general info is good. Scroll to the beginning of each to get all the info.


Pete
 
#26 ·
Just an update:

As I began looking for a 3-speed, I discovered that this particular vehicle has a rather uncommon Bellhoising for this year (3788421). The bearing retainer hole measures 4-1/8 inch, making virtually every trasmssion I've looked into not compatible. This even goes for the t-10 I have (BR 4-5/8") like almost every other CAR BH and tranny BRC for this time. I also have the 30" front drive shaft so the car will require a 16.5 " SHORT tranny (none O/D) - fortunately these can still be found.

Any suggestions for this? Anybody know an after market bearing retainer 4-1/8" in diameter? This is an original BH so would like to retain it rather than replace with a more conventional one if I can.

Thanks!
 
#27 · (Edited)
The ...421 is the bell housing GM used for 1963 only. It is not uncommon for 1963 :wink2:

Here's a quote from one of the links I posted earlier (the opinions are not mine):

'Now, one very last thing --------------- THIS IS IMPORTANT, READ IT!!!!
For 1963 only, repeat, 1963 only, the SMALL bell housing was unique and again one year only. You do not want a 63 Bell housing!!! Why? Because for 1963 ONLY, the front bearing retainer on manual transmissions was a smaller diameter. Thus, the hole in the 63 (small) bell housings where the bearing retainer fits into, is smaller than 62-earlier and 64-later bell housings. Why in God's green earth Chevy did this is somewhat of a mystery ------------------ not to mention dumb, dumb, dumb!
The 63 only (small) bell housing was the 421 (last 3 numbers of the casting number) version. '

Does you 'current' transmission have the 'small' bearing retainer? If so, is the one off your 'current' transmission compatible with your 'new' transmission? I do not know that answer, but you may already have the part you need (with a new gasket).

I do not know any source for the '63 only retainer. A different bell housing may be easier to find. Match any new one to your flywheel.

Hope this is helpful.

Pete
 
#28 ·
Yes, I did look at that link. But all the photo links are now broken and I had no context at the time. Makes perfect sense now. Trying to limit my information sources as it can get hard to keep track of every thing...

Yeah, it's looking like new bellhousing time. I guess I could turn down one of the 4-5/8 bearing retainers. Could also have an adapter plate made (but then the alignment of the drive shaft and and stress on the carrier bearing might be too wack - wonderful stuff).

Bizarre thing to do IMHO for 1963 - otherwise a good year!

Thanks for the response!
 
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