After many years of experience it is possible to overhaul the Lotus Esprit steering rack and achieve an outstanding result.
The original Lotus supplied item is built down to a price and was never intended to be serviced or overhauled.
Checking the Dealer Parts List reveals there are no internal components available from the Lotus Factory that would assist in rebuilding the rack.
The standard Lotus Esprit steering rack suffers from wear in several areas.
The passenger side rack bearing wears as the result of the road wheel being subjected to high loads created by curb-side drain covers etc.
Problems arise from lack of maintenance of the rack and pinion where the internal components are not routinely lubricated.
The external rubber gaiters can crack and split which allows moisture ingress.
The O-ring and weather seal on the input shaft can deteriorate and allow water to run down the shaft and damage the pinion gear
Once the inner ball joints are worn, this results in excessive clearance and unwanted movement.
If this happens, it is not possible for any Lotus Esprit to maintain a precise wheel alignment and uneven tyre wear results.
The key internal components that usually wear are the pinion bearings which maintain the correct pinion gear position.
Symptoms of pinion bearing wear normally results in excessive back-lash when the steering wheel is turned.
This can be detected by standing out side the vehicle with the window wound down, reach inside the cabin then turn the steering wheel and the road wheel should move instantly.
If it does not respond immediately then most likely the pinion is worn and/or does not mesh correctly because the bearings are worn.
Unfortunately the steering rack manufacturer decided to use a low cost ball bearing that is marginal in its performance
The pinion bearings have to accommodate two loads, one being radial and the other being axial.
Ball races by their design and not good at handling axial loads - see any manufacturers design specifications
The correct bearing for this application is in fact a tapered roller bearing that can withstand both high radial and axial loads.
The pinion bearings in the Esprit rack are a proprietary bearing and cannot be purchased from Lotus or any commercial bearing reseller.
Lotus Marques has developed a very good understanding of steering rack problems and has developed several unique components that allow the rack to be
overhaul and upgraded by installing tapered roller bearings.
Upgrading the steering rack to incorporate tapered roller bearings transforms the action so that is very smooth and precise
Numerous steering racks have been sent to Lotus Marques for overhaul and upgrading.
Some steering racks have been in very poor condition just like the rack below
Once internal rust sets in it is often necessary to replace the rack and pinion.
However satisfactory results can achieved by removing the rust and phosphating the internal moving parts.
This process provides another level of corrosion protection as well as slippery coating.
Inner ball joints need to be treated with great care when correcting the oval wear pattern that has been established.
The majority of manual steering racks maybe serviced using the components shown above.
Please contact Lotus Marques for a quotation before sending your worn steering rack.
Update 16th October 2013
The latest bearing conversion kit is now supplied with a custom spacer that comes pre-installed within the inner bearing race.
The newly designed single piece spacer tube and thrust washer locate the pinion shaft and set correct bearing installed height.
For additional information regarding the latest conversion kit, visit the product news article here.
The original Lotus supplied item is built down to a price and was never intended to be serviced or overhauled.
Checking the Dealer Parts List reveals there are no internal components available from the Lotus Factory that would assist in rebuilding the rack.
The standard Lotus Esprit steering rack suffers from wear in several areas.
The passenger side rack bearing wears as the result of the road wheel being subjected to high loads created by curb-side drain covers etc.
Problems arise from lack of maintenance of the rack and pinion where the internal components are not routinely lubricated.
The external rubber gaiters can crack and split which allows moisture ingress.
The O-ring and weather seal on the input shaft can deteriorate and allow water to run down the shaft and damage the pinion gear
Once the inner ball joints are worn, this results in excessive clearance and unwanted movement.
If this happens, it is not possible for any Lotus Esprit to maintain a precise wheel alignment and uneven tyre wear results.
The key internal components that usually wear are the pinion bearings which maintain the correct pinion gear position.
Symptoms of pinion bearing wear normally results in excessive back-lash when the steering wheel is turned.
This can be detected by standing out side the vehicle with the window wound down, reach inside the cabin then turn the steering wheel and the road wheel should move instantly.
If it does not respond immediately then most likely the pinion is worn and/or does not mesh correctly because the bearings are worn.
Unfortunately the steering rack manufacturer decided to use a low cost ball bearing that is marginal in its performance
The pinion bearings have to accommodate two loads, one being radial and the other being axial.
Ball races by their design and not good at handling axial loads - see any manufacturers design specifications
The correct bearing for this application is in fact a tapered roller bearing that can withstand both high radial and axial loads.
The pinion bearings in the Esprit rack are a proprietary bearing and cannot be purchased from Lotus or any commercial bearing reseller.
Lotus Marques has developed a very good understanding of steering rack problems and has developed several unique components that allow the rack to be
overhaul and upgraded by installing tapered roller bearings.
Upgrading the steering rack to incorporate tapered roller bearings transforms the action so that is very smooth and precise
Numerous steering racks have been sent to Lotus Marques for overhaul and upgrading.
Some steering racks have been in very poor condition just like the rack below
Once internal rust sets in it is often necessary to replace the rack and pinion.
However satisfactory results can achieved by removing the rust and phosphating the internal moving parts.
This process provides another level of corrosion protection as well as slippery coating.
Inner ball joints need to be treated with great care when correcting the oval wear pattern that has been established.
The majority of manual steering racks maybe serviced using the components shown above.
Please contact Lotus Marques for a quotation before sending your worn steering rack.
Update 16th October 2013
The latest bearing conversion kit is now supplied with a custom spacer that comes pre-installed within the inner bearing race.
The newly designed single piece spacer tube and thrust washer locate the pinion shaft and set correct bearing installed height.
For additional information regarding the latest conversion kit, visit the product news article here.