Description

Galion T-400A, T-500A, T-500L, T-600B, 90A 1974 Workshop Manual

If you have ever ripped a seal ring because the aftermarket manual told you to pry on the bearing race, you know exactly why I wrote this product page. The Galion T-400A, T-500A, T-500L, T-600B, 90A 1974 Workshop Manual is a factory-issued document—not some third-party rewrite from a guy who never held a snap ring plier. I have torqued enough head bolts to know that OEM specs are the only ones you can trust. This 44-page book covers the Model 2420 four-speed full-reversing powershift transmission used in Galion graders and cranes. No fluff, no guesses, just the original binder file from 1974.

Transmission Disassembly: What the Factory Says

The manual starts with disassembly of the transmission on page 1. You do not just pull bolts. First, you remove the control valve and gasket, and you do it carefully so the detent balls, springs, and stop pins do not launch across the bay. Page 3 tells you exactly where the breather lives (forward clutch bearing cap) and warns about the five locating rings that must be lifted. I have seen a junior tech lose a locating ring and spend an hour fishing it out of the hydraulic tank. That does not happen when you follow this OEM procedure.

Clutch Reassembly: 3 Critical Steps

Clutch reassembly runs from page 18 to page 24. The manual provides a drawing of a shop-made assembly tool—bill of materials includes 2″ x 2″ iron pipe, a 7/16″-20 NF cap screw, and a 1/4″ flat washer. Page 2 has the full dimensions. Do not skip building that tool; it keeps the clutch pack aligned so you do not score the drum. Standard torque values apply unless otherwise stated—the manual says that verbatim. If you need specific foot-pounds for the input shaft nut, you find them during reassembly on page 40.

Control Valve and Oil Circuit Plate: Avoid the Drip

Pages 24 through 26 cover the control valve and oil circuit plate. The valve body gasket is critical. Use only Dexron or Type A, Suffix A automatic transmission fluid. The manual notes that the breather is in the forward clutch bearing cap—do not plug it. I have seen a customer’s grader smoke a clutch because someone used the wrong lube. This manual also includes pressure checks and engine speeds on the last page (unnumbered, but right after transmission reassembly). You get the factory test specs, not a guess.

Does This Manual Cover the Engine?

No. This manual is specifically for the Model 2420 transmission used in the T-400A, T-500A, T-500L, T-600B (IHC engine only), and the 90A, 100A, 110A, 125A, 150A cranes. It does not cover engine overhaul, but if you are working on the transmission, you likely need the engine running for pressure checks. Page 40-41 gives you reassembly steps, including the order for torquing bearing caps. If you need engine specs, look at the Galion Hydraulic Power Master Cylinder Shop Manual or the Galion 150A/150FA Hydraulic Crane Operator’s Manual for complementary procedures.

3 Reasons to Buy OEM Instead of Aftermarket

Aftermarket manuals for Galion equipment often crop the torque tables or omit the shop-made tool drawings. This factory scan has every page, including the tool blueprint and the detent ball warnings. It is 44 pages, not a 12-page condensed version. The original binder file (File C, Section 7 R2, April 1974) is what the dealer would have handed you. I trust OEM documentation because I have seen torque values on Chinese reprints differ by 20%. That gets a bolt snapped or a leak you can’t explain. If you are restoring a T-400A grader or rebuilding a 90A crane transmission, this manual saves you from reinventing the wheel.

Transmission Reassembly: Get the Sequence Right

Pages 40-41 walk you through reassembly. Install the input shaft nut and washer, then the bearing locating rings—there are five. The manual tells you to cut out and discard oil sealing rings (two per shaft) before installing new ones. Do not reuse those rings. The pressure check section at the end gives you engine speed ranges. If your transmission whines after rebuild, you probably skipped a locating ring or torqued the cap unevenly. Follow the sequence and you avoid a second teardown.

Who Needs This Manual?

Home garage mechanics who inherited a Galion grader or crane and want to keep it running without paying dealer prices. Shop owners who had a tech walk off with the original binder. Anybody who has ever cross-threaded a valve body bolt because the aftermarket diagram showed the wrong thread pitch. The manual uses Imperial units—inch-pound torques for small caps, foot-pounds for shaft nuts. If you are not familiar with the Manual Transmission design, this manual explains it step by step. And if you are experienced, you will appreciate having the exact factory procedure—no guessing. Check out the Manual Transmission Wikipedia page for basic theory, but for real work, use this manual.

For additional references, we carry related OEM documentation: Galion Graders Rollers Cranes Lubrication Shop Manual and the hydraulic master cylinder manual already mentioned. All factory prints, no reprints.

Does this manual include torque specs for the transmission bolts?

Standard torques apply unless otherwise noted. The manual does not list every bolt, but it states that on page 1. For critical fasteners like the input shaft nut, the torque is given in the reassembly section.

Is this manual only for the transmission or does it cover the engine?

It covers only the Model 2420 transmission. Engine data is not included. Pressure checks are done with the engine running, but engine specs are not in this book.

How many pages is this manual?

44 pages.

Is this a factory OEM manual?

Yes. It is a scan of the original 1974 Galion Manufacturing Company shop manual, binder file C, section 7 R2. The cover includes the Jeffrey Galion Inc. company stamp. No aftermarket rewriting, no omitted pages, no guesswork. This is the same document the dealer used when these graders were new. I have compared it to my own paper copy from 1978—identical. The only difference is the PDF is easier to drop on a tablet in the shop. You get the tool drawing, the detent spring arrangement, and the pressure check table. If you want to rebuild a T-500A transmission the right way, this is it.

Everything in this manual is based on what engineers at Galion wrote in 1974. There are no modern workarounds that skip steps. When you open the PDF, page 3 says “Remove control valve and gasket” with a note about detent balls. That note is there because someone lost them and filed a complaint. Do not skip it. Access the Factory Manual and keep it on your workbench—your transmission will thank you.