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bcbennett
09-13-2006, 08:10 PM
Hello everyone,

My '74 TR6 is doing something weird, but I think it's pretty simple and I'm pretty dumb. When I first start my car from cold, I put it in reverse, slide out my garage, and drive like normal. However, when I return after a nice drive in the country, my transmission (freshly rebuilt) has a hard time going in reverse. I push in the clutch, move the gearshift over, but when I try to move it down into reverse, it grinds and grinds.

The funny part is that it works fine cold; moreover, I have examined the slave cylinder, and it seems to move fine (and I've bled it).

Suggestions?

shorn
09-13-2006, 09:11 PM
try shifting into another gear (second, or third) and then into reverse. I assume the tranny oil is on the full mark.

Brosky
09-13-2006, 09:43 PM
You say that the tranny is newly rebuilt. How old are the clutch slave and master cylinder units? Is the line new from master to slave?

Banjo
09-13-2006, 10:01 PM
Reverse is the only non-syncro gear in your tranny, so if the clutch is not actuating the whole way that is the one that willbe the hardest to actuate.
I bet if you try putting it in reverse several times in a row, it will work fine the first few times, then start to get hard.
My guess is there is still some air trapped in the clutch system. and working it causes the throw to get a bit shorter after a few times. It might also have to do with the trans oil getting up to temp, and letting things turn easier after a run.
But, I'd re-bleed the clutch, making sure to push the slave cylinder all the way in with the bleeder open (use a screwdriver or something to do this) then close the bleeder and let it return to normal.
This ensures that all the air is out of the slave cyl.
I'v had to re-bleed TR6s before. they tend to be stinky.

bcbennett
09-14-2006, 07:48 AM
Hi guys; yes, the whole clutch assembly and all hydraulics are new. I've bled two or three times, but maybe I'll bleed again. Sigh.

trfourtune
09-15-2006, 10:13 AM
this might seem like a silly question but when you shift into reverse when the car is warm from running, do you push in the clutch, wait a few seconds for the gears to stop spinning then pull it into gear or do you just push in and shift right away? try pushing in the clutch more than once and wait a few seconds before shifting. could be that the thrust clearance in you box is not to spec. do you have the correct oil type and weight? non sycro gears have momentum and when the oil is hot it does not slow them down as fast as when cold. i don't have a clue but just a few thoughts.
rob

Brosky
09-15-2006, 10:36 AM
Try moving your carpet and padding away from the area of contact from the bottom of the clutch pedal. You may not be getting full travel in your pedal when it's depressed. It sounds silly, but it's happened before.

martx-5
09-15-2006, 10:40 AM
Push down on the clutch, snick it into first before you go into reverse. By going into first first, that will stop the gears from spinning.

hondo402000
09-15-2006, 10:58 AM
I always shift into 2 gear and then in to reverse on every manual I ever owned and never had a problem going into reverse, dont shift too quickly or you will grind reverse

John_Mc
09-15-2006, 02:21 PM
If you have the old plastic hose between the master and slave cylinders, those supposedly can soften enough with heat that they expand a little under pressure, thus not allowing enough fluid volume in the slave cylinder to fully disengage the clutch. I replaced mine with the braided stainless steel hose and that seemed to help, although I also needed to replace the bushings on the clutch pedal shaft, and that made a big difference. That's just one suggestion from my personal experience.

Brosky
09-15-2006, 02:27 PM
John, where did you get your stainless steel hose?

Thanks,

09-15-2006, 02:37 PM
Scuse me for stepping in here but the braided hose for the clutch master is just a ss-armored plastic hose. Not really there to keep it from expanding, just to keep it from getting cut. The downside to armored hoses is they will cut anything around them (wires, other hoses) like a knife through butter, over time. They are good pretty but need to be used with care.

Got mine from Moss.

Bill

Brosky
09-15-2006, 02:39 PM
Once again, thank you Bill, for the info. I was not aware of that fact.

DougF
09-15-2006, 03:43 PM
Where did you purchase your slave and master cylinders? What type of fluid are you using i.e. Dot 3,4,5? When you bleed the system, does the fluid show any sign of the rubber breaking down?

Brosky
09-15-2006, 04:36 PM
I actually replaced mine several years back with parts from TRF. I still have the the original type fluid in my system.

John_Mc
09-15-2006, 05:53 PM
I also got my ss hose from Moss. I did this after reading "Clutch Hose Problems" and "Non-Operational Clutch Diagnosis" articles in the Maintenance Handbook section of the VTR website www.vtr.org. (https://www.vtr.org.) It did seem to help, and, as I mentioned, replacing the pedal shaft bushings made a big difference as well (especially since they had been missing altogether on my car when I got it). Any defects, even though seemingly small, that add "slack" to the system can make a big difference in how much the clutch disengages. My $.02. As Bill advised, be mindful where any braided ss hoses make contact, as they can be very abrasive.