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T140 Trans Lube?

3K views 29 replies 11 participants last post by  RetroRod 
#1 ·
Being that lubricants seem to change through the years, is there anything in the transmission that would make modern (GL-5) gear lubes unsuitable?

What is a safe flushing agent if changing from one spec of lube to another?
 
#2 ·
I think you want to make sure the gear oil is safe for yellow metals. The manufacturer should state if their additive blend is OK or not for bronze components. Not sure about the T140 but my T120 gearbox has a bronze thrust washer.

I would fill, run to temp and flush with a heavy motor oil.
 
#10 ·
Not so easy to find around here but I did just stumble upon and got some Brad Penn's Classic GL-4 Gear Oil that I put in an old BMW car. It never shifted so well so I think it's worth a try in the T140.
Only a mail order item but fortunately I have enough left over.
 
#7 ·
Valvolene 85w90 GL4/GL5 gear oil is what I use. Valvolene states it is safe for bronze bushing
 
#8 ·
I use any make 75/90 that i find when out at the jumbles.Often a 500cc bottle turns up at 50p.I have used the Mobil synthetic GL5 type but cannot say gearchanges are any better or worse.I do,however,change it at around 2000 miles due to its low cost.No gear wear that matters.I have broken a tooth off at one time.The little cog on the mainshaft lost a tooth and i later found it in the box when changing the crank.It made no extra noise with it missing.
GL4 Duckhams in at the moment.
 
#11 · (Edited)
Here's Valvolene's claim and why I use them. That and the fact I can buy it off the shelf at any autoparts store Had it in 3 bikes for a number of years and no gold in the pan so far.
"Apparently activated sulfate (used in some GL5 lubes) can eat brass synchros. Valvoline indicated: "The Valvoline High Performance Gear Oil 80-w90 can be used for both GL4 and GL5. The real concern is the type of sulfate used in the gear oil. You can not use an active sulfate for GL-4 applications. Valvoline uses an inactive sulfate that will not harm any yellow metal such as bronze. This allows our products to be used in manual transmissions that have bronze synchronizers."
 
#13 · (Edited)
That quote was from a thread dating back a few years. As you have mentioned there is nothing on their website now that says anything similar. Out of curiosity I email the question to Valvoline and this is the response I received.
"Is Valvoline high performance gear oil suitable for use in older British motorcycles that have bronze bushings?"
Reply
"All GL-5 gear oil products contain an active sulfate ingredient that can cause corrosion on yellow metals. Valvoline has produced a gear oil that is safe for bronze bushing. The Valvoline Synchromesh Style gear oil (part number 811095) will provide protection and performance for your application. The use of our High Performance Gear Oil would not be recommended where contact with yellow metal could cause issues."
I don't know if they changed their formula or why they no longer recommend the High Performance. Like I said I have always used it with not problems, but I will probably switch to the Synchromesh Style.
 
#15 ·
Mobil 1 Synthetic Gear Lube LS 75W-90.
"Excellent rust, staining and corrosion protection of copper and its alloys"

That covers bronze synchronizes or bushings.

http://www.mobil.com/USA-English/Lubes/PDS/GLXXENPVLMOMobil1_Syn_Gear_Lube_LS_75W-90.aspx
Like I've mentioned earlier, every time I made the mistake of putting synthetics in motors dated from mid 70's to late 80's they almost immediately hemorrhaged.

Maybe you've been lucky but I'll never go down that road again irregardless of how many people say they never has a problem.

That just reminds me of contractor's excuses "We've always done it that way and never had a problem", and then there's a problem and the story changes to "we're only contractors".
 
#18 ·
I use mostly GL4 and sometimes i use Mobil 1 gear oil which is GL5,it mixes alright.I have never had any parts in the gearbox with any corrosion and it all seems to be internet rumour and maybe a few 1920s gearboxes had metal dissolving.Not something i would worry about in a gearbox of a Triumph.It would appear these gear parts will last at least 80,000 miles before any repairs are needed,as long as they do have oil !
Not saying i would use it,but joung John lunmad is using plain engine oil in the box and it must be nearing 90,000 miles now.
The right oil is important and,as Norton found with race Commandos,the gears in their boxes were chopping up the long chain polymers causing poor old Pete Williams to keep walking back to the pits.Triumphs are not too rough on the EP oils and my own box has had just one problem,a chipped tooth on a cog.I did change the 2 thrust bearings at the last build,however,the ones taken out had no wear or corrosion.Bit of a waste of time changing them.I have also changed the bearings at 30,000 miles as the engine was apart and it seemed a good idea.Again,the bearings had no significant wear.
 
#20 ·
The right oil is important and,as Norton found with race Commandos,the gears in their boxes were chopping up the long chain polymers causing poor old Pete Williams to keep walking back to the pits.
In the late '70s I ran a 500cc Laverda proddy racer. The recommended oil was Duckhams Q20/50, changed every 500 miles. There were no plain bearings in that engine, built up crank with roller big ends, even the camshafts ran in needle rollers. It just thrashed the viscosity out of the oil. After 500 miles, it just ran out of the crankcase like water!
 
#21 ·
Considering the low cost of the gear oil and only 500cc needed,i change mine at 2000 miles.This is proving to be a good investment for a longer gear life and the oil is in a hostile environment.It cannot do any harm to change it early.
 
#22 ·
Hi Guys, Regarding flushing out the GL5 the trans has a little oil remaining in the floor of the box where the drain plug is after draining. However, it will retain a lot of oil in the gear change cover, down by where the old speedo drive used to be, think of the lowest point of the out right outer trans cover. I always siphon this oil out, about 1/4-1/2 cup or so. That oil is very dirty & that's where the metal chips tend to collect as well. I think?? the churning of the oil in the main case near the drain plug keeps that area clean so it congregates in the still area of the cover. I can't say that for a fact, but that's what I've observed on my bike. I also find any water from condensation or the like, or running down clutch cable in rain collects there also. That's why I suction it out. Personally I do the trans every 2-3k miles.
Don
 
#28 ·
Ah!! Those were the good old days Rambo.
In the good old days,most of us waited until the chain was slipping on the toothless rear sprocket or the chain snapped !
Never boiled a chain as many of my early bikes had a full chain enclosure.Those types would make the chain last years with the low power output of the old bikes.
I must say,it is amazing how long the transmission lasts in a near 50 bhp engine.Just so long as it stays wet with oil.
 
#30 ·
Ah!!
In the good old days,most of us waited until the chain was slipping on the toothless rear sprocket or the chain snapped !

I must say,it is amazing how long the transmission lasts in a near 50 bhp engine.Just so long as it stays wet with oil.
Hey, you been reading my posts about getting the most from chains. Glad to know I had a kindred spirit in the UK :laugh2:

50BHP? try 35 at the wheel. :grin2:
 
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