Technical Gearbox fluid and spark plugs

[dk500]

Hi
Having a little weeping at the gearbox plug and thought I might try and drain and refill. Also, I was going to try and change the spark plugs.

1- it is a 126 / 650cc engine and I presume the gearbox is the same.
Could you advise what would be a suitable replacement to refill. I have read on a post regarding some oils that can affect metals in the gearbox ?
Any tips appreciated as always !

2 - I am trying to borrow a spark plug spanner with the rubber to grip the plug. I will check what is fitted at the moment, but what type spark plugs should be in this engine ?
Again, any tips appreciated!

Thanks
Darryl

 

[Paolo66]

The book recommends 15w/40 oil for gearbox. I just put in the normal 20w/50 I use for the engine. It takes 1.1 ltr.
Again the book recommends Marelli CW8NP or Champion L81Y or equivalents. I have tried NGK 5 series and 6 series. The best thing for plugs is to run them and see
Damian

 

[the hobbler]

With regard to the gear-box oil; as the 126 box has synchromesh, you will require a NON EP oil. I believe Castrol, Penrite and Morris all make such oils, as do Millers (good Yorkshire company). Their oil--CRX 75/w90 sounds very similar to the factory oil, and is suitable for gear-boxes with synchromesh.
For your spark-plugs:- Champion---- L82YC
Bosch---------W225T35
Autolite-------273
NGK-----------BP6H or BP6HS
Marelli---------CW7NP
Hope this helps

 

[dk500]

Thank you !
Darryl

 

[dk500]

Just read that plugs should be torqued in, Is that correct ?

 

[Vitesse]

Just read that plugs should be torqued in, Is that correct ?

Personally I don't Darryl because over the years I have learnt what feels right. But as the threads are easily stripped it is probably a good idea to do it. IIRC it is 20 lb ft?

Tony

 

[fiat500]

Just read that plugs should be torqued in, Is that correct ?

You are supposed to but I doubt may people do. If you are inexperienced it might be a good idea. I wind them in as far as I can with my hand using the socket ( I have quite strong hands). Then I just nip them up maybe an eighth to a fifth of turn using the wrench. My tip with this to have your hand very close to the head of the wrench, so that even with strength you don't have the leverage to overtighten.
If the plugs are new there will be a bit of "crush" in the washers and once you have compressed them you're nearly there.

 

[the hobbler]

According to NGK, the correct torque for a 14mm spark-plug (which is what we fit in the 500/126s) is:- 25-30Nm, or 18-22FtIb

 

[fiat500]

According to NGK, the correct torque for a 14mm spark-plug (which is what we fit in the 500/126s) is:- 25-30Nm, or 18-22FtIb

That's quite reassuring Tom..it's fairly tight; about the same as the cylinder head nuts I would guess.

 

[dk500]

Torque wrench to the shopping list !
Thanks for the details.
Darryl

 

[fiat500]

personally i don't darryl because over the years i have learnt what feels right. But as the threads are easily stripped it is probably a good idea to do it. Iirc it is 20 lb ft?

Tony

snap!

 

[Vitesse]

snap!

Well your description pretty much summed it Peter. The word "nipped" is exactly the one I was thinking off as well and the way you place one hand over the top of the wrench to keep it square and the other one does the little nip.

 

[dk500]

With regard to the gear-box oil; as the 126 box has synchromesh, you will require a NON EP oil. I believe Castrol, Penrite and Morris all make such oils, as do Millers (good Yorkshire company). Their oil--CRX 75/w90 sounds very similar to the factory oil, and is suitable for gear-boxes with synchromesh.
For your spark-plugs:- Champion---- L82YC
Bosch---------W225T35
Autolite-------273
NGK-----------BP6H or BP6HS
Marelli---------CW7NP
Hope this helps

Hi tom,
I have sourced the millers oil locally, but it is an "LS" version. When I read the difference it is all jibber jabber. The guy selling assures me there is no difference but past experience makes me dubious ?

Regarding sparks, can only get Bosch locally. I presume the brand will not make any difference !

Enormous difference in prices locally to online !

Dublin
Millers €25 1 ltr
Bosch €5 each

U.K. Delivered to me
Castrol €18 1 ltr
Ngk €3.50 each

 

[g8rpi]

Hi,
I think Tom had a mix-up with Millers and Morris oils. Morris are in Yorkshire and do a lot of specialty lubricants inclding oil for steam engines. Their products are excellent and well priced. Just changed the gearbox oil in the Croma with their Lodexol MTF 75W-80 5l (don't put that in a classic 500 though Their product support is second to none. Check them out at:
http://www.morrislubricants.co.uk/

Robert G8RPI
Just a happy customer.

 

[g8rpi]

It looks like Morris AG90 is suitable for a 500 gearbox,
http://www.morrislubricants.co.uk/p...ssic-gear-oils/golden-film-ag90-gear-oil.html
But they say contact product support for the correct gear oil for the 126.
A minor point, it's not synchromesh per say that dictates non EP oil, it the presence of phosphor bronze. The sulphur in EP oils corrodes copper based alloys.

Robert G8RPI.

 

[AndrewHarvey]

I purchased a special gear oil for my 5 speeder. It was recommended from a 126 racing website
It's available easily and is called Redline MTL

 

[the hobbler]

With respect Robert (G8rpi) I have NOT got my knickers in a twist. Morris Lubricants are in Shrewsbury (SY1 2EL), make first-class lubricants (their non-detergent 30 grade oil is used by a lot of narrow-boat owners with 'classic' engines in them) and are probably the world leaders in steam lubrication--they give an excellent service. Millers Oils ARE in Yorkshire---Brighouse in West Yorkshire to be exact (HD6 3DP). Their 'LS' gear-box oils CAN be used in both synchro and non-synchro gear-boxes, although they are designed for gear-boxes and final drives with very high loads (including limited-slip). Their CRX LS 75w90NT would be as thick as you want to go! I would try to get your supplier to get you some CRX75w90--or go direct to Millers.
The Bosch plugs will be fine--they are very good plugs. M/Benz used them exclusively at one time. When I was doing my apprenticeship (on M/Benz) I always checked the 'service-removed' plugs, made them up into sets of 4 and flogged them to all my mates with Minis (I had a 500, even in those days)--even used, they made a noticeable improvement to the running of their cars.

 

[dk500]

Thanks all

 

[g8rpi]

With respect Robert (G8rpi) I have NOT got my knickers in a twist. Morris Lubricants are in Shrewsbury (SY1 2EL), make first-class lubricants (their non-detergent 30 grade oil is used by a lot of narrow-boat owners with 'classic' engines in them) and are probably the world leaders in steam lubrication--they give an excellent service. Millers Oils ARE in Yorkshire---Brighouse in West Yorkshire to be exact (HD6 3DP). Their 'LS' gear-box oils CAN be used in both synchro and non-synchro gear-boxes, although they are designed for gear-boxes and final drives with very high loads (including limited-slip). Their CRX LS 75w90NT would be as thick as you want to go! I would try to get your supplier to get you some CRX75w90--or go direct to Millers.
The Bosch plugs will be fine--they are very good plugs. M/Benz used them exclusively at one time. When I was doing my apprenticeship (on M/Benz) I always checked the 'service-removed' plugs, made them up into sets of 4 and flogged them to all my mates with Minis (I had a 500, even in those days)--even used, they made a noticeable improvement to the running of their cars.

Hi Tom,
Sincere apologies, Don't know what I was thinking of.


Regards,
Robert G8RPI.

 

[dk500]

Hi
Plugs changed out this evening, all went according to plan.
New plugs torqued in place.
A little thrown by the longer terminals on the old plugs, swopping about to get socket over them.
I have attached photos of old plugs. I was thinking they look ok, any opinions or observations appreciated.
Hopefully change gearbox oil this weekend.
Thanks all for advice.
Darryl