QUESTION
I am looking to replace the output shaft seals and pinion seal on my 1969 Lotus Elan S4 differential.
Can you provide any advice on carrying out this task?
D.O. - Davidson, Sydney, NSW
ANSWER
The oil seals are straight forward replacement once the output drive shafts and pinion drive flange have been removed.
However, there are some recommendations to be observed that are not mentioned in the Lotus workshop manual.
1) Removing the prop-shaft drive flange to access the pinion seal needs to be carried out with some caution.
If you have never dismantled an Elan differential before, then be aware that undoing the lock nut inside the flange will disturb the pinion gear mesh.
To ensure the pinion gear goes back in exactly the same position, scribe alignment marks on the nut, shaft and flange.
Located behind the flange is a crush tube that that provides the necessary pre-load on the pinion bearings.
If the lock nut is too tight or too loose then the pinion gear position will be altered and result in a noisy differential.
2) From experience, Elan owners who change pinion oil seals often continue to experience oil leaks from the front of the differential nose.
Evidence of this is oil on the rear chassis tray immediately below the differential drive flange.
To prevent a reoccurring oil leak after changing the pinion seal, apply Aviation Gasket Sealant No.3 to the splines on both pinion shaft and flange.
This excellent product is available from Loctite and is a non-hardening sealant that can be used as a substitute for Wellseal A907E6119ZA.
This sealant is very runny, brown in colour with a strong odour and is supplied with an application brush located in the screw-on cap.
Applying a thin coating of Aviation Gasket Sealant No.3 to the shaft and flange will prevent hot thin oil from creeping along the splines and exiting behind the lock nut.
Copyright © 2013 Lotus Marques
I am looking to replace the output shaft seals and pinion seal on my 1969 Lotus Elan S4 differential.
Can you provide any advice on carrying out this task?
D.O. - Davidson, Sydney, NSW
ANSWER
The oil seals are straight forward replacement once the output drive shafts and pinion drive flange have been removed.
However, there are some recommendations to be observed that are not mentioned in the Lotus workshop manual.
1) Removing the prop-shaft drive flange to access the pinion seal needs to be carried out with some caution.
If you have never dismantled an Elan differential before, then be aware that undoing the lock nut inside the flange will disturb the pinion gear mesh.
To ensure the pinion gear goes back in exactly the same position, scribe alignment marks on the nut, shaft and flange.
Located behind the flange is a crush tube that that provides the necessary pre-load on the pinion bearings.
If the lock nut is too tight or too loose then the pinion gear position will be altered and result in a noisy differential.
2) From experience, Elan owners who change pinion oil seals often continue to experience oil leaks from the front of the differential nose.
Evidence of this is oil on the rear chassis tray immediately below the differential drive flange.
To prevent a reoccurring oil leak after changing the pinion seal, apply Aviation Gasket Sealant No.3 to the splines on both pinion shaft and flange.
This excellent product is available from Loctite and is a non-hardening sealant that can be used as a substitute for Wellseal A907E6119ZA.
This sealant is very runny, brown in colour with a strong odour and is supplied with an application brush located in the screw-on cap.
Applying a thin coating of Aviation Gasket Sealant No.3 to the shaft and flange will prevent hot thin oil from creeping along the splines and exiting behind the lock nut.
Copyright © 2013 Lotus Marques
