Triumph Repair: Transmission Problems, triumph spitfire 1500, 1980 triumph spitfire 1500

Question
Hi Jim,
I have a 1980 Triumph Spitfire 1500 with 30000 on the odometer.  Over the winter I took my 4 speed with J type overdrive transmission apart and rebuilt it with a friend from my local Triumph group.  It went together well and I put it back in the car with a new clutch plate, pressure plate and throw out bairing.  The gearbox shifts through the gears good when the car is not running.  I have been driving the car for about 2 weeks and it appeared to be running good.  I tried to downshift, but it didn't down shift very well in first and second gear, but I attribute that to the rpm's and high transition ratios.  Would you recommend not downshifting?  From my standpoint-- brakes are easier to replace than the gearbox.

Today there was some resistance to shift upwards into gear.  It seems like I have to push the clutch pedal through the floor in order for it to shift nicely without grinding.  I tried to bleed the slave cylinder, but the problem is still present.  Heres the story: I try to shift into a higher gear and it doesn't go nicely, or if it goes it intermittently grinds, so when it grinds I do not push it, but let off the clutch and reapply and try a different gear and it sometimes goes and when it goes, than I return to the appropriate gear for the speed.  Any thoughts?  Do I have to adjust the clutch pedal? (Can I adjust the clutch pedal?)

Answer
Andy,

There are several reasons you'll have trouble shifting the trans... I'll try to list them in order of normal likelihood.

1)  Hydraulics.  Air in the system or bad seals can cause insufficient travel on the clutch slave.

To get all the air out I've found it helpful to prop the clutch pedal to the floor with a piece of 2x4 (something like 26" if memory serves) and leave the prop there for several days.  This allows air bubbles in the lines up near the master to work their way out into the reservoir.  Some may scoff.. but it generally works well enough to keep my autocrosser running.

2) wear in the linkage.  There's a clevis pin that connects the clutch pedal to the master cylinder push rod... with the years the clevis pin wears, the push rod wears and the pivot bushing on the clutch pedal also wears.  Any slack there will contribute to insufficent action on the hydraulics.

3)  You don't mention which brand clutch setup you used... sometimes the "budget" pressure plates don't stay parallel to the flywheel.. or if the pressure plate wasn't evenly torqued down it won't always release from the clutch properly.  

4) Synchros.  From your description it's not likely, but the consensus in the Triumph community is that they don't make 'em like they used to.. especially in the far east.  It's a matter of reading dimensions and quality control...  sometimes the SAE to Metric conversions don't get done properly.  If the synchros are not up to the task then it'll seem like the clutch isn't working.

Last variable... weather.  what oil did you put in the trans?  I've had trouble with older transmissions in cold weather.

Final advice:  learn to double clutch.  You can drive a Spitfire (once it's moving) without the clutch.  At very least you take quite a load off the synchros.


Cheers,

Jim