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MG MGB Technical - REBUILD KITS FOR LATE MODEL OE FAN MOTORS??

I have an '80 B that has a couple electric cooling fans. Through the years, several started making that terrible screeching noise and were replaced. Being the kind of person that is always reluctant to throw away any MGB part, ended up with a drawer full of these old fan motors. Well, today decided to take one of these critters apart. I always thought that there was a shaft bearing (roller type) inside, maybe two. Surprise - surprise, there ain't. There's an aluminum (?) bushing just under the front cover that's held in place with a circle of spring-steel fingers. All the noise comes from this bushing. This bushing and its retainer couldn't cost more than a few cents to produce. Can't imagine more that a few dollars retail price. Dismantled, cleaned and checked all of my noisy fan motors. Shaft diameters, for all motors, were all within 0.1 mm. When each motor was fitted with a relatively new end bushing, all functioned properly. At nearly $80 for a new fan motor, does anyone have a source for replacement bushings (and retainer)?
Steve Buchina

Throw those miserable things away!
Get a good aftemarket fan that covers most of the radiator, and solve this problem once and for all!

Sorry to shout, but the originals were terrible!
SF
Dwight
DCM McCullough

DCM,

'78 B w/two electric fans. Lost one of the fans and got lucky last year and found a used one on EBAY. Wanting to go to a single fan as you suggested, but don't know how to fit the larger fan on the radiator. I've seen pics on this and other web-sites and looks as if the larger fans are held in place by rods that go through the rad. Is this correct?

thanks
Shook

You expected *roller* bearings on a cooling fan motor? Are you mad!? :o)

One of the fans on my V8 has a grease or oil nipple for the back bearing, you can get oil to the front bearing anyway. It was the other motor that siezed. I had to get a new fan as well as I just couldn't get the old one off, and that did grieve me.

Some aftermarket fans use nylon ties through the core, I am sure there are other variations. Given the elongated area that is available for coolimg fans I would have thought that two were better, unless the after-market single is very much more efficient. But the factory fans *are* pretty inefficient. The biggest improvement I made to my V8 cooling system was with the electrics. As well as a number of slightly poor connections due simply to age, there are two major (in my opinion) design weaknesses. On the V8 at least the power for the cooling fan comes off the standard green circuit, along with everything else! This circuit drops enough voltage anyway, especially when the heated rear window is on which also comes off the same circuit (or did, mine now has a relay)! I connected a short heavy gauge brown wire between the relay and the spare output terminal on the alternator, and now get a couple of extra volts. The other thing is the fan grounds. As well as being of standard gauge wire instead of heavy gauge like for the 12v feed, it is shared with the headlights, and goes all the way back to by the fusebox before it reaches the body! I put a local ground for each fan to the bonnet slam panel, as well as the standard ground. As a result of all this the voltage at the fans has gone up by about 30%, at the heated rear window by about 25%, and the turn signals still flash at idle.
Paul Hunt 2

A long time ago I had the cooling fan SCREAM at me & I pulled it apart & saw what I had. What I did was drill a 1/8 inch hole in the back center of the motor & I shoot grease in there once a year (found a point end that goses on my grease gun at NAPA) & the motor is oiled behind the blade every oil chang. 250,000 miles & still going! I do this on ALL THE CARS I SERVICE & it has been years since I have had to change a fan motor. & I do what Paul said with the heaver wire, also. Cheap fix for a cheap part, that works.
Glenn Towery

Paul,
Am I mad? Not yet - psychologically. Am I guilty of expecting too much? Yes - but I'm losing faith.

The OE fan motors came with a closed top cap. Guess they didn't want anyone to see that aluminum bushing. However, looking at a replacement motor (also) from years ago, I can clearly see a KOYO 6200 end bearing supporting the shaft. This bearing is described by the manufacturer as being an "open type, single-row, deep groove ball bearing." The back of the replacement motor case has the follow identifications. PES-SURDULICA-YUGOSLAVIA, LICENCA LUCAS, 12V MH70 14L. Overall size of this unit is identical to the OE motor and it has the same two pin electrical connector. Now I'm wondering if BL/Lucas was buying surplus YUGO parts or did it take YUGO engineers to make a better product?
Steve Buchina

Steve, et al. A timely thread as I am restoring a 79B to running condition and the fan motors are one of the things which will need attention.

If they are using an alminium bushing at the front of the motor, I wonder if it could be replaced with an oil impregnated bronze bushing? Either material could be made into bushings by anyone having a lathe. Might be something to investigate while waiting for some parts to arrive.

Paul. You have often mentioned the addition of relays being run off of the existing systems and powered by a brown wire. Sounds is if one is to add several relays, a heavy brown wire to a common terminal or power strip would be in order. The brown wires to the various relays could be run from that point. What would you, or anyone else, recommend for such a power junction? Where should it be mounted and what form of weather protection (when it rains here, the streets become creeks) should it incorporate?

Thanks, Les
Les Bengtson

Les,
I see no reason why a bronze bushing couldn't be fashioned for these motors. The sticky problem (as I see it) is not removing the bushing, but getting one back in without destroying the spider leg style (?) retainer. Of course, with you having a lathe, don't think you would have much trouble making a better retainer. If you have any old motors laying around, take a look inside, push out the bushing (tapered drift) and try getting it back in. I was thinking of perhaps having a retainer with a press fitted bushing (e.g., aluminum disk with a centered bronze bushing or bearing) and then press fitting the retainer to the underside of the end cap.
Steve Buchina

Steve,

Unless you are trying to keep your MGB original I am with Dwight on this one. The aftermarket fan I have is a 14 inch Flex-a-Lite 12 blade electric fan. This one fan makes up for the two OEM fans which I have taken off. It covers just about the whole radiator and is very strong and not noisy. Talk about cooling down the engine temperature fast. 20 seconds and it is back down and off.

Take a look at: http://www.treasure-island-jewelers.com/1977mgbSupercharger.htm

Just a suggestion for $80.00

Ray

Shook: When you buy the aftermarket they come with four nylon strips that you insert through the radiator. You must be very careful when doing it. I use a very small screwdriver phillips and slowly rotating it making the whole for the nylon strips to go in. Once it is in that is it for a very long time. One picture on my web-site shows the fans removed and when I did that I was able to move my radiator up to the front 1 inch which made it even better for the fit. Before in another picture that still had the oem fans it seems a little tight on the bottom, but now the problem is fixed.

If you need help please do not hesitate to e-mail me and I will glady assist you.

Ray

Ray 1977mgb

Hi Les,

The most sensible place to take off a brown feed for a relay strip is probably the solenoid, bolted onto the battery cable stud like the later units, even on those solenoids that use spades for the browns.

An alternative could be direct from the alternator if it is the two large output spades and one of them is spare, and this would give slightly higher voltage than the solenoid - at least when the engine is running. As I mentioned this is what I have used for the cooling fan relay which is very close the the alternator on the V8.

A third possibilty is piggy-backing off the brown spade on the fusebox, but this has the longest run of the three and the weakest physical conenction and so potentially (ho ho) the greatest volt-drop. You could take it off the purple side, and so have it fused, but the whole shebang would be running off one fuse. For the heated rear window I used the brown at the fusebox, and a fused relay.

However all of these (except the purple source) would be adding extra unfused brown wires, so you may want to use a fusible link as close to the source as possible for safety (but accessible of course), plus fused relays at a lower rating for each circuit.

Best location for the relay strip is probably as far back and as high in the engine compartment as possible, like the heater shelf. Short of actually attempting 3ft depth I'd expect connections to relays here to be at least as good if not better protected than connections anywhere else on the B. I've driven through some pretty torrential stuff over the years and never had electrical problems. Water pouring down trouser legs and the like, but nothing electrical. having said that the worst the UK has experienced probably isn't as bad as the worst the US can get :o)
Paul Hunt 2

Paul. Many thanks. This is beginning to sound like both something I can do and want to do. Yet something else I have learned from you and these other gentleman. My thanks to all.

Les
Les Bengtson

This thread was discussed between 28/02/2006 and 05/03/2006

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