[ROVERNET - UK] SD1 gearbox( Second part of James Dean's last post)

[Kent Kinard]

Hi James,
The gearbox is dead.  It should have been attended to sooner in order to 
save it.  The TR7 box will do fine, but needs to be flushed and treated 
after installation. It is not a Getrag and neither is the Jag box.  It 
is a British Leland LT77.  Gear strength and bearing size were never the 
problems.  The use of tapered roller bearings resulted in heavy center 
bearing end loads and wear on the bearing that resides between the First 
Motion Gear and the Manshaft.  Partial failure of this bearing causes 
the clearance between the maninshaft gears and the countershaft gears to 
increase putting greater strain on each gear tooth and eventual failure 
of the sliding gears and the countershaft gears. Although it is not a 
foolproof test, try to move the First Motion Gear (input shaft to 
Americans) up and down with the trans out of the car. If the TR box 
shows appreciable movement at this point, it may not be good either, and 
at the very least needs a rebuild before installation.

Roverly,
Kent K.

James Dean wrote:
  He suddenly has a noise in first, second, third, but not 4th and
> 5th. It sounds like it is coming from the gearbox, he says. When he 
> jacks the car up and runs it, the noise goes away. Any ideas?. If it is 
> a gearbox, I have a good TR7 gearbox. I have been told Rover used 
> heavier bearings. An owner of a Tr shop told me he had a TR7 with a 
> superpowerful TR8 engine, drives it hard, and has had no problem for 
> years. He says yes, the bearings were changed, but it made no 
> difference. What is the real answer?I know Vitesse SD-1's had hardened 
> gears, but do not think regular SD-1 had that. Also, is this the same 
> Getrag 5 speed Jaguar used on the 80-87 Series III XJ6 5 speed? The box 
> looks almost the same, except the shifter.