Triumphrat

gabsdad8 · 07-05-2009, 10:00 PM

The manual calls for 90 wt gear oil for the tranny on my '78 T140v, but even after adjusting the clutch, the gearbox has gotten rather clunky. I was thinking of running straight 50 wt oil in her to see if that'll make shifting any smoother.
Does anyone have any thoughts yeah or nay?

KADUTZ · 07-05-2009, 10:38 PM

I have lots of thoughts which I will keep to myself.

Just I question have you found a 50wt oil that conforms to GL4/5 specs as in Hypoid gear oil?

thirdbike · 07-05-2009, 10:48 PM

Don't use engine oil in trannys and vice versa. If your're having a lot of trouble shifting, maybe check and find out why. Otherwise you could try synthetic gear oil.

gabsdad8 · 07-05-2009, 10:48 PM

Quote:

Originally Posted by KADUTZ

I have lots of thoughts which I will keep to myself.

Just I question have you found a 50wt oil that conforms to GL4/5 specs as in Hypoid gear oil?

KADUTZ, I've read some of your stuff on here, and I value your opinion. So if you will, please share your thoughts.

And no, I don't know anything about GL4/5 specs.

gabsdad8 · 07-05-2009, 11:42 PM

Thirdbike - Thanks; I value your opinion too. Maybe I was looking for a quick, easy fix for my tranny troubles - summer is way too short up here. I'll dig into the gearbox a little.

But why not put engine oil into the box? Are the stresses just too great? I had a Ford Ranger that called for ATF(!) in the manual transmission. And my Suzuki shares its 10-40 between the engine and gearbox.

aceaceca · 07-05-2009, 11:51 PM

Factory Triumph workshop manuals call for 50w engine oil in the trans. I run 50w in my 1970 T120 and it shifts great. My Brit sports cars call for 30w in the gearbox. I had 90w in there and once I realized they called for 30w I switched. Much better. I think either one will work fine.

thirdbike · 07-06-2009, 12:00 AM

Your Suzuki's tranny was designed and built to run on engine oil.
Hypoid gear oil is is meant to maintain a film of protection under extreme pressures and sort of sticks to the surfaces. The Triumph transmission has no pump to provide lubrication to the top of the box.
If you want to know more read on: http://www.amsoil.com/articlespr/200...oilbasics.aspx

KADUTZ · 07-06-2009, 12:01 AM

gabsdad8
Listen to thirdbike

you no want me to share my thoughts I would only get banned again.

you have a 1 owner 78 what does you owners manual call for? I use 85/140 Hypoid gear lube with an additive (made by Lubeguard) in my 78. Pat Owens 400,000 mile RT uses a mixture of gear lube and STP. Older Brit bikes may have used 50wt but then they changed to Hypoid and used that til the end. GL4/5 is a rating applied to Hypiod oils like SJ or SH to engine oils. I can see no advantage by reverting to 50wt
jus my pinion
K

KADUTZ · 07-06-2009, 12:21 AM

aceacea
my old friend good to see you out here granted the earlier manuals may have called for 50wt the later bikes(T140) called for 90 or 90/140wt Hypoid. (By the way I use the same mix in my RT as the T140's.)
By the way what do you use in the Nortons gearbox?
just the K's pinion

Plewsy · 07-06-2009, 08:21 AM

I must have read the same manual as aceaceca

I have always used 20/50 engine oil in my '72 T120R g/box, the only replaced bits in my box are kickstart and quadrant springs