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View Full Version : TR2/3/3A TR-3B Generator Problem?



af3683
07-29-2012, 07:22 PM
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

Andrew Mace
07-29-2012, 07:29 PM
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!

Geo Hahn
07-29-2012, 08:21 PM
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.

TR3driver
07-29-2012, 11:17 PM
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).

Geo Hahn
07-29-2012, 11:56 PM
...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).

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

angelfj1
07-30-2012, 07:33 AM
...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).

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

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

TR3driver
07-30-2012, 04:02 PM
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.

af3683
07-30-2012, 06:38 PM
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

Geo Hahn
07-30-2012, 06:45 PM
Comes right out the top. Can you tell what it is hanging up on?


...Do you need to remove the bracket that the generator pivots on?

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).

TR3driver
07-30-2012, 07:09 PM
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.

af3683
07-30-2012, 08:07 PM
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

TR3driver
07-30-2012, 08:25 PM
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.

Geo Hahn
07-30-2012, 08:30 PM
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.

af3683
07-30-2012, 10:42 PM
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

af3683
07-30-2012, 11:17 PM
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

TR3driver
07-30-2012, 11:30 PM
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.

af3683
08-01-2012, 10:24 PM
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

Geo Hahn
08-02-2012, 09:58 AM
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 &amp; 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.

af3683
08-02-2012, 05:36 PM
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

Andrew Mace
08-02-2012, 05:57 PM
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?

af3683
08-02-2012, 06:43 PM
My date code is 7 62 for July 1962 and my car was built in August 1962. Since my number is 22704D do anyone happen to know which other numbers besides 22704D are acceptable? I'm looking to buy a new rebuilt generator and don't want to get one that is not right for my car.

I'm afraid that my existing generator may be too expensive to fix since the bottom front mounting hole has been enlarged probably due to an improper bolt being used and vibration. I think it may be more economical to buy a rebuild and save mine for parts.

Art

TR3driver
08-02-2012, 06:48 PM
The earlier 22258 (C39PV-2) will also fit and work, although it might be best to use the matching control box. IIRC it is rated for 19 amps instead of 21 for the C40 and C40-1.

Also worth noting, any 22704x is functionally equivalent to your 22704D. The final letter indicates only minor changes in construction, all letters (eg 22704A) will interchange (even though the individual parts might not interchange).

Andrew Mace
08-02-2012, 07:49 PM
My date code is 7 62 for July 1962 and my car was built in August 1962....I'm afraid that my existing generator may be too expensive to fix since the bottom front mounting hole has been enlarged probably due to an improper bolt being used and vibration. I think it may be more economical to buy a rebuild and save mine for parts.If I were you, I'd save it regardless and keep your eye out for another "bad" 22704 or 22700 with a good front plate. Those two generators share virtually all parts, according to my Lucas Master Catalogue.

af3683
08-02-2012, 08:44 PM
Andy &amp; Randall, thank you so much for your help!

Art

TR3driver
08-03-2012, 11:11 AM
Those two generators share virtually all parts, according to my Lucas Master Catalogue.

Curious. It actually shows that they share <span style="text-decoration: underline">all</span> the listed parts. I wonder what changed?

Andrew Mace
08-03-2012, 11:44 AM
That's why I said "virtually" all listed parts. SOMETHING must differ between the two, other than the designation "C 40" or "C 40 1" (not to be confused with the longer "C 40 L")!

af3683
08-03-2012, 12:43 PM
I just got of the phone with TRF and the one rebuilt generator that they have in stock for a TR-3 has the number <span style="font-weight: bold">#22715J </span>which is not correct per the prior postings. Is there a chance that this number is also a replacement in addition to #22704 and #22700?? Thanks.

Art

TR3driver
08-03-2012, 01:03 PM
Should be fine. 22715 is listed as a later C40-1, and 22700 is listed as a replacement for it. The Lucas catalog I checked shows the 22715 as original equipment for a 71 Herald.

PS, you will probably need to keep your old pulley, though. Replacements are available separately I believe, if your old one is damaged.

PPS, watch for the little spacer that goes between the fan &amp; generator. It's easy to lose or forget.

af3683
08-03-2012, 04:26 PM
Could someone please explain how to get the pulley and fan off of the old generator. I'm not sure if it is wise to grab on to the fan blades to stop the motor from turning. There has to be a trick. Thanks.

Art

TR3driver
08-03-2012, 05:04 PM
There are several approaches, kind of depends on the tools you have available. An impact wrench works a treat, if you have one handy. I generally use one of these https://www.harborfreight.com/2-piece-rubber-strap-wrench-set-94119.html just so I don't have to mess with firing up the compressor. Or in a pinch, you can use an old fan belt and something to pinch it, like vise grips or the bench vise.

Once the nut is off, generally it only takes a few love taps with a brass hammer to get the pulley off the shaft. If yours is stuck tighter than that, I would suggest using a bearing separator or a puller similar to this: https://www.britishcarforum.com/bcforum/u..._on_#Post855114 (https://www.britishcarforum.com/bcforum/ubbthreads.php/topics/855114/Re_Removing_the_water_pump_on_#Post855114)

With the pulley out of the way, pry the Woodruff key out of its slot (side cutters work well for this, or you can use a small chisel as a pry bar) and lift away the fan &amp; spacer.

Geo Hahn
08-03-2012, 05:56 PM
...With the pulley out of the way, pry the Woodruff key out of its slot... and lift away the fan &amp; spacer.

On mine I seem to recall that the fan and spacer were notched to fit over the woodruff key so this step may or may not be necessary depending on what all you're doing.

af3683
08-04-2012, 01:08 PM
I was able to get the pulley and fan off with the help of a friend with a impact wrench. However, Randall and George both mentioned a small "spacer" between the fan and pulley. I did not see such a spacer! Can any one describe what it looks like. I checked the Moss catalog and did not see it either. Thanks.

Art

af3683
08-04-2012, 01:23 PM
Think I found it. There was a small washer about 1/4 inch thick with a space in it that was still on the shaft. I assume that is it.

Art

TR3driver
08-04-2012, 01:48 PM
That sounds right. It goes between the fan &amp; bearing, not between the fan &amp; pulley. Without it, the fan will rub on the front plate. Not shown in any of the catalogs (nor available separately) AFAIK, but important. Even the Lucas Master catalog only shows it as part of a "sundries" kit.

af3683
08-04-2012, 01:56 PM
Thanks Randall.

Art