New and improved 105E17269 speedometer gear housing with integral oil seal
If you own a Lotus Elan, Elan 2+2 or any other vehicle fitted with a Ford 2000E gearbox and you have experienced a slight leak from the speedometer gear housing,
then there is a solution. This solution has been driven by observing this problem operating a Lotus only workshop and requests from several Lotus owners.
Solving this annoying leak has involved working around existing components to design and manufacture an inexpensive component that is “plug and play”.
The first step in this process is to understand why the speedometer housing leaks.
The original aluminium housing was produced by using a die-cast process followed by machining of the features and critical dimensions.
This aluminium die-cast process is often used by the automotive industry (including Ford) to create complex aluminium components that need a minimal amount of machining.
Photograph kindly supplied by Duy Bui from Queensland
The above photograph shows gearbox oil escaping from around the speedometer gear driven shaft and dribbling down the extension housing casing.
This oil leak is usually hidden by the threaded aluminium pedestal that is clamped in position covering the end of the driven gear shaft.
This hidden oil leak is caused by hot oil escaping between worn speedometer gear driven shaft and the internal supporting bore.
The speedometer gear shaft has a contra-rotating spiral groove cut into the length of the shaft in an attempt to move oil back into the gearbox extension housing.
Such an arrangement can be likened to the historical Archimedes-principle seal.
Today, this simple arrangement is known as a “Windback Seal” and relies on a very small clearance between the rotating shaft and supporting body.
This type of seal was common on older engines until the 1960’s when engines operated at lower revs and lower oil pressure.
One notable Classic Car to use them at both ends of the crankshaft was the W.O. Bentleys.
The clearance between the crankshaft and the housing had to be precise to prevent oil leaks.
This required an experienced machinist to achieve this degree of accuracy when align boring freshly white metalled main bearings.
(thanks to Rowley Errington for providing Windback information)
Whilst this “Windback Seal” arrangement appears to be a simple and cost effective solution to retain oil in the gearbox, it does have an inherent design flaw.
This seal is only effective whilst minimal clearances are maintained.
So as normal wear gradually increases the shaft clearance, the oil scavenging action along the shaft decreases allowing oil to escape.
A simple solution to this is to design a replacement housing that incorporates a double lip seal.
Examining the top section of the driven gear shaft reveals there is a plain section that does not have a continuation of the spiral groove.
This plain cylindrical section is ideally suited to run in contact with a double lip seal that will prevent oil escaping along the driven shaft.
The solution is to design the new speedometer gear housing in Solidworks CAD software where it’s possible to view a 3D model that includes a double lip seal.
This important process allows dimensional checks to be made and to consider the final component assembly process.
Photograph kindly supplied by Duy Bui from Queensland
These housings have been CNC machined from 6061 aluminium alloy and have a tumbled finish to ensure there are no sharp edges.
To assist in the installation process, some silicon lubricant and a cotton bud are included in every parts order.
Please lubricate the seal, speedometer gear shaft, plus housing body and sealing O-ring prior to installing the assembly in the gearbox extension housing.
Other components that are available from Lotus Marques to complement the speedometer housing installation in a Lotus Elan or Elan 2+2 are as follows-
1) New housing complete with double lip seal and O-ring
2) Right-angle gear drive for speedometer cable
3) Aluminium pedestal 7/8UNF x 18tpi
4) Aluminium pedestal 3/4UNF x 26tpi
NOTE – Please measure relevant threads carefully before ordering a new pedestal.
Whilst the amount oil gradually lost via the speedometer gear housing may not be consider to be serious, over time and regular use the gearbox oil may reach a very low level where damage occurs. Therefore it is recommended that oil leak be checked and at the same time the oil level in the gearbox be checked.
A special mention to Classic Ford car owners, if you own a Ford Cortina or Escort fitted with a 2000E gearbox then this speedometer gear housing will fit your vehicle.
New housing complete with double lip seal and O-ring @ $60.00 excluding GST
To request more information or to order parts please contact Lotus Marques by email This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Please note carefully, pricing above does not included postage and packing.
Pricing information is correct as of 8/2/2025 but may alter with time and currency exchange rate fluctuations.
Shipping from Australia to UK, USA, New Zealand, anywhere worldwide!
Contact Lotus Marques now for postal or courier shipping costs.
If you own a Lotus Elan, Elan 2+2 or any other vehicle fitted with a Ford 2000E gearbox and you have experienced a slight leak from the speedometer gear housing,
then there is a solution. This solution has been driven by observing this problem operating a Lotus only workshop and requests from several Lotus owners.
Solving this annoying leak has involved working around existing components to design and manufacture an inexpensive component that is “plug and play”.
The first step in this process is to understand why the speedometer housing leaks.
The original aluminium housing was produced by using a die-cast process followed by machining of the features and critical dimensions.
This aluminium die-cast process is often used by the automotive industry (including Ford) to create complex aluminium components that need a minimal amount of machining.
Photograph kindly supplied by Duy Bui from Queensland
The above photograph shows gearbox oil escaping from around the speedometer gear driven shaft and dribbling down the extension housing casing.
This oil leak is usually hidden by the threaded aluminium pedestal that is clamped in position covering the end of the driven gear shaft.
This hidden oil leak is caused by hot oil escaping between worn speedometer gear driven shaft and the internal supporting bore.
The speedometer gear shaft has a contra-rotating spiral groove cut into the length of the shaft in an attempt to move oil back into the gearbox extension housing.
Such an arrangement can be likened to the historical Archimedes-principle seal.
Today, this simple arrangement is known as a “Windback Seal” and relies on a very small clearance between the rotating shaft and supporting body.
This type of seal was common on older engines until the 1960’s when engines operated at lower revs and lower oil pressure.
One notable Classic Car to use them at both ends of the crankshaft was the W.O. Bentleys.
The clearance between the crankshaft and the housing had to be precise to prevent oil leaks.
This required an experienced machinist to achieve this degree of accuracy when align boring freshly white metalled main bearings.
(thanks to Rowley Errington for providing Windback information)
Whilst this “Windback Seal” arrangement appears to be a simple and cost effective solution to retain oil in the gearbox, it does have an inherent design flaw.
This seal is only effective whilst minimal clearances are maintained.
So as normal wear gradually increases the shaft clearance, the oil scavenging action along the shaft decreases allowing oil to escape.
A simple solution to this is to design a replacement housing that incorporates a double lip seal.
Examining the top section of the driven gear shaft reveals there is a plain section that does not have a continuation of the spiral groove.
This plain cylindrical section is ideally suited to run in contact with a double lip seal that will prevent oil escaping along the driven shaft.
The solution is to design the new speedometer gear housing in Solidworks CAD software where it’s possible to view a 3D model that includes a double lip seal.
This important process allows dimensional checks to be made and to consider the final component assembly process.
Photograph kindly supplied by Duy Bui from Queensland
These housings have been CNC machined from 6061 aluminium alloy and have a tumbled finish to ensure there are no sharp edges.
To assist in the installation process, some silicon lubricant and a cotton bud are included in every parts order.
Please lubricate the seal, speedometer gear shaft, plus housing body and sealing O-ring prior to installing the assembly in the gearbox extension housing.
Other components that are available from Lotus Marques to complement the speedometer housing installation in a Lotus Elan or Elan 2+2 are as follows-
1) New housing complete with double lip seal and O-ring
2) Right-angle gear drive for speedometer cable
3) Aluminium pedestal 7/8UNF x 18tpi
4) Aluminium pedestal 3/4UNF x 26tpi
NOTE – Please measure relevant threads carefully before ordering a new pedestal.
Whilst the amount oil gradually lost via the speedometer gear housing may not be consider to be serious, over time and regular use the gearbox oil may reach a very low level where damage occurs. Therefore it is recommended that oil leak be checked and at the same time the oil level in the gearbox be checked.
A special mention to Classic Ford car owners, if you own a Ford Cortina or Escort fitted with a 2000E gearbox then this speedometer gear housing will fit your vehicle.
New housing complete with double lip seal and O-ring @ $60.00 excluding GST
To request more information or to order parts please contact Lotus Marques by email This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Please note carefully, pricing above does not included postage and packing.
Pricing information is correct as of 8/2/2025 but may alter with time and currency exchange rate fluctuations.
Shipping from Australia to UK, USA, New Zealand, anywhere worldwide!
Contact Lotus Marques now for postal or courier shipping costs.
