I am confused as to why the 4+3 transmission is such a hated transmission.

I recently read this on a website regarding the history of the Muncie's and T10/Super T10's:

Muncie 4 speed transmissions were used in General Motors cars from 1963 to early 1975. These gear boxes were used when power levels exceeded the limits of the early Borg Warner T10 4 speed. It was actually based on the T-10 design and uses the same basic gear layout. The T10 made it's appearance in GM cars in 1957. From 1957 to 1963 many changes took place inside the gearbox to meet the increasing horsepower the new engines were putting out. It was replaced by the Muncie in late 1963. The Muncie 4 speed was used in production vehicles until power levels dropped in 1975. 1975 was the first year catalytic converters , smog pumps, and low horsepower were introduced. These new requirements led to the demise of the Muncie and the reintroduction of the improved T10 called the Super T10.

While General Motors was switching gearboxes around from 1963 to 1975 other companies such as Ford and AMC kept the T10 in production. So we got to see T10, and First Design Super T10 transmissions end up in these cars. It was also an opportunity for Borg Warner to design replacement Super T10's for the Muncie. These 4 speeds offered 9310 nickel gears, had a wide variety of gear ratios, and were available from any auto parts store carrying the Borg Warner parts line. A variation of this Super T10 ended up in GM cars from 1975 to 1983. Also as the 4 speed section of the 4+3 Corvette Overdrive in 1984 to 1988 Corvettes.

Well enough of this little 4 speed history. I figured I pass these facts on to you so that one day you can tell your children and just maybe all won't be lost. Lets face it today's muscle car is the Honda Civic. A majority of kids today will never feel the awesome torque of the big blocks as well as the feeling of ripping thru a few sets of gears.


My understanding is the 4+3 is a Super T10, with basically a small automatic transmission on the back of it. So I would think usually the part to break would be the overdrive unit. So why not take the OD unit off, put on a regular T10 Tailshaft, and just run the 4 speed? or better yet, run the 4 speed with a US Gear OD unit on the back of it?

Also, the original 4 speeds did not have a hydraulic system. they had a "linkage" that was basically a series of rods attached to the throwout bearing. How does the Corvette 4+3 throwout bearing work? I'm sure it's hydraulic.

What can be done to strengthen the 4+3 OD unit? Does it even come with a cooler, like any automatic transmission should? Can one buy better clutches for it, and up the line pressure, etc. like you would upgrade an automatic?

I'm just trying to learn more about a subject I'm so ignorant on. I am also looking to buy a 4+3 tranny, pedal assembly, and master/slave cylinder, AND have a recently rebuilt and upgraded 700R4 available for trade if someone is looking to switch.

Thanks for reading this!

 

Also, It's hilarious how hard it is to find info on this site on the "4+3" tranny, because if you search for 4+3, the search function won't work because of the +!

haha!

 

P.S. - I am considering putting this behind my 383!

Hey, if those older Super T10's and muncies can handle big block power, why can't an 80's Super T10 do it?

 

sorry to re-post so many times, but didn't the earlier calloway cars have the 4+3? That's like a 430 horse motor, isn't it?

 

1. A normal tailshaft won't bolt up because of the c-beam. You'd have to fabricate some sort of bracketry.

2. Yes, it is a Super T-10 w/CC gear ratio combination.

3. Yes, the throwout bearing is hydraulically operated and non-adjustable.

4. Yes, the O/D uses the radiator as a cooler just like the automatics do.

5. Bronze clutch packs are available for the O/D, but are for seriously hardcore people.

6. Yes, the '87 B2K cars used the 4+3. They handled the torque just fine. I'm pretty sure Brian at S-K Speed did the work on them for Callaway and I do think increased line pressure was one of the items addressed.

 

Its not about the T10 strength, its about the automatic part on the tail end.

IMHO, if you dont drag race a lot, the 4+3 is a great tranny, I truely loved the 4+3

but,,,, if you pay to have teh 4+3 fixed once at @$1300, then it goes again, you will have already spent enough $$$$ to do a swap to another style of tranny.

Call the people that rebuild them and tell them about your application and they will tell you if it is adviseable or not.

If I were to do my swap again, I would do the TKO 600 / 5-speed.

 

I used to love those M-22 transmissions because of the whine and the gearspread. Unfortunately, I broke every single one of 'em.

 

Wow! thanks for all the info!
I had no Idea that the OD used a cooler.
I would like more info on the bronze clutch packs, like where to get them, etc.
I'll give S-K Speed a call and talk to brian about the OD as well.

For those that think I am crazy, I'm not. I just can't afford to put in a 6 speed right now, and thought I'd at least give the T10 a try.
I plan on doing some things to the t10 itself to strengthen it up as well.

Keep it coming! thanks for the posts!

 

What part did you usually break on them??


ALSO - I AM considering getting a t56 and fabricating the mount to get it to work. But that is another topic, and I will only be doing it if I can get a t56 for $700 or cheaper, in working condition. (I know, fat chance)

 

WOW.... I just got off the phone with brian at S-K's Tranny shop, and he really opened my eyes about the 4+3.

First of all, the 4+3 is NOT a super t10. the super t10 was only available as the aftermarket unit, and had a Iron case, and nickel gears.
In fact, the 4+3 t10 is actually weaker than some early models!

That being said, it is possible to get the 4+3 beefed up enough to work with a 475 horse motor, but that is the strongest they ever tested it to.

But THAT being said, he said it really isn't worth it. You would still have to be careful in shifting.

There are also the bronze clutch packs for the O/D unit available, but even with those you have to watch your shifting.

NOT A DRAG RACE TRANNY!

Brian also really dissed on the ZF6 Speed tranny, talking about how they have turned out to be a load of sh$t.




....... So much for that avenue. Guess I'll save up my pennies for a T56. Anybody have words of wisdom for me?

 

Exactly, they do this for a livving! Same thing they told me

Check into the TKO 600 5=speed, rated at 600TQ and only 1-extra gear!

 

Also Keisler released some 5spd, 6 spd drop in kits, but they were around 3k. Check em out, a guy on the forum, Carl Johonnason, or something like that was supposed to get one but there were shipping delays.

 

.... ya, I don't have 3k to drop into something "bolt on". I don't mind fabricating at all.

If I wanted to drop 3k in a tranny, I'd get a Richmond R.O.D. 6 speed.

thanks tho!

 

Brian also told me that a 4+3 can't handle 300HP so I tend to take what he says with a grain of salt even though the guy DOES know his stuff. There are way too many examples of 4+3 vehicles out there over 300HP that are just perfectly fine.

 

Scorp, I know you'll probably disagree, but IMO the 4+3 has a rather long shift throw even with the shorter arms. I really can't stand mine, although the 2-3 shift is pretty decent - you can pretty much punch it forward and it hits every time.

Though my 4+3 has been virtually trouble free (knock on wood) I'd swap to a richmond, keisler or ZF in a second if I had one of them in my garage.

 

No disagreement there. The 4+3 definitely has a longer throw when compared to a ZF6 or T56 with a short shifter installed. But... I'll gladly take my ~50% shorter throws with the short shift kit we CAN get.

 

You know, when I was speaking to him, I did get the vibe that he was just really trying to get me to not deal with a 4+3, more out of his dislike/etc. of the tranny, than whether it would or would not be a finacially positive thing to do, when compared with a more expensive swap.

 

Does anybody have some faster times and fast 60' times on the 4+3 that they can post? Like low 12's-mid 11's, and maybe even a 1.8-1.7 60'? and please, no BS.....

please put up engine specs as well.

thanks all!

 

this is kind of off topic, but my buddy has a 91 firebird with a 10 bolt, 4.11 gear and spool rear end, and a 400hp 425tq motor, in front of the STOCK WORLD CLASS T5!

He bang shifts it all the time too...

now I KNOW that the 4+3 has got to be stronger than that toothpick of a tranny!

 

The times in my sig are on one run with the 4+3