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TR2/3/3A TR-3B Generator Problem?

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af3683

af3683

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I took my TR3-B out for a ride today and noticed that the directional indicator light seemed to be dimly lit while I was driving. Then while the car was idling in a parking lot, I began to hear a rattle and squeak type noise from under the hood and noticed the ammeter needle was flickering back and forth. In addition, the ignition light would sometimes come on. I drive the car back home and opened the hood, and it appears as though the noises are coming from my Lucas generator.

Are these the typical symptoms of a bad generator? If so, is it worth trying to get what I believe is the original Lucas generator rebuilt (I do like originality) or simply buy a new one? Has anyone had there generator rebuit? Are the Moss genertors made by Lucas?

Any help would be appreciated. Thank you.

Art
 
Re: TR-3B Gererator Problem?

Find a good local shop and have it rebuilt. Ok, I'm a bit of a purist and usually don't add lots of power-hungry accessories that might require an alternator or overload an old C39 or C40 generator. But unless there's some physical damage, these old units tend to rebuild well and can continue to give reliable service (even on the TR3, where the generator is awfully close to the exhaust manifold)!

I've had two rebuilt in the last year or so. Yes, I paid around $140 for each, but both generators literally look and function better than new!
 
Re: TR-3B Gererator Problem?

The Moss version, while functional, does not look 'as original'. I too prefer to use rebuilt original.

The most common failures (in my experience) have been brushes, bearings and a broken front plate. Both the Lucas and Haynes manuals give detailed tests for confirming the function and usually pinpointing the problem.

If your electrical demands are within the units ability they are robust & reliable.

I actually carry a spare on long trips. Seems excessive but was worth it when a Mini owner's dynamo packed it in on a group drive 500 miles from home and I was able to say 'Hey, I've got one of those'. He swapped his pulley for the TR version and was good to go.
 
Re: TR-3B Gererator Problem?

You might consider at least having a look inside yourself. While the operating principles smack of magic, replacing bearings and brushes is pretty easy and, as Geo said, is usually enough to get them working again.

However, the flickering ammeter may indicate that the contacts in the control box are due for cleaning. Mine seem to need it every few years (and in fact could use it again right now).
 
Re: TR-3B Gererator Problem?

TR3driver said:
...the flickering ammeter may indicate that the contacts in the control box are due for cleaning. Mine seem to need it every few years (and in fact could use it again right now).
Click to expand...

Ooh, I've been seeing that needle flicking. What is the best way to clean the contacts?
 
Re: TR-3B Gererator Problem?

Geo Hahn said:
TR3driver said:
...the flickering ammeter may indicate that the contacts in the control box are due for cleaning. Mine seem to need it every few years (and in fact could use it again right now).
Click to expand...

Ooh, I've been seeing that needle flicking. What is the best way to clean the contacts?
Click to expand...

George: Avoid using a file or anything too coarse. I always use a relay burnishing tool, see this: https://www.crawfordtool.com/burnisher_gc.html

Actually lacking this I have used a piece of card stock running it in and out while pressing the contact closed. If dirty, you will see that the paper is abrasive enough to remove the deposits. But, the burnishing tool is best. if the contacts are badly pitted, no amount of burnishing will restore them - they need to be replaced.

HTH Frank
 
Re: TR-3B Gererator Problem?

I also use a burnishing tool, but I'm not sure if it is "best" or not. The book says to use a fine carborundum stone, or emory cloth; but only for the voltage regulator contacts. There is a specific warning not to use them on the cutout contacts.

My burnishing tool is thicker than the normal VR contact gap, so to clean them I have to back out the adjustment and then put it back afterwards. Good time to double-check the voltage setting as well.
 
Re: TR-3B Gererator Problem?

I just attempted to remove my generator. I removed the 2 bolts that hold it on as well as the bolt that adjust the fan belt tension. However, I'm not sure how to get it out of the engine compartment. Do you need to remove the bracket that the generator pivots on?? Do you remove it below? Thank you.

Art
 
Re: TR-3B Gererator Problem?

Comes right out the top. Can you tell what it is hanging up on?

af3683 said:
...Do you need to remove the bracket that the generator pivots on?
Click to expand...

If you mean the one below the generator then no, that stays in place but the bolt have to be out (which it sounds like they are).
 
Re: TR-3B Gererator Problem?

It's a little bit tricky, mostly due to restricted working space. But as Geo says, it comes out the top. You'll need to loosen the adjustment link at the water pump as well, so it can pivot upwards. Then lift the generator straight up until it clears the mounts, before you turn it endwise to slide out between the front carb & the horn. I find it really hard to access the wires with the generator in place (fat arms), so I pull it off the mounts first and then detach the wires. No room for both arms and the generator, so the final lift is grasping the pulley in one hand.
 
Re: TR-3B Gererator Problem?

I did not remove the bottom bracket. The bracket on top that the generator pivots on in order to tighten the fan belt appears to be in the way. The vacuum advance line is in the way a bit but I should be able to get around it.
Do I have to remove or maybe just loosen that top bracket?

Art
 
Maybe a diagram will make it clearer (cribbed from a Moss catalog). Bolt 16 will have to be loosened or removed, so that adjustable link 15 can be pivoted or removed. Items 18 and 19 do not have to be removed or loosened. Bolts 17, 20 and 19b have to be removed.
 

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Re: TR-3B Gererator Problem?

I have never had to remove the adjustment bracket/arm (not even sure I loosen it) but you could start be loosening and swing it up.

The bolt that holds that bracket to the block should have a locking tab on it. If that is missing you may want to add one. They are available from the usual sources but I made one from a washer dressed down to the correct shape on a grinder.
 
Re: TR-3B Gererator Problem?

George and Randall, thank you. The picture was very helpful and it appears as though I removed everything correctly. Now I just have to loosened #16 so that adjustable link #15 can be pivoted. I plan on taking the generator to a local auto electric shop. Hopefully, they can rebuild it.

Art
 
I also noticed that bolt #17 on my car is just long enough to go into the threated hole on the generator and does not protrude out far enough for a nut. Not sure which is correct as my car is pretty original.

Art
 
I won't argue what's original, but Practical Hints pretty clearly shows the nut; while the SPC lists it for both configurations of the generator mount.

And my personal experience has been that it is a whole lot easier to keep that bolt tight with the nut added.
 

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Anyone have any experience with the New or Rebuilt TR3 generators offered by TRF? Since they are both the <span style="text-decoration: underline">same price </span>, I'm not sure which one to purchase. I was thinking that a rebuilt original Lucas generator might be of better quality than the new ones which I believe look different than the originals. I was told that the new ones are <span style="text-decoration: underline">supplied</span> by a company in the U.S. but not sure where they are manufacturered. Any help would be appreciated. Thanks.

Art
 
I suppose I would favor the rebuilt Lucas as down the road I am assured of knowing what parts would work in any future repair or rebuild. These things are so simple I'd like to be able to work on them and parts for the Lucas are readily available & swappable. Don't know if this is true of the other.

The new ones I have seen (from Moss not TRF) didn't look like the Lucas unit either, a difference which mattered to me.
 
My problem C40 Lucas generator has the # 22704D on the case. Is it imperitive that any replacement Lucas generator contain the exact same number on the case? Will any C40 generator fit and work properly?

Thanks.

Art
 
There are a couple different numbers of C40 that essentially can interchange without problem, most notably the 22700. Is there a date code on yours and, if so, is it pretty close to the build of your car, indicating that it might well be the original?
 
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