Folks, I'm a very infrequent visitor to the HAMB but I could really use a bit of advice from someone who really knows Chevy transmissions. My Japanese daily driver/work truck/tow vehicle/what-have-you finally went out in a blaze of rod-through-the-block glory and since everything else on the truck had pretty much shit the bed in the previous year, I sent it to the crusher. Now I'm shopping replacement trucks and on the lookout for a good C10. (If anyone in the Middle Tennessee area has a decent one PM me please! ;-) Most of the C10s I'm looking at are three-on-the-tree and I know I won't be able to live with that setup for long. Because I can't abide driving one, but also for fuel economy and highway cruising speed reasons. What I want to know is, if I end up buying a 3 speed truck because everything else is in good shape, what are my options for a bolt-in transmission swap with 4 or 5 gears and a floor shifter? I'm comfortable cutting a hole in the floor but I'd rather avoid fabbing custom driveshafts/input shafts/clutch packages, etc. Is there an option that will pretty much bolt in to place in a 1980s C10 or where I can order one specific clutch from a GM parts house and be done? I don't feel comfortable relocating frame crossmembers and that kind of thing. Muncie 4spd? T5 from a specific car? Thanks and Merry Christmas, Brandon Valentine
denpends what years. 60-66 had 4 speeds (granny first) with no rear mount, so a muncie/T5 would be work (x-member, driveshaft). 67-73 had th350's so a muncie/saginaw swap would be easy. also the 60-66 tend to have low rearend gears (4.10) so any non o/d would be slow on the highway. you can always convert a 60-66 3 on the tree to a floor shift.
This would be a great question to ask on this other board: http://67-72chevytrucks.com/vboard/forumdisplay.php?f=4 I assume your question is about manual transmissions. You won't find many 80s C10s with a manual transmission, so complete bolt-in options are pretty limited. You are pretty much out of luck if you want a manual 5 speed. The T5 isn't really stout enough for a full size pickup, especially if you plan to do some towing with it. If you are open to automatics, there's the 700R4. A lot of those were installed from the factory in 80s C10s, so that could be a bolt-in deal. They have overdrive, so they are good for gas mileage and highway driving, but they aren't known for their durability. BTW, driveshaft shops can fab up a driveshaft for you pretty reasonably, and crossmembers can often just be slid forward or back to accommodate transmissions of different lengths. You might be able to use a 5 speed from the next generation of Chevy 1/2 tons, but they aren't known for their durability either. AFAIK, they all use a hydraulic clutch. Slonaker
if you want to row a 5 speed and tow with it I think you probably want to look at the NV4500. I'm pretty sure they used the 4500 in the newer(late 80's/90's) chevy trucks and I know they're behind the Cummins powered dodge trucks from 94-02(different bellhousing and all that, same gearbox though.) between my truck and two of my dad's work trucks, we have 3 NV4500's in our cummins dodges. they're a very solid trans and hold up to a lot of abuse, it'll be more than sufficient behind a small block. if you'd rather do an auto, a 700r4 is the way to go if you're sticking with a small block; any trans shop worth anything can build an overstout one without a whole lot of money...these things still carry a bad reputation because GM set them up so poorly and a few too many trans shops didn't deliver on what they said they could do. if you go this route, make sure you get a dedicated electric fan on an auxiliary cooler, especially if you're going to tow. setup properly(really not much effort) the 700's are awesome transmissions.
Close but not quite THe 55-72 trucks with manual transmissions used a bellhousing that mounted to the frame, and no rear transmission crossmember. So if you get a truck like this, and a transmission that will bolt to the bellhousing in it already, then things will be pretty easy. However, if you get a trans that has an integral bellhousing (like the NV things?) then you will be looking at doing about as much work as swapping in an automatic, you'll need to find a rear trans crossmember, possibly remove the middle crossmember under the bellhousing for clearance, and maybe even change the front mounts if it's an early truck before they used the side mount setup. Also beware the hole in the bellhousing that the trans bearing retainer fits into got bigger around 1968 when they started using the SM465 4 speed granny gear transmission, so you do need to pay attention to that when doing a swap in a 68-up truck. The powerglide TurboHydro transmissions were available in trucks from the mid 60s on, with the "modern" rear mount setup, so if you get one of these trucks life would be a bit easier.
Thanks for the advice, everyone. It sounds like it's definitely possible without too too much work. I'll see what kind of truck I end up with and then I'll be back with more detailed questions. If it's up to me I'll end up with an automatic anyway since they're easier to tow with, but for some reason everybody in Middle Tennessee seems to have bought a stripper 3-on-the-tree C10. Merry (belated) Christmas!
What year truck are you looking at? You mention "'80s C10" but are also talking about bolt-action 3-speeds on the column. I'm not sure when that set-up went away, but '80s seems late to me. In fact, I know they had 4spd OD manual transmissions from '81-'87, and those are on the floor. It'll make a difference on what generation truck you get. And our answers will reflect that. -Brad
If it were me, I would look for a 60s-70s Saginaw 3 speed w/OD. Should bolt right up, use the same linkage and give you 6 speeds. And you can shift the OD up/down automatically if wired correctly. So, second gear becomes a 'do everything' gear around town without using the clutch, except at stops. IMHO, much better than a 5 speed on the floor.
Brad, Thanks. Most of the trucks I'm looking at are 77-87 or so. Believe it or not I've seen an 81 and 87 model with 3 on the tree. Apparently the 4 speed was an option. I was as surprised as you to learn that was still going on in the 80s.
yea what he said........i just re-read what i posted. it was late and i'm still sick . i think i was thinking of an A/T ?!?! well that's what happens when i post with a 103 temp.
In the last four months, I've become sort of an expert on these transmissions: two of them were just sold on ebay; I've got two, I now have two of the Hurst shifters for them (bayonette style, with a shift mechanism and rods that are unique to these transmissions), and had one of mine rebuilt. The second one became a donor for parts. Chrysler main case body, with GM input and tail shaft. Some came with a GM-style mounting flange, others came with a Chrysler-style mount, and require the unique GM retooled aluminum bellhousing to mount up. There are no provisions for the chassis mounts, as required with the '60-'62 Chevy trucks, so you'll need the one that has the GM-style mounting ears on the case to bolt to your stock truck bellhousing. BUT, you'll need to remove the front bearing retainer plate and have it turned down about .250-inch to fit in the pilot hole in the bellhousing, and you'll need allen bolts (cap screws) to hold the retainer plate on, since bolt heads will now hit the opening in the bellhousing. Good transmission, not great for high-hp applications, but I'm happy with mine. It's not terribly commmon, but if you come across one, don't walk past it. -Brad oh...3rd gear is what would normally be 4th, 1:1. 4th gear is .72:1 overdrive.
not gonna lie, I really like the 3 on the tree O/D trannies, especially in something older. but if you're wanting to set up an 80's chevy truck to work and tow with as a daily driver, the NV4500 is going to be more readily available in good condition, super heavy duty and reliable and easy to do. they're the 5 speed offered in the 93-newer Chevy and Dodge 1/2, 3/4 and 1 ton trucks in all engine configurations. 5th gear is a substantial overdrive, the shift is smooth and throw is short. being that they come in the next generation newer chevy trucks means that A: it'll be easy to find one and B: it will take very little effort to swap one over, you should be able to use the 90's driveshaft, crossmember and all that from a GM truck. as far as clutch goes, I know the dodge NV's are a hydraulic clutch and I don't see why the GM ones wouldn't be...the hydraulic clutch makes a pretty big difference in pedal feel and ease of driving. all that said, unless you really like the 80's chevy trucks, it may not be worth your time and money for a trans swap in that thing, you can pick up a clean 5 speed chevy truck for a few grand, factoring what your time is worth with parts cost of any donor. the TBI 305/350's are a far cry better than the vacuum-carb'd early 80's(I've owned, operated and maintained all of the above mentioned, all autos though). the 95 had the interior upgrade and the 96-98 had the vortec engine(also owned and absolutely loved that one, a 96 1/2 ton) the vortec trucks can be picked up easily for 4-5k in good condition. the TBI trucks respond very well with mileage and power with some minor, inexpensive performance upgrades(cold air intake, exhaust, computer chip...)
I may have missed anyone else saying this, but just making sure you know that a 3-speed and 4-speed standard both have the same gearing (1:1) for the top gear. Putting a Muncie 4-speed in place of a regular 3 speed will net the same RPM's at the same highway speed.
sounds like the tranny brad54 mentioned is a good choice, will direct bolt in place of a sag 3 speed and 4th is od.this is a truck tranny used 81-87,
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