tansmission question [not problem, yet]

[charlie74]

recently i have had occassional trouble getting my '6 into first gear. today, i had trouble getting it into any gear except reverse, then it was fine. changing underway is no problem and the transmission feels really good.
at the beginning of the season i had switched from gear lube to 30wt oil and did my best to fill to correct level with a squirt can (my pump was awol). could this be just a low fluid level, something more ominous, or nothing to be concerned about?
TIA!
c74

 

[tomgt6]

It could be the spring and bushing under that shifter.

 

[Mark Jones]

Did it work fine before you switched from gear oil to 30wt oil?

 

[charlie74]

yes, it did...

 

[TR3driver]

What does "occasional trouble getting it into gear" mean? Can't move the lever; gears grind; lever moves but gears don't engage ?

If no grinding and the lever just doesn't want to move; what happens if you shift back to neutral, let the clutch out briefly (engine running), then depress the clutch fully and try again. If that solves the problem, I would deem it "no big deal" and switch back to gear oil. The TR gearbox really needs the additional protection of extreme pressure gear oil (which is why that's what the factory recommended).

 

[Marvin Gruber]

Have you checked the fluid level in clutch master for any telltale signs. Pump the pedal a couple of times to see if that helps getting it in gear. If its been a while since you rebuilt the clutch hydraulics, it might be time.

 

[Mark Jones]

Switch back to gear oil. 30wt motor oil is not the right oil for a gearbox.

 

[charlie74]

ok, thanks guys, i will start the hunt for some GL4.
actually it has been a long time since the hydraulics have been rebuilt and i was thinking of sending out the master and slave for a rebuild this winter.

the lever can always be moved but the trouble starts when selection of first is difficult. this has only happened a couple of times (once all of the gears except reverse) and was alleviated after breifly putting the trans into reverse. no grinding has been heard but after an instance it will "clunk" somewhat when going into gear.

 

[TR4nut]

Charlie-

You may also be fighting a broken clutch fork pin, sounds like your clutch may not be releasing properly.

Randy

 

[charlie74]

i hope not...
i'll try replacing the fluids first and see if that makes it go away before i start taking the car apart. :shocked:

 

[TR4nut]

Didn't want to scare you, it very well may not be the issue. But I've been bit by it a couple of times already so it always springs to mind.

Randy

 

[charlie74]

ok, GL4 is impossible to find in my area (hence the change to 30wt ND that i had read was acceptable) so i am thinking of ordering some from Redline. just to confirm the accepted weight would be M-90 75/90 rather than the MTL 70/80 which also available?
thanks
c74

 

[SpannerMan]

My recollection is that you want to go with the MT90 if you use the Redline. If you have any leaks from your gearbox, you might have a faster leak with MT90. It is a lot thinner than gear oil. I switched to ND 30wt after trying it, for that reason. You may have a dragging clutch as has been suggested. You may try to detect whether the car is being propelled forward slightly when you sit in a level parking lot in 1st gear with the brakes off. Could be hydraulics as was suggested - e.g. that red plastic hose from the master to the slave is expanding under the pressure.

 

[TR3driver]

The MT-90 will work fine. So will the lighter MTL if the pump & seals in your OD are in good shape.

Valvoline 20W50 Racing motor oil (the stuff that says "not street legal") also works quite well. It has enough ZDDP in it to act as an extreme pressure additive and help protect the thrust washers.

 

[TR3driver]

Easy test for a dragging clutch is to shift into a forward gear, then into neutral with the clutch held fully depressed. If it grinds when you then try to go into reverse after a few seconds, the clutch (or pilot bearing) is dragging.