The Stovebolt Site Forums The Shop Area Engine Shop Other option besides a T-5?

Has anybody tried, or would you know if a full size pickup manual trans can be swapped into a Task Force? I recently drove an early 90's Chevy 1/2 ton with an overdrive manual trans. This would seem like a good option for those looking for overdive in a 3/4 ton. Much stronger I would think than a T-5. I didn't crawl underneath and eyeball it so I have no idea what it looks like. Any thoughts?

Thanks, John

I'm not sure if it'll work or not.

Many of today's transmissions are electronically controlled/enhanced and must be coupled with an engine that "speaks" its language.

There's also the question of bellhousing compatibility.

But, then again, the only modern manual tranny that I've messed with lately has been the one in my dad's 'vette (it's a ZF 6 speed), so I may be full of something-or-other.

I use a new process manual with overdrive that came out of an 84 chevy pickup. They made these for about 5 years so if you look on ebay you will find one. You do have to shorted your driveshaft and you have to remove the nosepiece from the front of the tranny and get it machined down about a quarter of an inch. The rest is a bolt in. It really lowers your rpm in 4th gear. It is heavydury enough to handle a 350 with no problem.

Hey John I think the T-5 may be a little light duty for a two ton.
You may want to think about an NV4500 used in chevy full sized trucks since 93. However 93 and 94 sufferd from stiff shifting and a noisy 3rd gear so 95 and on is a better choice. They are 5 speeds with 6.34 to 1 1st; 3.44 to 1 2nd; 1.71 to 1 3rd; 1 to 1 4th; and a 27% overdrive. And the best part is Advance Adapters Inc. makes what you ned to put it in pace of your Sm-420. You will need to shorten the drive line 2 1/4".
Do this and say hellow to the free-way.
Grant

Sorry John I thought you had a two ton I see now it's a 3/4 ton. this would be a good choice still

This isn't a cheap option, but you can go with a Gear Vendors O.D. It bolts on the the sm420 via an adapter that they provide. I had to have my driveline shortened, my torsion bar crossmember slightly modified(I don't think you will need to do this with your truck) and a custom rear mount fabricated to hold the extra weight. The adapter provides a nice mounting spot to fit a stock mount. With this O.D., you still have your granny gear, and you can overdrive 2nd, 3rd, and 4th, giving you 7 forward gears. IMO, this gives you most versatility. By the way the O.D. is advertised to be able to handle 1500 hp. Your strong SM420 will break before the O.D. will.

I believe the 88 to 95 Chevy 5 speed manuals for full size p/ups have the bellhousing made with the transmission and does not separate. Unless your truck is already a V8, the bellhousing will not attach to a stovebolt 6 without some kind of adapter plate. They make adapter plates to install later model (th350) (400) automatics to the older sixes. If you had one of these you might be able to fit the 5 speed to your motor, if flywheel, clutch and transmission shaft all works out. I would think you to go to a hydraulic clutch set-up. Would be nice to know if anybody else has tried that set-up.

Hey bigmacdaddy, I just went to your website. Nice looking truck. Was looking at the water heat to manifold, very nice job. Could you have hooked that water line to the plug in your header and hooked it to the heat plate and had exhaust heat to manifold instead of water? I have a set of tube headers and was thinking about drilling a hole and welding in something like a 02 sensor bung into the pipe then attaching a line to plate on bottom of intake. Was worried more about sealing plate so it didn't leak to use water and thought heat would be less complicated. Thanks, Spoon

You would also have to fabricate motor and trans mounts to use the 5 speed from the late model truck with the integrated bellhousing. they do not havr the mounts for the rear of the engine. They also will not bolt up to the 235/261 engine.
The NV4500 would also reguire an adapter as the bolt pattern for the bellhousing is different.
The Gear Venders or Ranger overdrive might be a better solution.

Spoon, I left you a P.M. We'll keep this thread all about gearing and tranny choices.

I am using a nv4500 in my project. The one to use for a 2wd where you need to retain your original clutch and bellhousing would be the dodge version from 1994- 1997. This version has an input shaft that is 1 inch longer than the chevy transmission. It gives you the extra room for an adapter plate to be made. The 94- 97 dodge 2wd transmission is the only one of the nv4500s that has provisions for a mechanical speedo. 4wd trannys don't have a speedo hook up. and all the other years for dodge and chevy used an electronic velocity sensor.

Stay clear of the dodge diesel nv4500. It has a much stronger input shaft... 10 spline 1 1/4 diameter. You can use your stock clutch with the standard duty dodge version which has the 10 spline 1 1/8 pilot shaft. You will need to get a new pilot bearing as the dodge has a .750 inch tip.

I have fit a 6610 Roadranger 10 speed with overdrive in my 52 truck.
It takes a bit of work though.

Might look at the adapters advertised at this website. I talked to the guy briefly, he seemed pretty knowledgeable. If anyone buys an adapter from him I'd like to hear how it works out.

http://www.transmissionadapters.com/Pricing.htm

The ZF 6-speed used in a 'vette has a device that forces it to skip 2nd and 3rd unless under hard acceleration. Probably not the right choice for a truck though it can be defeated with a simple modification.

The ZF is not the strongest transmission out there. It can handle significant horsepower in a light car. I don't think its up to the torque requirements of a truck really used as a truck. Vette guys are very aware of its limitations.

Another Corvette transmission not used anywhere else is called the 4+3. It's basically a Super T-10 4-speed with an automatic overdive in the tail shaft. Well maintainted they are pretty stout, but like the ZF definitely not a 'truck' transmission and would not be right in a 3/4-ton or any other truck not used like a car.

I've never heard of a 4+3 installed in anything but a 'vette. I own one and like some the way it works (most the time) so I keep watching to see if anyone has transplanted one.

I would like to add the fact that the ZF 6 speed is a double overdrive trans. 4th is direct drive, 5th is .7:1 and 6th is .5:1 . That means the drive shaft is turning twice the engine rpms, when in 6th. The Vette shaft is short, aluminum and designed to spin that fast.
I also have a 4+3, in a '87 coupe.
You said, "I own one and like some the way it works (most the time)".
I know exactly what you mean. Sometimes the computer doesn't think the way we do and you have to remind it, what it is you wanted.
A lot of people have removed the 4+3 in favor of a 5spd or 6spd. Sometimes it was because the OD unit broke, but I really think most of the reasons were because of electrical problems or the driver never learned how to use the trans.
I've also noticed that the guys that replaced a 4+3 for a 6spd ended up also replacing the rear gears. The 4+3 used 3.08 and the ZF's used 3.43 rear gears.
A couple of years back, Tony posted some pictures here of his Saginaw 4spd mated to a OD(from a 3spd). That's as close to a 4+3 in a truck as I have ever seen. Just no computer.

One small addition. The current 'Vette 6-speed is attached to the differential and the driveshaft runs at engine speed from the engine mounted clutch.

Yeah C5 ('97 to '04) and C6 ('05 to ?)'vettes use completely different stuff. I think the switch to ZF was '89 or '90. Earlier C4s with manual transmissions are the 4+3 like my '85.

The 4+3 is something like .68 in 4th and over. I understand the ZF guys actually get top speed running in 5th but best economy running 6th. I've never driven one.

I once owned a Saginaw 4-speed with an OD adapted from a 3-speed. I was going to put it in my Suburban until I called Patricks and asked if their shifter would work on it. The answer was no, then yes, but with modifications.

I ran a modified shifter with the OD Saginaw when it was in an F-body in the 70's and didn't want to play that game again.

My preference would be to run a 4+3 in a truck before I'd try the modified Saginaw route or the ZF either one. But running a mild six like I've currently got in my Suburban a T-5 seems the best option.

If I ever get around to changing it.

The 4+3 'vette will get 25 mpg driving on the highway driving pretty agressively. I don't think the ZF guys do any better.