5 Speed Datsun Conversion for Morris Minor MG Midget and Austin Healey Sprite

poster frame

  5 speed conversion kit for Austin Healey Sprite/MG Midget/Morris Minor
Contact Me for more Information and Availability

September 6, 2010

Using the Datsun 210 4 or 5 speed transmission, this kit will allow you to make a turnkey installion in your Sprite Midget or Morris Minor. (or any other in-line A-series engine powered car like the Austin A30/35 or Austin A40 Farina)

October 8, 2012

I was recently corrected regarding the legacy of the Datsun 5 speed development. Here is the information I received in a message from Terry Odenbach.

"In the 70's and early 80's I owned Bowmans Foreigh Car Repair in Redding Ca. For many of those years we were the authorized JRT service center between Sacramento and Portland We actually developed the kit and I sold several kits to Bruce when he was in Redwood City. The original kits can be identified by the Sports Conversion logo between the upper two mounting bolt holes. I sold many of these kits around the USA and other countries. I was never notified of a single problem. I still have several of the original plates plus the drill fixtures for the adapter plates and flywheels as proof"

Bruce Wyman who owned Morriservice in Redwood City later sold Morriservice to Paul Asgeirsson. Paul further improved after he took over Morriservice from Bruce and moved Morriservice north to Portland Oregon from Redwood Cty, California. Later, due to the similar drivetrain in the Sprite and Midget, it has been popularly used in those as well. The Morriservice design is considered by many ethusiasts to be a superior design over the Rivergate product and easier to install. I have made a number of subtle improvements in the current iteration that should make installation even smoother and easier. I have seen it written that the Morriservice 5 speed conversion "came later", but indeed, just the opposite is true, and was actually conceived in the late 70's

In addition, by following my recommended installation procedure, modification of the heater plenum in Spridget models is not required.

Depending on which car you are upgradiing, the kit will include some or all of the following as necessary.

The Spridget kit includes:

  • Adapter Plate
  • Custom Pilot bush
  • Special cradle to mount stock slave cylinder
  • Adjustable slave cylinder push rod and special adj.nut
  • Conversion Driveshaft Yoke
  • Conversion Universal Joint
  • Rear Transmissin mount
  • HQ Bolt kit
  • Installation manual and templates


Optional items

  • Speedometer cable
  • Rear lip seal conversion
  • Gear reduction starter, including New Speedwell HQ Starters
  • Quality clutch kit
  • replacement front and rear transmission seal
  • replacement fork boot
  • shifter bushings
  • modified shifter (shortened and offset) (needed for Sprite/Midget only)
  • transmission case modifications (you must send me your transmission)
  • Drivesaft spacer (needed for Sprite/Midget only)

Transmission required is 1979-1982 Datsun 210 (not the same as B210 )


Datsun 5 speed conversion for AH Sprite or MG Midget kit
Basic Spridget Kit

not RivergateBasic Morris Kit

id arrow How to ID the correct transmission

(click thumbnail to view details)

Slave mounting cradle   Adapter Plate

Datsun 210 adapter for slave cylinder


Datsun 210 adapter plate

seal   sealCU
Contact Me for more Information and Availability   Adapter plate shown above left and above with optional seal kit
1275 rear seal   1098 rear seal
1275 Rear seal installed (shown with optional 5 speed kit)   1098 Rear seal installed (shown with optional 5 speed kit)

Which would you prefer? ^


* A Word about Seal Kits

The original BMC rear engine seal design for in-line A-series engines is what is called a "scroll seal". Simply explained, there is a helical groove at the rear of the crankshaft that will throw oil back towards the internal engine while the crankshaft spins. A vertical flange called a slinger, acts as both a barrier and a means to divert oil from it's natural path as it tries to exit the rear main.

archemedes screw

In Theory

In order for this system to work properly, it is of primary importance that the engine be in decent operating condition, properly vented, and be accompanied by vacuum pressure and a PCV. Often, if these conditions are met, the original design is sufficient. However, sometimes these engines aren't built with the correct tolerances to make this system work 100% of the time. Hence, the rear lip seal kit has been designed to help out as a substitute. Even with the lip seal, it is still important that that the vent and vacuum conditions be observed. Unfortunately however, one of the weaknesses in the lip seal retrofit design has been, the replacement half moon seal that is supplied with the kit. Because it does not follow the original design concept to take advantage of the original scroll seal design desribed above, it instead relies entirely on the lip seal to retain the oil.

The Big Difference

My seal kit is different. Instead of depending entirely on the lip seal, it incorporates a half moon seal that takes advantage of the original scroll seal design and has the added benefit of the lip seal as a back up. This design incorporates several improvements and is not available elsewhere.


How an Archimedes screw works to move fluids.    

clutch kit

Optional Clutch kit




Each plate is serialized


Optional Gaiter Ring >>>

Aluminum Gaiter ring for use with vinyl gaiters found in post 1972 Midgets

An exact replica of the stamped steel ones are NLA and sometimes needed with you modified shifter that won't clear the "can"


Available pre-drilled or blank.

  Gaiter ring
gaiter ring

kit mounted

Kit mounted on 1275cc engine with Datsun 7" Clutch kit.



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Speedo cable accuracy without any correction.

Test done on '73 Midget with stock speedo and 3.9 gear ratio

Speedo reads GPS readout



<<< Optional Gear Reduction Starter

Speedwell Engineering HIgh Quality Gear Reduction starter is an excellent option, which will prevent damaged teeth on the ring gear. These starters are new, compact, lightweight, and very easy to install. Available as an optional accessory.

  Speedwell Starter  

Additional information on the Speedwel Starter

  NEW- Quick Shift/Short Shift Kit    

This custom shifter* will reduce the gear-to-gear shift stroke by 50%

and fits under the original shift turret and rubber gaier without modification.

*Shift knobs are optional. Billet knob is available in machine finish or black anodized. Engraving choices are with the Flying "g" logo or the Datsun 5 speed "H" pattern engraved, exposing the bright aluminum.


Black anodized with design engraved.