QUESTION
I'm in the midst of overhauling my transaxle on my 79 Esprit S2 and observed that my input shaft is worn on the crankshaft end
I believe this is typical for S1/S2's ?
I noted you offer a part (A089F0404F) that fits over the end of the input shaft to correct this problem.
This would be much less expensive than replacing the shaft but I was wondering if this can be used on all S2's or if it is only for later cars where the tip of the shaft is removable (by design).
Can you please clarify if this part will work on my car (I don't believe the tip is removable on my car but I'll have to check more closely).
Judging by the Lotus part number I'm guessing it is only for later cars ?
L.R. - New Jersey, USA
ANSWER
If you have an early type gearbox from a 1979 S2 Esprit, then the standard input shaft spigot diameter is machined to 15mm to accomodate the needle roller bearing located in the crankshaft.
The early input shaft does not have a sacrificial spigot sleeve that can be easily replaced.
Unfortunately the spigot needle roller bearing will not tolerate misalignment or any ingress of dirt or clutch material.
This makes the bearing prone to failure and quite often cause damage to the gearbox input shaft spigot.
It is possible to machine your existing input shaft spigot to accept the later type hardened and ground sleeve.
However the input shaft is retained by an internal circlip (Lotus part number A079F6068F) concealed in the end of the gearbox primary shaft.
This retaining ring is located just inside the female splines of the primary shaft.
The quickest way to remove the floating input shaft is by attaching a sliding hammer to the shaft.
Once the shaft has been removed it is a simple matter of reducing the spigot diameter in a lathe to accommodate the new sleeve.
The input shaft should be mounted in the vertical position whilst the sleeve is secured to the newly machined spigot section with Loctite 620.
If you happen to be rebuilding your engine and the crankshaft is out of the block then there is another useful modification.
From experience it is possible to counter-bore the back of the crankshaft to accept the later ball-bearing fitted to 88 Esprit's onwards
The later spigot arrangement is located by a ball bearing instead of a needle bearing.
The spigot ball-bearing is a sealed unit and will also tolerate a small amount of axil misalignment.
Hence you hardly ever hear about spigot bearing problems in later Esprit's.
Copyright © 2014 Lotus Marques
I'm in the midst of overhauling my transaxle on my 79 Esprit S2 and observed that my input shaft is worn on the crankshaft end
I believe this is typical for S1/S2's ?
I noted you offer a part (A089F0404F) that fits over the end of the input shaft to correct this problem.
This would be much less expensive than replacing the shaft but I was wondering if this can be used on all S2's or if it is only for later cars where the tip of the shaft is removable (by design).
Can you please clarify if this part will work on my car (I don't believe the tip is removable on my car but I'll have to check more closely).
Judging by the Lotus part number I'm guessing it is only for later cars ?
L.R. - New Jersey, USA
ANSWER
If you have an early type gearbox from a 1979 S2 Esprit, then the standard input shaft spigot diameter is machined to 15mm to accomodate the needle roller bearing located in the crankshaft.
The early input shaft does not have a sacrificial spigot sleeve that can be easily replaced.
Unfortunately the spigot needle roller bearing will not tolerate misalignment or any ingress of dirt or clutch material.
This makes the bearing prone to failure and quite often cause damage to the gearbox input shaft spigot.
It is possible to machine your existing input shaft spigot to accept the later type hardened and ground sleeve.
However the input shaft is retained by an internal circlip (Lotus part number A079F6068F) concealed in the end of the gearbox primary shaft.
This retaining ring is located just inside the female splines of the primary shaft.
The quickest way to remove the floating input shaft is by attaching a sliding hammer to the shaft.
Once the shaft has been removed it is a simple matter of reducing the spigot diameter in a lathe to accommodate the new sleeve.
The input shaft should be mounted in the vertical position whilst the sleeve is secured to the newly machined spigot section with Loctite 620.
If you happen to be rebuilding your engine and the crankshaft is out of the block then there is another useful modification.
From experience it is possible to counter-bore the back of the crankshaft to accept the later ball-bearing fitted to 88 Esprit's onwards
The later spigot arrangement is located by a ball bearing instead of a needle bearing.
The spigot ball-bearing is a sealed unit and will also tolerate a small amount of axil misalignment.
Hence you hardly ever hear about spigot bearing problems in later Esprit's.
Copyright © 2014 Lotus Marques