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TR2/3/3A TR-4A Gearbox Fluid
- Thread starter Redoakboo
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TR3driver
Great Pumpkin - R.I.P
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Triumph switched from motor oil to recommending GL4 gear oil around 1957. Legend has it that they were seeing too many countershaft failures and felt the GL4 would provide better protection. I don't know how well that worked, but they continued to recommend GL4 through the end of TR6 production; so they must've at least felt it wasn't any worse.
Next, there is the GL4 vs GL5 debate, and conventional vs synthetic. Personally, I use Redline's MT-90 which is a GL4 rated synthetic developed specifically for synchronized manual transmissions. It's not cheap, but made a noticeable improvement in my TR3 (which has a TR4 gearset and OD).
https://www.redlineoil.com/mt-90-75w90-gl-4-gear-oil
Next, there is the GL4 vs GL5 debate, and conventional vs synthetic. Personally, I use Redline's MT-90 which is a GL4 rated synthetic developed specifically for synchronized manual transmissions. It's not cheap, but made a noticeable improvement in my TR3 (which has a TR4 gearset and OD).
https://www.redlineoil.com/mt-90-75w90-gl-4-gear-oil
Randall,
I sent you a reply, but noticed it was under the Clutch Adjustments. So, here it is again. I drained the gearbox, but only got about 1 pt of oil out of it, strange because I it always shows oil on the dip stick? The manual says a TR-4A with overdrive takes 3 1/2 pts? Does the OD section have its own plug? I was going to use the dipstick hole to add the new oil but wonder if 3 1/2 pts is right? I don't want to overfill it.
Dick
I sent you a reply, but noticed it was under the Clutch Adjustments. So, here it is again. I drained the gearbox, but only got about 1 pt of oil out of it, strange because I it always shows oil on the dip stick? The manual says a TR-4A with overdrive takes 3 1/2 pts? Does the OD section have its own plug? I was going to use the dipstick hole to add the new oil but wonder if 3 1/2 pts is right? I don't want to overfill it.
Dick
TR3driver
Great Pumpkin - R.I.P
Offline
Yes, the OD has it's own drain plug, plus a screen and (on the later ones) magnets to clean.
No reason not to use the dipstick that I can see, in fact I made the swap myself (later gearboxes don't normally have a dipstick, it's only found on TR2 through early 3A). But you can check the plug if you want, to double-check the dipstick. Just make sure it's level, since being tilted either side-to-side or fore/aft will affect the oil level at both dipstick and plug.
I don't pay too much attention to absolute amount, since I'm usually starting with a partially full bottle anyway. But ISTR it takes most of two quarts after draining both gearbox and OD. The level is not super critical anyway, IMO, a little high or low isn't going to hurt anything. If it's way high, it will tend to self-correct by leaking more
If you have the later type drain plug with notches around the edge, I definitely recommend either building or buying a tool to engage more than one notch at a time. I've seen lots of people try to get them off with a hammer and drift (or similar), and the result is often a plug that leaks. Best to have a new gasket on hand too (or suitable O-ring per CJD). Sorry, I forget offhand who sells the tool commercially; here's a shot of the tools I made; with the best one (IMO) in the foreground and the previous version in the background. The old version worked well enough, but was awkward to use as it put your knuckles at risk between the bar and frame if it broke loose suddenly.
No reason not to use the dipstick that I can see, in fact I made the swap myself (later gearboxes don't normally have a dipstick, it's only found on TR2 through early 3A). But you can check the plug if you want, to double-check the dipstick. Just make sure it's level, since being tilted either side-to-side or fore/aft will affect the oil level at both dipstick and plug.
I don't pay too much attention to absolute amount, since I'm usually starting with a partially full bottle anyway. But ISTR it takes most of two quarts after draining both gearbox and OD. The level is not super critical anyway, IMO, a little high or low isn't going to hurt anything. If it's way high, it will tend to self-correct by leaking more
If you have the later type drain plug with notches around the edge, I definitely recommend either building or buying a tool to engage more than one notch at a time. I've seen lots of people try to get them off with a hammer and drift (or similar), and the result is often a plug that leaks. Best to have a new gasket on hand too (or suitable O-ring per CJD). Sorry, I forget offhand who sells the tool commercially; here's a shot of the tools I made; with the best one (IMO) in the foreground and the previous version in the background. The old version worked well enough, but was awkward to use as it put your knuckles at risk between the bar and frame if it broke loose suddenly.
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Thanks again, Randall,
You ought to get a patent on that neat tool you made. I figured that brass star had to be a plug of some sort, I will forget the hammer/screwdriver idea. Must be a pint or two hiding in that OD section. I have the Service/Instruction manual for the Laycock OD Unit, but it made NO mention of where or how the drain plug was removed??
Dick
You ought to get a patent on that neat tool you made. I figured that brass star had to be a plug of some sort, I will forget the hammer/screwdriver idea. Must be a pint or two hiding in that OD section. I have the Service/Instruction manual for the Laycock OD Unit, but it made NO mention of where or how the drain plug was removed??
Dick
TR3driver
Great Pumpkin - R.I.P
Offline
I just copied an existing design and sized it to fit. It's a 2.5" axle nut socket (originally for a Ford apparently) with the edge milled down to form the 6 lugs.
FWIW, here's what I started with
https://www.ebay.com/itm/OEM-Tools-...708979&hash=item464afc2346:g:l2MAAOSwNkJaAiol
Randall,
I made a tool just like the one you made but, no matter how tight I screw the cap back on, it still lacks about 1/8" from closing. I thought about putting it in the freezer for acouple days and then try again. Would a thick "o" ring seal it up? Is there much pressure inside the box?
Dick
I made a tool just like the one you made but, no matter how tight I screw the cap back on, it still lacks about 1/8" from closing. I thought about putting it in the freezer for acouple days and then try again. Would a thick "o" ring seal it up? Is there much pressure inside the box?
Dick
TR3driver
Great Pumpkin - R.I.P
Offline
There's no pressure at that point, just the weight of the oil above the plug.
But it should go all the way home easily (even without a gasket). IMO you need to find what the plug is hitting and deal with that.
There are two different configurations running around; the early setup used a bolt, flat washer and spacer to hold the screen in place, while the later one (with the notches around the plug) takes a different screen that just fits over a projection on the plug itself (no bolt or spacer). IIRC the early screen has a smaller hole and won't work with the later plug (unless you crush the screen, maybe). Could you have mismatched components?
PS, the early setup also lacks room for the magnet rings used with the later one. I managed to squeeze one magnet into mine, but even that was tight and interfered to some extent with tightening the plug.
But it should go all the way home easily (even without a gasket). IMO you need to find what the plug is hitting and deal with that.
There are two different configurations running around; the early setup used a bolt, flat washer and spacer to hold the screen in place, while the later one (with the notches around the plug) takes a different screen that just fits over a projection on the plug itself (no bolt or spacer). IIRC the early screen has a smaller hole and won't work with the later plug (unless you crush the screen, maybe). Could you have mismatched components?
PS, the early setup also lacks room for the magnet rings used with the later one. I managed to squeeze one magnet into mine, but even that was tight and interfered to some extent with tightening the plug.
I have the later one that just fits over a round section of the plug. The problem seems to be the brass plug. The threads are fine on both plug and gearbox projection. I tried to screw it, leaving out the screen. It only screws in halfway and then become so tight it barely turns. I put my "Randall Tool" on the end of a socket with a breaker bar. Still stops 1/8" from totally in.
It was fairly easy to remove intially, with my RT and a socket wrench. Maybe I need to order a new brass cover?
Dick
It was fairly easy to remove intially, with my RT and a socket wrench. Maybe I need to order a new brass cover?
Dick
TR3driver
Great Pumpkin - R.I.P
Offline
All I can say is check the threads carefully. Somewhere there is a nick or ding interfering with smooth operation. I would probably try coating them with layout dye (aka Dykem) and screwing together lightly, then undo and look closely for the spots where the dye got rubbed off.
I ran a thin file through the threads on the brass cap, as there are only about 3 rings on the cap. The second thread appeared flattened. I did remove a bit of metal and they looked much better. I wire brushed the cap, installed a new thick o ring, removed the old washer. and added a little bearing grease.
The cap went on much smoother and with the RT, I tightened it up to the o ring. I then tightened it about 1/4 turn seating it on the o ring. Installed almost 2 guarts of Redline 90 and there doesn't appear to have any leaks.
Tomorrow I take it out for a test drive. Thanks for all your help, hope the fires are away from you?
Dick
The cap went on much smoother and with the RT, I tightened it up to the o ring. I then tightened it about 1/4 turn seating it on the o ring. Installed almost 2 guarts of Redline 90 and there doesn't appear to have any leaks.
Tomorrow I take it out for a test drive. Thanks for all your help, hope the fires are away from you?
Dick
TR3driver
Great Pumpkin - R.I.P
Offline
Closer than I would like; but no real threat.
I also have a TR4 gearbox with OD in my 59TR3 installed by prev owner. lately, the OD doesnt engage immediately, even though i treat it like 5th gear (backoff the gas pedal and put in the clutch when flipping the OD switch). it engages after 3 -6 seconds. I guess it is time to check the fluids and drain the gearbox and the OD unit. am going for the Redline 90wt.
how do you check car level without a lift? four jack stands?
how do you check car level without a lift? four jack stands?
