Figuring out the right 73-87 c10 driveshaft length is a single of these tasks that will sounds incredibly basic until you're in fact under the truck along with a grease-stained tape measure. Whether you're swapping out the tired old Turbocharged 350 for the contemporary overdrive or you've just dropped the rear end six inches, that spinning hunk of metallic between your transmission as well as your rear differential box is a lot more delicate than it looks. If it's as well long, you'll quickly pull the yoke into the transmission and destroy your result shaft seal (or worse). If it's too short, you're taking a look at an awful vibration or maybe having the shaft fall out on the highway.
The reality using these squarebody Chevys is that right now there isn't only one "standard" measurement. Chevy made millions of these trucks, and they came in so a lot of configurations that supposing your buddy's truck has the exact same shaft as yours is a formula for the headache. You've got different wheelbases, a dozen transmission choices, and varying posterior types. Let's break up down ways to get this particular right so you can get back on the street without worrying about your own drivetrain shaking alone to pieces.
Why One Dimension Doesn't Fit Just about all
When you begin looking for a 73-87 c10 driveshaft length , the very first thing you have to account regarding may be the wheelbase. The short-bed C10 provides a wheelbase associated with 117. 5 inches, while a long-bed comes in in 131. 5 inches. That's an enormous 14-inch difference right out from the gate. Most short-bed trucks utilized an one-piece driveshaft, while long-beds usually featured a two piece design with the carrier bearing in the middle in order to prevent the shaft from "whipping" with high speeds.
But even inside those categories, points get messy. Let's say you have a 1978 short-bed. If this arrived with a straight-six and a regular transmission, the driveshaft length is going to be various than if it got a 350 OF V8 and a TH350 automatic. The length from the transmission itself determines where that output shaft sits in relation to the back axle. If you've done an LS swap recently—which appears to be the particular law for C10 owners these days—you've likely moved the transmission forward or even backward from the manufacturing plant perch, making all those old forum graphs completely useless.
The Impact associated with Lowering Your Pickup truck
Most 73-87 C10s aren't sitting at factory trip height anymore. We like to get these points down in the weeds. However, when you lower a 52 pick up, the distance between the transmission and the rear-end yoke changes. As the rear axle moves up into the frame, this also moves forward or backward slightly based on your own suspension setup.
If you're using a flip kit or lowering blocks, the axle's arch changes. This can push the driveshaft further into the transmission. In case you don't have enough "slip" room, every period you hit the bump, the driveshaft will act such as a battering memory against your transmitting. That's las vegas dui attorney can't just buy the "stock" shaft if your truck is sitting down four inches less than it was within 1982. You need to measure this at ride height to be 100% sure.
Exactly how to Measure Like a Pro
To get your 73-87 c10 driveshaft length right, you need in order to gauge the truck while it's sitting upon its own pounds. Don't do this with the frame up on jack holds and the rear axle hanging down. If the suspension system reaches full bad, the measurement will be drastically wrong. Generate it onto the set of ramps or use a drive-on lift if you have entry to one.
First, make sure your transmission yoke is pushed all the method in to the transmission until it bottoms out. Then, pull this back out regarding 3/4 of the inch to 1 inch. This "slip" is essential; it gives the particular driveshaft room in order to move since the suspension system compresses and expands. If you don't leave this difference, you're going in order to have a very bad day the first time you have a heavy load or even hit a pothole.
Once the particular yoke is positioned with that 1-inch space, measure from the center of the U-joint hole on the transmission yoke to the center of the U-joint seat for the rear differential yoke. This "center-to-center" measurement is exactly what any custom driveshaft shop is going to request for. Don't gauge the total length from the tube itself; that doesn't tell the entire story.
Transmitting Swaps and Length Changes
Probably the most common reasons men are looking intended for a new 73-87 c10 driveshaft length is since they've upgraded their transmission. The old-school TH350 was the particular king for a long time, yet today we all want a 700R4 or even a 4L60E for that special, sweet overdrive.
Here's the particular catch: a 700R4 is roughly several inches longer than a standard short-tail TH350. If you're producing that swap, you can't just "make it work" with your old shaft. You'll almost certainly require to have your existing driveshaft reduced and rebalanced. Alternatively, if you're moving from a guide SM465 (the "granny gear" 4-speed) to something different, the measures are going to be all over the map.
Also, keep an eye on the spline count number. A TH350 and a 700R4 usually discuss a 27-spline result, but if you step up to the heavy-duty TH400 or a 4L80E, you're looking at the 32-spline setup. Actually if the length was magically exactly the same, the yoke wouldn't fit.
One-Piece vs. Two piece Shafts
If you're working on a long-bed C10, you most likely have a carrier bearing mounted to a crossmember in the middle of the body. This splits the driveshaft into 2 pieces. While this particular was great for preventing vibration in a long truck back in the 70s, it's a lot of additional parts to decorate out there.
Numerous guys with 73-87 long-beds eventually change to a beefy one-piece aluminum or steel shaft. If you go this route, you have to be extra cautious with your 73-87 c10 driveshaft length calculation. A one-piece shaft over a long distance is prone in order to "critical speed" problems, where the shaft begins to whip like a jump string at high RPMs. In case your measurement is off even simply by a little, that will whip is amplified. If you're pressing a long-bed pickup truck to high rates of speed, a high-quality, large-diameter aluminum shaft will be usually the most trusted bet to change the two-piece set up.
Don't Overlook the U-Joints
While you're obsessing over the length, don't ignore the U-joints. Most C10s used 1310 series U-joints from the factory, sometimes of the heavier-duty 3/4-ton or 1-ton variants (the C20s and C30s) used 1350 series joints.
If you've swapped in the 14-bolt rear end from a more recent truck or a 9-inch Ford back, your U-joint sizes might not match your transmission yoke any longer. You may want a "conversion" U-joint that provides one size upon one axis and a different size within the other. It's a typical fix, but it's something you want to know before you try in order to bolt the base in on the Sunday afternoon plus realize nothing suits.
Final Thoughts on Getting it Right
At the end of the day, chasing the particular perfect 73-87 c10 driveshaft length is about patience and precision. Don't trust the "standard" numbers you discover on a randomly 15-year-old forum article. Every truck provides lived a different life; frames obtain tweaked, engines get shifted, and leaf springs sag.
The best advice? Measure twice, or even three times. Measure with the particular truck on the wheels. If you're unsure, call a local drivetrain store. Most of individuals guys have observed every possible C10 settings available and can tell you exactly where to put the tape measure. Spending an extra twenty moments getting a precise dimension is really a whole great deal cheaper than buying a new tranny case because your driveshaft was an inch too long and punched the hole with the back again of it.
Once a person get that length dialed in, your truck will experience smoother, quieter, and much more reliable. There's nothing very like the feeling of a squarebody that doesn't vibrate each tooth out at sixty-five mph. Take your own time, have the quantities right, and revel in the ride.