These four numbers are the standard SAE/industry series codes for single-cardan U-joints, and they only describe two physical measurements: bearing cap diameter and overall cap-to-cap width. Going up the series (1310 → 1330 → 1350 → 1410) means the joint gets physically bigger and stronger, but the series alternate which dimension changes: 1310→1330 only widens the body, 1330→1350 only enlarges the caps, 1350→1410 only widens the body again. No two series are directly interchangeable — but Spicer makes conversion U-joints that bridge specific pairs without replacing your whole driveshaft.
Size Reference Chart
| Series | Cap Diameter | Overall (cap-to-cap) Width | What Changed From the Previous Series |
|---|---|---|---|
| 1310 | 1.062″ (1-1/16″) | 3.219″ (3-7/32″) | — (baseline, in production since 1940) |
| 1330 | 1.062″ (1-1/16″) | 3.625″ (3-5/8″) | Wider body only; cap size unchanged |
| 1350 | 1.188″ (1-3/16″) | 3.625″ (3-5/8″) | Larger caps only; width unchanged |
| 1410 | 1.188″ (1-3/16″) | 4.188″ (4-3/16″) | Wider body only; cap size unchanged |
These dimensions are confirmed consistently across three independent driveline-parts references (Torque King 4×4, Speedway Motors, The Ranger Station) and match the tables Google, ChatGPT, and Gemini return for the same query. The only variance found: one source lists 1330’s width as 3.622″ instead of 3.625″ — a rounding difference in the same measurement, not a different spec.
How to measure your own U-joint: you need two numbers — the outside diameter of the bearing cap, and the overall installed width measured cap-to-cap when the joint is seated in the yoke. Dial calipers, not a tape measure, are the right tool here: the difference between a 1310 and a 1350 cap is only 1/8″ (0.125″), and the difference between some adjacent-generation variants (like 1410 vs. the AAM 1415) is as small as 0.003″–0.010″ — enough to matter for fit, too small to eyeball.
Strength: What Actually Gets Stronger and Why
Every source agrees on the direction: strength increases as the series number goes up, because a bigger cap diameter means a larger cross and larger needle bearings carrying the load. What we could not find is a reliable, consistent set of torque numbers across all four series — AI-generated answers we cross-checked gave different torque figures for the same series in different runs, which is a sign of estimation, not a lookup from a real spec sheet.
One specific number is citable, from a snippet reference (the full page was inaccessible to verify): Off Road Xtreme reports the 1350 series is “about 37.5% stronger than the 1310 series” and rates the 1350 at roughly 2,200 lb-ft minimum elastic limit. We could not find matching, equally-sourced figures for 1310, 1330, or 1410 to build a complete torque table — if you need an exact torque rating for a build, verify against SAE J498 or your U-joint manufacturer’s catalog rather than trusting any round number you see quoted online, including this one.
What is well-supported qualitatively:
- 1310 → 1330: same cap, wider body. MotorTrend describes this jump as giving “more angularity” but only “marginally” more strength — the trunnions and caps carrying the actual load didn’t get bigger.
- 1330 → 1350: same width, bigger caps. This is the step that matters most for strength — larger caps mean larger needle bearings and a beefier cross, which is why 1350 is the de facto standard for 1-ton trucks and serious off-road builds.
- 1350 → 1410: same caps, wider body again. The extra width mainly buys more clearance for steep operating angles and a bit more leverage, not a cap-size strength jump.
Wider bodies also tend to tolerate a steeper driveline operating angle before binding — this relationship is confirmed qualitatively by multiple sources, but we did not find a reliable degree-by-degree angle spec for each series, so we’re not publishing specific angle numbers here.
Interchangeability: Why You Can’t Just Swap Series
U-joints are not interchangeable across series — a 1310 will not fit a 1350 yoke, full stop. This holds even when the difference looks trivial on paper: some adjacent variants differ by as little as 0.003″, but that’s still enough to produce a dangerously tight or loose fit.
That doesn’t mean you’re stuck rebuilding an entire driveshaft when you mix parts from different eras or upgrade an axle. Spicer makes conversion (combination) U-joints — one cross with two different cap sizes, one pair matching each series — specifically to bridge a mismatch:
| Conversion | Spicer Part # |
|---|---|
| 1310 to 1330 | 5-134X |
| 1330 to 1350 | 5-648X |
| 1310 to 1350 | 5-460X |
These exist because the swap scenario is common: you install a heavier axle with 1350 yokes but keep your factory 1330 driveshaft, for example, and a conversion joint lets the two halves mate without cutting a new shaft.
A note on lookalike series: don’t assume the four-digit number alone guarantees a match. AAM’s 1355 series shares the 1350’s 1.188″ cap but differs in width by only 0.003″ — close enough that the two are generally treated as interchangeable. AAM’s 1415, on the other hand, differs from the 1410 by 0.010″ in width — small on paper, but enough that swapping them produces a joint that’s either too tight (shortened part life) or too loose (driveshaft balance issues). If your parts catalog or a forum thread mentions a “355” or “415” suffix alongside the base series number, treat it as a separate spec, not a typo.
Typical Applications by Series
These are common patterns, not universal rules — actual OEM usage varies by manufacturer, model year, and trim, and a full driveline identification guide will always beat guessing from “what year is my truck.”
| Series | Commonly Found On |
|---|---|
| 1310 | Jeeps, half-ton and lighter trucks, older passenger cars — the original light-duty standard since 1940 |
| 1330 | 3/4-ton trucks; Ford used it widely from 1978 through the mid-1990s; also common on 1994–2004 Ram front CV shafts |
| 1350 | 1-ton trucks, off-road and performance builds — the de facto heavy-duty standard since the 1960s |
| 1410 | Heavy-duty diesel trucks (e.g., Ford Super Duty-class applications) where high torque and steep angles are routine |
Which One Do You Actually Need?
- If you’re replacing a broken joint on a stock vehicle: match what’s already there — measure cap diameter and width rather than assuming based on truck class, since running changes within a single model year are common (Dodge Ram front CV shafts alone used at least four different series across their production history).
- If you’re upgrading for more power or bigger tires: stepping from 1310 to 1330 buys you only marginal strength — if you’re upgrading specifically for strength, going to 1350 (bigger caps) is the more meaningful jump.
- If you’re mating mismatched parts (new axle, old driveshaft, or vice versa): check the conversion-joint table above before assuming you need an entirely new shaft.
- If in doubt: measure, don’t guess. Cap diameter and cap-to-cap width, checked with calipers, settle the question in under a minute.
Related reading: 1310 vs. 1350 U-Joint: What’s the Difference? · How to Measure a U-Joint (Driveline hub, measurement-questions cluster — link once published) · What Is a Universal Joint? (Driveline hub, definitional-questions cluster — link once published)
