BritBike Forum logo
BritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorThe Bonneville ShopBritBike Sponsor
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
ShoutChat Box
Comment Guidelines: Do post respectful and insightful comments.
Buy BritBike staff a coffee
Buy BritBike's staff a coffeeStill here since 1996 serving BritBike enthusiasts..
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Random Gallery photo
Member Spotlight
Dennis M
Dennis M
California, USA
Posts: 125
Joined: August 2001
Show All Member Profiles 
Newest Members
Mr. Bean, rudi, Derek, Psychorider, Shedengineering
10861 Registered Users
Top Posters(30 Days)
franko 168
DavidP 66
reverb 64
NickL 61
Popular Topics(Views)
1,012,290 mail-order LSR
a word from..
Forum Statistics
Forums34
Topics67,781
Posts680,187
Members10,861
Most Online14,755
May 5th, 2019
Who's Online Now
46 registered members (Beach), 357 guests, and 598 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Pre-Unit transmission service. #780924 08/08/19 3:37 pm
Joined: Aug 2013
Posts: 73
1
1958superrocket Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
1
Joined: Aug 2013
Posts: 73
Servicing the transmission oil on my 1957 T110 and a couple of questions. Where is the drain plug and what weight/type of oil should I be re-installing. Thanks in advance. 😁

Support Your #1 BritBike Forum!

Check out British motorcycles for sale:
British Motorcycles on e-Bay UK
British motorcycles on e-Bay North America
Re: Pre-Unit transmission service. [Re: 1958superrocket] #780927 08/08/19 4:50 pm
Joined: Aug 2001
Posts: 7,911
triton thrasher Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Aug 2001
Posts: 7,911
The drain plug is a hex headed bolt screwed into the front of the gearbox bottom mounting lug.

It is not the vertical domed detent plunger holder.

With the bike upright, fill the gearbox with just enough oil to cover the speedo driven gear. That’s the one that meshes with the speedo driving gear on the timing side end of the layshaft. Any more oil and it will leak.


Amateur Loctite enthusiast.
Re: Pre-Unit transmission service. [Re: triton thrasher] #780929 08/08/19 5:16 pm
Joined: Aug 2013
Posts: 73
1
1958superrocket Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
1
Joined: Aug 2013
Posts: 73
Thx! What is the proper weight/type of oil to use. Owners manual says 50 wt. motor oil but many say don’t use motor type oil. 80/90 gear lube, std. or synthetic?

Re: Pre-Unit transmission service. [Re: 1958superrocket] #780930 08/08/19 5:24 pm
Joined: Aug 2001
Posts: 7,911
triton thrasher Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Aug 2001
Posts: 7,911
I’m using a gear oil, SAE 90 I think, GL4.

You’ll get a lot of opinions about oil.


Amateur Loctite enthusiast.
Re: Pre-Unit transmission service. [Re: 1958superrocket] #780931 08/08/19 5:33 pm
Joined: Aug 2001
Posts: 7,911
triton thrasher Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Aug 2001
Posts: 7,911


Amateur Loctite enthusiast.
Re: Pre-Unit transmission service. [Re: triton thrasher] #780932 08/08/19 6:00 pm
Joined: Aug 2013
Posts: 73
1
1958superrocket Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
1
Joined: Aug 2013
Posts: 73
Thanks for all your input!

Re: Pre-Unit transmission service. [Re: 1958superrocket] #780942 08/08/19 8:05 pm
Joined: Nov 2012
Posts: 1,123
K
koan58 Offline
BritBike Forum member
Offline
BritBike Forum member
K
Joined: Nov 2012
Posts: 1,123
Quote TT:
Your gearbox May be better represented in this one:
http://www.classicbike.biz/Triumph/Repair/45-55/45-55TriumphRepair.pdf

I'm doubtful that this is more helpful, as the only diagram is for the rigid gearbox, which has the drain bolt to the rear of the lower lug (as well as the more forward location of the upper lug).

The later swingarm gearbox (which the OP should have) should have the drain plug at the forward side of the lower lug, as you originally said.

I have no idea why the change was made, both sides are easily accessible in my triton, maybe it was more important in the original Triumph frame?

Re: Pre-Unit transmission service. [Re: 1958superrocket] #780943 08/08/19 8:12 pm
Joined: Feb 2007
Posts: 812
E
edunham Offline
BritBike Forum member
Offline
BritBike Forum member
E
Joined: Feb 2007
Posts: 812
For what it's worth... I have had a number of unit Triumphs and BSAs. Used 90 wt gear oil/hypoid in all of them. Always assumed that the specification of non-gear oil in older machines was because good gear oil wasn't available when the specifications were written. My Velocette calls for 40 or 50 wt non-gear oil. The transmission always leaked and it didn't shift as nicely as I thought it should. Tried all sorts of things to improve the situation. None made much difference. Finally at the suggestion of some folks on the Velo forum, I switched to regular motor oil. The shifting improved about 80% and it stopped leaking (haven't figured that one out!). Now I am using Bel-Ray non-hypoid (basically a beefed up motor oil) and it shifts quite nicely. I have no explanation for this and I am still using gear oil/hypoid in the unit engines (and my Norton). But if you try gear oil and have problems, don't hesitate to try the 50 wt. motor oil the factory recommended.
By the way, some hypoids attack yellow metal (bronze, brass, etc.). Modern ones supposedly do not. If you have any yellow metal in your transmission ( like bronze bushings or shifting forks) and you have decided to use a hypoid, do an internet search on what is safe for your transmission.

Ed from NJ

Re: Pre-Unit transmission service. [Re: koan58] #780951 08/08/19 9:19 pm
Joined: Aug 2001
Posts: 7,911
triton thrasher Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Aug 2001
Posts: 7,911
Originally Posted by koan58
Quote TT:
Your gearbox May be better represented in this one:
http://www.classicbike.biz/Triumph/Repair/45-55/45-55TriumphRepair.pdf

I'm doubtful that this is more helpful, as the only diagram is for the rigid gearbox, which has the drain bolt to the rear of the lower lug (as well as the more forward location of the upper lug).

The later swingarm gearbox (which the OP should have) should have the drain plug at the forward side of the lower lug, as you originally said.

I have no idea why the change was made, both sides are easily accessible in my triton, maybe it was more important in the original Triumph frame?


All true, but the earlier manual shows the pre-slickshift outer cover and the level plug in the rear of the inner cover. The level plug that is too high!


Amateur Loctite enthusiast.
Re: Pre-Unit transmission service. [Re: 1958superrocket] #780955 08/08/19 10:09 pm
Joined: Nov 2012
Posts: 1,123
K
koan58 Offline
BritBike Forum member
Offline
BritBike Forum member
K
Joined: Nov 2012
Posts: 1,123
My slickshift has the level plug in the rear of the inner cover also, though I haven't used it for decades. I agree that it is far too high, I just stick 350ml in and have done with it. It only needs a level that safely covers the lower half of the layshaft gears, even much lower will give "survival" lubrication, as long as the level isn't below the lowest gear teeth.
I've always used engine oil (20/50) in the gearbox, with changes at the same times as the engine (about 2000 miles).
Maybe I've been lucky, but I'm still running the same shafts and gears that came with the box in '79. Were I racing it may have been different, of course.

Re: Pre-Unit transmission service. [Re: triton thrasher] #781018 08/09/19 4:00 pm
Joined: Aug 2013
Posts: 73
1
1958superrocket Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
1
Joined: Aug 2013
Posts: 73
Just getting a good look at the parts breakdown and see the level bolt/fill bolt is listed in two different places. I see the level? bolt in the rear of the inner case but am not seeing the “drain” bolt as it appears in a different location? Have tried looking from both sides of the bike from below and above. Am I missing something? Thx in advance.

Re: Pre-Unit transmission service. [Re: 1958superrocket] #781028 08/09/19 4:58 pm
Joined: Aug 2001
Posts: 7,911
triton thrasher Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Aug 2001
Posts: 7,911
Originally Posted by 1958superrocket
Am I missing something?



Yes.

This is the front face of a swing arm Triumph gearbox: the side nearest the engine.

The hex head facing us is the drain plug.

[Linked Image from i.ebayimg.com]


Amateur Loctite enthusiast.
Re: Pre-Unit transmission service. [Re: triton thrasher] #781030 08/09/19 5:27 pm
Joined: Aug 2013
Posts: 73
1
1958superrocket Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
1
Joined: Aug 2013
Posts: 73
😁👌😁👌💥

Re: Pre-Unit transmission service. [Re: 1958superrocket] #781036 08/09/19 6:16 pm
Joined: Aug 2001
Posts: 7,911
triton thrasher Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Aug 2001
Posts: 7,911
You can see why they leak when over-filled. Look at the two spindles sticking out the side nearest us. There’s another one, the selector fork rail, sitting in a hole in front of the sprocket.


Amateur Loctite enthusiast.
Re: Pre-Unit transmission service. [Re: 1958superrocket] #781376 08/13/19 1:52 pm
Joined: Aug 2013
Posts: 73
1
1958superrocket Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
1
Joined: Aug 2013
Posts: 73
How can you differentiate between a slickshift transmission and a std.? Just got a manual from Baxter’s that covers 1956-1962 pre-unit bikes and the transmission section seems to only deal with the slick shift. I have a 1957 T-110 I’m dealing with.

Re: Pre-Unit transmission service. [Re: 1958superrocket] #781405 08/13/19 7:03 pm
Joined: Jun 2007
Posts: 6,454
HawaiianTiger Online Content
BritBike Forum member
Online Content
BritBike Forum member
Joined: Jun 2007
Posts: 6,454
I suppose most folks call the transmission from 57-62, the slickshift, even if the parts are not inside to make it a semi-automatic clutch. They're recognizable by the horizontal clutch arm and the chrome plated access plate.
A true slickshift device can be disabled by removing the roller from the internal clutch lever.
Cheers,
Bill


Bikes
1974 Commando
1985 Honda Nighthawk 650
1957 Thunderbird/T110 "Black Tiger"
Antique Fans: Loads of Emersons (Two six wingers) plus gyros and orbiters.
Re: Pre-Unit transmission service. [Re: 1958superrocket] #781406 08/13/19 7:19 pm
Joined: Aug 2013
Posts: 73
1
1958superrocket Offline OP
BritBike Forum member
OP Offline
BritBike Forum member
1
Joined: Aug 2013
Posts: 73
Thanks. Mine appears to be the std set up.

Re: Pre-Unit transmission service. [Re: 1958superrocket] #781907 08/18/19 11:14 pm
Joined: Jan 2006
Posts: 234
Beljum Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Jan 2006
Posts: 234
Dont mind me. I'm just getting back into the swing of things but whatever TT and HT says....listen and heed their advice. I love the preunit transmission!

TT izzat you in the aviator?



'55 "The Mighty 6T", '01 DR650, '13 KTM300XC

Re: Pre-Unit transmission service. [Re: 1958superrocket] #781927 08/19/19 6:06 am
Joined: Jun 2007
Posts: 6,454
HawaiianTiger Online Content
BritBike Forum member
Online Content
BritBike Forum member
Joined: Jun 2007
Posts: 6,454
Beljum! Good to have you back!
Fan biz is rockin....
Cheers,
Bill


Bikes
1974 Commando
1985 Honda Nighthawk 650
1957 Thunderbird/T110 "Black Tiger"
Antique Fans: Loads of Emersons (Two six wingers) plus gyros and orbiters.
Re: Pre-Unit transmission service. [Re: Beljum] #781932 08/19/19 8:23 am
Joined: Aug 2001
Posts: 7,911
triton thrasher Offline
BritBike Forum member
Offline
BritBike Forum member
Joined: Aug 2001
Posts: 7,911
Originally Posted by Beljum

TT izzat you in the aviator?


No, that’s an old singer: Gene Vincent.


Amateur Loctite enthusiast.

Moderated by  John Healy 

Home | Sponsors | Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons | DVD- Manuals & Parts books
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
Powered by UBB.threads™ PHP Forum Software 7.7.3