Freewheel lubrication (filling and draining) - 1936 Rover 12

Post Reply
Frost015
Posts: 10
Joined: Wed Oct 10, 2018 3:48 pm
Location: Stamford (Lincs)

Freewheel lubrication (filling and draining) - 1936 Rover 12

Post by Frost015 » Thu Nov 28, 2019 6:10 pm

I have a spare gearbox and freewheel, so decided to unbolt the freewheel from the gearbox, open the freewheel mechanism up (all looks good, no discernible wear), and reassemble it all. An interesting exercise, a chance to check, clean, and re-oil bearings, and interesting to physically see exactly how it all operates.

For future storage I have filled the gearbox with 3.5 pints of Millerol 30 (and if and when I decide to use this spare assembly, can run for a few hundred miles, and then drain and refill with Millerol 40 .. which is I believe the more correct grade to use). Was hoping that 1/2 pint would transfer through from the gearbox to the freewheel ... but may have to drain 1/2 pint, and fill the freewheel separately.

My question relates to how oil gets into the freewheel, and how one 'drains' this oil from the freewheel as and when necessary. I can see a small square taper plug for oil filling / level (P2 workshop manual, Page F20, Plate J, Component '87'), however I can't see any way to drain the freewheel.

Draining the gearbox will surely leave 99% of the freewheel oil in-situ ..

Filling the freewheel from the gearbox only would rely on very very slow transfer of oil through the bearing between the gearbox and the freewheel (mine has sat for 48-hrs with 3.5 pints of oil in the gearbox, and the gearbox oil level is showing almost no signs of slowly dropping (as oil drips through into the freewheel casing).

Surely there must be a way to drain the freewheel ?? Why is there no mention of checking / changing freewheel oil in the owners handbook ?? I guess that within the freewheel casing its a relatively low stress environment (from an oil perspective), but NEVER to change the oil to the freewheel mechanism and end bearing seems strange ..

Apologies in advance if I have missed some very obvious point, but perhaps someone can clarify !
1936 Rover 12 Saloon

User avatar
luli
Posts: 386
Joined: Sat Jun 04, 2011 6:49 am
Contact:

Re: Freewheel lubrication (filling and draining) - 1936 Rover 12

Post by luli » Thu Nov 28, 2019 10:39 pm

Just pull out the tail shaft and turn the gearbox so that the freewheel points down.
Rover 10 1946 RHD
Rover 10 1947 LHD
Rover 12 1947 tourer LHD
http://lulisml.wordpress.com/

Frost015
Posts: 10
Joined: Wed Oct 10, 2018 3:48 pm
Location: Stamford (Lincs)

Re: Freewheel lubrication (filling and draining) - 1936 Rover 12

Post by Frost015 » Mon Dec 02, 2019 1:54 pm

Thanks Luli,

That will work to fill and empty the freewheel with the gearbox / freewheel assembly out of the car, but in normal daily / monthly / annual/ 10-yearly use, does the freewheel oil never need changing ?? Did Rover intend this ??

Why is there not a large transfer hole between the gearbox and freewheel ??

I still feel that I am missing something important ...

Anyway, if I am that bothered, I can use my oil change suction device (and various tubes) to suck out the oil from the freewheel through the square taper oil filling plug (referenced below). Just seems strange ...

Ian
1936 Rover 12 Saloon

RobHomewood
Posts: 158
Joined: Tue Oct 22, 2013 8:04 pm

Re: Freewheel lubrication (filling and draining) - 1936 Rover 12

Post by RobHomewood » Tue Dec 03, 2019 11:46 am

This thread has caused me to look up how to fill the freewheel oil on my 47 P2 becasue I have never considered it necessary on the assumption that there was a free flow of oil from the gearbox. The handbook does not mention filling the freewheel anywhere although the gearbox is listed in regular tasks (with a capacity of 3 pints - which seems light if it is supposed include the freewheel).
I see in the parts book Plate H item H39 is listed as 'Taper plug, oil filler' but that is the only reference I have seen for filling the freewheel. Does the earlier freewheel have a similar filler plug?
Perhaps someone could enlighten me on topping up freewheel oil levels which I presume would be at the same intervals as the gearbox?
Rob

GOY189
Posts: 417
Joined: Sun Oct 19, 2008 5:08 pm

Re: Freewheel lubrication (filling and draining) - 1936 Rover 12

Post by GOY189 » Tue Dec 03, 2019 11:33 pm

I am looking for some notes that may well have the answer. I will advise as soon as I find them.
Rgds
Mike

User avatar
luli
Posts: 386
Joined: Sat Jun 04, 2011 6:49 am
Contact:

Re: Freewheel lubrication (filling and draining) - 1936 Rover 12

Post by luli » Wed Dec 04, 2019 9:25 am

A common trouble is oil leak from the rear oil seal of the free wheel. If oil leaks from there it is a sign that it has got into there. The rear bearing of the gear box has enough "gaps" in it to let the oil pass through. The same is for the rear bearing of the freewheel. Removing the square plug makes this process faster, but it happens without it too. See more here: https://wp.me/pXLKy-1OM and here https://wp.me/pXLKy-1Ll
Rover 10 1946 RHD
Rover 10 1947 LHD
Rover 12 1947 tourer LHD
http://lulisml.wordpress.com/

TonyG
Posts: 97
Joined: Mon Sep 07, 2015 4:38 pm

Re: Freewheel lubrication (filling and draining) - 1936 Rover 12

Post by TonyG » Wed Dec 04, 2019 9:32 am

Ian,
You have got us all thinking on this one! I’ve looked through the original Rover instruction manual and my Rover Cars maintenance book by VH Watson and neither makes any mention of separately filling the freewheel unit in the text. The exploded view of the gearbox and freewheel unit in the Watson book details the small plug in the freewheel unit as ‘Vent plug (air, when filling with oil)’. From which, I would assume, must be removed when filling the box so that oil can flow into freewheel unit.

I must admit that, until your post, I’d never given the matter a thought although, clearly, I should have. Especially given that my Tourer box was drained and removed from the car for over 30 years. I just filled the box with oil. That said, it hasn’t been a problem but I don’t use the freewheel as it removes the engine braking and the fun of all those slick (or sometimes not) double de-clutch gear changes!

I look forward to seeing what Mike unearths on the subject but, on the list for Springtime maintenance, checking gearbox oil with freewheel plug removed and testing operation of the freewheel are things to be done in the New Year.

How are things going with your 12 Saloon? Progress with mine has been slow this year but I’m determined to get it on the road in 2020!

Tony
Tony Gilbert

P1 12 Tourer
P2 12 6 Light Saloon
Discovery 3
Discovery Sport

TonyG
Posts: 97
Joined: Mon Sep 07, 2015 4:38 pm

Re: Freewheel lubrication (filling and draining) - 1936 Rover 12

Post by TonyG » Wed Dec 04, 2019 9:53 am

Luli,
Your post arrived while I was writing mine. You have put my mind at rest that oil flows between box and freewheel so I won’t worry if I decide to brave the Winter and take my car out for an icy blast!

I know it’s been said before, but the detailed information on these Rovers that you have collected, documented and made available to us is simply superb and such bonus to us as we struggle to keep our old cars going. I’m so pleased you have been out in my Tourer but I can’t help thinking how much better my car would be if you had undertaken the restoration!

Tony.
Tony Gilbert

P1 12 Tourer
P2 12 6 Light Saloon
Discovery 3
Discovery Sport

User avatar
luli
Posts: 386
Joined: Sat Jun 04, 2011 6:49 am
Contact:

Re: Freewheel lubrication (filling and draining) - 1936 Rover 12

Post by luli » Wed Dec 04, 2019 11:53 am

Thank you, Tony, for your nice words. My visit to you was a pure Joy, and your work had been inspiration to me. Have you seen my impressions? and the video of that drive? https://wp.me/pXLKy-2Xp
P.S. I always use the freewheel and enjoy turning the knob to 'fix' when necessary!
Rover 10 1946 RHD
Rover 10 1947 LHD
Rover 12 1947 tourer LHD
http://lulisml.wordpress.com/

TonyG
Posts: 97
Joined: Mon Sep 07, 2015 4:38 pm

Re: Freewheel lubrication (filling and draining) - 1936 Rover 12

Post by TonyG » Thu Dec 05, 2019 9:54 am

Luli, I have seen your pictures, notes and video of my car before but great to look again. In fact, after watching the video, I’m inspired to face the cold weather and go out for a drive. Almost a year I think since I took Ian for a similar drive and I hope that encouraged him with his Rover project. Getting these great cars out on the road is what it’s all about!

Tony.
Tony Gilbert

P1 12 Tourer
P2 12 6 Light Saloon
Discovery 3
Discovery Sport

Post Reply