Description

Allison 640, 643, 650, 653 1997 Parts Catalog

You've got an Allison 640 or 653 on the bench. The job's stalled because you can't find a part number. I've been there – digging through aftermarket catalogs that list obsolete supersessions, guessing at seal sizes because the drawing looks close. That's why this Parts Catalog matters. It's the factory-issued document from 1997, covering the 640, 643, 650, and 653 automatic transmissions. Twenty-two pages of OEM part numbers, figure call-outs, and assembly breaks. No reprints, no third-party guesswork.

Page 1 confirms the copyright: General Motors Corp., 1997. That's the real deal. Every number in here came from Allison’s engineering department. If you're ordering a clutch piston or a center-support seal, you want the factory number – not something a manual writer typed in twenty years later.

What This Parts Catalog Covers

This isn't a service manual. It won't tell you how to rebuild a 643 or how to adjust the bands. But if you need the exact part number for a third clutch drum, a second clutch hub, or the center support assembly, this is your source. The catalog uses the same figure-reference system Allison used on the shop floor. For example, Figure 1rt-3 on page 5 breaks down the third clutch, center support, and second clutch – with numbered call-outs that tie to the master parts list. That means you can point to a worn spline and say “part 17” instead of holding up a greasy finger.

7 Major Transmission Sections Documented

Flip through the 22 pages and you'll find: front pump housing, converter housing, main case, clutch assemblies (first, second, third), planetary gear sets, valve body components, and the oil pan/gasket kit. Each section lists the original Allison part numbers, quantities per assembly, and in some cases the supersession notes. The 650 and 653 models share many common internals with the 640 and 643, but the catalog separates them where they differ – for instance, the output shaft and rear cover part numbers are specific to the 653. You won't mix up a 640 input shaft with a 650 shaft because the parts list makes the distinction clear.

Use the Factory Parts List Before Ordering

I've watched guys order a clutch pack without checking the stack-up. Then it doesn't fit, and the truck sits another week. This catalog gives you the original equipment numbers so you can compare to what's on the shelf. Run the number against your local dealer's system – if it crosses to a newer revision, you'll know. But start with the OEM number, not the aftermarket cross-reference. Every number in the 1997 Parts Catalog came from Allison. That includes the 643, 650, and 653 models. Page 1 alone saves hours of cross-checking.

Third Clutch and Center Support: Figure Reference

Page 5 shows Figure 1rt-3, which details the third clutch, center support, and second clutch. The center support is a common wear item on high-mileage 600-series transmissions – the bushing wears, the seal leaks, and pressure drops. Without the factory part number, you risk ordering a generic bushing that doesn't match the oil hole location. This catalog lists the exact Allison bushing, thrust washer, and seal rings. Pair it with a genuine service manual for the assembly sequence, but use this catalog for the part numbers.

Related Manuals You Might Need

• Allison TC 200-300 TCA TCRD 200 1976 Parts Catalog”>Allison TC 200-300 TCA TCRD 200 1976 Parts Catalog
• Allison 200, 300 1967 Parts Catalog – OEM Torqmatic Parts”>Allison 200, 300 1967 Parts Catalog – OEM Torqmatic Parts
• Allison Torqmatic Converters 200-300 Series Parts Catalog”>Allison Torqmatic Converters 200-300 Series Parts Catalog

FAQ – Allison 640, 643, 650, 653 Parts Catalog

Is this a service manual or a parts catalog?

Parts catalog only – 22 pages of OEM part numbers and exploded views.

Does it include torque specs for the 653?

No. This catalog lists component part numbers, not assembly torque values. For clutch pack clearances and bolt torques you need the factory service manual (not included). Use the parts catalog to order the correct seals, bearings, and clutch discs, then follow the service manual for assembly. The two documents work together – one tells you what to buy, the other tells you how to put it in.

Can I use this to rebuild a 640 transmission?

You'll need the service manual for disassembly and adjustment specs. But the parts catalog ensures you order the genuine Allison piston, drum, and seal kits. Without it you risk mismatching the 643 and 650 components – the 640 uses a different input shaft than the 653. The catalog makes those differences visible.

What years and models are covered?

1997 publication covers Allison 640, 643, 650, and 653 automatic transmissions. Cross-references to earlier production years (1980s and 1990s) are generally valid because the basic design remained stable until the MD/T series replaced them. Check your serial number against the catalog's part numbers for confirmation.

External Resources

For broader context on transmission technology, see the Automotive Industry Overview”>Automotive Industry Overview and the Internal Combustion Engine”>Internal Combustion Engine article.

Access the Factory Manual – get the OEM part numbers in your hands. 22 pages, genuine 1997 Allison documentation. No reprints, no aftermarket guesses. Access the Factory Manual and keep your rebuild on track.