What The Part Is
The SPL-170X is a four-bearing universal joint cross with a 55mm bearing cap diameter and 164mm across the cap faces. Those two dimensions are the whole identity of the joint. Measure cap outside diameter with a micrometer and overall span with a caliper across the installed caps, not across the trunnion ends, or you will read short.
This size class runs in main driveline and interaxle shafts on tandem-axle tractors and vocational chassis. It is a greaseable-style heavy joint, so expect a cross-drilled trunnion and a zerk location that either sits on the body or at the end of one trunnion. Note which one you pulled out, because lube access drives your choice when the shaft runs tight to a crossmember.
We sell this as an aftermarket direct replacement, premium quality, built by Zhuhai Fengli Auto Technology Co.,Ltd. Other manufacturers' numbers on this page are listed for identification only. We are not affiliated with, endorsed by, or authorised by any of them.
Why These Numbers Cross
Numbers like SPL170, SPL170X-4X, US170X, WA170X, UJ578 and S-E358 all describe the same 55x164mm envelope. The driveline world indexes u-joints by cap diameter and cap-to-cap span first, because that is what has to drop into the yoke bore and sit between the snap ring grooves. Once those two dimensions match and the retention style matches, the joints interchange.
The rest of the spread is just how each cataloguer formats the same core. Kit suffixes such as SPI-SPL170-4X, DSSPL1704X and 25SPL1704X flag a four-bearing kit. Prefixes like 01SPL170X, SPSPL170X, 2104-SPL170X and 752.SPL170X are seller or distributor codes layered on the base. SPL170XR and WA170XR carry an R for a revised or reman-channel listing of the same size.
A few entries come from a different numbering family entirely: 6-1170, 3947697, SP170-3X, NSSSE358, 2500678C and 2500678C91. Those are chassis-builder and supplier part numbers assigned to a joint of this same size class. They trace to the same physical part, but they tell you nothing about retention style, so verify that detail separately.
Check Before You Order
Confirm retention style. Inside-snap-ring, outside-snap-ring and bearing-plate yokes all exist in this size range, and a joint that measures correct will still not retain in the wrong yoke. Look at the old yoke, not the old joint, and find the groove or the bolt pads. Then confirm the caps are full round and not flatted for a plate.
Inspect the yoke bores while the shaft is out. Egg-shaped bores, fretting, or a cap that spun will chew a new joint in weeks. Check the slip spline for twist and the shaft tube for dents. A cross-reference is a starting point only — confirm fit against your VIN or the number stamped on the part you removed before you commit.
SPL-170X Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to SPL-170X. Use them to identify the part — then confirm the exact fit by VIN or the number stamped on your old unit before you order. An interchange is a starting point, not a fitment guarantee.
| Brand / Line | Cross-Reference Numbers |
|---|---|
| Cross-Reference | SPL170, SPI-SPL170-4X, SPL170X-4X, US170X, 6-1170, 752.SPL170X, 3947697, DSSPL1704X, SP170-3X, 25SPL1704X, 01SPL170X, SPSPL170X, 2104-SPL170X, 2500678C, 2500678C91, NSSSE358, SPL170XR, WA170X, WA170XR, UJ578, S-E358 |
Frequently asked questions
How do I measure a u-joint to confirm it's a 55x164mm?
Measure the outside diameter of one bearing cap with a micrometer; you are looking for 55mm. Then measure across the outer faces of two opposing caps with a caliper for the 164mm span. Measure with the caps seated on the cross, not loose, and check a second pair to catch a worn or collapsed cap.
Is SPL170X-4X the same as SPL-170X?
They point to the same 55x164mm joint. The 4X suffix is catalogue shorthand for a four-bearing kit, meaning the cross ships with all four caps and the retention hardware. The base number describes the joint itself. Compare the physical dimensions and retention style on the part you removed before ordering.
Does this joint need greasing after install?
If the joint you pulled had a zerk, treat the replacement the same way. Grease it at install until you see fresh lube purge at all four seals, then follow your fleet's driveline interval. If one cap will not purge, the joint is not seated square or a seal is already damaged — pull it and look.
Not sure it fits? We check before you pay.
Run your VIN and we’ll match parts to your exact truck, or call the counter — a person who knows trucks verifies fitment by OEM number before the order ships. No wrong-box returns.
More cross-reference guides
Need the part, not just the reading?
Every part below is a Premium Quality aftermarket Direct Replacement with published OEM cross-reference numbers, a 6+ month warranty and same-business-day shipping from Tacoma, WA. Not sure it fits? Run your VIN — or call and a person who knows trucks will verify fitment before you pay.