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4-Speed Clutch For Splined Mainshaft

You know the sad story. The torque on the clutch nut backs off a hair and the key on the transmission mainshaft shears off. This usually happens at the most inconvenient time and place. And the probability of this sad story playing out is greater with performance applications.

The splined Shovel clutch kit retrofits and upgrades the stock tapered mainshaft and clutch to a modern 18 tooth spline configuration. Kit includes a fully assembled clutch and splined 4-speed mainshaft to retrofit stock 1970-E84 Big Twins.

The clutch is based off of our 9-plate clutch used on 1990-2006 applications and fits in the stock Shovelhead primary housing and TTP. We offer 35, 36, 37, and 38 tooth clutch sprockets with our clutches to dial in your overall gear ratio. 18 tooth mainshaft installs into the stock 4-speed transmission just like stock.

  • Fully assembled
  • 35, 36, 37, and 38 tooth clutch sprockets
  • Based off of our 9-plate clutch used on 1990-2006 applications
Benefits
  • 18 tooth mainshaft installs into the stock 4-speed transmission just like stock
  • upgrades the stock tapered mainshaft and clutch to a modern 18 tooth spline configuration
  • 1970-E84 Big Twins

Mainshaft: This is a direct replacement for 1970-1985 tapered mainshafts. If you already have purchased a BAKER 4-Speed with a splined mainshaft, you do not need another splined mainshaft. For further information, please contact us through the website chat, email us at info@bakerdrivetrain.com, or call us Monday-Friday 8AM-7PM EST/EDT and Saturday 10AM-3PM EST/EDT at 517-339-3835.

Clutch Sprocket: We offer 35, 36, 37, and 38 tooth clutch sprockets with our clutches so that you can dial in your overall gear ratio. You can easily calculate your overall gear ratio here.

Kicker Setup: You have the option of having the BAKER Shovel Clutch as a kick only application or as a stock replacement with starter ring gear for electric start applications. Both styles can be run with wet or dry applications.

Stock Clutch Layout with Splined Mainshaft Fix

Stock Clutches
Shovelhead clutches from the 70's were prone to have several issues.  Two of the leading issues were the sticky / jerky clutch release from a stop light, in which you would never know if it was going to happen, the other was a the starter ring gear.  The ring gear design on the stock clutches was a 3-piece riveted together then welded to the basket.  Over time the ring gear would wear and become skewed cause starting issues.  The image on the left shows the stock clutch in pieces along with our Splined Shaft at the bottom.

Clutch Sprockets

Shovel Clutch Design
The clutch is based off of our 9-plate clutch used on 1990-up applications and fits in the stock primary housing and TTP. We offer 35, 36, 37, and 38 tooth clutch sprockets with our clutches to dial in your overall gear ratio. 

The fundamental design approach of the BAKER clutches is different than anything available from the factory or other aftermarket manufacturers. For strength reasons, we manufacture our clutch with a 1-piece ring gear/basket. First, a large donut shaped forging is turned on a CNC lathe to the shape of the finished basket. Next the internal splines for the friction plates are formed with a 6-foot long broach. Threads for attachment of the carrier are machined on a mill, then the ring gear teeth are hobbed on the same type of machine that makes our gears. It is not cheap to make the heart and soul of our clutches in this manner but the end result justifies the expense. The radial strength gained by integrally putting the ring gear around the basket is analogous to the steel bands placed around a whiskey barrel. Without the steel bands, the barrel would explode and that would be alcohol abuse. Additionally, the ring gear is supported by the hoop of the basket and this guarantees the T.I.R. at the pitch line of the ring gear teeth (no egg shaped ring gear). 

Splined Shovel Clutch Baskets

Kick or Electric
You have the option of having the Shovel Clutch as a Kick Only application or as a stock replacement with starter ring gear for electric start applications. Both styles can be ran wet or in a dry application, note the differences in clutch basket design. 

Requirements
Clutch is to be used in conjunction with a splined mainshaft; 1970-early 1984 models. BAKER offers the splined mainshaft for your stock 4-Speed for a complete retrofit conversion.

Recommended
BAKER highly recommends when replacing/converting your stock 4-Speed to a splined shaft that you completely rebuild the transmission replacing any worn out items or components.

BAKER DRIVETRAIN DOES NOT SUPPLY THE SNAP RINGS, BEARINGS OR RELATED COMPONENTS FOR THE MAINSHAFT INSTALLATION. PLEASE REFER TO THE FACTORY SERVICE MANUAL AND AFTERMARKET PARTS CATALOG FOR THESE ITEMS. DO NOT REUSE YOUR OLD MAINSHAFT SNAP RINGS OR BEARINGS AFTER DISASSEMBLY AS THIS MIGHT CAUSE FAILURE TO COMPONENTS. 

PN

Description

Fitment

9P400*

Splined Shovel Clutch Assembly

1970-E84 Shovelheads

9P401*

Splined Shovel Clutch w/Splined Mainshaft

1970-E84 Shovelheads

MS-4-SPLINE

18 Tooth Splined Mainshaft

1970-E84 Shovelheads

 

Notes

  • * Specify clutch sprocket by adding a "-35", "-36", "-37" or "-38" to the part number.
  • Specify a "-K" for kick only or "-S" for starter version after the part number; example: 9P400-37-S

Instructions
Splined Shovel Clutch Instructions: Coming Soon

Standard Gear Case Finish Examples (Not applicable to all products)

Chrome

Polished

Raw

Wrinkle Black

These example finishes are intended to show the exterior treatments of cases, top covers and doors.

TERM AND CONDITIONS                                                                                         

 

BAKER Drivetrain reserves the right to change prices, terms or policies at any time without notice.

Orders can be pre-paid using Visa, MasterCard, American Express, Discover or PayPal.

All orders not pre-paid will be sent C.O.D. certified check or money order only unless pre-approved for company check acceptance.

Any orders from outside the USA must be pre-paid in US funds via wire transfer; a $30 transfer fee will apply.

Prices shown are F.O.B. Haslett, MI.

 

LIMITED WARRANTY POLICY

 

BAKER™ transmission assemblies, transmission kits, primaries, and oil pans are guaranteed to the original purchaser to be free of manufacturing defects in materials and workmanship for a period of 5 years from the date of purchase or up to 50,000 miles. BAKER™ clutches, kicker cover kits, belt drives, F6F kit, reverse systems, covers and accessories are guaranteed to the original purchaser to be free of manufacturing defects in materials and workmanship for a period of 2 years from the date of purchase or up to 24,000 miles - whichever occurs first. If the product is found by BAKER™ to be defective, such products will, at the option of BAKER™, be replaced or repaired at cost to BAKER™. 

 

In the event warranty service is required, the original purchaser must call or write BAKER™ immediately with a description of the problem. If it is deemed necessary for BAKER™ to make an evaluation to determine whether the transmission assembly or transmission kit or accessory is defective, the entire transmission assembly, whether originally purchased as an assembly or kit, must be properly packaged and returned prepaid to BAKER™ with a copy of the original invoice of purchase. If after an evaluation has been made by BAKER™ and a defect in materials and/or workmanship is found, BAKER™  will, at BAKER™  option, repair or replace the defective part of the assembly. 

 

RETURNS AND EXCHANGES

 

Any merchandise returned for any reason (exchange, credit or modification) must be accompanied by a Return Goods Authorization (RGA) number or it will be refused. Call BAKER™ to obtain this number prior to returning goods for any reason. There is a 15% re-stocking fee for all returned items. BAKER™ is not liable for any shipping charges. 

 

ADDITIONAL WARRANTY PROVISIONS

 

NOTE: Limited warranty does not cover labor or other costs or expenses incidental to the repair and or replacement of BAKER™ products.

 

This warranty does not apply if one or more of the following situations is judged by BAKER™ to be relevant: BAKER™ OEM transmissions; (these are subject to the OEM manufactures warranty only), Improper installation, accident, modification (including but not limited to use of unauthorized parts, transmission oils or lubricants), racing, high performance application, mishandling, misapplication, neglect (including but not limited to improper maintenance), or improper repair. 

 

BAKER™ shall not be liable for any consequential or incidental damages arising out of or in connection with a BAKER™ transmission assembly, transmission kit, component or part. Consequential damages shall include without limitation, loss of use, income or profit, or losses sustained as the result of injury (including death) to any person or loss of or damage to property.

 

BAKER™ transmissions, transmission kits and accessories are designed exclusively for use in American V-Twin motorcycles. BAKER™ shall have no warranty or liability obligation if BAKER™ parts are used in any other application.

 

If it is determined that a BAKER™ product has been disassembled during the warranty period for any reason, this limited warranty will no longer apply unless you were instructed to do so by a BAKER Drivetrain technician for diagnostic purposes.

 

The words H-D®, Softail®, FXR®, Dyna®, FLT®, FLH®, Sportster®, and Buell® are registered trademarks and are for reference only.

 

Questions? Ask us anything:
Contact us
Or just call us at 517-339-3835. We're glad to help.

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