In reply to Rotaryracer :
WOW! Those guys sell stuff cheap for what you get! $2500 for a complete, upgraded gearbox? I wouldn't expect a gearkit to be that cheap, let alone a complete transmission!
At prices like that, why bother with used junk that needs to be overhauled anyway? And it will still drool oil all over the place and shift funny because the case is egged out, the shift shafts are a sloppy fit, etc, even after you spend $$$ on an overhaul...
Knurled. said:
In reply to Rotaryracer :
WOW! Those guys sell stuff cheap for what you get! $2500 for a complete, upgraded gearbox? I wouldn't expect a gearkit to be that cheap, let alone a complete transmission!
At prices like that, why bother with used junk that needs to be overhauled anyway? And it will still drool oil all over the place and shift funny because the case is egged out, the shift shafts are a sloppy fit, etc, even after you spend $$$ on an overhaul...
Yep - that's the ticket! You'll still need a bellhousing, shifter, and a quart of Royal Purple, but aside from that, it's pretty much ready to go. I considered getting a rebuilt Super T10 and/or trying to find an elusive Muncie with the correct gear ratio, but for equal or only slightly more money, got a completely brand new everything. I don't know how they manage to do it for that price, but I am certainly not complaining.
I think every SCCA Runoffs winner in the American Sedan class in recent history has been running an AutoGear box. It works out well to keep our costs down, and they get a ton of data for R&D with racers out there slamming through the gears and doing their best to break them. There are probably more of them running around on the street in Pro Touring cars and the like, but I can't comment on streetability...I'm assuming it's at least better than an old Rockcrusher due to some of the updates they've made to the design.
If you call, you'll probably talk to Nathan or George...they are both good people and have probably forgotten more about transmissions then I will ever know.
In reply to Rotaryracer :
The Pro Touring cars that I have seen all had some variant of T56 or TKO or Richmond overdrive. They all want overdrive transmissions for highway cruising.
I've got an extra Corvette 4+3 trans that might be the easiest manual with overdrive to swap, if you think it'll hold up.
SVreX
MegaDork
1/30/19 4:26 p.m.
In reply to oldopelguy :
Isn’t a 4+3 basically a Super T10 with an overdrive bolted on the tail end?
I understand the auto OD acting strange, but why wouldn’t the basic ST10 hold up?
ShawnG
PowerDork
1/30/19 5:23 p.m.
In reply to SVreX :
If you read the history of it, it was done to pass new federal emissions and fuel consumption regulations. Having a car drop into O/D as soon as possible was a way to work around the EPA regulations.
It's designed for small block cars. It can be a bit finicky and probably suffers from folks not taking the time to learn about it and take care of it properly.
It's an ST-10 with some planetary gears on the back of it. I've been told it used TH350 guts for the planetary gear but I have never been able to prove or disprove it.
I think it would probably be fine as long as you aren't power shifting in and out of overdrive, but you were looking for a Muncie and I don't know if it's because you don't like T10s.
A lot of the Corvette weirdness with the 4+3 is the rudimentary computer that came with it and made it do weird skip shifts for mpgs. I think with a regular 4-speed shifter plus a 2-speed rear type high/low manual switch it would be pretty intuitive to drive.
If you want to pay shipping and take a chance I also have a locked up nv5600 that is currently bolted to a Vortec 454 that might be rebuildable.
SVreX
MegaDork
1/31/19 8:08 a.m.
In reply to oldopelguy :
Yeah, I’d never heard of the 4+3 until you mentioned it.
Seems like it would be awfully easy to change to something useful. Manual switches, or a simple Arduino.
Hmmm... that would be really interesting to play with. If you could customize the shift points. Some of the advantages of a close ratio, with the OD cruising gear....
SVreX
MegaDork
1/31/19 10:12 a.m.
In reply to oldopelguy :
You have piqued my interest. You’ve got mail.
I Have a Corvette that HAD a 4/3 but never owned one . what I see in Pics are parts that must fit the trans tunnel.but that's a skinny tunnel on the Vette. A Couple Corvette sites around to ask about them.
Dropping this in here as a follow-up about the AutoGear Muncie...some pics from my "field trip" to Syracuse to watch my new transmission be built.
AutoGear Muncie Pics (last post on that page)