View Full Version : Modern or rebuilt alternator?

10-04-2006, 10:59 AM
So, about a mile from home (which is, thankfully, where most of my problems seem to appear), I heard the characteristic whining/whirring sound of an unhappy alternator -- Greenie has his original 1968 Lucas unit. Sure enough, I got home, and the alternator was outrageously hot, making a terrible noise, and smoking. /ubbthreads/images/graemlins/ooo.gif Of course, I shut the car off, disconnected the battery and kept an eye on it until it cooled down.

So, here's the question -- should I get a modern replacement or have it rebuilt/find a rebuilt unit? I'm a bit of a nut for originality, so I'm strongly leaning towards a rebuilt unit, but that will keep me off the road longer during the best part of the driving season. /ubbthreads/images/graemlins/cryin.gif

10-04-2006, 11:49 AM
My car is a driver, so over the years, I have had my 73 Lucas alternator repaired a couple of times. The next time it goes out, a modern unit will be installed, and the old one placed on the shelf for nostalgia.

Andrew Mace
10-04-2006, 01:35 PM
Bill, why not call around and see if your original can be rebuilt locally? It's done you and the car well enough for 37 years.... /ubbthreads/images/graemlins/smile.gif

10-04-2006, 01:43 PM

I had a mounting tab break on my Spit's alternator. The price of new ones gave me sticker-shock. I stripped it down, had a local welding shop weld the tab back on and had another auto electrics specialist rebuild it like new. And it worked fine for the next three years til I sold it....

10-04-2006, 01:59 PM
Bill, I saw a bunch of TR6s at a show this weekend that have GM alternators. Every owner said the change was worth the effort. However the modern alternators do stick out like a sore thumb. Particularily the ones where they used a chrome Mr Gasket adjusting arm. I must add that several of the conversions were in engine bays that were not especially clean. There is quite a contrast between a new alternator and a well used 30+ year old engine.
You may want to consider a temporary conversion. Buy a rebuilt GM alternator and the associated hardware. Install it for use while your original unit is being rebuilt. This will alow you to enjoy the fall driving season and return to original over the winter. The only risk is that you may grow to appreciate fully functional turn signals AND headlights.
If you hurry yu can still make the show this weekend.

10-04-2006, 02:25 PM
You may want to consider a temporary conversion. Buy a rebuilt GM alternator and the associated hardware. Install it for use while your original unit is being rebuilt.

[/ QUOTE ]

I'm now thinking about that. The only question is doesn't a conversion require cutting some of the original wires to go from a five terminal-deal to a three-terminal deal (I'm reading the Moss catalog as we speak). If there are less violent ways to do a temporary conversion, please let me know!


10-04-2006, 02:56 PM
For a temporary installation, run the appropriate gauge wires alongside the existing wire loom attached with tie wraps. Not pretty, but functional.

10-04-2006, 04:35 PM
Hi Bill:

Earlier this year I had to replace the alternator on my '74 TR6. Believe it or not, I got a rebuilt Lucas one from NAPA that matched the removed one exactly (I actually used www.napaonline.com (https://www.napaonline.com)). I am very happy with it, and it was considerably cheaper than buying one from the "big three".

I just looked up the alternator for Greenie, and they list two:

BSHAL298X for $109.00 with a $3.00 core or BA1860022 for $104.00 with a $12.00 core. Both are listed as 28 amp with internal regulator, but the first is called a "lucas type". There are pictures of each on their website.

If you order online, you might have it before the weekend, and your local NAPA store might even be able to get it by tomorrow. The core prices are cheap enough that if you wanted to hang onto your original, it wouldn't break your wallet.

Good luck with whatever you end up with. You have to get him back on the road soon as possible. I live (drive) vicariously through your updates in the "Did you Drive your Triumph today" thread. /ubbthreads/images/graemlins/grin.gif


10-04-2006, 04:43 PM
I not a stickler for originality, but if you are as you say, I would stick with the original, and follow pa297pass' suggestion. As long as you haven't added a bunch of power hungry accesories or electric fans, the original should surfice. Plus, the installation will be easier.

10-04-2006, 05:32 PM
As long as you haven't added a bunch of power hungry accesories or electric fans, the original should surfice.

[/ QUOTE ]

I think this is the key to alternator upgrade. Those of us that have upgraded to something like the Bosch or Delco-style, have done so usually because we have added accessories that require more power. My rebuilt Lucas served me well, until I added halogen lights and fogs and electric fan. I bought the AutoZone top of the line for about $100 and it serves me well (well, until the bearings started to scream - it does have a lifetime guarantee.


Andrew Mace
10-04-2006, 05:57 PM
Another thing occurs to me regarding originality: you've got the alternator with the separate external regulator, right? So even temporary rewiring might require some "butchering"? Besides, it shouldn't take more than a few days for a good local shop to rebuild yours (at least I hope it wouldn't).

10-04-2006, 10:03 PM
My car is stock and I had a local shop rebuild it on the day before a club event when it suddenly died. I'm happy that I did, but I have no big fans or other things like Bill, so mine is what the car needs for now. It cost me about $110 and they did everything including installation. Which was more than fair at 3:00PM on a Friday afternoon, when I needed to be on the road Saturday at 7:00AM.

If you have no locals, this guy will do a great job for you.

10-05-2006, 01:30 PM
Question - Once rebuilt do the original alternators crank out any more power than the stock units? Or do they produce the same power?

Just wondering if rebuilding them with more modern materials helps at all...

10-05-2006, 01:37 PM
I think that the output would be the same unless you did some major replacements inside.

10-05-2006, 01:58 PM
Output is the result of the combination of the stator and the rotor (field circuit). They are the two major components in the alternator. There probably isn't any availability of higher output components that will fit inside the Lucas casing. Of course, once the alternator is putting out more, you will need a higher capacity rectifier and possibly a higher capacity voltage regulator to handle the extra amperage the the rotor will be seeing. The original Lucas rectifier is barely adequate as it is.

The unit was never designed to put out alot, because the electrical needs of these cars in stock configuration is pretty low.